gpui_windows: Report the global cursor state for drag tracking

Implement Platform::global_cursor_state with GetCursorPos scaled by the
DPI of the monitor under the cursor, and the left button state from
GetAsyncKeyState, so drags released outside every window reach the
tear-off handler on Windows too.

assets/keymaps/default-linux.json

@@ -1630,7 +1630,6 @@
       "ctrl-g": "image_viewer::FindNext",
       "ctrl-shift-g": "image_viewer::FindPrevious",
       "ctrl-s": "image_viewer::SaveCopyAs",
-      "ctrl-z": "image_viewer::UndoEdit",
       "ctrl-shift-t": "image_viewer::ToggleTextPanel"
     },
   },

assets/keymaps/default-macos.json

@@ -1682,7 +1682,6 @@
       "cmd-g": "image_viewer::FindNext",
       "cmd-shift-g": "image_viewer::FindPrevious",
       "cmd-s": "image_viewer::SaveCopyAs",
-      "cmd-z": "image_viewer::UndoEdit",
       "cmd-shift-t": "image_viewer::ToggleTextPanel"
     },
   },

assets/keymaps/default-windows.json

@@ -1605,7 +1605,6 @@
       "ctrl-g": "image_viewer::FindNext",
       "ctrl-shift-g": "image_viewer::FindPrevious",
       "ctrl-s": "image_viewer::SaveCopyAs",
-      "ctrl-z": "image_viewer::UndoEdit",
       "ctrl-shift-t": "image_viewer::ToggleTextPanel"
     },
   },

crates/gpui/src/app.rs

@@ -44,14 +44,14 @@ use crate::{
     Action, ActionBuildError, ActionRegistry, ActivityGuard, Any, AnyView, AnyWindowHandle,
     AppContext, Arena, ArenaBox, Asset, AssetSource, BackgroundExecutor, Bounds, ClipboardItem,
     ClipboardReadError, CursorStyle, DispatchPhase, DisplayId, EventEmitter, ExternalDragPayload,
-    FocusHandle, FocusMap, ForegroundExecutor, Global, KeyBinding, KeyContext, Keymap, Keystroke,
-    LayoutId, Menu, MenuItem, MissingGlyph, OwnedMenu, PathPromptOptions, Pixels, Platform,
-    PlatformDisplay, PlatformKeyboardLayout, PlatformKeyboardMapper, Point, Priority,
-    PromptBuilder, PromptButton, PromptHandle, PromptLevel, Render, RenderImage,
+    FocusHandle, FocusMap, ForegroundExecutor, Global, GlobalCursorState, KeyBinding, KeyContext,
+    Keymap, Keystroke, LayoutId, Menu, MenuItem, MissingGlyph, OwnedMenu, PathPromptOptions,
+    Pixels, Platform, PlatformDisplay, PlatformKeyboardLayout, PlatformKeyboardMapper, Point,
+    Priority, PromptBuilder, PromptButton, PromptHandle, PromptLevel, Render, RenderImage,
     RenderablePromptHandle, Reservation, ScreenCaptureSource, SharedString, SubscriberSet,
     Subscription, SvgRenderer, SystemNotification, SystemNotificationResponse, Task,
-    TextRenderingMode, TextSystem, ThermalState, Window, WindowAppearance, WindowButtonLayout,
-    WindowHandle, WindowId, WindowInvalidator,
+    TextRenderingMode, TextSystem, ThermalState, Window, WindowAppearance, WindowBounds,
+    WindowButtonLayout, WindowHandle, WindowId, WindowInvalidator,
     colors::{Colors, GlobalColors},
     hash, init_app_menus,
 };
@@ -738,6 +738,10 @@ enum PlatformOwnedDragState {
     RestoredInSourceWindow,
 }
 
