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rdparser_app.html
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rdparser_app.html
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<h1>Source code for nltk.app.rdparser_app</h1><div class="highlight"><pre>
<span></span><span class="c1"># Natural Language Toolkit: Recursive Descent Parser Application</span>
<span class="c1">#</span>
<span class="c1"># Copyright (C) 2001-2021 NLTK Project</span>
<span class="c1"># Author: Edward Loper <edloper@gmail.com></span>
<span class="c1"># URL: <https://www.nltk.org/></span>
<span class="c1"># For license information, see LICENSE.TXT</span>
<span class="sd">"""</span>
<span class="sd">A graphical tool for exploring the recursive descent parser.</span>
<span class="sd">The recursive descent parser maintains a tree, which records the</span>
<span class="sd">structure of the portion of the text that has been parsed. It uses</span>
<span class="sd">CFG productions to expand the fringe of the tree, and matches its</span>
<span class="sd">leaves against the text. Initially, the tree contains the start</span>
<span class="sd">symbol ("S"). It is shown in the main canvas, to the right of the</span>
<span class="sd">list of available expansions.</span>
<span class="sd">The parser builds up a tree structure for the text using three</span>
<span class="sd">operations:</span>
<span class="sd"> - "expand" uses a CFG production to add children to a node on the</span>
<span class="sd"> fringe of the tree.</span>
<span class="sd"> - "match" compares a leaf in the tree to a text token.</span>
<span class="sd"> - "backtrack" returns the tree to its state before the most recent</span>
<span class="sd"> expand or match operation.</span>
<span class="sd">The parser maintains a list of tree locations called a "frontier" to</span>
<span class="sd">remember which nodes have not yet been expanded and which leaves have</span>
<span class="sd">not yet been matched against the text. The leftmost frontier node is</span>
<span class="sd">shown in green, and the other frontier nodes are shown in blue. The</span>
<span class="sd">parser always performs expand and match operations on the leftmost</span>
<span class="sd">element of the frontier.</span>
<span class="sd">You can control the parser's operation by using the "expand," "match,"</span>
<span class="sd">and "backtrack" buttons; or you can use the "step" button to let the</span>
<span class="sd">parser automatically decide which operation to apply. The parser uses</span>
<span class="sd">the following rules to decide which operation to apply:</span>
<span class="sd"> - If the leftmost frontier element is a token, try matching it.</span>
<span class="sd"> - If the leftmost frontier element is a node, try expanding it with</span>
<span class="sd"> the first untried expansion.</span>
<span class="sd"> - Otherwise, backtrack.</span>
<span class="sd">The "expand" button applies the untried expansion whose CFG production</span>
<span class="sd">is listed earliest in the grammar. To manually choose which expansion</span>
<span class="sd">to apply, click on a CFG production from the list of available</span>
<span class="sd">expansions, on the left side of the main window.</span>
<span class="sd">The "autostep" button will let the parser continue applying</span>
<span class="sd">applications to the tree until it reaches a complete parse. You can</span>
<span class="sd">cancel an autostep in progress at any time by clicking on the</span>
<span class="sd">"autostep" button again.</span>
<span class="sd">Keyboard Shortcuts::</span>
<span class="sd"> [Space]\t Perform the next expand, match, or backtrack operation</span>
<span class="sd"> [a]\t Step through operations until the next complete parse</span>
<span class="sd"> [e]\t Perform an expand operation</span>
<span class="sd"> [m]\t Perform a match operation</span>
<span class="sd"> [b]\t Perform a backtrack operation</span>
<span class="sd"> [Delete]\t Reset the parser</span>
<span class="sd"> [g]\t Show/hide available expansions list</span>
<span class="sd"> [h]\t Help</span>
<span class="sd"> [Ctrl-p]\t Print</span>
<span class="sd"> [q]\t Quit</span>
<span class="sd">"""</span>
<span class="kn">from</span> <span class="nn">tkinter</span> <span class="kn">import</span> <span class="n">Button</span><span class="p">,</span> <span class="n">Frame</span><span class="p">,</span> <span class="n">IntVar</span><span class="p">,</span> <span class="n">Label</span><span class="p">,</span> <span class="n">Listbox</span><span class="p">,</span> <span class="n">Menu</span><span class="p">,</span> <span class="n">Scrollbar</span><span class="p">,</span> <span class="n">Tk</span>
<span class="kn">from</span> <span class="nn">tkinter.font</span> <span class="kn">import</span> <span class="n">Font</span>
<span class="kn">from</span> <span class="nn">nltk.draw</span> <span class="kn">import</span> <span class="n">CFGEditor</span><span class="p">,</span> <span class="n">TreeSegmentWidget</span><span class="p">,</span> <span class="n">tree_to_treesegment</span>
<span class="kn">from</span> <span class="nn">nltk.draw.util</span> <span class="kn">import</span> <span class="n">CanvasFrame</span><span class="p">,</span> <span class="n">EntryDialog</span><span class="p">,</span> <span class="n">ShowText</span><span class="p">,</span> <span class="n">TextWidget</span>
<span class="kn">from</span> <span class="nn">nltk.parse</span> <span class="kn">import</span> <span class="n">SteppingRecursiveDescentParser</span>
<span class="kn">from</span> <span class="nn">nltk.tree</span> <span class="kn">import</span> <span class="n">Tree</span>
<span class="kn">from</span> <span class="nn">nltk.util</span> <span class="kn">import</span> <span class="n">in_idle</span>
<span class="k">class</span> <span class="nc">RecursiveDescentApp</span><span class="p">:</span>
<span class="sd">"""</span>
<span class="sd"> A graphical tool for exploring the recursive descent parser. The tool</span>
<span class="sd"> displays the parser's tree and the remaining text, and allows the</span>
<span class="sd"> user to control the parser's operation. In particular, the user</span>
<span class="sd"> can expand subtrees on the frontier, match tokens on the frontier</span>
<span class="sd"> against the text, and backtrack. A "step" button simply steps</span>
<span class="sd"> through the parsing process, performing the operations that</span>
<span class="sd"> ``RecursiveDescentParser`` would use.</span>
<span class="sd"> """</span>
<span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">grammar</span><span class="p">,</span> <span class="n">sent</span><span class="p">,</span> <span class="n">trace</span><span class="o">=</span><span class="mi">0</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_sent</span> <span class="o">=</span> <span class="n">sent</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_parser</span> <span class="o">=</span> <span class="n">SteppingRecursiveDescentParser</span><span class="p">(</span><span class="n">grammar</span><span class="p">,</span> <span class="n">trace</span><span class="p">)</span>
<span class="c1"># Set up the main window.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span> <span class="o">=</span> <span class="n">Tk</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">title</span><span class="p">(</span><span class="s2">"Recursive Descent Parser Application"</span><span class="p">)</span>
<span class="c1"># Set up key bindings.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_bindings</span><span class="p">()</span>
<span class="c1"># Initialize the fonts.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_fonts</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="c1"># Animations. animating_lock is a lock to prevent the demo</span>
<span class="c1"># from performing new operations while it's animating.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span> <span class="o">=</span> <span class="n">IntVar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="c1"># The user can hide the grammar.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_show_grammar</span> <span class="o">=</span> <span class="n">IntVar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_show_grammar</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<span class="c1"># Create the basic frames.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_menubar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_buttons</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_feedback</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_grammar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_init_canvas</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">)</span>
<span class="c1"># Initialize the parser.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">initialize</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_sent</span><span class="p">)</span>
<span class="c1"># Resize callback</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Configure>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_configure</span><span class="p">)</span>
<span class="c1">#########################################</span>
<span class="c1">## Initialization Helpers</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_init_fonts</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">root</span><span class="p">):</span>
<span class="c1"># See: <http://www.astro.washington.edu/owen/ROTKFolklore.html></span>
<span class="bp">self</span><span class="o">.</span><span class="n">_sysfont</span> <span class="o">=</span> <span class="n">Font</span><span class="p">(</span><span class="n">font</span><span class="o">=</span><span class="n">Button</span><span class="p">()[</span><span class="s2">"font"</span><span class="p">])</span>
<span class="n">root</span><span class="o">.</span><span class="n">option_add</span><span class="p">(</span><span class="s2">"*Font"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_sysfont</span><span class="p">)</span>
