From 83e11d23d87fb8d236961b28fed95bf249c98993 Mon Sep 17 00:00:00 2001
From: Alain Dumesny <alaind831+github@gmail.com>
Date: Thu, 30 Dec 2021 08:45:26 -0800
Subject: [PATCH] nested grid column:'auto' option

* partial fix #1009
* we now have a new column:'auto' option which is used for nested grids to column size themselves to match their container (same # of column)
This make sure outside and inside items stay the same size
* this will eventually be required when creating grids on the fly dynamically (as good default)
* updated nested.html to showcase this
---
 demo/nested.html | 35 +++++++++++++-----------
 doc/CHANGES.md   |  1 +
 doc/README.md    | 15 +++++++----
 src/gridstack.ts | 69 +++++++++++++++++++++++++++++++++++-------------
 src/types.ts     |  7 +++--
 5 files changed, 85 insertions(+), 42 deletions(-)
diff --git a/demo/nested.html b/demo/nested.html
index e3e8a64a3..00cbb5c90 100644
--- a/demo/nested.html
+++ b/demo/nested.html
@@ -9,11 +9,13 @@
   <link rel="stylesheet" href="../dist/gridstack-extra.min.css"/>
   <script src="../dist/gridstack-h5.js"></script>
   <style type="text/css">
-    .grid-stack .grid-stack {
-      background: rgba(255, 255, 255, 0.3);
+    /* make nested grids have slightly darker bg */
+    .grid-stack.grid-stack-nested {
+      background: #e4e4c1;
     }
-    .grid-stack .grid-stack .grid-stack-item-content {
-      background: lightpink;
+    /* make nested grid take almost all space (need some to tell them apart) so items inside can have similar to external size+margin */
+    .grid-stack > .grid-stack-item.grid-stack-nested > .grid-stack-item-content {
+      inset: 2px;
     }
     /* make nested grid take entire item content */
     .grid-stack-item-content .grid-stack {
@@ -25,11 +27,12 @@
 <body>
   <div class="container-fluid">
     <h1>Nested grids demo</h1>
-    <p>This example uses new v3.1 API to load the entire nested grid from JSON, and shows dragging between nested grid items (pink) vs dragging higher items (green)</p>
-    <p>Note: HTML5 release doesn't yet support 'dragOut:false' constrain so use JQ version if you need that (nested 2 case).</p>
+    <p>This example shows v5.x dragging between nested grids (dark yellow) and parent grid (bright yellow.)<br>
+      Uses v3.1 API to load the entire nested grid from JSON.<br>
+      Nested grids uses new <b>column:'auto'</b> to keep items same size during resize.</p>
     <a class="btn btn-primary" onClick="addNested()" href="#">Add Widget</a>
-    <a class="btn btn-primary" onClick="addNewWidget('.nested1')" href="#">Add Widget Grid1</a>
-    <a class="btn btn-primary" onClick="addNewWidget('.nested2')" href="#">Add Widget Grid2</a>
+    <a class="btn btn-primary" onClick="addNewWidget('.sub1')" href="#">Add Widget Grid1</a>
+    <a class="btn btn-primary" onClick="addNewWidget('.sub2')" href="#">Add Widget Grid2</a>
     <span>entire save/re-create:</span>
     <a class="btn btn-primary" onClick="save()" href="#">Save</a>
     <a class="btn btn-primary" onClick="destroy()" href="#">Destroy</a>
@@ -49,21 +52,21 @@ <h1>Nested grids demo</h1>
     let count = 0;
     [...sub1, ...sub2].forEach(d => d.content = String(count++));
     let subOptions = {
-      cellHeight: 30,
-      column: 4, // make sure to include gridstack-extra.min.css
+      cellHeight: 50,
+      column: 'auto', // size to match container. make sure to include gridstack-extra.min.css
       acceptWidgets: true, // will accept .grid-stack-item by default
-      minWidth: 300, // min to go 1 column mode (much smaller than default)
-      margin: 2
+      margin: 5,
     };
     let options = { // main grid options
-      cellHeight: 70,
+      cellHeight: 50,
+      margin: 5,
       minRow: 2, // don't collapse when empty
       acceptWidgets: true,
       id: 'main',
       children: [
         {y:0, content: 'regular item'},
-        {x:1, w:4, h:4, subGrid: {children: sub1, dragOut: true, id: 'sub1', ...subOptions}},
-        {x:5, w:4, h:4, subGrid: {children: sub2, id: 'sub2', ...subOptions}},
+        {x:1, w:4, h:4, subGrid: {children: sub1, dragOut: true, class: 'sub1', ...subOptions}},
+        {x:5, w:3, h:4, subGrid: {children: sub2, class: 'sub2', ...subOptions}},
       ]
     };
 