+/// How often the global cursor state is sampled while an in-app drag is
+/// active, to notice releases that happen outside of every window.
+const DRAG_POLL_INTERVAL: Duration = Duration::from_millis(30);
+
 /// Contains the state of the full application, and passed as a reference to a variety of callbacks.
 /// Other [Context] derefs to this type.
 /// You need a reference to an `App` to access the state of a [Entity].
@@ -749,6 +753,10 @@ pub struct App {
     pub(crate) actions: Rc<ActionRegistry>,
     pub(crate) active_drag: Option<AnyDrag>,
     platform_owned_drag: Option<PlatformOwnedDrag>,
+    pub(crate) drag_hover_window: Option<Option<WindowId>>,
+    drag_poll_running: bool,
+    drag_poll_task: Option<Task<()>>,
+    drag_dropped_outside_handler: Option<Box<dyn FnMut(&AnyDrag, Point<Pixels>, &mut App)>>,
     pub(crate) background_executor: BackgroundExecutor,
     pub(crate) foreground_executor: ForegroundExecutor,
     #[cfg(feature = "profiler")]
@@ -875,6 +883,10 @@ impl App {
                 pending_updates: 0,
                 active_drag: None,
                 platform_owned_drag: None,
+                drag_hover_window: None,
+                drag_poll_running: false,
+                drag_poll_task: None,
+                drag_dropped_outside_handler: None,
                 background_executor,
                 foreground_executor,
                 #[cfg(feature = "profiler")]
@@ -2636,6 +2648,7 @@ impl App {
     pub fn stop_active_drag(&mut self, window: &mut Window) -> bool {
         if self.active_drag.is_some() {
             self.active_drag = None;
+            self.drag_hover_window = None;
             if self.platform_owned_drag.as_ref().is_some_and(|drag| {
                 drag.source_window == window.window_handle().window_id()
                     && matches!(&drag.state, PlatformOwnedDragState::RestoredInSourceWindow)
@@ -2649,6 +2662,107 @@ impl App {
         }
     }
 
+    /// Registers a handler invoked when an in-app drag is released outside of
+    /// every application window, on platforms that report the global cursor
+    /// state.
+    pub fn set_drag_dropped_outside_handler(
+        &mut self,
+        handler: impl FnMut(&AnyDrag, Point<Pixels>, &mut App) + 'static,
+    ) {
+        self.drag_dropped_outside_handler = Some(Box::new(handler));
+    }
+
+    pub(crate) fn should_paint_drag_in(&self, window_id: WindowId) -> bool {
+        match self.drag_hover_window {
+            None => true,
+            Some(hovered_window) => hovered_window == Some(window_id),
+        }
+    }
+
+    pub(crate) fn set_drag_hover_window(&mut self, hovered: Option<Option<WindowId>>) {
+        if self.drag_hover_window == hovered {
+            return;
+        }
+        let previous = mem::replace(&mut self.drag_hover_window, hovered).flatten();
+        let next = hovered.flatten();
+        for window_id in [previous, next].into_iter().flatten() {
+            if let Some(handle) = self.window_handles.get(&window_id).copied() {
+                handle
+                    .update(self, |_, window, _| window.refresh())
+                    .log_err();
+            }
+        }
+    }
+
+    pub(crate) fn ensure_drag_poll_running(&mut self) {
+        if self.drag_poll_running || self.active_drag.is_none() {
+            return;
+        }
+        if self.platform.global_cursor_state().is_none() {
+            return;
+        }
+        self.drag_poll_running = true;
+        self.drag_poll_task = Some(self.spawn(async move |cx| {
+            loop {
+                cx.background_executor.timer(DRAG_POLL_INTERVAL).await;
+                let Some(state) = cx.update(|cx: &mut App| cx.platform.global_cursor_state())
+                else {
+                    break;
+                };
+                let finished = cx.update(|cx: &mut App| cx.poll_drag_state(state));
+                if finished {
+                    break;
+                }
+            }
+            cx.update(|cx: &mut App| cx.drag_poll_running = false);
+        }));
+    }
+
+    fn poll_drag_state(&mut self, state: GlobalCursorState) -> bool {
+        if self.active_drag.is_none() {
+            self.set_drag_hover_window(None);
+            return true;
+        }
+        let hovered_window = self.window_under_point(state.position);
+        self.set_drag_hover_window(Some(hovered_window));
+        if state.left_button_pressed {
+            return false;
+        }
+        if hovered_window.is_none()
+            && let Some(drag) = self.active_drag.take()
+        {
+            self.set_drag_hover_window(None);
+            let mut handler = self.drag_dropped_outside_handler.take();
+            if let Some(handler) = handler.as_mut() {
+                handler(&drag, state.position, self);
+            }
+            self.drag_dropped_outside_handler = handler;
+            self.refresh_windows();
+        }
+        true
+    }
+
+    fn window_under_point(&mut self, position: Point<Pixels>) -> Option<WindowId> {
+        let ordered_handles = self
+            .platform
+            .window_stack()
+            .unwrap_or_else(|| self.window_handles.values().copied().collect());
+        for handle in ordered_handles {
+            let Ok(bounds) = handle.update(self, |_, window, _| window.window_bounds()) else {
+                continue;
+            };
+            let bounds = match bounds {
+                WindowBounds::Windowed(bounds)
+                | WindowBounds::Maximized(bounds)
+                | WindowBounds::Fullscreen(bounds) => bounds,
+            };
+            if bounds.contains(&position) {
+                return Some(handle.window_id());
+            }
+        }
+        None
+    }
+
     pub(crate) fn hand_active_drag_to_platform(&mut self, source_window: WindowId) -> bool {
         let Some(drag) = self.active_drag.take() else {
             return false;

