feat: implement OSC 1 (set icon name) and fix icon name push/pop

Add iconName field and setIconName method to InputHandler. Register
OSC 1 handler and update OSC 0 to set both title and icon name.

Fix CSI 22/23 (windowOptions) to push/pop the actual icon name instead
of the window title, and restore icon name state on pop instead of
discarding it.

Expose IconName() accessor and OnIconNameChange event on Terminal.

Fixes #16

Co-authored-by: Ona <no-reply@ona.com>

Author: ona-automations

inputhandler.go

@@ -83,13 +83,15 @@ type InputHandler struct {
 	parseBuffer     []uint32
 	dirtyRowTracker *DirtyRowTracker
 
-	windowTitle    string
+	windowTitle      string
+	iconName         string
 	windowTitleStack []string
 	iconNameStack    []string
 
 	// Events
 	OnCursorMoveEmitter           EventEmitter[struct{}]
 	OnTitleChangeEmitter          EventEmitter[string]
+	OnIconNameChangeEmitter       EventEmitter[string]
 	OnLineFeedEmitter             EventEmitter[struct{}]
 	OnA11yCharEmitter             EventEmitter[string]
 	OnA11yTabEmitter              EventEmitter[int]
@@ -250,8 +252,9 @@ func NewInputHandler(
 	p.RegisterDcsHandler(FunctionIdentifier{Intermediates: "$", Final: 'q'}, NewDcsStringHandler(h.requestStatusString))
 
 	// OSC handlers
-	p.RegisterOscHandler(0, NewOscStringHandler(h.SetTitle)) // OSC 0 — set title + icon
-	p.RegisterOscHandler(2, NewOscStringHandler(h.SetTitle)) // OSC 2 — set title
+	p.RegisterOscHandler(0, NewOscStringHandler(h.setTitleAndIconName)) // OSC 0 — set title + icon name
+	p.RegisterOscHandler(1, NewOscStringHandler(h.setIconName))        // OSC 1 — set icon name
+	p.RegisterOscHandler(2, NewOscStringHandler(h.SetTitle))           // OSC 2 — set title
 	p.RegisterOscHandler(4, NewOscStringHandler(h.SetOrReportIndexedColor))
 	p.RegisterOscHandler(8, NewOscStringHandler(h.SetHyperlink))
 	p.RegisterOscHandler(10, NewOscStringHandler(h.SetOrReportFgColor))
@@ -530,6 +533,7 @@ func (h *InputHandler) Dispose() {
 	h.parser.Dispose()
 	h.OnCursorMoveEmitter.Dispose()
 	h.OnTitleChangeEmitter.Dispose()
+	h.OnIconNameChangeEmitter.Dispose()
 	h.OnLineFeedEmitter.Dispose()
 	h.OnA11yCharEmitter.Dispose()
 	h.OnA11yTabEmitter.Dispose()

inputhandler_csi.go

@@ -927,8 +927,7 @@ func (h *InputHandler) windowOptions(params *Params) bool {
 			h.windowTitleStack = append(h.windowTitleStack, h.windowTitle)
 		}
 		if ps2 == 0 || ps2 == 1 {
-			// Icon name shares the window title in this implementation.
-			h.iconNameStack = append(h.iconNameStack, h.windowTitle)
+			h.iconNameStack = append(h.iconNameStack, h.iconName)
 		}
 	case 23:
 		// Pop title from stack.
@@ -946,7 +945,10 @@ func (h *InputHandler) windowOptions(params *Params) bool {
 		}
 		if ps2 == 0 || ps2 == 1 {
 			if len(h.iconNameStack) > 0 {
+				name := h.iconNameStack[len(h.iconNameStack)-1]
 				h.iconNameStack = h.iconNameStack[:len(h.iconNameStack)-1]
+				h.iconName = name
+				h.OnIconNameChangeEmitter.Fire(name)
 			}
 		}
 	default:

inputhandler_csi_test.go

@@ -1401,5 +1401,80 @@ func TestWindowOptionsUnknownSubcommand(t *testing.T) {
 	}
 }
 