<span class="c1"># TWhat's our font size (default=same as sysfont)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">=</span> <span class="n">IntVar</span><span class="p">(</span><span class="n">root</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_sysfont</span><span class="o">.</span><span class="n">cget</span><span class="p">(</span><span class="s2">"size"</span><span class="p">))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span> <span class="o">=</span> <span class="n">Font</span><span class="p">(</span><span class="n">family</span><span class="o">=</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="n">weight</span><span class="o">=</span><span class="s2">"bold"</span><span class="p">,</span> <span class="n">size</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">())</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_font</span> <span class="o">=</span> <span class="n">Font</span><span class="p">(</span><span class="n">family</span><span class="o">=</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="n">size</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">())</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="o"><</span> <span class="mi">0</span><span class="p">:</span>
<span class="n">big</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="o">-</span> <span class="mi">2</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">big</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="o">+</span> <span class="mi">2</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_bigfont</span> <span class="o">=</span> <span class="n">Font</span><span class="p">(</span><span class="n">family</span><span class="o">=</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="n">weight</span><span class="o">=</span><span class="s2">"bold"</span><span class="p">,</span> <span class="n">size</span><span class="o">=</span><span class="n">big</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_init_grammar</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="c1"># Grammar view.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span> <span class="o">=</span> <span class="n">listframe</span> <span class="o">=</span> <span class="n">Frame</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">fill</span><span class="o">=</span><span class="s2">"both"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist_label</span> <span class="o">=</span> <span class="n">Label</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span><span class="p">,</span> <span class="n">text</span><span class="o">=</span><span class="s2">"Available Expansions"</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist_label</span><span class="o">.</span><span class="n">pack</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span> <span class="o">=</span> <span class="n">Listbox</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="p">,</span>
<span class="n">selectmode</span><span class="o">=</span><span class="s2">"single"</span><span class="p">,</span>
<span class="n">relief</span><span class="o">=</span><span class="s2">"groove"</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"white"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"#909090"</span><span class="p">,</span>
<span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">,</span>
<span class="n">selectforeground</span><span class="o">=</span><span class="s2">"#004040"</span><span class="p">,</span>
<span class="n">selectbackground</span><span class="o">=</span><span class="s2">"#c0f0c0"</span><span class="p">,</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"right"</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"both"</span><span class="p">,</span> <span class="n">expand</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_productions</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">grammar</span><span class="p">()</span><span class="o">.</span><span class="n">productions</span><span class="p">())</span>
<span class="k">for</span> <span class="n">production</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">insert</span><span class="p">(</span><span class="s2">"end"</span><span class="p">,</span> <span class="p">(</span><span class="s2">" </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">production</span><span class="p">))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">config</span><span class="p">(</span><span class="n">height</span><span class="o">=</span><span class="nb">min</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">),</span> <span class="mi">25</span><span class="p">))</span>
<span class="c1"># Add a scrollbar if there are more than 25 productions.</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">)</span> <span class="o">></span> <span class="mi">25</span><span class="p">:</span>
<span class="n">listscroll</span> <span class="o">=</span> <span class="n">Scrollbar</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="p">,</span> <span class="n">orient</span><span class="o">=</span><span class="s2">"vertical"</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">config</span><span class="p">(</span><span class="n">yscrollcommand</span><span class="o">=</span><span class="n">listscroll</span><span class="o">.</span><span class="n">set</span><span class="p">)</span>
<span class="n">listscroll</span><span class="o">.</span><span class="n">config</span><span class="p">(</span><span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">yview</span><span class="p">)</span>
<span class="n">listscroll</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"y"</span><span class="p">)</span>
<span class="c1"># If they select a production, apply it.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<<ListboxSelect>>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">_prodlist_select</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_init_bindings</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># Key bindings are a good thing.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-q>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-x>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Escape>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"e"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">expand</span><span class="p">)</span>
<span class="c1"># self._top.bind('<Alt-e>', self.expand)</span>
<span class="c1"># self._top.bind('<Control-e>', self.expand)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"m"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">match</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Alt-m>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">match</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-m>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">match</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"b"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">backtrack</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Alt-b>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">backtrack</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-b>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">backtrack</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-z>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">backtrack</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<BackSpace>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">backtrack</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"a"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">autostep</span><span class="p">)</span>
<span class="c1"># self._top.bind('<Control-a>', self.autostep)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-space>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">autostep</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-c>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">cancel_autostep</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<space>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">step</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Delete>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">reset</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-p>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">postscript</span><span class="p">)</span>
<span class="c1"># self._top.bind('<h>', self.help)</span>
<span class="c1"># self._top.bind('<Alt-h>', self.help)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-h>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">help</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<F1>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">help</span><span class="p">)</span>
<span class="c1"># self._top.bind('<g>', self.toggle_grammar)</span>
<span class="c1"># self._top.bind('<Alt-g>', self.toggle_grammar)</span>
<span class="c1"># self._top.bind('<Control-g>', self.toggle_grammar)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-g>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">edit_grammar</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">bind</span><span class="p">(</span><span class="s2">"<Control-t>"</span><span class="p">,</span> <span class="bp">self</span><span class="o">.</span><span class="n">edit_sentence</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_init_buttons</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="c1"># Set up the frames.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_buttonframe</span> <span class="o">=</span> <span class="n">buttonframe</span> <span class="o">=</span> <span class="n">Frame</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="n">buttonframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">fill</span><span class="o">=</span><span class="s2">"none"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"bottom"</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">3</span><span class="p">,</span> <span class="n">pady</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Step"</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#90c0d0"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">step</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Autostep"</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#90c0d0"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">autostep</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Expand"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#90f090"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">expand</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Match"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#90f090"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">match</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">Button</span><span class="p">(</span>