crates/gpui/src/app/test_context.rs

@@ -1,12 +1,13 @@
 use crate::{
     Action, AnyView, AnyWindowHandle, App, AppCell, AppContext, AsyncApp, AvailableSpace,
     BackgroundExecutor, BorrowAppContext, Bounds, Capslock, ClipboardItem, DrawPhase, Drawable,
-    Element, Empty, EntityId, EventEmitter, ForegroundExecutor, Global, InputEvent, Keystroke,
-    Modifiers, ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent,
-    Pixels, Platform, PlatformTextSystem, Point, Render, Result, SharedString, Size,
-    SystemNotification, SystemNotificationResponse, Task, TestDispatcher, TestPlatform,
-    TestScreenCaptureSource, TestWindow, TextSystem, VisualContext, Window, WindowBounds,
-    WindowHandle, WindowOptions, WindowVisibility, app::GpuiMode, window::ElementArenaScope,
+    Element, Empty, EntityId, EventEmitter, ForegroundExecutor, Global, GlobalCursorState,
+    InputEvent, Keystroke, Modifiers, ModifiersChangedEvent, MouseButton, MouseDownEvent,
+    MouseMoveEvent, MouseUpEvent, Pixels, Platform, PlatformTextSystem, Point, Render, Result,
+    SharedString, Size, SystemNotification, SystemNotificationResponse, Task, TestDispatcher,
+    TestPlatform, TestScreenCaptureSource, TestWindow, TextSystem, VisualContext, Window,
+    WindowBounds, WindowHandle, WindowOptions, WindowVisibility, app::GpuiMode,
+    window::ElementArenaScope,
 };
 use anyhow::{anyhow, bail};
 use futures::{Stream, StreamExt, channel::oneshot};
@@ -500,6 +501,12 @@ impl TestAppContext {
         self.test_platform.set_screen_capture_sources(sources);
     }
 
