add a special type for IDs

Alignment.go

@@ -87,7 +87,7 @@ var _ Widget = &AlignmentSetter{}
 type AlignmentSetter struct {
 	alignType AlignmentType
 	layout    Layout
-	id        string
+	id        ID
 }
 
 // Align sets widgets alignment.
@@ -107,8 +107,8 @@ func (a *AlignmentSetter) To(widgets ...Widget) *AlignmentSetter {
 // ID allows to manually set AlignmentSetter ID
 // NOTE: there isn't any known reason to use this method, however
 // it is here for some random cases. YOU DON'T NEED TO USE IT
-// in normal conditions.
-func (a *AlignmentSetter) ID(id string) *AlignmentSetter {
+// in normal cases.
+func (a *AlignmentSetter) ID(id ID) *AlignmentSetter {
 	a.id = id
 	return a
 }
@@ -178,7 +178,7 @@ func (a *AlignmentSetter) Build() {
 // if you find anything else, please report it on
 // https://github.com/AllenDang/giu Any contribution is appreciated!
 func GetWidgetWidth(w Widget) (result float32) {
-	imgui.PushIDStr(GenAutoID("GetWidgetWidthMeasurement"))
+	imgui.PushIDStr(string(GenAutoID("GetWidgetWidthMeasurement")))
 	defer imgui.PopID()
 
 	// save cursor position before doing anything

ClickableWidgets.go

@@ -13,7 +13,7 @@ var _ Widget = &ButtonWidget{}
 
 // ButtonWidget represents a ImGui button widget.
 type ButtonWidget struct {
-	id       string
+	id       ID
 	width    float32
 	height   float32
 	disabled bool
@@ -56,7 +56,7 @@ func (b *ButtonWidget) Size(width, height float32) *ButtonWidget {
 	return b
 }
 
-func (b *ButtonWidget) ID(id string) *ButtonWidget {
+func (b *ButtonWidget) ID(id ID) *ButtonWidget {
 	b.id = id
 	return b
 }
@@ -68,7 +68,7 @@ func (b *ButtonWidget) Build() {
 		defer imgui.EndDisabled()
 	}
 
-	if imgui.ButtonV(Context.FontAtlas.RegisterString(b.id), imgui.Vec2{X: b.width, Y: b.height}) && b.onClick != nil {
+	if imgui.ButtonV(Context.FontAtlas.RegisterString(b.id.String()), imgui.Vec2{X: b.width, Y: b.height}) && b.onClick != nil {
 		b.onClick()
 	}
 }
@@ -77,7 +77,7 @@ var _ Widget = &ArrowButtonWidget{}
 
 // ArrowButtonWidget represents a square button with an arrow.
 type ArrowButtonWidget struct {
-	id      string
+	id      ID
 	dir     Direction
 	onClick func()
 }
@@ -98,14 +98,14 @@ func (b *ArrowButtonWidget) OnClick(onClick func()) *ArrowButtonWidget {
 }
 
 // ID allows to manually set widget's id.
-func (b *ArrowButtonWidget) ID(id string) *ArrowButtonWidget {
+func (b *ArrowButtonWidget) ID(id ID) *ArrowButtonWidget {
 	b.id = id
 	return b
 }
 
 // Build implements Widget interface.
 func (b *ArrowButtonWidget) Build() {
-	if imgui.ArrowButton(b.id, imgui.Dir(b.dir)) && b.onClick != nil {
+	if imgui.ArrowButton(b.id.String(), imgui.Dir(b.dir)) && b.onClick != nil {
 		b.onClick()
 	}
 }
@@ -114,7 +114,7 @@ var _ Widget = &SmallButtonWidget{}
 
 // SmallButtonWidget is like a button but without frame padding.
 type SmallButtonWidget struct {
-	id      string
+	id      ID
 	onClick func()
 }
 
@@ -140,7 +140,7 @@ func (b *SmallButtonWidget) OnClick(onClick func()) *SmallButtonWidget {
 
 // Build implements Widget interface.
 func (b *SmallButtonWidget) Build() {
-	if imgui.SmallButton(Context.FontAtlas.RegisterString(b.id)) && b.onClick != nil {
+	if imgui.SmallButton(Context.FontAtlas.RegisterString(b.id.String())) && b.onClick != nil {
 		b.onClick()
 	}
 }
@@ -151,7 +151,7 @@ var _ Widget = &InvisibleButtonWidget{}
 // NOTE: you may want to display other widgets on this button.
 // to do so, you may move drawing cursor back by Get/SetCursor(Screen)Pos.
 type InvisibleButtonWidget struct {
-	id      string
+	id      ID
 	width   float32
 	height  float32
 	onClick func()
@@ -180,14 +180,14 @@ func (b *InvisibleButtonWidget) OnClick(onClick func()) *InvisibleButtonWidget {
 }
 