@@ -71,7 +74,7 @@ <h1>Nested grids demo</h1>
     let grid = GridStack.addGrid(document.querySelector('.container-fluid'), options);
 
     addNested = function() {
-      grid.addWidget({x:0, y:0, content:"new item"});
+      grid.addWidget({x:0, y:100, content:"new item"});
     }
 
     addNewWidget = function(selector) {
diff --git a/doc/CHANGES.md b/doc/CHANGES.md
index 5114e24e1..69df0febb 100644
--- a/doc/CHANGES.md
+++ b/doc/CHANGES.md
@@ -68,6 +68,7 @@ Change log
 
 ## 4.4.1-dev (TBD)
 * add [#992](https://github.com/gridstack/gridstack.js/issues/992) support dragging into and out of nested grids from parents! Thank you [@arclogos132](https://github.com/arclogos132) for sponsoring it.
+* add [#1910](https://github.com/gridstack/gridstack.js/pull/1910) new `column:'auto'` option to size nested grids to their parent grid item column count, keeping items the same size inside and outside. Thank you [@arclogos132](https://github.com/arclogos132) for also sponsoring it.
 * fix [#1902](https://github.com/gridstack/gridstack.js/pull/1902) nested.html: dragging between sub-grids show items clipped
 * fix [#1558](https://github.com/gridstack/gridstack.js/issues/1558) dragging between vertical grids causes too much growth, not follow mouse.
 
diff --git a/doc/README.md b/doc/README.md
index d731c026f..995a0fb18 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -34,7 +34,7 @@ gridstack.js API
   - [`cellHeight(val: number, update = true)`](#cellheightval-number-update--true)
   - [`cellWidth()`](#cellwidth)
   - [`commit()`](#commit)
-  - [`column(column: number, layout: ColumnOptions = 'moveScale')`](#columncolumn-number-layout-columnoptions--movescale)
+  - [`column(column: number | 'auto', layout: ColumnOptions = 'moveScale')`](#columncolumn-number--auto-layout-columnoptions--movescale)
   - [`destroy([removeDOM])`](#destroyremovedom)
   - [`disable()`](#disable)
   - [`enable()`](#enable)
@@ -43,6 +43,7 @@ gridstack.js API
   - [`float(val?)`](#floatval)
   - [`getCellHeight()`](#getcellheight)
   - [`getCellFromPixel(position[, useOffset])`](#getcellfrompixelposition-useoffset)
+  - [`getColumn(): number`](#getcolumn-number)
   - [`getGridItems(): GridItemHTMLElement[]`](#getgriditems-griditemhtmlelement)
   - [`getMargin()`](#getmargin)
   - [`isAreaEmpty(x, y, width, height)`](#isareaemptyx-y-width-height)
@@ -365,14 +366,14 @@ Gets current cell width (grid width / # of columns).
 
 Ends batch updates. Updates DOM nodes. You must call it after `batchUpdate()`.
 
-### `column(column: number, layout: ColumnOptions = 'moveScale')`
+### `column(column: number | 'auto', layout: ColumnOptions = 'moveScale')`
 
-set/get the number of columns in the grid. Will update existing widgets to conform to new number of columns,
+set the number of columns in the grid. Will update existing widgets to conform to new number of columns,
 as well as cache the original layout so you can revert back to previous positions without loss.
-Requires `gridstack-extra.css` or `gridstack-extra.min.css` for [2-11],
+Requires `gridstack-extra.css` (or minimized version) for [2-11],
 else you will need to generate correct CSS (see https://github.com/gridstack/gridstack.js#change-grid-columns)
 
-- `column` - Integer > 0 (default 12), if missing it will return the current count instead.
+- `column` - Integer > 0 (default 12), or 'auto' for nested grids to size themselves to the parent grid container (to make su-items the same size inside and outside)
 - `layout` - specify the type of re-layout that will happen (position, size, etc...).
 Note: items will never be outside of the current column boundaries. default ('moveScale'). Ignored for 1 column.
 Possible values: 'moveScale' | 'move' | 'scale' | 'none' | (column: number, oldColumn: number, nodes: GridStackNode[], oldNodes: GridStackNode[]) => void.
@@ -445,6 +446,10 @@ Parameters :
 
 Returns an object with properties `x` and `y` i.e. the column and row in the grid.
 