+    /// Sets the global cursor state reported by the test platform, for
+    /// exercising drags that leave every window.
+    pub fn set_global_cursor_state(&self, state: Option<GlobalCursorState>) {
+        self.test_platform.set_global_cursor_state(state);
+    }
+
     /// Returns all windows open in the test.
     pub fn windows(&self) -> Vec<AnyWindowHandle> {
         self.app.borrow().windows()

crates/gpui/src/platform.rs

@@ -182,6 +182,16 @@ pub fn guess_compositor() -> &'static str {
     }
 }
 
+/// The global cursor position and mouse button state, used to follow
+/// in-app drags once the cursor leaves every application window.
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
+pub struct GlobalCursorState {
+    /// The cursor position in global display coordinates.
+    pub position: Point<Pixels>,
+    /// Whether the left mouse button is currently pressed.
+    pub left_button_pressed: bool,
+}
+
 #[expect(missing_docs)]
 pub trait Platform: 'static {
     fn background_executor(&self) -> BackgroundExecutor;
@@ -203,6 +213,13 @@ pub trait Platform: 'static {
         None
     }
 
+    /// The global cursor position and button state, for platforms that can
+    /// query it without an active pointer grab. Returning `None` disables
+    /// following drags outside of the application's windows.
+    fn global_cursor_state(&self) -> Option<GlobalCursorState> {
+        None
+    }
+
     fn is_screen_capture_supported(&self) -> bool {
         false
     }

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

@@ -4,11 +4,11 @@ use crate::NoopTextSystem;
 use crate::PathPromptOptions;
 use crate::{
     ActivityGuard, AnyWindowHandle, BackgroundExecutor, ClipboardItem, CursorStyle, DevicePixels,
-    DummyKeyboardMapper, ForegroundExecutor, Keymap, OwnedMenu, Platform, PlatformDisplay,
-    PlatformHeadlessRenderer, PlatformKeyboardLayout, PlatformKeyboardMapper, PlatformTextSystem,
-    PromptButton, ScreenCaptureFrame, ScreenCaptureSource, ScreenCaptureStream, SharedString,
-    SourceMetadata, SystemNotification, SystemNotificationResponse, Task, TestDisplay, TestWindow,
-    ThermalState, WindowAppearance, WindowParams, size,
+    DummyKeyboardMapper, ForegroundExecutor, GlobalCursorState, Keymap, OwnedMenu, Platform,
+    PlatformDisplay, PlatformHeadlessRenderer, PlatformKeyboardLayout, PlatformKeyboardMapper,
+    PlatformTextSystem, PromptButton, ScreenCaptureFrame, ScreenCaptureSource, ScreenCaptureStream,
+    SharedString, SourceMetadata, SystemNotification, SystemNotificationResponse, Task,
+    TestDisplay, TestWindow, ThermalState, WindowAppearance, WindowParams, size,
 };
 use anyhow::Result;
 #[cfg(any(test, feature = "test-support"))]
@@ -42,6 +42,7 @@ pub(crate) struct TestPlatform {
     #[cfg(any(test, feature = "test-support"))]
     pub(crate) prompts: RefCell<TestPrompts>,
     screen_capture_sources: RefCell<Vec<TestScreenCaptureSource>>,
+    pub(crate) global_cursor_state: RefCell<Option<GlobalCursorState>>,
     pub opened_url: RefCell<Option<String>>,
     pub(crate) system_notifications: RefCell<TestSystemNotifications>,
     pub text_system: Arc<dyn PlatformTextSystem>,
@@ -153,6 +154,7 @@ impl TestPlatform {
             #[cfg(any(test, feature = "test-support"))]
             prompts: Default::default(),
             screen_capture_sources: Default::default(),
+            global_cursor_state: Default::default(),
             active_cursor: Default::default(),
             active_display: Rc::new(TestDisplay::new()),
             active_window: Default::default(),
@@ -174,6 +176,11 @@ impl TestPlatform {
         })
     }
 
+    /// Sets the global cursor state reported by [`Platform::global_cursor_state`].
+    pub fn set_global_cursor_state(&self, state: Option<GlobalCursorState>) {
+        *self.global_cursor_state.borrow_mut() = state;
+    }
+
     #[cfg(any(test, feature = "test-support"))]
     pub(crate) fn simulate_new_path_selection(
         &self,
@@ -489,6 +496,10 @@ impl Platform for TestPlatform {
             .map(|window| window.0.lock().handle)
     }
 
