fixes #356 Vim cursors shapes?

This adds a new method, SetCursorStyle() to the screen API.
It also automatically restores the cursor when disengaging to
the default cursor.  Modern terminals (and Windows console) support
this.

console_win.go

@@ -46,11 +46,12 @@ type cScreen struct {
 	w int
 	h int
 
-	oscreen consoleInfo
-	ocursor cursorInfo
-	oimode  uint32
-	oomode  uint32
-	cells   CellBuffer
+	oscreen     consoleInfo
+	ocursor     cursorInfo
+	cursorStyle CursorStyle
+	oimode      uint32
+	oomode      uint32
+	cells       CellBuffer
 
 	finiOnce sync.Once
 
@@ -138,20 +139,37 @@ const (
 
 const (
 	// VT100/XTerm escapes understood by the console
-	vtShowCursor = "\x1b[?25h"
-	vtHideCursor = "\x1b[?25l"
-	vtCursorPos  = "\x1b[%d;%dH" // Note that it is Y then X
-	vtSgr0       = "\x1b[0m"
-	vtBold       = "\x1b[1m"
-	vtUnderline  = "\x1b[4m"
-	vtBlink      = "\x1b[5m" // Not sure this is processed
-	vtReverse    = "\x1b[7m"
-	vtSetFg      = "\x1b[38;5;%dm"
-	vtSetBg      = "\x1b[48;5;%dm"
-	vtSetFgRGB   = "\x1b[38;2;%d;%d;%dm" // RGB
-	vtSetBgRGB   = "\x1b[48;2;%d;%d;%dm" // RGB
+	vtShowCursor              = "\x1b[?25h"
+	vtHideCursor              = "\x1b[?25l"
+	vtCursorPos               = "\x1b[%d;%dH" // Note that it is Y then X
+	vtSgr0                    = "\x1b[0m"
+	vtBold                    = "\x1b[1m"
+	vtUnderline               = "\x1b[4m"
+	vtBlink                   = "\x1b[5m" // Not sure this is processed
+	vtReverse                 = "\x1b[7m"
+	vtSetFg                   = "\x1b[38;5;%dm"
+	vtSetBg                   = "\x1b[48;5;%dm"
+	vtSetFgRGB                = "\x1b[38;2;%d;%d;%dm" // RGB
+	vtSetBgRGB                = "\x1b[48;2;%d;%d;%dm" // RGB
+	vtCursorDefault           = "\x1b[0 q"
+	vtCursorBlinkingBlock     = "\x1b[1 q"
+	vtCursorSteadyBlock       = "\x1b[2 q"
+	vtCursorBlinkingUnderline = "\x1b[3 q"
+	vtCursorSteadyUnderline   = "\x1b[4 q"
+	vtCursorBlinkingBar       = "\x1b[5 q"
+	vtCursorSteadyBar         = "\x1b[6 q"
 )
 
+var vtCursorStyles = map[CursorStyle]string{
+	CursorStyleDefault:           vtCursorDefault,
+	CursorStyleBlinkingBlock:     vtCursorBlinkingBlock,
+	CursorStyleSteadyBlock:       vtCursorSteadyBlock,
+	CursorStyleBlinkingUnderline: vtCursorBlinkingUnderline,
+	CursorStyleSteadyUnderline:   vtCursorSteadyUnderline,
+	CursorStyleBlinkingBar:       vtCursorBlinkingBar,
+	CursorStyleSteadyBar:         vtCursorSteadyBar,
+}
+
 // NewConsoleScreen returns a Screen for the Windows console associated
 // with the current process.  The Screen makes use of the Windows Console
 // API to display content and read events.
@@ -280,6 +298,9 @@ func (s *cScreen) disengage() {
 
 	s.wg.Wait()
 
