Add taskbar progress and state support for Windows & macOS

[SheepYhangCN]

Use ITaskbarList3 for Windows
Use NSView for macOS (by @bruvzg )

Fixes godotengine/godot-proposals#2414

[RedMser]

Thanks for the PR, this is a feature I was personally missing in Godot!
While I realize the PR is still in draft, here's a few things I noticed.

Also you probably saw CI is failing because other display servers still need the methods implemented (even if they do nothing).

[bruvzg]

macOS does not have a default progress bar for the dock, but arbitrary control can be added to the icon, so it is possible to replicate the same behavior. Not sure about other platforms, probably not supported.

[SheepYhangCN]

macOS does not have a default progress bar for the dock, but arbitrary control can be added to the icon, so it is possible to replicate the same behavior. Not sure about other platforms, probably not supported.

I have no mac device and I don't have any experience on macOS app development
I don't know how to do and I also can't test
Sooooo this pr only for Windows I guess

[m4gr3d]

A taskbar is not supported on all platforms we support, so instead we - should change the terminology to notification; on Windows it'll be via the taskbar, on other platforms the appropriate mechanism will be used instead.

For example, window_set_taskbar_progress_state should become window_notify_progress_state.

[SheepYhangCN]

A taskbar is not supported on all platforms we support, so instead we - should change the terminology to notification; on Windows it'll be via the taskbar, on other platforms the appropriate mechanism will be used instead.

The progress bar on taskbar is what I want to implement
Not only a progress bar for current window
This is an addition of request_attention, not a new feature.

Besides, I don't know is there another visual of progress bar in another OS
It will be better to implement that as another feature.

[bruvzg]

A taskbar is not supported on all platforms we support, so instead we - should change the terminology to notification; on Windows it'll be via the taskbar, on other platforms the appropriate mechanism will be used instead.

I do not think it should be mixed with notifications (which, unlike this, can be implemented on all platforms), it's a different feature.

[bruvzg]

For the reference, it is implementable on macOS, and Linux (not standard, but seems to be supported by multiple DEs - https://wiki.ubuntu.com/Unity/LauncherAPI#Low_level_DBus_API:_com.canonical.Unity.LauncherEntry).

[bruvzg]

A quick POC for macOS implementation (style of process bar is questionable, but in case of macOS anything can be drawn):

Patch

diff --git a/platform/macos/display_server_macos.h b/platform/macos/display_server_macos.h
index 8d76b4b8ad..89790be158 100644
--- a/platform/macos/display_server_macos.h
+++ b/platform/macos/display_server_macos.h
@@ -66,6 +66,7 @@
 @class GodotWindowDelegate;
 @class GodotButtonView;
 @class GodotEmbeddedView;
+@class GodotProgressView;
 @class CALayerHost;
 
 #undef BitMap
@@ -150,6 +151,8 @@ public:
 	List<WindowID> popup_list;
 	uint64_t time_since_popup = 0;
 
+	GodotProgressView *dock_progress = nullptr;
+
 private:
 #if defined(GLES3_ENABLED)
 	GLManagerLegacy_MacOS *gl_manager_legacy = nullptr;
diff --git a/platform/macos/display_server_macos.mm b/platform/macos/display_server_macos.mm
index d1f9d95298..be2ac7b130 100644
--- a/platform/macos/display_server_macos.mm
+++ b/platform/macos/display_server_macos.mm
@@ -2902,12 +2902,98 @@ void DisplayServerMacOS::window_request_attention(WindowID p_window) {
 	[NSApp requestUserAttention:NSCriticalRequest];
 }
 