+    fn global_cursor_state(&self) -> Option<GlobalCursorState> {
+        *self.global_cursor_state.borrow()
+    }
+
     fn open_window(
         &self,
         handle: AnyWindowHandle,

crates/gpui/src/text_system.rs

@@ -1442,7 +1442,9 @@ pub fn font_name_with_fallbacks_shared<'a>(
     // IBM Plex/Lilex, and so retained here for backward compatibility.
     match name.as_str() {
         ".SystemUIFont" => system,
-        ".GwenSans" | ".ZedSans" | "Zed Plex Sans" => const { &SharedString::new_static("IBM Plex Sans") },
+        ".GwenSans" | ".ZedSans" | "Zed Plex Sans" => {
+            const { &SharedString::new_static("IBM Plex Sans") }
+        }
         ".GwenMono" | ".ZedMono" | "Zed Plex Mono" => const { &SharedString::new_static("Lilex") },
         _ => name,
     }

crates/gpui/src/window.rs

@@ -3563,7 +3563,9 @@ impl Window {
             element.prepaint_as_root(Point::default(), root_size.into(), self, cx);
             prompt_element = Some(element);
             self.prompt = Some(prompt);
-        } else if let Some(active_drag) = cx.active_drag.take() {
+        } else if cx.should_paint_drag_in(self.handle.window_id())
+            && let Some(active_drag) = cx.active_drag.take()
+        {
             let mut element = active_drag.view.clone().into_any_element();
             let offset = self.mouse_position() - active_drag.cursor_offset;
             element.prepaint_as_root(offset, AvailableSpace::min_size(), self, cx);
@@ -5789,14 +5791,17 @@ impl Window {
         self.rendered_frame.mouse_listeners = mouse_listeners;
 
         if cx.has_active_drag() {
+            cx.ensure_drag_poll_running();
             if event.is::<MouseMoveEvent>() {
                 // If this was a mouse move event, redraw the window so that the
                 // active drag can follow the mouse cursor.
+                cx.set_drag_hover_window(Some(Some(self.handle.window_id())));
                 self.refresh();
             } else if event.is::<MouseUpEvent>() {
                 // If this was a mouse up event, cancel the active drag and redraw
                 // the window.
                 cx.active_drag = None;
+                cx.set_drag_hover_window(None);
                 self.refresh();
             }
         }
@@ -7640,15 +7645,16 @@ mod tests {
         cell::{Cell, RefCell},
         path::PathBuf,
         rc::Rc,
+        sync::Arc,
         time::Duration,
     };
 