+func TestWindowOptionsPushPopIconName(t *testing.T) {
+	t.Parallel()
+	h := newTestInputHandler(80, 24)
+	var lastIconName string
+	h.OnIconNameChangeEmitter.Event(func(name string) {
+		lastIconName = name
+	})
+
+	// Set icon name via OSC 1.
+	h.ParseString("\x1b]1;first-icon\x07")
+	if lastIconName != "first-icon" {
+		t.Fatalf("expected icon name %q, got %q", "first-icon", lastIconName)
+	}
+
+	// Push icon name only (CSI 22;1t).
+	h.ParseString("\x1b[22;1t")
+
+	// Change icon name.
+	h.ParseString("\x1b]1;second-icon\x07")
+	if lastIconName != "second-icon" {
+		t.Fatalf("expected icon name %q, got %q", "second-icon", lastIconName)
+	}
+
+	// Pop icon name only (CSI 23;1t).
+	h.ParseString("\x1b[23;1t")
+	if lastIconName != "first-icon" {
+		t.Errorf("expected icon name %q after pop, got %q", "first-icon", lastIconName)
+	}
+}
+
+func TestWindowOptionsPushPopIconNameIndependentOfTitle(t *testing.T) {
+	t.Parallel()
+	h := newTestInputHandler(80, 24)
+	var lastTitle, lastIconName string
+	h.OnTitleChangeEmitter.Event(func(s string) { lastTitle = s })
+	h.OnIconNameChangeEmitter.Event(func(s string) { lastIconName = s })
+
+	// Set different title and icon name.
+	h.ParseString("\x1b]2;my-title\x1b\\")
+	h.ParseString("\x1b]1;my-icon\x07")
 
+	// Push both (CSI 22;0t).
+	h.ParseString("\x1b[22;0t")
+
+	// Change both.
+	h.ParseString("\x1b]2;new-title\x1b\\")
+	h.ParseString("\x1b]1;new-icon\x07")
+
+	// Pop both (CSI 23;0t).
+	h.ParseString("\x1b[23;0t")
+	if lastTitle != "my-title" {
+		t.Errorf("expected title %q, got %q", "my-title", lastTitle)
+	}
+	if lastIconName != "my-icon" {
+		t.Errorf("expected icon name %q, got %q", "my-icon", lastIconName)
+	}
+}
+
+func TestWindowOptionsPopIconNameEmptyStack(t *testing.T) {
+	t.Parallel()
+	h := newTestInputHandler(80, 24)
+	iconNameChanges := 0
+	h.OnIconNameChangeEmitter.Event(func(string) {
+		iconNameChanges++
+	})
+
+	// Set initial icon name.
+	h.ParseString("\x1b]1;initial\x07")
+	iconNameChanges = 0
+
+	// Pop from empty stack — should not fire event.
+	h.ParseString("\x1b[23;1t")
+	if iconNameChanges != 0 {
+		t.Errorf("expected no icon name change on empty stack pop, got %d changes", iconNameChanges)
+	}
+}
 

inputhandler_osc.go

@@ -15,13 +15,27 @@ var specialColors = []SpecialColorIndex{
 	SpecialColorCursor,
 }
 
-// SetTitle (OSC 0, OSC 2) — set the terminal window title.
+// SetTitle (OSC 2) — set the terminal window title.
 func (h *InputHandler) SetTitle(data string) bool {
 	h.windowTitle = data
 	h.OnTitleChangeEmitter.Fire(data)
 	return true
 }
 