+	if s.vten {
+		s.emitVtString(vtCursorStyles[CursorStyleDefault])
+	}
 	s.setInMode(s.oimode)
 	s.setOutMode(s.oomode)
 	s.setBufferSize(int(s.oscreen.size.x), int(s.oscreen.size.y))
@@ -406,6 +427,7 @@ func (s *cScreen) emitVtString(vs string) {
 func (s *cScreen) showCursor() {
 	if s.vten {
 		s.emitVtString(vtShowCursor)
+		s.emitVtString(vtCursorStyles[s.cursorStyle])
 	} else {
 		s.setCursorInfo(&cursorInfo{size: 100, visible: 1})
 	}
@@ -429,6 +451,17 @@ func (s *cScreen) ShowCursor(x, y int) {
 	s.Unlock()
 }
 
+func (s *cScreen) SetCursorStyle(cs CursorStyle) {
+	s.Lock()
+	if !s.fini {
+		if _, ok := vtCursorStyles[cs]; ok {
+			s.cursorStyle = cs
+			s.doCursor()
+		}
+	}
+	s.Unlock()
+}
+
 func (s *cScreen) doCursor() {
 	x, y := s.curx, s.cury
 

screen.go

@@ -71,9 +71,14 @@ type Screen interface {
 	ShowCursor(x int, y int)
 
 	// HideCursor is used to hide the cursor.  Its an alias for
-	// ShowCursor(-1, -1).
+	// ShowCursor(-1, -1).sim
 	HideCursor()
 
+	// SetCursorStyle is used to set the cursor style.  If the style
+	// is not supported (or cursor styles are not supported at all),
+	// then this will have no effect.
+	SetCursorStyle(CursorStyle)
+
 	// Size returns the screen size as width, height.  This changes in
 	// response to a call to Clear or Flush.
 	Size() (width, height int)
@@ -258,3 +263,17 @@ const (
 	MouseDragEvents   = MouseFlags(2) // Click-drag events (includes button events)
 	MouseMotionEvents = MouseFlags(4) // All mouse events (includes click and drag events)
 )
+
+// CursorStyle represents a given cursor style, which can include the shape and
+// whether the cursor blinks or is solid.  Support for changing these is not universal.
+type CursorStyle int
+
+const (
+	CursorStyleDefault = CursorStyle(iota) // The default
+	CursorStyleBlinkingBlock
+	CursorStyleSteadyBlock
+	CursorStyleBlinkingUnderline
+	CursorStyleSteadyUnderline
+	CursorStyleBlinkingBar
+	CursorStyleSteadyBar
+)

simulation.go

@@ -281,6 +281,8 @@ func (s *simscreen) hideCursor() {
 	s.cursorvis = false
 }
 
+func (s *simscreen) SetCursorStyle(CursorStyle) {}
+
 func (s *simscreen) Show() {
 	s.Lock()
 	s.resize()

terminfo/mkinfo.go

@@ -609,6 +609,13 @@ func dotGoInfo(w io.Writer, terms []*TData) {
 		dotGoAddFlag(w, "TrueColor", t.TrueColor)
 		dotGoAddFlag(w, "AutoMargin", t.AutoMargin)
 		dotGoAddStr(w, "InsertChar", t.InsertChar)
+		dotGoAddStr(w, "CursorDefault", t.CursorDefault)
+		dotGoAddStr(w, "CursorBlinkingBlock", t.CursorBlinkingBlock)
+		dotGoAddStr(w, "CursorSteadyBlock", t.CursorSteadyBlock)
+		dotGoAddStr(w, "CursorBlinkingUnderline", t.CursorBlinkingUnderline)
+		dotGoAddStr(w, "CursorSteadyUnderline", t.CursorSteadyUnderline)
+		dotGoAddStr(w, "CursorBlinkingBar", t.CursorBlinkingBar)
+		dotGoAddStr(w, "CursorSteadyBar", t.CursorSteadyBar)
 		fmt.Fprintln(w, "\t})")
 	}
 	fmt.Fprintln(w, "}")

terminfo/terminfo.go

@@ -167,59 +167,66 @@ type Terminfo struct {
 	// Terminal support for these are going to vary amongst XTerm
 	// emulations, so don't depend too much on them in your application.
 
