Add multiple cursor support

This commit creates new keybindings and actions to handle multiple
cursors.

Here are the defaults:

    "Alt-n": "SpawnMultiCursor",
    "Alt-p": "RemoveMultiCursor",
    "Alt-c": "RemoveAllMultiCursors",
    "Alt-x": "SkipMultiCursor",

cmd/micro/actions.go

@@ -1829,7 +1829,112 @@ func (v *View) PlayMacro(usePlugin bool) bool {
 	return true
 }
 
-// None is no action
+func (v *View) SpawnMultiCursor(usePlugin bool) bool {
-func None() bool {
+	spawner := v.Buf.cursors[len(v.Buf.cursors)-1]
+	// You can only spawn a cursor from the main cursor
+	if v.Cursor == spawner {
+		if usePlugin && !PreActionCall("SpawnMultiCursor", v) {
+			return false
+		}
+
+		if !spawner.HasSelection() {
+			spawner.SelectWord()
+		} else {
+			c := &Cursor{
+				buf: v.Buf,
+			}
+
+			sel := spawner.GetSelection()
+
+			searchStart = ToCharPos(spawner.CurSelection[1], v.Buf)
+			v.Cursor = c
+			Search(sel, v, true)
+			messenger.Message(v.Cursor.Loc)
+
+			for _, cur := range v.Buf.cursors {
+				if c.Loc == cur.Loc {
+					return false
+				}
+			}
+			v.Buf.cursors = append(v.Buf.cursors, c)
+			v.Relocate()
+			v.Cursor = spawner
+		}
+
+		if usePlugin {
+			PostActionCall("SpawnMultiCursor", v)
+		}
+	}
+
+	return false
+}
+
+func (v *View) SkipMultiCursor(usePlugin bool) bool {
+	cursor := v.Buf.cursors[len(v.Buf.cursors)-1]
+
+	if v.Cursor == cursor {
+		messenger.Message("SKIP")
+		if usePlugin && !PreActionCall("SkipMultiCursor", v) {
+			return false
+		}
+		sel := cursor.GetSelection()
+
+		searchStart = ToCharPos(cursor.CurSelection[1], v.Buf)
+		v.Cursor = cursor
+		Search(sel, v, true)
+		v.Relocate()
+		v.Cursor = cursor
+
+		if usePlugin {
+			PostActionCall("SkipMultiCursor", v)
+		}
+	}
+	return false
+}
+
+func (v *View) RemoveMultiCursor(usePlugin bool) bool {
+	end := len(v.Buf.cursors)
+	if end > 1 {
+		nextOne := v.Buf.cursors[len(v.Buf.cursors)-2]
+		if v.Cursor == nextOne {
+			if usePlugin && !PreActionCall("RemoveMultiCursor", v) {
+				return false
+			}
+
+			if end > 1 {
+				v.Buf.cursors[end-1] = nil
+				v.Buf.cursors = v.Buf.cursors[:end-1]
+			}
+			v.Relocate()
+
+			if usePlugin {
+				return PostActionCall("RemoveMultiCursor", v)
+			}
+			return true
+		}
+	} else {
+		v.RemoveAllMultiCursors(usePlugin)
+	}
+	return false
+}
+
+func (v *View) RemoveAllMultiCursors(usePlugin bool) bool {
+	if v.Cursor == &v.Buf.Cursor {
+		if usePlugin && !PreActionCall("RemoveAllMultiCursors", v) {
+			return false
+		}
+
+		for i := 1; i < len(v.Buf.cursors); i++ {
+			v.Buf.cursors[i] = nil
+		}
+		v.Buf.cursors = v.Buf.cursors[:1]
+		v.Cursor.ResetSelection()
+		v.Relocate()
+
+		if usePlugin {
+			return PostActionCall("RemoveAllMultiCursors", v)
+		}
+		return true
+	}
 	return false
 }

cmd/micro/bindings.go

@@ -98,6 +98,10 @@ var bindingActions = map[string]func(*View, bool) bool{
 	"Suspend":               (*View).Suspend,
 	"ScrollUp":              (*View).ScrollUpAction,
 	"ScrollDown":            (*View).ScrollDownAction,
+	"SpawnMultiCursor":      (*View).SpawnMultiCursor,
+	"RemoveMultiCursor":     (*View).RemoveMultiCursor,
+	"RemoveAllMultiCursors": (*View).RemoveAllMultiCursors,
+	"SkipMultiCursor":       (*View).SkipMultiCursor,
 