<span class="n">buttonframe</span><span class="p">,</span>
<span class="n">text</span><span class="o">=</span><span class="s2">"Backtrack"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#f0a0a0"</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"black"</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">backtrack</span><span class="p">,</span>
<span class="p">)</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="c1"># Replace autostep...</span>
<span class="c1"># self._autostep_button = Button(buttonframe, text='Autostep',</span>
<span class="c1"># underline=0, command=self.autostep)</span>
<span class="c1"># self._autostep_button.pack(side='left')</span>
<span class="k">def</span> <span class="nf">_configure</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">event</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="p">(</span><span class="n">x1</span><span class="p">,</span> <span class="n">y1</span><span class="p">,</span> <span class="n">x2</span><span class="p">,</span> <span class="n">y2</span><span class="p">)</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">scrollregion</span><span class="p">()</span>
<span class="n">y2</span> <span class="o">=</span> <span class="n">event</span><span class="o">.</span><span class="n">height</span> <span class="o">-</span> <span class="mi">6</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">[</span><span class="s2">"scrollregion"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"</span><span class="si">%d</span><span class="s2"> </span><span class="si">%d</span><span class="s2"> </span><span class="si">%d</span><span class="s2"> </span><span class="si">%d</span><span class="s2">"</span> <span class="o">%</span> <span class="p">(</span><span class="n">x1</span><span class="p">,</span> <span class="n">y1</span><span class="p">,</span> <span class="n">x2</span><span class="p">,</span> <span class="n">y2</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">_init_feedback</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_feedbackframe</span> <span class="o">=</span> <span class="n">feedbackframe</span> <span class="o">=</span> <span class="n">Frame</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="n">feedbackframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">fill</span><span class="o">=</span><span class="s2">"x"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"bottom"</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">3</span><span class="p">,</span> <span class="n">pady</span><span class="o">=</span><span class="mi">3</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper_label</span> <span class="o">=</span> <span class="n">Label</span><span class="p">(</span>
<span class="n">feedbackframe</span><span class="p">,</span> <span class="n">text</span><span class="o">=</span><span class="s2">"Last Operation:"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper_label</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="n">lastoperframe</span> <span class="o">=</span> <span class="n">Frame</span><span class="p">(</span><span class="n">feedbackframe</span><span class="p">,</span> <span class="n">relief</span><span class="o">=</span><span class="s2">"sunken"</span><span class="p">,</span> <span class="n">border</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="n">lastoperframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">fill</span><span class="o">=</span><span class="s2">"x"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"right"</span><span class="p">,</span> <span class="n">expand</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">5</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span> <span class="o">=</span> <span class="n">Label</span><span class="p">(</span>
<span class="n">lastoperframe</span><span class="p">,</span> <span class="n">foreground</span><span class="o">=</span><span class="s2">"#007070"</span><span class="p">,</span> <span class="n">background</span><span class="o">=</span><span class="s2">"#f0f0f0"</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span> <span class="o">=</span> <span class="n">Label</span><span class="p">(</span>
<span class="n">lastoperframe</span><span class="p">,</span>
<span class="n">anchor</span><span class="o">=</span><span class="s2">"w"</span><span class="p">,</span>
<span class="n">width</span><span class="o">=</span><span class="mi">30</span><span class="p">,</span>
<span class="n">foreground</span><span class="o">=</span><span class="s2">"#004040"</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"#f0f0f0"</span><span class="p">,</span>
<span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">,</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"x"</span><span class="p">,</span> <span class="n">expand</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_init_canvas</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span> <span class="o">=</span> <span class="n">CanvasFrame</span><span class="p">(</span>
<span class="n">parent</span><span class="p">,</span>
<span class="n">background</span><span class="o">=</span><span class="s2">"white"</span><span class="p">,</span>
<span class="c1"># width=525, height=250,</span>
<span class="n">closeenough</span><span class="o">=</span><span class="mi">10</span><span class="p">,</span>
<span class="n">border</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span>
<span class="n">relief</span><span class="o">=</span><span class="s2">"sunken"</span><span class="p">,</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span><span class="n">expand</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">fill</span><span class="o">=</span><span class="s2">"both"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"top"</span><span class="p">,</span> <span class="n">pady</span><span class="o">=</span><span class="mi">2</span><span class="p">)</span>
<span class="n">canvas</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">canvas</span><span class="p">()</span>
<span class="c1"># Initially, there's no tree or text</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_tree</span> <span class="o">=</span> <span class="kc">None</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span> <span class="o">=</span> <span class="p">[]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_textline</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">def</span> <span class="nf">_init_menubar</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">parent</span><span class="p">):</span>
<span class="n">menubar</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="n">filemenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">filemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Reset Parser"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">reset</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Del"</span>
<span class="p">)</span>
<span class="n">filemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Print to Postscript"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">postscript</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-p"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">filemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Exit"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">destroy</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-x"</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"File"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">filemenu</span><span class="p">)</span>
<span class="n">editmenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">editmenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Edit Grammar"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">5</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">edit_grammar</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-g"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">editmenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Edit Text"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">5</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">edit_sentence</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-t"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"Edit"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">editmenu</span><span class="p">)</span>
<span class="n">rulemenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Step"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">step</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Space"</span>
<span class="p">)</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_separator</span><span class="p">()</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Match"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">match</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-m"</span>
<span class="p">)</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Expand"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">expand</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-e"</span>
<span class="p">)</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_separator</span><span class="p">()</span>
<span class="n">rulemenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Backtrack"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">backtrack</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"Ctrl-b"</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"Apply"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">rulemenu</span><span class="p">)</span>