+// setTitleAndIconName (OSC 0) — set both the window title and icon name.
+func (h *InputHandler) setTitleAndIconName(data string) bool {
+	h.SetTitle(data)
+	h.setIconName(data)
+	return true
+}
+
+// setIconName (OSC 1) — set the terminal icon name.
+func (h *InputHandler) setIconName(data string) bool {
+	h.iconName = data
+	h.OnIconNameChangeEmitter.Fire(data)
+	return true
+}
+
 // SetOrReportIndexedColor (OSC 4) — set or query palette colors.
 func (h *InputHandler) SetOrReportIndexedColor(data string) bool {
 	var events []ColorEvent

inputhandler_osc_test.go

@@ -63,6 +63,87 @@ func TestOSC_SetTitle_Empty(t *testing.T) {
 	}
 }
 
+// --- OSC icon name tests ---
+
+func TestOSC1_SetIconName(t *testing.T) {
+	t.Parallel()
+	h := newTestHandler()
+	var iconName string
+	h.OnIconNameChangeEmitter.Event(func(s string) { iconName = s })
+
+	// OSC 1 ; <name> BEL
+	h.ParseString("\x1b]1;my-icon\x07")
+
+	if iconName != "my-icon" {
+		t.Errorf("expected icon name 'my-icon', got %q", iconName)
+	}
+	if h.iconName != "my-icon" {
+		t.Errorf("expected h.iconName 'my-icon', got %q", h.iconName)
+	}
+}
+
+func TestOSC1_SetIconName_ST(t *testing.T) {
+	t.Parallel()
+	h := newTestHandler()
+	var iconName string
+	h.OnIconNameChangeEmitter.Event(func(s string) { iconName = s })
+
+	// OSC 1 ; <name> ST (ESC \)
+	h.ParseString("\x1b]1;icon-st\x1b\\")
+
+	if iconName != "icon-st" {
+		t.Errorf("expected icon name 'icon-st', got %q", iconName)
+	}
+}
+
+func TestOSC1_SetIconName_Empty(t *testing.T) {
+	t.Parallel()
+	h := newTestHandler()
+	// Set a non-empty icon name first.
+	h.ParseString("\x1b]1;something\x07")
+
+	var iconName string
+	h.OnIconNameChangeEmitter.Event(func(s string) { iconName = s })
+
+	h.ParseString("\x1b]1;\x07")
+
+	if iconName != "" {
+		t.Errorf("expected empty icon name, got %q", iconName)
+	}
+}
+
+func TestOSC0_SetsTitleAndIconName(t *testing.T) {
+	t.Parallel()
+	h := newTestHandler()
+	var title, iconName string
+	h.OnTitleChangeEmitter.Event(func(s string) { title = s })
+	h.OnIconNameChangeEmitter.Event(func(s string) { iconName = s })
+
+	// OSC 0 should set both title and icon name.
+	h.ParseString("\x1b]0;both-value\x07")
+
+	if title != "both-value" {
+		t.Errorf("expected title 'both-value', got %q", title)
+	}
+	if iconName != "both-value" {
+		t.Errorf("expected icon name 'both-value', got %q", iconName)
+	}
+}
+
+func TestOSC2_DoesNotSetIconName(t *testing.T) {
+	t.Parallel()
+	h := newTestHandler()
+	iconNameChanged := false
+	h.OnIconNameChangeEmitter.Event(func(s string) { iconNameChanged = true })
+
+	// OSC 2 should only set title, not icon name.
+	h.ParseString("\x1b]2;title-only\x07")
+
+	if iconNameChanged {
+		t.Error("OSC 2 should not fire icon name change event")
+	}
+}
+
 // --- OSC color tests ---
 
 func TestOSC4_SetIndexedColor(t *testing.T) {

terminal.go

@@ -34,13 +34,14 @@ type Terminal struct {
 	inputHandler   *InputHandler
 
 	// Public event emitters (forwarded from sub-components).
-	OnBellEmitter        EventEmitter[struct{}]
-	OnTitleChangeEmitter EventEmitter[string]
-	OnLineFeedEmitter    EventEmitter[struct{}]
-	OnCursorMoveEmitter  EventEmitter[struct{}]
-	OnResizeEmitter      EventEmitter[BufferResizeEvent]
-	OnScrollEmitter      EventEmitter[int]
-	OnRenderEmitter      EventEmitter[RowRange]
+	OnBellEmitter           EventEmitter[struct{}]
+	OnTitleChangeEmitter    EventEmitter[string]
+	OnIconNameChangeEmitter EventEmitter[string]
+	OnLineFeedEmitter       EventEmitter[struct{}]
+	OnCursorMoveEmitter     EventEmitter[struct{}]
+	OnResizeEmitter         EventEmitter[BufferResizeEvent]
+	OnScrollEmitter         EventEmitter[int]
+	OnRenderEmitter         EventEmitter[RowRange]
 }
 