 	// This was changed to InsertNewline but I don't want to break backwards compatibility
 	"InsertEnter": (*View).InsertNewline,
@@ -496,8 +500,8 @@ func DefaultBindings() map[string]string {
 		"Alt-b": "WordLeft",
 		"Alt-a": "StartOfLine",
 		"Alt-e": "EndOfLine",
-		"Alt-p": "CursorUp",
+		// "Alt-p": "CursorUp",
-		"Alt-n": "CursorDown",
+		// "Alt-n": "CursorDown",
 
 		// Integration with file managers
 		"F1":  "ToggleHelp",
@@ -513,5 +517,10 @@ func DefaultBindings() map[string]string {
 		"MouseWheelDown": "ScrollDown",
 		"MouseLeft":      "MousePress",
 		"MouseMiddle":    "PastePrimary",
+
+		"Alt-n": "SpawnMultiCursor",
+		"Alt-p": "RemoveMultiCursor",
+		"Alt-c": "RemoveAllMultiCursors",
+		"Alt-x": "SkipMultiCursor",
 	}
 }

cmd/micro/buffer.go

@@ -29,6 +29,7 @@ type Buffer struct {
 	*LineArray
 
 	Cursor  Cursor
+	cursors []*Cursor // for multiple cursors
 
 	// Path to the file on disk
 	Path string
@@ -169,6 +170,8 @@ func NewBuffer(reader io.Reader, size int64, path string) *Buffer {
 		file.Close()
 	}
 
+	b.cursors = []*Cursor{&b.Cursor}
+
 	return b
 }
 

cmd/micro/messenger.go

@@ -153,7 +153,7 @@ func (m *Messenger) YesNoPrompt(prompt string) (bool, bool) {
 	for {
 		m.Clear()
 		m.Display()
-		screen.ShowCursor(Count(m.message), h-1)
+		ShowCursor(Count(m.message), h-1)
 		screen.Show()
 		event := <-events
 
@@ -190,7 +190,7 @@ func (m *Messenger) LetterPrompt(prompt string, responses ...rune) (rune, bool)
 	for {
 		m.Clear()
 		m.Display()
-		screen.ShowCursor(Count(m.message), h-1)
+		ShowCursor(Count(m.message), h-1)
 		screen.Show()
 		event := <-events
 
@@ -470,7 +470,7 @@ func (m *Messenger) Display() {
 	}
 
 	if m.hasPrompt {
-		screen.ShowCursor(Count(m.message)+m.cursorx, h-1)
+		ShowCursor(Count(m.message)+m.cursorx, h-1)
 		screen.Show()
 	}
 }

cmd/micro/view.go

@@ -499,9 +499,13 @@ func (v *View) HandleEvent(event tcell.Event) {
 					}
 				}
 				if e.Modifiers() == key.modifiers {
+					for _, c := range v.Buf.cursors {
+						v.Cursor = c
 						relocate = false
 						isBinding = true
-					relocate = v.ExecuteActions(actions)
+						relocate = v.ExecuteActions(actions) || relocate
+					}
+					v.Cursor = &v.Buf.Cursor
 					break
 				}
 			}
@@ -509,6 +513,9 @@ func (v *View) HandleEvent(event tcell.Event) {
 		if !isBinding && e.Key() == tcell.KeyRune {
 			// Check viewtype if readonly don't insert a rune (readonly help and log view etc.)
 			if v.Type.readonly == false {
+				for _, c := range v.Buf.cursors {
+					v.Cursor = c
+
 					// Insert a character
 					if v.Cursor.HasSelection() {
 						v.Cursor.DeleteSelection()
@@ -528,6 +535,8 @@ func (v *View) HandleEvent(event tcell.Event) {
 						curMacro = append(curMacro, e.Rune())
 					}
 				}
+				v.Cursor = &v.Buf.Cursor
+			}
 		}
 	case *tcell.EventPaste:
 		// Check viewtype if readonly don't paste (readonly help and log view etc.)
@@ -536,14 +545,16 @@ func (v *View) HandleEvent(event tcell.Event) {
 				break
 			}
 
+			for _, c := range v.Buf.cursors {
+				v.Cursor = c
 				v.paste(e.Text())
 
+			}
+			v.Cursor = &v.Buf.Cursor
+
 			PostActionCall("Paste", v)
 		}
 	case *tcell.EventMouse:
-		x, y := e.Position()
-		x -= v.lineNumOffset - v.leftCol + v.x
-		y += v.Topline - v.y
 		// Don't relocate for mouse events
 		relocate = false
 
@@ -551,7 +562,11 @@ func (v *View) HandleEvent(event tcell.Event) {
 
 		for key, actions := range bindings {
 			if button == key.buttons {
-				relocate = v.ExecuteActions(actions)
+				for _, c := range v.Buf.cursors {
+					v.Cursor = c
+					relocate = v.ExecuteActions(actions) || relocate
+				}
+				v.Cursor = &v.Buf.Cursor
 			}
 		}
 