<span class="n">viewmenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_checkbutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Show Grammar"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_show_grammar</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_toggle_grammar</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_separator</span><span class="p">()</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Tiny"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">10</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Small"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">12</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Medium"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">14</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Large"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">18</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">viewmenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Huge"</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">24</span><span class="p">,</span>
<span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">resize</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"View"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">viewmenu</span><span class="p">)</span>
<span class="n">animatemenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">animatemenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"No Animation"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="p">,</span> <span class="n">value</span><span class="o">=</span><span class="mi">0</span>
<span class="p">)</span>
<span class="n">animatemenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Slow Animation"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">10</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"-"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">animatemenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Normal Animation"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">5</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"="</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">animatemenu</span><span class="o">.</span><span class="n">add_radiobutton</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Fast Animation"</span><span class="p">,</span>
<span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span>
<span class="n">variable</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="p">,</span>
<span class="n">value</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span>
<span class="n">accelerator</span><span class="o">=</span><span class="s2">"+"</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"Animate"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">1</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">animatemenu</span><span class="p">)</span>
<span class="n">helpmenu</span> <span class="o">=</span> <span class="n">Menu</span><span class="p">(</span><span class="n">menubar</span><span class="p">,</span> <span class="n">tearoff</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span>
<span class="n">helpmenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"About"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">about</span><span class="p">)</span>
<span class="n">helpmenu</span><span class="o">.</span><span class="n">add_command</span><span class="p">(</span>
<span class="n">label</span><span class="o">=</span><span class="s2">"Instructions"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">command</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">help</span><span class="p">,</span> <span class="n">accelerator</span><span class="o">=</span><span class="s2">"F1"</span>
<span class="p">)</span>
<span class="n">menubar</span><span class="o">.</span><span class="n">add_cascade</span><span class="p">(</span><span class="n">label</span><span class="o">=</span><span class="s2">"Help"</span><span class="p">,</span> <span class="n">underline</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">menu</span><span class="o">=</span><span class="n">helpmenu</span><span class="p">)</span>
<span class="n">parent</span><span class="o">.</span><span class="n">config</span><span class="p">(</span><span class="n">menu</span><span class="o">=</span><span class="n">menubar</span><span class="p">)</span>
<span class="c1">#########################################</span>
<span class="c1">## Helper</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_get</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">widget</span><span class="p">,</span> <span class="n">treeloc</span><span class="p">):</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="n">treeloc</span><span class="p">:</span>
<span class="n">widget</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">subtrees</span><span class="p">()[</span><span class="n">i</span><span class="p">]</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">widget</span><span class="p">,</span> <span class="n">TreeSegmentWidget</span><span class="p">):</span>
<span class="n">widget</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">label</span><span class="p">()</span>
<span class="k">return</span> <span class="n">widget</span>
<span class="c1">#########################################</span>
<span class="c1">## Main draw procedure</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_redraw</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">canvas</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span>
<span class="c1"># Delete the old tree, widgets, etc.</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_tree</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">destroy_widget</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_tree</span><span class="p">)</span>
<span class="k">for</span> <span class="n">twidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">destroy_widget</span><span class="p">(</span><span class="n">twidget</span><span class="p">)</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_textline</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">delete</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_textline</span><span class="p">)</span>
<span class="c1"># Draw the tree.</span>
<span class="n">helv</span> <span class="o">=</span> <span class="p">(</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="o">-</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">())</span>
<span class="n">bold</span> <span class="o">=</span> <span class="p">(</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="o">-</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">(),</span> <span class="s2">"bold"</span><span class="p">)</span>
<span class="n">attribs</span> <span class="o">=</span> <span class="p">{</span>
<span class="s2">"tree_color"</span><span class="p">:</span> <span class="s2">"#000000"</span><span class="p">,</span>
<span class="s2">"tree_width"</span><span class="p">:</span> <span class="mi">2</span><span class="p">,</span>
<span class="s2">"node_font"</span><span class="p">:</span> <span class="n">bold</span><span class="p">,</span>
<span class="s2">"leaf_font"</span><span class="p">:</span> <span class="n">helv</span><span class="p">,</span>
<span class="p">}</span>
<span class="n">tree</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">tree</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_tree</span> <span class="o">=</span> <span class="n">tree_to_treesegment</span><span class="p">(</span><span class="n">canvas</span><span class="p">,</span> <span class="n">tree</span><span class="p">,</span> <span class="o">**</span><span class="n">attribs</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">add_widget</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_tree</span><span class="p">,</span> <span class="mi">30</span><span class="p">,</span> <span class="mi">5</span><span class="p">)</span>
<span class="c1"># Draw the text.</span>
<span class="n">helv</span> <span class="o">=</span> <span class="p">(</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="o">-</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">())</span>
<span class="n">bottom</span> <span class="o">=</span> <span class="n">y</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">scrollregion</span><span class="p">()[</span><span class="mi">3</span><span class="p">]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span> <span class="o">=</span> <span class="p">[</span>
<span class="n">TextWidget</span><span class="p">(</span><span class="n">canvas</span><span class="p">,</span> <span class="n">word</span><span class="p">,</span> <span class="n">font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">)</span> <span class="k">for</span> <span class="n">word</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_sent</span>
<span class="p">]</span>
<span class="k">for</span> <span class="n">twidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">add_widget</span><span class="p">(</span><span class="n">twidget</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="n">twidget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">bottom</span> <span class="o">-</span> <span class="n">twidget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">3</span><span class="p">]</span> <span class="o">-</span> <span class="mi">5</span><span class="p">)</span>
<span class="n">y</span> <span class="o">=</span> <span class="nb">min</span><span class="p">(</span><span class="n">y</span><span class="p">,</span> <span class="n">twidget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">1</span><span class="p">])</span>