+### `getColumn(): number`
+
+returns the number of columns in the grid.
+
 ### `getGridItems(): GridItemHTMLElement[]`
 
 Return list of GridItem HTML elements (excluding temporary placeholder) in DOM order, wether they are node items yet or not (looks by class)
diff --git a/src/gridstack.ts b/src/gridstack.ts
index b0e201881..69d64410c 100644
--- a/src/gridstack.ts
+++ b/src/gridstack.ts
@@ -228,6 +228,8 @@ export class GridStack {
   private _insertNotAppend: boolean;
   /** @internal extra row added when dragging at the bottom of the grid */
   private _extraDragRow = 0;
+  /** @internal true if nested grid should get column count from our width */
+  private _autoColumn?: boolean;
 
   /**
    * Construct a grid item from the given element and options
@@ -245,6 +247,11 @@ export class GridStack {
     }
     let rowAttr = Utils.toNumber(el.getAttribute('gs-row'));
 
+    // flag only valid in sub-grids (handled by parent, not here)
+    if (opts.column === 'auto') {
+      delete opts.column;
+    }
+
     // elements attributes override any passed options (like CSS style) - merge the two together
     let defaults: GridStackOptions = {...Utils.cloneDeep(GridDefaults),
       column: Utils.toNumber(el.getAttribute('gs-column')) || 12,
@@ -276,7 +283,7 @@ export class GridStack {
 
     // Now check if we're loading into 1 column mode FIRST so we don't do un-necessary work (like cellHeight = width / 12 then go 1 column)
     if (this.opts.column !== 1 && !this.opts.disableOneColumnMode && this._widthOrContainer() <= this.opts.minWidth) {
-      this._prevColumn = this.opts.column;
+      this._prevColumn = this.getColumn();
       this.opts.column = 1;
     }
 
@@ -315,7 +322,7 @@ export class GridStack {
     this._setStaticClass();
 
     this.engine = new GridStackEngine({
-      column: this.opts.column,
+      column: this.getColumn(),
       float: this.opts.float,
       maxRow: this.opts.maxRow,
       onChange: (cbNodes) => {
@@ -344,7 +351,7 @@ export class GridStack {
         elements.push({
           el,
           // if x,y are missing (autoPosition) add them to end of list - but keep their respective DOM order
-          i: (Number.isNaN(x) ? 1000 : x) + (Number.isNaN(y) ? 1000 : y) * this.opts.column
+          i: (Number.isNaN(x) ? 1000 : x) + (Number.isNaN(y) ? 1000 : y) * this.getColumn()
         });
       });
       elements.sort((a, b) => a.i - b.i).forEach(e => this._prepareElement(e.el));
@@ -435,8 +442,17 @@ export class GridStack {
 
     // check if nested grid definition is present
     if (node.subGrid && !(node.subGrid as GridStack).el) { // see if there is a sub-grid to create too
+      // if column special case it set, remember that flag and set default
+      let autoColumn: boolean;
+      let ops = node.subGrid as GridStackOptions;
+      if (ops.column === 'auto') {
+        ops.column = node.w;
+        ops.disableOneColumnMode = true; // driven by parent
+        autoColumn = true;
+      }
       let content = node.el.querySelector('.grid-stack-item-content') as HTMLElement;
       node.subGrid = GridStack.addGrid(content, node.subGrid as GridStackOptions);
+      if (autoColumn) { node.subGrid._autoColumn = true; }
     }
 
     this._triggerAddEvent();
@@ -483,7 +499,13 @@ export class GridStack {
         delete o.marginTop; delete o.marginRight; delete o.marginBottom; delete o.marginLeft;
       }
       if (o.rtl === (this.el.style.direction === 'rtl')) { o.rtl = 'auto' }
-      if (this._isAutoCellHeight) { o.cellHeight = 'auto' }
+      if (this._isAutoCellHeight) {
+        o.cellHeight = 'auto'
+      }
+      if (this._autoColumn) {
+        o.column = 'auto';
+        delete o.disableOneColumnMode;
+      }
       Utils.removeInternalAndSame(o, GridDefaults);
       o.children = list;
       return o;
@@ -503,7 +525,7 @@ export class GridStack {
    * see http://gridstackjs.com/demo/serialization.html
    **/
   public load(layout: GridStackWidget[], addAndRemove: boolean | ((g: GridStack, w: GridStackWidget, add: boolean) => GridItemHTMLElement)  = true): GridStack {
-    let items = GridStack.Utils.sort([...layout], -1, this._prevColumn || this.opts.column); // make copy before we mod/sort
+    let items = GridStack.Utils.sort([...layout], -1, this._prevColumn || this.getColumn()); // make copy before we mod/sort
     this._insertNotAppend = true; // since create in reverse order...
 
