wayland: Window controls and drag (#11525)

Based on https://github.com/zed-industries/zed/pull/11046

- Partially fixes #10346 
- Fixes https://github.com/zed-industries/zed/issues/9964

## Features
Window buttons

![image](https://github.com/zed-industries/zed/assets/71973804/1b7e0504-3925-45ba-90b5-5adb55e0d739)

Window drag

![image](https://github.com/zed-industries/zed/assets/71973804/9c509a37-e5a5-484c-9f80-c722aeee4380)

Native window context menu

![image](https://github.com/zed-industries/zed/assets/71973804/048ecf52-e277-49bb-a106-91cad226fd8a)

### Limitations

- No resizing
- Wayland only (though X11 always has window decorations)

### Technical

This PR adds three APIs to gpui.

1. `show_window_menu`: Triggers the native title bar context menu.
2. `start_system_move`: Tells the compositor to start dragging the
window.
3. `should_render_window_controls`: Whether the compositor doesn't
support server side decorations.

These APIs have only been implemented for Wayland, but they should be
portable to other platforms.

Release Notes:

- N/A

---------

Co-authored-by: Akilan Elango <akilan1997@gmail.com>

crates/gpui/src/platform.rs

@@ -226,6 +226,10 @@ pub(crate) trait PlatformWindow: HasWindowHandle + HasDisplayHandle {
     #[cfg(target_os = "windows")]
     fn get_raw_handle(&self) -> windows::HWND;
 
+    fn show_window_menu(&self, position: Point<Pixels>);
+    fn start_system_move(&self);
+    fn should_render_window_controls(&self) -> bool;
+
     #[cfg(any(test, feature = "test-support"))]
     fn as_test(&mut self) -> Option<&mut TestWindow> {
         None

crates/gpui/src/platform/linux/wayland/client.rs

@@ -23,6 +23,7 @@ use wayland_client::globals::{registry_queue_init, GlobalList, GlobalListContent
 use wayland_client::protocol::wl_callback::{self, WlCallback};
 use wayland_client::protocol::wl_data_device_manager::DndAction;
 use wayland_client::protocol::wl_pointer::{AxisRelativeDirection, AxisSource};
+use wayland_client::protocol::wl_seat::WlSeat;
 use wayland_client::protocol::{
     wl_data_device, wl_data_device_manager, wl_data_offer, wl_data_source, wl_output, wl_region,
 };
@@ -80,6 +81,7 @@ pub struct Globals {
     pub data_device_manager: Option<wl_data_device_manager::WlDataDeviceManager>,
     pub wm_base: xdg_wm_base::XdgWmBase,
     pub shm: wl_shm::WlShm,
+    pub seat: wl_seat::WlSeat,
     pub viewporter: Option<wp_viewporter::WpViewporter>,
     pub fractional_scale_manager:
         Option<wp_fractional_scale_manager_v1::WpFractionalScaleManagerV1>,
@@ -93,6 +95,7 @@ impl Globals {
         globals: GlobalList,
         executor: ForegroundExecutor,
         qh: QueueHandle<WaylandClientStatePtr>,
+        seat: wl_seat::WlSeat,
     ) -> Self {
         Globals {
             activation: globals.bind(&qh, 1..=1, ()).ok(),
@@ -113,6 +116,7 @@ impl Globals {
                 )
                 .ok(),
             shm: globals.bind(&qh, 1..=1, ()).unwrap(),
+            seat,
             wm_base: globals.bind(&qh, 1..=1, ()).unwrap(),
             viewporter: globals.bind(&qh, 1..=1, ()).ok(),
             fractional_scale_manager: globals.bind(&qh, 1..=1, ()).ok(),
@@ -193,6 +197,10 @@ impl WaylandClientStatePtr {
             .expect("The pointer should always be valid when dispatching in wayland")
     }
 
+    pub fn get_serial(&self, kind: SerialKind) -> u32 {
+        self.0.upgrade().unwrap().borrow().serial_tracker.get(kind)
+    }
+
     pub fn drop_window(&self, surface_id: &ObjectId) {
         let mut client = self.get_client();
         let mut state = client.borrow_mut();
@@ -303,7 +311,12 @@ impl WaylandClient {
         });
 
         let seat = seat.unwrap();
-        let globals = Globals::new(globals, common.foreground_executor.clone(), qh.clone());
+        let globals = Globals::new(
+            globals,
+            common.foreground_executor.clone(),
+            qh.clone(),
+            seat.clone(),
+        );
 
         let data_device = globals
             .data_device_manager
@@ -962,6 +975,7 @@ impl Dispatch<wl_pointer::WlPointer, ()> for WaylandClientStatePtr {
             } => {
                 state.serial_tracker.update(SerialKind::MouseEnter, serial);
                 state.mouse_location = Some(point(px(surface_x as f32), px(surface_y as f32)));
+                state.button_pressed = None;
 
                 if let Some(window) = get_window(&mut state, &surface.id()) {
                     state.mouse_focused_window = Some(window.clone());
@@ -990,6 +1004,7 @@ impl Dispatch<wl_pointer::WlPointer, ()> for WaylandClientStatePtr {
                     });
                     state.mouse_focused_window = None;
                     state.mouse_location = None;
+                    state.button_pressed = None;
 
                     drop(state);
                     focused_window.handle_input(input);