<span class="c1"># Draw a line over the text, to separate it from the tree.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_textline</span> <span class="o">=</span> <span class="n">canvas</span><span class="o">.</span><span class="n">create_line</span><span class="p">(</span><span class="o">-</span><span class="mi">5000</span><span class="p">,</span> <span class="n">y</span> <span class="o">-</span> <span class="mi">5</span><span class="p">,</span> <span class="mi">5000</span><span class="p">,</span> <span class="n">y</span> <span class="o">-</span> <span class="mi">5</span><span class="p">,</span> <span class="n">dash</span><span class="o">=</span><span class="s2">"."</span><span class="p">)</span>
<span class="c1"># Highlight appropriate nodes.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_highlight_nodes</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_highlight_prodlist</span><span class="p">()</span>
<span class="c1"># Make sure the text lines up.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_position_text</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">_redraw_quick</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># This should be more-or-less sufficient after an animation.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_highlight_nodes</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_highlight_prodlist</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_position_text</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">_highlight_nodes</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># Highlight the list of nodes to be checked.</span>
<span class="n">bold</span> <span class="o">=</span> <span class="p">(</span><span class="s2">"helvetica"</span><span class="p">,</span> <span class="o">-</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">(),</span> <span class="s2">"bold"</span><span class="p">)</span>
<span class="k">for</span> <span class="n">treeloc</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">frontier</span><span class="p">()[:</span><span class="mi">1</span><span class="p">]:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_get</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_tree</span><span class="p">,</span> <span class="n">treeloc</span><span class="p">)[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#20a050"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_get</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_tree</span><span class="p">,</span> <span class="n">treeloc</span><span class="p">)[</span><span class="s2">"font"</span><span class="p">]</span> <span class="o">=</span> <span class="n">bold</span>
<span class="k">for</span> <span class="n">treeloc</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">frontier</span><span class="p">()[</span><span class="mi">1</span><span class="p">:]:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_get</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_tree</span><span class="p">,</span> <span class="n">treeloc</span><span class="p">)[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#008080"</span>
<span class="k">def</span> <span class="nf">_highlight_prodlist</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># Highlight the productions that can be expanded.</span>
<span class="c1"># Boy, too bad tkinter doesn't implement Listbox.itemconfig;</span>
<span class="c1"># that would be pretty useful here.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">delete</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="s2">"end"</span><span class="p">)</span>
<span class="n">expandable</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">expandable_productions</span><span class="p">()</span>
<span class="n">untried</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">untried_expandable_productions</span><span class="p">()</span>
<span class="n">productions</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_productions</span>
<span class="k">for</span> <span class="n">index</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">productions</span><span class="p">)):</span>
<span class="k">if</span> <span class="n">productions</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="ow">in</span> <span class="n">expandable</span><span class="p">:</span>
<span class="k">if</span> <span class="n">productions</span><span class="p">[</span><span class="n">index</span><span class="p">]</span> <span class="ow">in</span> <span class="n">untried</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">insert</span><span class="p">(</span><span class="n">index</span><span class="p">,</span> <span class="s2">" </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">productions</span><span class="p">[</span><span class="n">index</span><span class="p">])</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">insert</span><span class="p">(</span><span class="n">index</span><span class="p">,</span> <span class="s2">" </span><span class="si">%s</span><span class="s2"> (TRIED)"</span> <span class="o">%</span> <span class="n">productions</span><span class="p">[</span><span class="n">index</span><span class="p">])</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_set</span><span class="p">(</span><span class="n">index</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">insert</span><span class="p">(</span><span class="n">index</span><span class="p">,</span> <span class="s2">" </span><span class="si">%s</span><span class="s2">"</span> <span class="o">%</span> <span class="n">productions</span><span class="p">[</span><span class="n">index</span><span class="p">])</span>
<span class="k">def</span> <span class="nf">_position_text</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="c1"># Line up the text widgets that are matched against the tree</span>
<span class="n">numwords</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_sent</span><span class="p">)</span>
<span class="n">num_matched</span> <span class="o">=</span> <span class="n">numwords</span> <span class="o">-</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">remaining_text</span><span class="p">())</span>
<span class="n">leaves</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_tree_leaves</span><span class="p">()[:</span><span class="n">num_matched</span><span class="p">]</span>
<span class="n">xmax</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_tree</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="nb">len</span><span class="p">(</span><span class="n">leaves</span><span class="p">)):</span>
<span class="n">widget</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
<span class="n">leaf</span> <span class="o">=</span> <span class="n">leaves</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
<span class="n">widget</span><span class="p">[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#006040"</span>
<span class="n">leaf</span><span class="p">[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#006040"</span>
<span class="n">widget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">leaf</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span> <span class="o">-</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">],</span> <span class="mi">0</span><span class="p">)</span>
<span class="n">xmax</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">+</span> <span class="mi">10</span>
<span class="c1"># Line up the text widgets that are not matched against the tree.</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="nb">len</span><span class="p">(</span><span class="n">leaves</span><span class="p">),</span> <span class="n">numwords</span><span class="p">):</span>
<span class="n">widget</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
<span class="n">widget</span><span class="p">[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#a0a0a0"</span>
<span class="n">widget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">xmax</span> <span class="o">-</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">],</span> <span class="mi">0</span><span class="p">)</span>
<span class="n">xmax</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">+</span> <span class="mi">10</span>
<span class="c1"># If we have a complete parse, make everything green :)</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">currently_complete</span><span class="p">():</span>
<span class="k">for</span> <span class="n">twidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span><span class="p">:</span>
<span class="n">twidget</span><span class="p">[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#00a000"</span>
<span class="c1"># Move the matched leaves down to the text.</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="nb">len</span><span class="p">(</span><span class="n">leaves</span><span class="p">)):</span>
<span class="n">widget</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
<span class="n">leaf</span> <span class="o">=</span> <span class="n">leaves</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
<span class="n">dy</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">1</span><span class="p">]</span> <span class="o">-</span> <span class="n">leaf</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">3</span><span class="p">]</span> <span class="o">-</span> <span class="mf">10.0</span>
<span class="n">dy</span> <span class="o">=</span> <span class="nb">max</span><span class="p">(</span><span class="n">dy</span><span class="p">,</span> <span class="n">leaf</span><span class="o">.</span><span class="n">parent</span><span class="p">()</span><span class="o">.</span><span class="n">label</span><span class="p">()</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">3</span><span class="p">]</span> <span class="o">-</span> <span class="n">leaf</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">3</span><span class="p">]</span> <span class="o">+</span> <span class="mi">10</span><span class="p">)</span>
<span class="n">leaf</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">dy</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_tree_leaves</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">tree</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="k">if</span> <span class="n">tree</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="n">tree</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_tree</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">tree</span><span class="p">,</span> <span class="n">TreeSegmentWidget</span><span class="p">):</span>