 // New creates a new Terminal with the given options.
@@ -71,6 +72,7 @@ func New(opts ...Option) *Terminal {
 	// Forward input handler events.
 	ih.OnRequestBellEmitter.Event(func(struct{}) { t.OnBellEmitter.Fire(struct{}{}) })
 	ih.OnTitleChangeEmitter.Event(func(s string) { t.OnTitleChangeEmitter.Fire(s) })
+	ih.OnIconNameChangeEmitter.Event(func(s string) { t.OnIconNameChangeEmitter.Fire(s) })
 	ih.OnLineFeedEmitter.Event(func(struct{}) { t.OnLineFeedEmitter.Fire(struct{}{}) })
 	ih.OnCursorMoveEmitter.Event(func(struct{}) { t.OnCursorMoveEmitter.Fire(struct{}{}) })
 	ih.OnRequestRefreshRowsEmitter.Event(func(r RowRange) { t.OnRenderEmitter.Fire(r) })
@@ -185,6 +187,14 @@ func (t *Terminal) OnTitleChange(fn func(string)) Disposable {
 	return t.OnTitleChangeEmitter.Event(fn)
 }
 
+// IconName returns the current icon name set via OSC 1 or OSC 0.
+func (t *Terminal) IconName() string { return t.inputHandler.iconName }
+
+// OnIconNameChange registers a callback for icon name change events.
+func (t *Terminal) OnIconNameChange(fn func(string)) Disposable {
+	return t.OnIconNameChangeEmitter.Event(fn)
+}
+
 // OnLineFeed registers a callback for line feed events.
 func (t *Terminal) OnLineFeed(fn func()) Disposable {
 	return t.OnLineFeedEmitter.Event(func(struct{}) { fn() })
@@ -239,6 +249,7 @@ func (t *Terminal) Dispose() {
 	t.coreService.Dispose()
 	t.OnBellEmitter.Dispose()
 	t.OnTitleChangeEmitter.Dispose()
+	t.OnIconNameChangeEmitter.Dispose()
 	t.OnLineFeedEmitter.Dispose()
 	t.OnCursorMoveEmitter.Dispose()
 	t.OnResizeEmitter.Dispose()

terminal_test.go

@@ -352,6 +352,39 @@ func TestTerminalTitleChange(t *testing.T) {
 	}
 }
 
+func TestTerminalIconNameChange(t *testing.T) {
+	t.Parallel()
+	term := newTestTerminal(80, 24)
+	var iconName string
+	term.OnIconNameChange(func(s string) { iconName = s })
+
+	// OSC 1 ; <name> BEL
+	term.WriteString("\x1b]1;my-icon\x07")
+	if iconName != "my-icon" {
+		t.Errorf("iconName = %q, want %q", iconName, "my-icon")
+	}
+	if term.IconName() != "my-icon" {
+		t.Errorf("IconName() = %q, want %q", term.IconName(), "my-icon")
+	}
+}
+
+func TestTerminalOSC0_SetsTitleAndIconName(t *testing.T) {
+	t.Parallel()
+	term := newTestTerminal(80, 24)
+	var title, iconName string
+	term.OnTitleChange(func(s string) { title = s })
+	term.OnIconNameChange(func(s string) { iconName = s })
+
+	// OSC 0 should set both.
+	term.WriteString("\x1b]0;both\x07")
+	if title != "both" {
+		t.Errorf("title = %q, want %q", title, "both")
+	}
+	if iconName != "both" {
+		t.Errorf("iconName = %q, want %q", iconName, "both")
+	}
+}
+
 func TestTerminalBell(t *testing.T) {
 	t.Parallel()
 	term := newTestTerminal(80, 24)