-	StrikeThrough   string // smxx
-	SetFgBg         string // setfgbg
-	SetFgBgRGB      string // setfgbgrgb
-	SetFgRGB        string // setfrgb
-	SetBgRGB        string // setbrgb
-	KeyShfUp        string // shift-up
-	KeyShfDown      string // shift-down
-	KeyShfPgUp      string // shift-kpp
-	KeyShfPgDn      string // shift-knp
-	KeyCtrlUp       string // ctrl-up
-	KeyCtrlDown     string // ctrl-left
-	KeyCtrlRight    string // ctrl-right
-	KeyCtrlLeft     string // ctrl-left
-	KeyMetaUp       string // meta-up
-	KeyMetaDown     string // meta-left
-	KeyMetaRight    string // meta-right
-	KeyMetaLeft     string // meta-left
-	KeyAltUp        string // alt-up
-	KeyAltDown      string // alt-left
-	KeyAltRight     string // alt-right
-	KeyAltLeft      string // alt-left
-	KeyCtrlHome     string
-	KeyCtrlEnd      string
-	KeyMetaHome     string
-	KeyMetaEnd      string
-	KeyAltHome      string
-	KeyAltEnd       string
-	KeyAltShfUp     string
-	KeyAltShfDown   string
-	KeyAltShfLeft   string
-	KeyAltShfRight  string
-	KeyMetaShfUp    string
-	KeyMetaShfDown  string
-	KeyMetaShfLeft  string
-	KeyMetaShfRight string
-	KeyCtrlShfUp    string
-	KeyCtrlShfDown  string
-	KeyCtrlShfLeft  string
-	KeyCtrlShfRight string
-	KeyCtrlShfHome  string
-	KeyCtrlShfEnd   string
-	KeyAltShfHome   string
-	KeyAltShfEnd    string
-	KeyMetaShfHome  string
-	KeyMetaShfEnd   string
-	EnablePaste     string // bracketed paste mode
-	DisablePaste    string
-	PasteStart      string
-	PasteEnd        string
-	Modifiers       int
-	InsertChar      string // string to insert a character (ich1)
-	AutoMargin      bool   // true if writing to last cell in line advances
-	TrueColor       bool   // true if the terminal supports direct color
+	StrikeThrough           string // smxx
+	SetFgBg                 string // setfgbg
+	SetFgBgRGB              string // setfgbgrgb
+	SetFgRGB                string // setfrgb
+	SetBgRGB                string // setbrgb
+	KeyShfUp                string // shift-up
+	KeyShfDown              string // shift-down
+	KeyShfPgUp              string // shift-kpp
+	KeyShfPgDn              string // shift-knp
+	KeyCtrlUp               string // ctrl-up
+	KeyCtrlDown             string // ctrl-left
+	KeyCtrlRight            string // ctrl-right
+	KeyCtrlLeft             string // ctrl-left
+	KeyMetaUp               string // meta-up
+	KeyMetaDown             string // meta-left
+	KeyMetaRight            string // meta-right
+	KeyMetaLeft             string // meta-left
+	KeyAltUp                string // alt-up
+	KeyAltDown              string // alt-left
+	KeyAltRight             string // alt-right
+	KeyAltLeft              string // alt-left
+	KeyCtrlHome             string
+	KeyCtrlEnd              string
+	KeyMetaHome             string
+	KeyMetaEnd              string
+	KeyAltHome              string
+	KeyAltEnd               string
+	KeyAltShfUp             string
+	KeyAltShfDown           string
+	KeyAltShfLeft           string
+	KeyAltShfRight          string
+	KeyMetaShfUp            string
+	KeyMetaShfDown          string
+	KeyMetaShfLeft          string
+	KeyMetaShfRight         string
+	KeyCtrlShfUp            string
+	KeyCtrlShfDown          string
+	KeyCtrlShfLeft          string
+	KeyCtrlShfRight         string
+	KeyCtrlShfHome          string
+	KeyCtrlShfEnd           string
+	KeyAltShfHome           string
+	KeyAltShfEnd            string
+	KeyMetaShfHome          string
+	KeyMetaShfEnd           string
+	EnablePaste             string // bracketed paste mode
+	DisablePaste            string
+	PasteStart              string
+	PasteEnd                string
+	Modifiers               int
+	InsertChar              string // string to insert a character (ich1)
+	AutoMargin              bool   // true if writing to last cell in line advances
+	TrueColor               bool   // true if the terminal supports direct color
+	CursorDefault           string
+	CursorBlinkingBlock     string
+	CursorSteadyBlock       string
+	CursorBlinkingUnderline string
+	CursorSteadyUnderline   string
+	CursorBlinkingBar       string
+	CursorSteadyBar         string
 }
 