<span class="n">leaves</span> <span class="o">=</span> <span class="p">[]</span>
<span class="k">for</span> <span class="n">child</span> <span class="ow">in</span> <span class="n">tree</span><span class="o">.</span><span class="n">subtrees</span><span class="p">():</span>
<span class="n">leaves</span> <span class="o">+=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_tree_leaves</span><span class="p">(</span><span class="n">child</span><span class="p">)</span>
<span class="k">return</span> <span class="n">leaves</span>
<span class="k">else</span><span class="p">:</span>
<span class="k">return</span> <span class="p">[</span><span class="n">tree</span><span class="p">]</span>
<span class="c1">#########################################</span>
<span class="c1">## Button Callbacks</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">destroy</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_top</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
<span class="k">return</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">destroy</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span> <span class="o">=</span> <span class="kc">None</span>
<span class="k">def</span> <span class="nf">reset</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">initialize</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_sent</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Reset Application"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">""</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">autostep</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="o">.</span><span class="n">get</span><span class="p">()</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">1</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_step</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">cancel_autostep</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="c1"># self._autostep_button['text'] = 'Autostep'</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="c1"># Make sure to stop auto-stepping if we get any user input.</span>
<span class="k">def</span> <span class="nf">step</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_step</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">match</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_match</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">expand</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_expand</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">backtrack</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_backtrack</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">_step</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span><span class="p">:</span>
<span class="k">return</span>
<span class="c1"># Try expanding, matching, and backtracking (in that order)</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_expand</span><span class="p">():</span>
<span class="k">pass</span>
<span class="k">elif</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">untried_match</span><span class="p">()</span> <span class="ow">and</span> <span class="bp">self</span><span class="o">.</span><span class="n">_match</span><span class="p">():</span>
<span class="k">pass</span>
<span class="k">elif</span> <span class="bp">self</span><span class="o">.</span><span class="n">_backtrack</span><span class="p">():</span>
<span class="k">pass</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Finished"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">""</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="c1"># Check if we just completed a parse.</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">currently_complete</span><span class="p">():</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">+=</span> <span class="s2">" [COMPLETE PARSE]"</span>
<span class="k">def</span> <span class="nf">_expand</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span><span class="p">:</span>
<span class="k">return</span>
<span class="n">old_frontier</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">frontier</span><span class="p">()</span>
<span class="n">rv</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">expand</span><span class="p">()</span>
<span class="k">if</span> <span class="n">rv</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Expand:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="n">rv</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_clear</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="s2">"end"</span><span class="p">)</span>
<span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="n">rv</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_set</span><span class="p">(</span><span class="n">index</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_expand</span><span class="p">(</span><span class="n">old_frontier</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
<span class="k">return</span> <span class="kc">True</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Expand:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"(all expansions tried)"</span>
<span class="k">return</span> <span class="kc">False</span>
<span class="k">def</span> <span class="nf">_match</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span><span class="p">:</span>
<span class="k">return</span>
<span class="n">old_frontier</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">frontier</span><span class="p">()</span>
<span class="n">rv</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">match</span><span class="p">()</span>
<span class="k">if</span> <span class="n">rv</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Match:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="n">rv</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_match</span><span class="p">(</span><span class="n">old_frontier</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
<span class="k">return</span> <span class="kc">True</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Match:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"(failed)"</span>
<span class="k">return</span> <span class="kc">False</span>
<span class="k">def</span> <span class="nf">_backtrack</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span><span class="p">:</span>
<span class="k">return</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">backtrack</span><span class="p">():</span>
<span class="n">elt</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">tree</span><span class="p">()</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">frontier</span><span class="p">()[</span><span class="mi">0</span><span class="p">]:</span>
<span class="n">elt</span> <span class="o">=</span> <span class="n">elt</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Backtrack"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">""</span>
<span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">elt</span><span class="p">,</span> <span class="n">Tree</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_backtrack</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">frontier</span><span class="p">()[</span><span class="mi">0</span><span class="p">])</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_match_backtrack</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">frontier</span><span class="p">()[</span><span class="mi">0</span><span class="p">])</span>
<span class="k">return</span> <span class="kc">True</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Finished"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">""</span>
<span class="k">return</span> <span class="kc">False</span>
<span class="k">def</span> <span class="nf">about</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="n">ABOUT</span> <span class="o">=</span> <span class="p">(</span>
<span class="s2">"NLTK Recursive Descent Parser Application</span><span class="se">\n</span><span class="s2">"</span> <span class="o">+</span> <span class="s2">"Written by Edward Loper"</span>
<span class="p">)</span>
<span class="n">TITLE</span> <span class="o">=</span> <span class="s2">"About: Recursive Descent Parser Application"</span>
<span class="k">try</span><span class="p">:</span>
<span class="kn">from</span> <span class="nn">tkinter.messagebox</span> <span class="kn">import</span> <span class="n">Message</span>
<span class="n">Message</span><span class="p">(</span><span class="n">message</span><span class="o">=</span><span class="n">ABOUT</span><span class="p">,</span> <span class="n">title</span><span class="o">=</span><span class="n">TITLE</span><span class="p">)</span><span class="o">.</span><span class="n">show</span><span class="p">()</span>
<span class="k">except</span><span class="p">:</span>
<span class="n">ShowText</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">,</span> <span class="n">TITLE</span><span class="p">,</span> <span class="n">ABOUT</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">help</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="c1"># The default font's not very legible; try using 'fixed' instead.</span>
<span class="k">try</span><span class="p">:</span>
<span class="n">ShowText</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">,</span>
<span class="s2">"Help: Recursive Descent Parser Application"</span><span class="p">,</span>
<span class="p">(</span><span class="vm">__doc__</span> <span class="ow">or</span> <span class="s2">""</span><span class="p">)</span><span class="o">.</span><span class="n">strip</span><span class="p">(),</span>
<span class="n">width</span><span class="o">=</span><span class="mi">75</span><span class="p">,</span>
<span class="n">font</span><span class="o">=</span><span class="s2">"fixed"</span><span class="p">,</span>
<span class="p">)</span>