 // ID allows to manually set widget's id (no need to use in normal conditions).
-func (b *InvisibleButtonWidget) ID(id string) *InvisibleButtonWidget {
+func (b *InvisibleButtonWidget) ID(id ID) *InvisibleButtonWidget {
 	b.id = id
 	return b
 }
 
 // Build implements Widget interface.
 func (b *InvisibleButtonWidget) Build() {
-	if imgui.InvisibleButton(Context.FontAtlas.RegisterString(b.id), imgui.Vec2{X: b.width, Y: b.height}) && b.onClick != nil {
+	if imgui.InvisibleButton(Context.FontAtlas.RegisterString(b.id.String()), imgui.Vec2{X: b.width, Y: b.height}) && b.onClick != nil {
 		b.onClick()
 	}
 }
@@ -279,13 +279,13 @@ func (b *ImageButtonWidget) FramePadding(padding int) *ImageButtonWidget {
 
 var _ Widget = &ImageButtonWithRgbaWidget{}
 
-// ImageButtonWithRgbaWidget does similar to ImageButtonWIdget,
+// ImageButtonWithRgbaWidget does similar to ImageButtonWidget,
 // but implements image.Image instead of giu.Texture. It is probably
-// more useful than the original ImageButtonWIdget.
+// more useful than the original ImageButtonWidget.
 type ImageButtonWithRgbaWidget struct {
 	*ImageButtonWidget
 	rgba image.Image
-	id   string
+	id   ID
 }
 
 // ImageButtonWithRgba creates a new widget.
@@ -335,11 +335,11 @@ func (b *ImageButtonWithRgbaWidget) FramePadding(padding int) *ImageButtonWithRg
 
 // Build implements Widget interface.
 func (b *ImageButtonWithRgbaWidget) Build() {
-	if state := GetState[imageState](Context, b.id); state == nil {
-		SetState(Context, b.id, &imageState{})
+	if state := GetState[imageState](Context, b.id.String()); state == nil {
+		SetState(Context, b.id.String(), &imageState{})
 
 		NewTextureFromRgba(b.rgba, func(tex *Texture) {
-			SetState(Context, b.id, &imageState{texture: tex})
+			SetState(Context, b.id.String(), &imageState{texture: tex})
 		})
 	} else {
 		b.ImageButtonWidget.texture = state.texture
@@ -352,7 +352,7 @@ var _ Widget = &CheckboxWidget{}
 
 // CheckboxWidget adds a checkbox.
 type CheckboxWidget struct {
-	text     string
+	text     ID
 	selected *bool
 	onChange func()
 }
@@ -374,7 +374,7 @@ func (c *CheckboxWidget) OnChange(onChange func()) *CheckboxWidget {
 
 // Build implements Widget interface.
 func (c *CheckboxWidget) Build() {
-	if imgui.Checkbox(Context.FontAtlas.RegisterString(c.text), c.selected) && c.onChange != nil {
+	if imgui.Checkbox(Context.FontAtlas.RegisterString(c.text.String()), c.selected) && c.onChange != nil {
 		c.onChange()
 	}
 }
@@ -385,7 +385,7 @@ var _ Widget = &RadioButtonWidget{}
 // It is common to use it for single-choice questions.
 // see examples/widgets.
 type RadioButtonWidget struct {
-	text     string
+	text     ID
 	active   bool
 	onChange func()
 }
@@ -407,7 +407,7 @@ func (r *RadioButtonWidget) OnChange(onChange func()) *RadioButtonWidget {
 
 // Build implements Widget interface.
 func (r *RadioButtonWidget) Build() {
-	if imgui.RadioButtonBool(Context.FontAtlas.RegisterString(r.text), r.active) && r.onChange != nil {
+	if imgui.RadioButtonBool(Context.FontAtlas.RegisterString(r.text.String()), r.active) && r.onChange != nil {
 		r.onChange()
 	}
 }
@@ -417,7 +417,7 @@ var _ Widget = &SelectableWidget{}
 // SelectableWidget is a window-width button with a label which can get selected (highlighted).
 // useful for certain lists.
 type SelectableWidget struct {
-	label    string
+	label    ID
 	selected bool
 	flags    SelectableFlags
 	width    float32
@@ -482,7 +482,7 @@ func (s *SelectableWidget) Build() {
 		s.flags |= SelectableFlagsAllowDoubleClick
 	}
 