     // if we're loading a layout into 1 column (_prevColumn is set only when going to 1) and items don't fit, make sure to save
@@ -633,7 +655,7 @@ export class GridStack {
 
   /** Gets current cell width. */
   public cellWidth(): number {
-    return this._widthOrContainer() / this.opts.column;
+    return this._widthOrContainer() / this.getColumn();
   }
   /** return our expected width (or parent) for 1 column check */
   private _widthOrContainer(): number {
@@ -671,7 +693,7 @@ export class GridStack {
    */
   public column(column: number, layout: ColumnOptions = 'moveScale'): GridStack {
     if (column < 1 || this.opts.column === column) return this;
-    let oldColumn = this.opts.column;
+    let oldColumn = this.getColumn();
 
     // if we go into 1 column mode (which happens if we're sized less than minW unless disableOneColumnMode is on)
     // then remember the original columns so we can restore.
@@ -709,7 +731,7 @@ export class GridStack {
    * get the number of columns in the grid (default 12)
    */
   public getColumn(): number {
-    return this.opts.column;
+    return this.opts.column as number;
   }
 
   /** returns an array of grid HTML elements (no placeholder) - used to iterate through our children in DOM order */
@@ -783,7 +805,7 @@ export class GridStack {
     let relativeLeft = position.left - containerPos.left;
     let relativeTop = position.top - containerPos.top;
 
-    let columnWidth = (box.width / this.opts.column);
+    let columnWidth = (box.width / this.getColumn());
     let rowHeight = (box.height / parseInt(this.el.getAttribute('gs-current-row')));
 
     return {x: Math.floor(relativeLeft / columnWidth), y: Math.floor(relativeTop / rowHeight)};
@@ -1336,29 +1358,38 @@ export class GridStack {
 
   /**
    * called when we are being resized by the window - check if the one Column Mode needs to be turned on/off
-   * and remember the prev columns we used, as well as check for auto cell height (square)
+   * and remember the prev columns we used, or get our count from parent, as well as check for auto cell height (square)
    */
   public onParentResize(): GridStack {
     if (!this.el || !this.el.clientWidth) return; // return if we're gone or no size yet (will get called again)
-    let oneColumn = !this.opts.disableOneColumnMode && this.el.clientWidth <= this.opts.minWidth;
-    let changedOneColumn = false;
+    let changedColumn = false;
 
-    if ((this.opts.column === 1) !== oneColumn) {
-      changedOneColumn = true;
-      if (this.opts.animate) { this.setAnimation(false); } // 1 <-> 12 is too radical, turn off animation
-      this.column(oneColumn ? 1 : this._prevColumn);
-      if (this.opts.animate) { this.setAnimation(true); }
+    // see if we're nested and take our column count from our parent....
+    if (this._autoColumn && this.opts._isNested) {
+      if (this.opts.column !== this.opts._isNested.w) {
+        changedColumn = true;
+        this.column(this.opts._isNested.w, 'none');
+      }
+    } else {
+      // else check for 1 column in/out behavior
+      let oneColumn = !this.opts.disableOneColumnMode && this.el.clientWidth <= this.opts.minWidth;
+      if ((this.opts.column === 1) !== oneColumn) {
+        changedColumn = true;
+        if (this.opts.animate) { this.setAnimation(false); } // 1 <-> 12 is too radical, turn off animation
+        this.column(oneColumn ? 1 : this._prevColumn);
+        if (this.opts.animate) { this.setAnimation(true); }
+      }
     }
 
     // make the cells content square again
     if (this._isAutoCellHeight) {
-      if (!changedOneColumn && this.opts.cellHeightThrottle) {
+      if (!changedColumn && this.opts.cellHeightThrottle) {
         if (!this._cellHeightThrottle) {
           this._cellHeightThrottle = Utils.throttle(() => this.cellHeight(), this.opts.cellHeightThrottle);
         }
         this._cellHeightThrottle();
       } else {
-        // immediate update if we've changed to/from oneColumn or have no threshold
+        // immediate update if we've changed column count or have no threshold
         this.cellHeight();
       }
     }
diff --git a/src/types.ts b/src/types.ts
index 67cd68bea..d7c63bd3b 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -71,8 +71,11 @@ export interface GridStackOptions {
   /** list of children item to create when calling load() or addGrid() */
   children?: GridStackWidget[];
 
-  /** number of columns (default?: 12). Note: IF you change this, CSS also have to change. See https://github.com/gridstack/gridstack.js#change-grid-columns */
-  column?: number;
+  /** number of columns (default?: 12). Note: IF you change this, CSS also have to change. See https://github.com/gridstack/gridstack.js#change-grid-columns.
+   * Note: for nested grids, it is recommended to use 'auto' which will always match the container grid-item current width (in column) to keep inside and outside
+   * items always to same. flag is ignored for non nested grids.
+   */
+  column?: number | 'auto';
 
   /** additional class on top of '.grid-stack' (which is required for our CSS) to differentiate this instance.
   Note: only used by addGrid(), else your element should have the needed class */