 const (

tscreen.go

@@ -148,6 +148,8 @@ type tScreen struct {
 	finiOnce     sync.Once
 	enablePaste  string
 	disablePaste string
+	cursorStyles map[CursorStyle]string
+	cursorStyle  CursorStyle
 	saved        *term.State
 	stopQ        chan struct{}
 	running      bool
@@ -332,6 +334,35 @@ func (t *tScreen) prepareBracketedPaste() {
 	}
 }
 
+func (t *tScreen) prepareCursorStyles() {
+	// Another workaround for lack of reporting in terminfo.
+	// We assume if the terminal has a mouse entry, that it
+	// offers bracketed paste.  But we allow specific overrides
+	// via our terminal database.
+	if t.ti.CursorDefault != "" {
+		t.cursorStyles = map[CursorStyle]string{
+			CursorStyleDefault: t.ti.CursorDefault,
+			CursorStyleBlinkingBlock: t.ti.CursorBlinkingBlock,
+			CursorStyleSteadyBlock: t.ti.CursorSteadyBlock,
+			CursorStyleBlinkingUnderline: t.ti.CursorBlinkingUnderline,
+			CursorStyleSteadyUnderline: t.ti.CursorSteadyUnderline,
+			CursorStyleBlinkingBar: t.ti.CursorBlinkingBar,
+			CursorStyleSteadyBar: t.ti.CursorSteadyBar,
+		}
+	} else if t.ti.Mouse != "" {
+		t.cursorStyles = map[CursorStyle]string{
+			CursorStyleDefault:           "\x1b[0 q",
+			CursorStyleBlinkingBlock:     "\x1b[1 q",
+			CursorStyleSteadyBlock:       "\x1b[2 q",
+			CursorStyleBlinkingUnderline: "\x1b[3 q",
+			CursorStyleSteadyUnderline:   "\x1b[4 q",
+			CursorStyleBlinkingBar:       "\x1b[5 q",
+			CursorStyleSteadyBar:         "\x1b[6 q",
+
+		}
+	}
+}
+
 func (t *tScreen) prepareKey(key Key, val string) {
 	t.prepareKeyMod(key, ModNone, val)
 }
@@ -471,6 +502,7 @@ func (t *tScreen) prepareKeys() {
 	t.prepareKey(keyPasteEnd, ti.PasteEnd)
 	t.prepareXtermModifiers()
 	t.prepareBracketedPaste()
+	t.prepareCursorStyles()
 
 outer:
 	// Add key mappings for control keys.
@@ -754,6 +786,12 @@ func (t *tScreen) ShowCursor(x, y int) {
 	t.Unlock()
 }
 
+func (t *tScreen) SetCursorStyle(cs CursorStyle) {
+	t.Lock()
+	t.cursorStyle = cs
+	t.Unlock()
+}
+
 func (t *tScreen) HideCursor() {
 	t.ShowCursor(-1, -1)
 }
@@ -768,6 +806,11 @@ func (t *tScreen) showCursor() {
 	}
 	t.TPuts(t.ti.TGoto(x, y))
 	t.TPuts(t.ti.ShowCursor)
+	if t.cursorStyles != nil {
+		if esc, ok := t.cursorStyles[t.cursorStyle]; ok {
+			t.TPuts(esc)
+		}
+	}
 	t.cx = x
 	t.cy = y
 }
@@ -1737,6 +1780,9 @@ func (t *tScreen) disengage() {
 	ti := t.ti
 	t.cells.Resize(0, 0)
 	t.TPuts(ti.ShowCursor)
+	if t.cursorStyles != nil && t.cursorStyle != CursorStyleDefault {
+		t.TPuts(t.cursorStyles[t.cursorStyle])
+	}
 	t.TPuts(ti.ResetFgBg)
 	t.TPuts(ti.AttrOff)
 	t.TPuts(ti.Clear)