<span class="k">except</span><span class="p">:</span>
<span class="n">ShowText</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="p">,</span>
<span class="s2">"Help: Recursive Descent Parser Application"</span><span class="p">,</span>
<span class="p">(</span><span class="vm">__doc__</span> <span class="ow">or</span> <span class="s2">""</span><span class="p">)</span><span class="o">.</span><span class="n">strip</span><span class="p">(),</span>
<span class="n">width</span><span class="o">=</span><span class="mi">75</span><span class="p">,</span>
<span class="p">)</span>
<span class="k">def</span> <span class="nf">postscript</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_autostep</span> <span class="o">=</span> <span class="mi">0</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">print_to_file</span><span class="p">()</span>
<span class="k">def</span> <span class="nf">mainloop</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Enter the Tkinter mainloop. This function must be called if</span>
<span class="sd"> this demo is created from a non-interactive program (e.g.</span>
<span class="sd"> from a secript); otherwise, the demo will close as soon as</span>
<span class="sd"> the script completes.</span>
<span class="sd"> """</span>
<span class="k">if</span> <span class="n">in_idle</span><span class="p">():</span>
<span class="k">return</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_top</span><span class="o">.</span><span class="n">mainloop</span><span class="p">(</span><span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kwargs</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">resize</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">size</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
<span class="k">if</span> <span class="n">size</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">set</span><span class="p">(</span><span class="n">size</span><span class="p">)</span>
<span class="n">size</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="o">.</span><span class="n">get</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="o">.</span><span class="n">configure</span><span class="p">(</span><span class="n">size</span><span class="o">=-</span><span class="p">(</span><span class="nb">abs</span><span class="p">(</span><span class="n">size</span><span class="p">)))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span><span class="o">.</span><span class="n">configure</span><span class="p">(</span><span class="n">size</span><span class="o">=-</span><span class="p">(</span><span class="nb">abs</span><span class="p">(</span><span class="n">size</span><span class="p">)))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_sysfont</span><span class="o">.</span><span class="n">configure</span><span class="p">(</span><span class="n">size</span><span class="o">=-</span><span class="p">(</span><span class="nb">abs</span><span class="p">(</span><span class="n">size</span><span class="p">)))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_bigfont</span><span class="o">.</span><span class="n">configure</span><span class="p">(</span><span class="n">size</span><span class="o">=-</span><span class="p">(</span><span class="nb">abs</span><span class="p">(</span><span class="n">size</span> <span class="o">+</span> <span class="mi">2</span><span class="p">)))</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_redraw</span><span class="p">()</span>
<span class="c1">#########################################</span>
<span class="c1">## Expand Production Selection</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_toggle_grammar</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">e</span><span class="p">):</span>
<span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_show_grammar</span><span class="o">.</span><span class="n">get</span><span class="p">():</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="o">.</span><span class="n">pack</span><span class="p">(</span>
<span class="n">fill</span><span class="o">=</span><span class="s2">"both"</span><span class="p">,</span> <span class="n">side</span><span class="o">=</span><span class="s2">"left"</span><span class="p">,</span> <span class="n">padx</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span> <span class="n">after</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_feedbackframe</span>
<span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Show Grammar"</span>
<span class="k">else</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodframe</span><span class="o">.</span><span class="n">pack_forget</span><span class="p">()</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Hide Grammar"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">""</span>
<span class="c1"># def toggle_grammar(self, *e):</span>
<span class="c1"># self._show_grammar = not self._show_grammar</span>
<span class="c1"># if self._show_grammar:</span>
<span class="c1"># self._prodframe.pack(fill='both', expand='y', side='left',</span>
<span class="c1"># after=self._feedbackframe)</span>
<span class="c1"># self._lastoper1['text'] = 'Show Grammar'</span>
<span class="c1"># else:</span>
<span class="c1"># self._prodframe.pack_forget()</span>
<span class="c1"># self._lastoper1['text'] = 'Hide Grammar'</span>
<span class="c1"># self._lastoper2['text'] = ''</span>
<span class="k">def</span> <span class="nf">_prodlist_select</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">event</span><span class="p">):</span>
<span class="n">selection</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">curselection</span><span class="p">()</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">selection</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">1</span><span class="p">:</span>
<span class="k">return</span>
<span class="n">index</span> <span class="o">=</span> <span class="nb">int</span><span class="p">(</span><span class="n">selection</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
<span class="n">old_frontier</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">frontier</span><span class="p">()</span>
<span class="n">production</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">expand</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="p">[</span><span class="n">index</span><span class="p">])</span>
<span class="k">if</span> <span class="n">production</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper1</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"Expand:"</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_lastoper2</span><span class="p">[</span><span class="s2">"text"</span><span class="p">]</span> <span class="o">=</span> <span class="n">production</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_clear</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="s2">"end"</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_set</span><span class="p">(</span><span class="n">index</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_expand</span><span class="p">(</span><span class="n">old_frontier</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
<span class="k">else</span><span class="p">:</span>
<span class="c1"># Reset the production selections.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_clear</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="s2">"end"</span><span class="p">)</span>
<span class="k">for</span> <span class="n">prod</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">expandable_productions</span><span class="p">():</span>
<span class="n">index</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_productions</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="n">prod</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_prodlist</span><span class="o">.</span><span class="n">selection_set</span><span class="p">(</span><span class="n">index</span><span class="p">)</span>
<span class="c1">#########################################</span>
<span class="c1">## Animation</span>
<span class="c1">#########################################</span>
<span class="k">def</span> <span class="nf">_animate_expand</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">treeloc</span><span class="p">):</span>
<span class="n">oldwidget</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_get</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_tree</span><span class="p">,</span> <span class="n">treeloc</span><span class="p">)</span>
<span class="n">oldtree</span> <span class="o">=</span> <span class="n">oldwidget</span><span class="o">.</span><span class="n">parent</span><span class="p">()</span>
<span class="n">top</span> <span class="o">=</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">oldtree</span><span class="o">.</span><span class="n">parent</span><span class="p">(),</span> <span class="n">TreeSegmentWidget</span><span class="p">)</span>
<span class="n">tree</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_parser</span><span class="o">.</span><span class="n">tree</span><span class="p">()</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="n">treeloc</span><span class="p">:</span>
<span class="n">tree</span> <span class="o">=</span> <span class="n">tree</span><span class="p">[</span><span class="n">i</span><span class="p">]</span>
<span class="n">widget</span> <span class="o">=</span> <span class="n">tree_to_treesegment</span><span class="p">(</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="p">,</span>
<span class="n">tree</span><span class="p">,</span>
<span class="n">node_font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_boldfont</span><span class="p">,</span>
<span class="n">leaf_color</span><span class="o">=</span><span class="s2">"white"</span><span class="p">,</span>
<span class="n">tree_width</span><span class="o">=</span><span class="mi">2</span><span class="p">,</span>
<span class="n">tree_color</span><span class="o">=</span><span class="s2">"white"</span><span class="p">,</span>
<span class="n">node_color</span><span class="o">=</span><span class="s2">"white"</span><span class="p">,</span>