@@ -569,6 +584,10 @@ func (v *View) HandleEvent(event tcell.Event) {
 			if !v.mouseReleased {
 				// Mouse was just released
 
+				x, y := e.Position()
+				x -= v.lineNumOffset - v.leftCol + v.x
+				y += v.Topline - v.y
+
 				// Relocating here isn't really necessary because the cursor will
 				// be in the right place from the last mouse event
 				// However, if we are running in a terminal that doesn't support mouse motion
@@ -822,6 +841,8 @@ func (v *View) DisplayView() {
 				}
 
 				charLoc := char.realLoc
+				for _, c := range v.Buf.cursors {
+					v.Cursor = c
 					if v.Cursor.HasSelection() &&
 						(charLoc.GreaterEqual(v.Cursor.CurSelection[0]) && charLoc.LessThan(v.Cursor.CurSelection[1]) ||
 							charLoc.LessThan(v.Cursor.CurSelection[0]) && charLoc.GreaterEqual(v.Cursor.CurSelection[1])) {
@@ -832,12 +853,8 @@ func (v *View) DisplayView() {
 							lineStyle = style
 						}
 					}
-
-				if tabs[curTab].CurView == v.Num && !v.Cursor.HasSelection() &&
-					v.Cursor.Y == char.realLoc.Y && v.Cursor.X == char.realLoc.X && !cursorSet {
-					screen.ShowCursor(xOffset+char.visualLoc.X, yOffset+char.visualLoc.Y)
-					cursorSet = true
 				}
+				v.Cursor = &v.Buf.Cursor
 
 				if v.Buf.Settings["cursorline"].(bool) && tabs[curTab].CurView == v.Num &&
 					!v.Cursor.HasSelection() && v.Cursor.Y == realLineN {
@@ -848,6 +865,16 @@ func (v *View) DisplayView() {
 
 				screen.SetContent(xOffset+char.visualLoc.X, yOffset+char.visualLoc.Y, char.drawChar, nil, lineStyle)
 
+				for _, c := range v.Buf.cursors {
+					v.Cursor = c
+					if tabs[curTab].CurView == v.Num && !v.Cursor.HasSelection() &&
+						v.Cursor.Y == char.realLoc.Y && v.Cursor.X == char.realLoc.X && !cursorSet {
+						ShowCursor(xOffset+char.visualLoc.X, yOffset+char.visualLoc.Y)
+						// cursorSet = true
+					}
+				}
+				v.Cursor = &v.Buf.Cursor
+
 				lastChar = char
 			}
 		}
@@ -858,19 +885,27 @@ func (v *View) DisplayView() {
 		var cx, cy int
 		if lastChar != nil {
 			lastX = xOffset + lastChar.visualLoc.X + lastChar.width
+			for _, c := range v.Buf.cursors {
+				v.Cursor = c
 				if tabs[curTab].CurView == v.Num && !v.Cursor.HasSelection() &&
 					v.Cursor.Y == lastChar.realLoc.Y && v.Cursor.X == lastChar.realLoc.X+1 {
-				screen.ShowCursor(lastX, yOffset+lastChar.visualLoc.Y)
+					ShowCursor(lastX, yOffset+lastChar.visualLoc.Y)
 					cx, cy = lastX, yOffset+lastChar.visualLoc.Y
 				}
+			}
+			v.Cursor = &v.Buf.Cursor
 			realLoc = Loc{lastChar.realLoc.X + 1, realLineN}
 			visualLoc = Loc{lastX - xOffset, lastChar.visualLoc.Y}
 		} else if len(line) == 0 {
+			for _, c := range v.Buf.cursors {
+				v.Cursor = c
 				if tabs[curTab].CurView == v.Num && !v.Cursor.HasSelection() &&
 					v.Cursor.Y == realLineN {
-				screen.ShowCursor(xOffset, yOffset+visualLineN)
+					ShowCursor(xOffset, yOffset+visualLineN)
 					cx, cy = xOffset, yOffset+visualLineN
 				}
+			}
+			v.Cursor = &v.Buf.Cursor
 			lastX = xOffset
 			realLoc = Loc{0, realLineN}
 			visualLoc = Loc{0, visualLineN}
@@ -912,6 +947,11 @@ func (v *View) DisplayView() {
 	}
 }
 
+func ShowCursor(x, y int) {
+	r, _, _, _ := screen.GetContent(x, y)
+	screen.SetContent(x, y, r, nil, defStyle.Reverse(true))
+}
+
 // Display renders the view, the cursor, and statusline
 func (v *View) Display() {
 	if globalSettings["termtitle"].(bool) {