+@interface GodotProgressView : NSView {
+	DisplayServer::ProgressState pr_state;
+	float pr_value;
+	float pr_offset;
+}
+- (void)setValue:(float)value;
+- (void)setState:(DisplayServer::ProgressState)state;
+@end
+
+@implementation GodotProgressView
+
+- (id)init {
+	self = [super init];
+	pr_state = DisplayServer::PROGRESS_STATE_NOPROGRESS;
+	pr_value = 0.f;
+	pr_offset = 0.f;
+	return self;
+}
+
+- (void)setValue:(float)value {
+	pr_value = value;
+}
+
+- (void)setState:(DisplayServer::ProgressState)state {
+	pr_state = state;
+}
+
+- (void)drawRect:(NSRect)dirtyRect {
+	// Icon draw.
+	[[NSGraphicsContext currentContext] setImageInterpolation:NSImageInterpolationHigh];
+	[[NSApp applicationIconImage] drawInRect:self.bounds];
+
+	if (pr_state == DisplayServer::PROGRESS_STATE_NOPROGRESS) {
+		return;
+	}
+
+	// Border draw.
+	NSRect rect = NSMakeRect(1.f, 1.f, self.bounds.size.width - 2.f, 16.f);
+	NSBezierPath* bezier_path = [NSBezierPath bezierPathWithRoundedRect:rect xRadius:8.f yRadius:8.f];
+	[bezier_path setLineWidth:2.0];
+	[[NSColor grayColor] set];
+	[bezier_path stroke];
+
+	// Fill clip path.
+	rect = NSMakeRect(2.f, 2.f, self.bounds.size.width - 4.f, 14.f);
+	bezier_path = [NSBezierPath bezierPathWithRoundedRect:rect xRadius:7.f yRadius:7.f];
+	[bezier_path setLineWidth:1.0];
+	[bezier_path addClip];
+
+	// Fill draw.
+	if (pr_state == DisplayServer::PROGRESS_STATE_INDETERMINATE) {
+		rect.size.width /= 5.0;
+		pr_offset += rect.size.width / 10.0;
+		if (pr_offset > self.bounds.size.width - rect.size.width) {
+			pr_offset = 0.f;
+		}
+		rect.origin.x += pr_offset;
+	} else {
+		rect.size.width = floor(rect.size.width * pr_value);
+	}
+	if (pr_state == DisplayServer::PROGRESS_STATE_ERROR) {
+		[[NSColor colorWithSRGBRed:1.0 green:0.2 blue:0.2 alpha:1.0] set];
+	} else if (pr_state == DisplayServer::PROGRESS_STATE_PAUSED) {
+		[[NSColor colorWithSRGBRed:1.0 green:1.0 blue:0.2 alpha:1.0] set];
+	} else {
+		[[NSColor colorWithSRGBRed:0.2 green:0.6 blue:1.0 alpha:1.0] set];
+	}
+	NSRectFill(rect);
+}
+
+@end
+
 void DisplayServerMacOS::window_set_taskbar_progress_value(float p_value, WindowID p_window) {
-	// Not supported.
+	ERR_FAIL_COND(p_window != MAIN_WINDOW_ID);
+
+	if (!dock_progress) {
+		dock_progress = [[GodotProgressView alloc] init];
+		[NSApp.dockTile setContentView:dock_progress];
+	}
+
+	[dock_progress setValue:p_value];
 }
 
 void DisplayServerMacOS::window_set_taskbar_progress_state(ProgressState p_state, WindowID p_window) {
-	// Not supported.
+	ERR_FAIL_COND(p_window != MAIN_WINDOW_ID);
+
+	if (!dock_progress) {
+		dock_progress = [[GodotProgressView alloc] init];
+		[NSApp.dockTile setContentView:dock_progress];
+	}
+
+	[dock_progress setState:p_state];
 }
 
 void DisplayServerMacOS::window_move_to_foreground(WindowID p_window) {
@@ -3511,6 +3597,11 @@ void DisplayServerMacOS::_process_events(bool p_pump) {
 		}
 	}
 
+	if (dock_progress) {
+		dock_progress.needsDisplay = true;
+		[NSApp.dockTile display];
+	}
+
 	_THREAD_SAFE_UNLOCK_
 }
 

Screen.Recording.2025-05-20.at.11.43.41.mov

[SheepYhangCN]

A quick POC for macOS implementation

Thank you very much!
I will add it later

For the reference, it is implementable on macOS, and Linux (not standard, but seems to be supported by multiple DEs - https://wiki.ubuntu.com/Unity/LauncherAPI#Low_level_DBus_API:_com.canonical.Unity.LauncherEntry).

I am looking into this for Linux support
How can I get app_uri?

[bruvzg]

How can I get app_uri?

I do not think you can, there's no standard .desktop file for Godot, so if it depends on it, this API might be unusable.

[SheepYhangCN]

All done