-	if imgui.SelectableBoolV(Context.FontAtlas.RegisterString(s.label), s.selected, imgui.SelectableFlags(s.flags), imgui.Vec2{X: s.width, Y: s.height}) && s.onClick != nil {
+	if imgui.SelectableBoolV(Context.FontAtlas.RegisterString(s.label.String()), s.selected, imgui.SelectableFlags(s.flags), imgui.Vec2{X: s.width, Y: s.height}) && s.onClick != nil {
 		s.onClick()
 	}
 

CodeEditor.go

@@ -32,7 +32,7 @@ var _ Widget = &CodeEditorWidget{}
 
 // CodeEditorWidget represents imgui.TextEditor.
 type CodeEditorWidget struct {
-	title string
+	title ID
 	width,
 	height float32
 	border bool
@@ -50,7 +50,7 @@ func CodeEditor() *CodeEditorWidget {
 // ID allows to manually set editor's ID.
 // It isn't necessary to use it in a normal conditions.
 
-func (ce *CodeEditorWidget) ID(id string) *CodeEditorWidget {
+func (ce *CodeEditorWidget) ID(id ID) *CodeEditorWidget {
 	ce.title = id
 	return ce
 }
@@ -216,12 +216,12 @@ func (ce *CodeEditorWidget) Build() {
 }
 
 func (ce *CodeEditorWidget) getState() (state *codeEditorState) {
-	if state = GetState[codeEditorState](Context, ce.title); state == nil {
+	if state = GetState[codeEditorState](Context, ce.title.String()); state == nil {
 		state = &codeEditorState{
 			// editor: imgui.NewTextEditor(),
 		}
 
-		SetState(Context, ce.title, state)
+		SetState(Context, ce.title.String(), state)
 	}
 
 	return state

Context.go

@@ -8,6 +8,20 @@ import (
 	"gopkg.in/eapache/queue.v1"
 )
 
+// GenAutoID automatically generates widget's ID.
+// It returns an unique value each time it is called.
+func GenAutoID(id string) ID {
+	idx, ok := Context.widgetIndex[id]
+	if !ok {
+		Context.widgetIndex[id] = 0
+		return ID(id)
+	}
+
+	Context.widgetIndex[id]++
+
+	return ID(fmt.Sprintf("%s##%d", id, idx))
+}
+
 // Context represents a giu context.
 var Context *context
 
@@ -32,7 +46,7 @@ type context struct {
 
 	isRunning bool
 
-	widgetIndexCounter int
+	widgetIndex map[string]int
 
 	// Indicate whether current application is running
 	isAlive bool
@@ -57,6 +71,7 @@ func CreateContext(b imgui.Backend[imgui.GLFWWindowFlags]) *context {
 		FontAtlas:           newFontAtlas(),
 		textureLoadingQueue: queue.New(),
 		m:                   &sync.Mutex{},
+		widgetIndex:         make(map[string]int),
 	}
 
 	// Create font
@@ -106,8 +121,8 @@ func (c *context) cleanState() {
 		return true
 	})
 
-	// Reset widgetIndexCounter
-	c.widgetIndexCounter = 0
+	// Reset widgetIndex
+	c.widgetIndex = make(map[string]int)
 }
 
 func SetState[T any, PT genericDisposable[T]](c *context, id string, data PT) {
@@ -154,11 +169,3 @@ func (c *context) load(id any) (*state, bool) {
 
 	return nil, false
 }
-
-// Get widget index for current layout.
-func (c *context) GetWidgetIndex() int {
-	i := c.widgetIndexCounter
-	c.widgetIndexCounter++
-
-	return i
-}

Context_test.go

@@ -95,10 +95,3 @@ func Test_invalidState(t *testing.T) {
 	assert.Nil(t, GetState[teststate](ctx, state1ID),
 		"although state hasn't been accessed during the frame, it hasn't ben deleted by invalidAllState/cleanState")
 }
-
-func Test_GetWidgetIndex(t *testing.T) {
-	ctx := CreateContext(nil)
-	for i := 0; i <= 3; i++ {
-		assert.Equal(t, i, ctx.GetWidgetIndex(), "widget index wasn't increased")
-	}
-}

EventHandler.go

@@ -124,9 +124,9 @@ func (eh *EventHandler) Build() {
 		var state *eventHandlerState
 
 		stateID := GenAutoID("eventHandlerState")
-		if state = GetState[eventHandlerState](Context, stateID); state == nil {
+		if state = GetState[eventHandlerState](Context, stateID.String()); state == nil {
 			state = &eventHandlerState{}
-			SetState(Context, stateID, state)
+			SetState(Context, stateID.String(), state)
 		}
 
 		if eh.onActivate != nil && isActive && !state.isActive {