Text input history is looking good

internal/history/history.go

@@ -4,7 +4,7 @@ import "time"
 
 // History stores a stack of items, always keeping the bottom-most one. It must
 // be created using the NewHistory constructor, otherwise it will be invalid.
-type History[T any] struct {
+type History[T comparable] struct {
 	max      int
 	stack    []T
 	topIndex int
@@ -14,7 +14,7 @@ type History[T any] struct {
 // NewHistory creates a new History. The initial item will be on the bottom, and
 // it will remain there until the History overflows and chooses the item after
 // it to be the initial item.
-func NewHistory[T any] (initial T, max int) *History[T] {
+func NewHistory[T comparable] (initial T, max int) *History[T] {
 	return &History[T] {
 		max:   max,
 		stack: []T { initial },
@@ -29,14 +29,28 @@ func (this *History[T]) Top () T {
 // Swap replaces the most recent item with another.
 func (this *History[T]) Swap (item T) {
 	this.topTime = time.Now()
+	this.SwapSilently(item)
+}
+
+// SwapSilently replaces the most recent item with another without updating the
+// time.
+func (this *History[T]) SwapSilently (item T) {
 	this.stack[this.topIndex] = item
 }
 
-// Push pushes a new item onto the stack.
+// Push pushes a new item onto the stack. If the stack overflows (becomes bigger
+// than the specified max value), the initial item is removed and the one on top
+// of it takes its place.
 func (this *History[T]) Push (item T) {
 	this.topTime = time.Now()
-	this.topIndex ++
+	if this.Top() != item {
-	this.stack = append(this.stack[:this.topIndex], item)
+		this.topIndex ++
+		this.stack = append(this.stack[:this.topIndex], item)
+	}
+
+	if len(this.stack) > this.max {
+		this.stack = this.stack[1:]
+	}
 }
 
 // PushWeak replaces the most recent item if it was added recently (sooner than

textinput.go

@@ -24,6 +24,7 @@ type TextInput struct {
 	multiline bool
 	history   *history.History[textHistoryItem]
 	on struct {
+		dotChange   event.FuncBroadcaster
 		valueChange event.FuncBroadcaster
 		confirm     event.FuncBroadcaster
 	}
@@ -54,6 +55,7 @@ func newTextInput (text string, multiline bool) *TextInput {
 	textInput.box.OnKeyDown(textInput.handleKeyDown)
 	textInput.box.OnKeyUp(textInput.handleKeyUp)
 	textInput.box.OnScroll(textInput.handleScroll)
+	textInput.box.OnDotChange(textInput.handleDotChange)
 	return textInput	
 }
 
@@ -83,6 +85,7 @@ func (this *TextInput) SetFocused (focused bool) {
 // Select sets the text cursor or selection.
 func (this *TextInput) Select (dot text.Dot) {
 	this.box.Select(dot)
+	this.historySwapDot()
 }
 
 // Dot returns the text cursor or selection.
@@ -93,7 +96,7 @@ func (this *TextInput) Dot () text.Dot {
 // OnDotChange specifies a function to be called when the text cursor or
 // selection changes.
 func (this *TextInput) OnDotChange (callback func ()) event.Cookie {
-	return this.box.OnDotChange(callback)
+	return this.on.dotChange.Connect(callback)
 }
 
 // SetAlign sets the X and Y alignment of the text input.
@@ -176,6 +179,12 @@ func (this *TextInput) logLargeAction () {
 	this.history.Push(this.currentHistoryState())
 }
 
+func (this *TextInput) historySwapDot () {
+	top := this.history.Top()
+	top.dot = this.Dot()
+	this.history.SwapSilently(top)
+}
+
 func (this *TextInput) currentHistoryState () textHistoryItem {
 	return textHistoryItem {
 		text: string(this.text),
@@ -193,29 +202,31 @@ func (this *TextInput) recoverHistoryItem (item textHistoryItem) {
 
 func (this *TextInput) handleKeyDown (key input.Key, numpad bool) bool {
 	dot        := this.Dot()
+	txt        := this.text
 	modifiers  := this.box.Window().Modifiers()
 	word       := modifiers.Control
 	changed    := false
 
 	defer func () {
-		this.Select(dot)
 		if changed {
-			this.box.SetText(string(this.text))
+			this.historySwapDot()
+			this.text = txt
+			this.box.SetText(string(txt))
+			this.box.Select(dot)
 			this.on.valueChange.Broadcast()
 			this.logKeystroke()
 		}
 	} ()
 
-	typ := func () {
+	typeRune := func () {
-		this.text, dot = text.Type(this.text, dot, rune(key))
+		txt, dot = text.Type(txt, dot, rune(key))
 		changed = true
 	}
 
 	if this.multiline && !modifiers.Control {
 		switch {
 		case key == '\n', key == '\t':
-			typ()
+			typeRune()
-			this.logKeystroke()
 			return true
 		}
 	}
@@ -225,15 +236,15 @@ func (this *TextInput) handleKeyDown (key input.Key, numpad bool) bool {
 		this.on.confirm.Broadcast()
 		return true
 	case key == input.KeyBackspace:
-		this.text, dot = text.Backspace(this.text, dot, word)
+		txt, dot = text.Backspace(txt, dot, word)
 		changed = true
 		return true
 	case key == input.KeyDelete:
-		this.text, dot = text.Delete(this.text, dot, word)
+		txt, dot = text.Delete(txt, dot, word)
 		changed = true
 		return true
 	case key.Printable() && !modifiers.Control:
-		typ()
+		typeRune()
 		return true
 	case key == 'z' && modifiers.Control:
 		if modifiers.Shift {
@@ -283,3 +294,9 @@ func (this *TextInput) handleScroll (x, y float64) bool {
 	this.ScrollTo(this.ContentBounds().Min.Sub(image.Pt(int(x), int(y))))
 	return true
 }
+
+func (this *TextInput) handleDotChange () {
+	println("asdjhk")
+	this.historySwapDot()
+	this.on.dotChange.Broadcast()
+}