crates/gpui/src/platform/linux/wayland/window.rs

@@ -23,12 +23,13 @@ use wayland_protocols_plasma::blur::client::{org_kde_kwin_blur, org_kde_kwin_blu
 
 use crate::platform::blade::{BladeRenderer, BladeSurfaceConfig};
 use crate::platform::linux::wayland::display::WaylandDisplay;
+use crate::platform::linux::wayland::serial::SerialKind;
 use crate::platform::{PlatformAtlas, PlatformInputHandler, PlatformWindow};
 use crate::scene::Scene;
 use crate::{
     px, size, Bounds, DevicePixels, Globals, Modifiers, Pixels, PlatformDisplay, PlatformInput,
-    Point, PromptLevel, Size, WaylandClientState, WaylandClientStatePtr, WindowAppearance,
-    WindowBackgroundAppearance, WindowBounds, WindowParams,
+    Point, PromptLevel, Size, WaylandClientStatePtr, WindowAppearance, WindowBackgroundAppearance,
+    WindowBounds, WindowParams,
 };
 
 #[derive(Default)]
@@ -753,6 +754,27 @@ impl PlatformWindow for WaylandWindow {
         let state = self.borrow();
         state.renderer.sprite_atlas().clone()
     }
+
+    fn show_window_menu(&self, position: Point<Pixels>) {
+        let state = self.borrow();
+        let serial = state.client.get_serial(SerialKind::MousePress);
+        state.toplevel.show_window_menu(
+            &state.globals.seat,
+            serial,
+            position.x.0 as i32,
+            position.y.0 as i32,
+        );
+    }
+
+    fn start_system_move(&self) {
+        let state = self.borrow();
+        let serial = state.client.get_serial(SerialKind::MousePress);
+        state.toplevel._move(&state.globals.seat, serial);
+    }
+
+    fn should_render_window_controls(&self) -> bool {
+        self.borrow().decoration_state == WaylandDecorationState::Client
+    }
 }
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]

crates/gpui/src/platform/linux/x11/window.rs

@@ -8,6 +8,7 @@ use crate::{
     Scene, Size, WindowAppearance, WindowBackgroundAppearance, WindowBounds, WindowOptions,
     WindowParams, X11Client, X11ClientState, X11ClientStatePtr,
 };
+
 use blade_graphics as gpu;
 use parking_lot::Mutex;
 use raw_window_handle as rwh;
@@ -719,4 +720,14 @@ impl PlatformWindow for X11Window {
         let inner = self.0.state.borrow();
         inner.renderer.sprite_atlas().clone()
     }
+
+    // todo(linux)
+    fn show_window_menu(&self, _position: Point<Pixels>) {}
+
+    // todo(linux)
+    fn start_system_move(&self) {}
+
+    fn should_render_window_controls(&self) -> bool {
+        false
+    }
 }

crates/gpui/src/platform/mac/window.rs

@@ -1100,6 +1100,14 @@ impl PlatformWindow for MacWindow {
     fn sprite_atlas(&self) -> Arc<dyn PlatformAtlas> {
         self.0.lock().renderer.sprite_atlas().clone()
     }
+
+    fn show_window_menu(&self, _position: Point<Pixels>) {}
+
+    fn start_system_move(&self) {}
+
+    fn should_render_window_controls(&self) -> bool {
+        false
+    }
 }
 
 impl rwh::HasWindowHandle for MacWindow {

crates/gpui/src/platform/test/window.rs

@@ -257,6 +257,18 @@ impl PlatformWindow for TestWindow {
     fn get_raw_handle(&self) -> windows::Win32::Foundation::HWND {
         unimplemented!()
     }
+
+    fn show_window_menu(&self, _position: Point<Pixels>) {
+        unimplemented!()
+    }
+
+    fn start_system_move(&self) {
+        unimplemented!()
+    }
+
+    fn should_render_window_controls(&self) -> bool {
+        false
+    }
 }
 
 pub(crate) struct TestAtlasState {

crates/gpui/src/platform/windows/window.rs

@@ -628,6 +628,14 @@ impl PlatformWindow for WindowsWindow {
     fn get_raw_handle(&self) -> HWND {
         self.0.hwnd
     }
+
+    fn show_window_menu(&self, _position: Point<Pixels>) {}
+
+    fn start_system_move(&self) {}
+
+    fn should_render_window_controls(&self) -> bool {
+        false
+    }
 }
 
 #[implement(IDropTarget)]

crates/gpui/src/window.rs

@@ -1143,6 +1143,23 @@ impl<'a> WindowContext<'a> {
         self.window.platform_window.zoom();
     }
 
+    /// Opens the native title bar context menu, useful when implementing client side decorations (Wayland only)
+    pub fn show_window_menu(&self, position: Point<Pixels>) {
+        self.window.platform_window.show_window_menu(position)
+    }
+
+    /// Tells the compositor to take control of window movement (Wayland only)
+    ///
+    /// Events may not be received during a move operation.
+    pub fn start_system_move(&self) {
+        self.window.platform_window.start_system_move()
+    }
+
+    /// Returns whether the title bar window controls need to be rendered by the application (Wayland and X11)
+    pub fn should_render_window_controls(&self) -> bool {
+        self.window.platform_window.should_render_window_controls()
+    }
+
     /// Updates the window's title at the platform level.
     pub fn set_window_title(&mut self, title: &str) {
         self.window.platform_window.set_title(title);