<span class="n">leaf_font</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_font</span><span class="p">,</span>
<span class="p">)</span>
<span class="n">widget</span><span class="o">.</span><span class="n">label</span><span class="p">()[</span><span class="s2">"color"</span><span class="p">]</span> <span class="o">=</span> <span class="s2">"#20a050"</span>
<span class="p">(</span><span class="n">oldx</span><span class="p">,</span> <span class="n">oldy</span><span class="p">)</span> <span class="o">=</span> <span class="n">oldtree</span><span class="o">.</span><span class="n">label</span><span class="p">()</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[:</span><span class="mi">2</span><span class="p">]</span>
<span class="p">(</span><span class="n">newx</span><span class="p">,</span> <span class="n">newy</span><span class="p">)</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">label</span><span class="p">()</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[:</span><span class="mi">2</span><span class="p">]</span>
<span class="n">widget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">oldx</span> <span class="o">-</span> <span class="n">newx</span><span class="p">,</span> <span class="n">oldy</span> <span class="o">-</span> <span class="n">newy</span><span class="p">)</span>
<span class="k">if</span> <span class="n">top</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">add_widget</span><span class="p">(</span><span class="n">widget</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">5</span><span class="p">)</span>
<span class="n">widget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="mi">30</span> <span class="o">-</span> <span class="n">widget</span><span class="o">.</span><span class="n">label</span><span class="p">()</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">],</span> <span class="mi">0</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_tree</span> <span class="o">=</span> <span class="n">widget</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">oldtree</span><span class="o">.</span><span class="n">parent</span><span class="p">()</span><span class="o">.</span><span class="n">replace_child</span><span class="p">(</span><span class="n">oldtree</span><span class="p">,</span> <span class="n">widget</span><span class="p">)</span>
<span class="c1"># Move the children over so they don't overlap.</span>
<span class="c1"># Line the children up in a strange way.</span>
<span class="k">if</span> <span class="n">widget</span><span class="o">.</span><span class="n">subtrees</span><span class="p">():</span>
<span class="n">dx</span> <span class="o">=</span> <span class="p">(</span>
<span class="n">oldx</span>
<span class="o">+</span> <span class="n">widget</span><span class="o">.</span><span class="n">label</span><span class="p">()</span><span class="o">.</span><span class="n">width</span><span class="p">()</span> <span class="o">/</span> <span class="mi">2</span>
<span class="o">-</span> <span class="n">widget</span><span class="o">.</span><span class="n">subtrees</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span> <span class="o">/</span> <span class="mi">2</span>
<span class="o">-</span> <span class="n">widget</span><span class="o">.</span><span class="n">subtrees</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">/</span> <span class="mi">2</span>
<span class="p">)</span>
<span class="k">for</span> <span class="n">subtree</span> <span class="ow">in</span> <span class="n">widget</span><span class="o">.</span><span class="n">subtrees</span><span class="p">():</span>
<span class="n">subtree</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">dx</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_makeroom</span><span class="p">(</span><span class="n">widget</span><span class="p">)</span>
<span class="k">if</span> <span class="n">top</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_cframe</span><span class="o">.</span><span class="n">destroy_widget</span><span class="p">(</span><span class="n">oldtree</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">oldtree</span><span class="o">.</span><span class="n">destroy</span><span class="p">()</span>
<span class="n">colors</span> <span class="o">=</span> <span class="p">[</span>
<span class="s2">"gray</span><span class="si">%d</span><span class="s2">"</span> <span class="o">%</span> <span class="p">(</span><span class="mi">10</span> <span class="o">*</span> <span class="nb">int</span><span class="p">(</span><span class="mi">10</span> <span class="o">*</span> <span class="n">x</span> <span class="o">/</span> <span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="o">.</span><span class="n">get</span><span class="p">()))</span>
<span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_animation_frames</span><span class="o">.</span><span class="n">get</span><span class="p">(),</span> <span class="mi">0</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">)</span>
<span class="p">]</span>
<span class="c1"># Move the text string down, if necessary.</span>
<span class="n">dy</span> <span class="o">=</span> <span class="n">widget</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">3</span><span class="p">]</span> <span class="o">+</span> <span class="mi">30</span> <span class="o">-</span> <span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">coords</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_textline</span><span class="p">)[</span><span class="mi">1</span><span class="p">]</span>
<span class="k">if</span> <span class="n">dy</span> <span class="o">></span> <span class="mi">0</span><span class="p">:</span>
<span class="k">for</span> <span class="n">twidget</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">_textwidgets</span><span class="p">:</span>
<span class="n">twidget</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">dy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_canvas</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_textline</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="n">dy</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animate_expand_frame</span><span class="p">(</span><span class="n">widget</span><span class="p">,</span> <span class="n">colors</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_makeroom</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">treeseg</span><span class="p">):</span>
<span class="sd">"""</span>
<span class="sd"> Make sure that no sibling tree bbox's overlap.</span>
<span class="sd"> """</span>
<span class="n">parent</span> <span class="o">=</span> <span class="n">treeseg</span><span class="o">.</span><span class="n">parent</span><span class="p">()</span>
<span class="k">if</span> <span class="ow">not</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">parent</span><span class="p">,</span> <span class="n">TreeSegmentWidget</span><span class="p">):</span>
<span class="k">return</span>
<span class="n">index</span> <span class="o">=</span> <span class="n">parent</span><span class="o">.</span><span class="n">subtrees</span><span class="p">()</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="n">treeseg</span><span class="p">)</span>
<span class="c1"># Handle siblings to the right</span>
<span class="n">rsiblings</span> <span class="o">=</span> <span class="n">parent</span><span class="o">.</span><span class="n">subtrees</span><span class="p">()[</span><span class="n">index</span> <span class="o">+</span> <span class="mi">1</span> <span class="p">:]</span>
<span class="k">if</span> <span class="n">rsiblings</span><span class="p">:</span>
<span class="n">dx</span> <span class="o">=</span> <span class="n">treeseg</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">-</span> <span class="n">rsiblings</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span> <span class="o">+</span> <span class="mi">10</span>
<span class="k">for</span> <span class="n">sibling</span> <span class="ow">in</span> <span class="n">rsiblings</span><span class="p">:</span>
<span class="n">sibling</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">dx</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="c1"># Handle siblings to the left</span>
<span class="k">if</span> <span class="n">index</span> <span class="o">></span> <span class="mi">0</span><span class="p">:</span>
<span class="n">lsibling</span> <span class="o">=</span> <span class="n">parent</span><span class="o">.</span><span class="n">subtrees</span><span class="p">()[</span><span class="n">index</span> <span class="o">-</span> <span class="mi">1</span><span class="p">]</span>
<span class="n">dx</span> <span class="o">=</span> <span class="nb">max</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">lsibling</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">2</span><span class="p">]</span> <span class="o">-</span> <span class="n">treeseg</span><span class="o">.</span><span class="n">bbox</span><span class="p">()[</span><span class="mi">0</span><span class="p">]</span> <span class="o">+</span> <span class="mi">10</span><span class="p">)</span>
<span class="n">treeseg</span><span class="o">.</span><span class="n">move</span><span class="p">(</span><span class="n">dx</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
<span class="c1"># Keep working up the tree.</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_makeroom</span><span class="p">(</span><span class="n">parent</span><span class="p">)</span>
<span class="k">def</span> <span class="nf">_animate_expand_frame</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">widget</span><span class="p">,</span> <span class="n">colors</span><span class="p">):</span>
<span class="k">if</span> <span class="nb">len</span><span class="p">(</span><span class="n">colors</span><span class="p">)</span> <span class="o">></span> <span class="mi">0</span><span class="p">:</span>
<span class="bp">self</span><span class="o">.</span><span class="n">_animating_lock</span> <span class="o">=</span> <span class="mi">1</span>