     use crate::{
-        AnyWindowHandle, AppContext as _, Bounds, ContentMask, Context, DispatchPhase,
+        AnyDrag, AnyWindowHandle, AppContext as _, Bounds, ContentMask, Context, DispatchPhase,
         DragMoveEvent, Empty, ExternalDragPayload, ExternalPaths, FileDragPaths, FileDropEvent,
-        FocusHandle, InputEvent as _, InteractiveElement as _, IntoElement, KeyDownEvent,
-        Keystroke, LongPressEvent, MouseButton, MouseDownEvent, MouseMoveEvent, ParentElement,
-        Pixels, PlatformInput, Point, Render, RequestFrameOptions, ScaledPixels,
+        FocusHandle, GlobalCursorState, InputEvent as _, InteractiveElement as _, IntoElement,
+        KeyDownEvent, Keystroke, LongPressEvent, MouseButton, MouseDownEvent, MouseMoveEvent,
+        ParentElement, Pixels, PlatformInput, Point, Render, RequestFrameOptions, ScaledPixels,
         StatefulInteractiveElement as _, Styled, TestAppContext, TouchDragEvent, TouchEvent,
         TouchId, TouchPhase, Underline, UnderlineStyle, Window, WindowAppearance, WindowOptions,
         canvas, div, hsla, point, px, size,
@@ -9109,6 +9115,65 @@ mod tests {
             })
             .unwrap();
     }
+
+    #[gpui::test]
+    fn test_drag_release_outside_windows_notifies_handler(cx: &mut TestAppContext) {
+        let dropped_position = Rc::new(RefCell::new(None));
+        let observed_position = dropped_position.clone();
+        cx.update(|cx| {
+            cx.set_drag_dropped_outside_handler(move |_drag, position, _cx| {
+                *observed_position.borrow_mut() = Some(position);
+            });
+        });
+
+        let window: AnyWindowHandle = cx.add_window(|_, _| EmptyView).into();
+        cx.set_global_cursor_state(Some(GlobalCursorState {
+            position: point(px(10.), px(10.)),
+            left_button_pressed: true,
+        }));
+        cx.update_window(window, |_, window, cx| {
+            cx.active_drag = Some(AnyDrag {
+                value: Arc::new("payload"),
+                view: cx.new(|_| Empty).into(),
+                cursor_offset: point(px(0.), px(0.)),
+                cursor_style: None,
+                external_payload_source: None,
+            });
+            cx.ensure_drag_poll_running();
+            window.refresh();
+        })
+        .unwrap();
+        cx.executor().advance_clock(Duration::from_millis(50));
+        cx.run_until_parked();
+        assert_eq!(
+            cx.read(|cx| cx.drag_hover_window),
+            Some(Some(window.window_id()))
+        );
+
+        // While the button stays pressed outside every window, the drag lives
+        // on but no window is asked to paint the ghost.
+        cx.set_global_cursor_state(Some(GlobalCursorState {
+            position: point(px(10_000.), px(10_000.)),
+            left_button_pressed: true,
+        }));
+        cx.executor().advance_clock(Duration::from_millis(50));
+        cx.run_until_parked();
+        assert_eq!(cx.read(|cx| cx.drag_hover_window), Some(None));
+        assert!(cx.read(|cx| cx.active_drag.is_some()));
+
+        // Releasing outside every window hands the drag to the handler.
+        cx.set_global_cursor_state(Some(GlobalCursorState {
+            position: point(px(10_000.), px(10_000.)),
+            left_button_pressed: false,
+        }));
+        cx.executor().advance_clock(Duration::from_millis(50));
+        cx.run_until_parked();
+        assert_eq!(
+            *dropped_position.borrow(),
+            Some(point(px(10_000.), px(10_000.)))
+        );
+        assert!(cx.read(|cx| cx.active_drag.is_none()));
+    }
 }
 
 #[cfg(all(test, any(feature = "inspector", debug_assertions)))]

crates/gpui_linux/src/linux/headless/client.rs

@@ -7,8 +7,8 @@ use gpui_util::ResultExt;
 use crate::linux::headless::window::{HeadlessDisplay, HeadlessWindow};
 use crate::linux::{LinuxClient, LinuxCommon, LinuxKeyboardLayout};
 use gpui::{
-    AnyWindowHandle, CursorStyle, DisplayId, PlatformDisplay, PlatformKeyboardLayout,
-    PlatformWindow, WindowParams,
+    AnyWindowHandle, CursorStyle, DisplayId, GlobalCursorState, PlatformDisplay,
+    PlatformKeyboardLayout, PlatformWindow, WindowParams,
 };
 
 pub struct HeadlessClientState {
@@ -97,6 +97,10 @@ impl LinuxClient for HeadlessClient {
         None
     }
 
+    fn global_cursor_state(&self) -> Option<GlobalCursorState> {
+        None
+    }
+
     fn open_window(
         &self,
         _handle: AnyWindowHandle,

crates/gpui_linux/src/linux/platform.rs

@@ -33,10 +33,10 @@ use xkbcommon::xkb::{self, Keycode, Keysym, State};
 use crate::linux::{LinuxDispatcher, PriorityQueueCalloopReceiver};
 use gpui::{
     Action, ActivityGuard, AnyWindowHandle, BackgroundExecutor, ClipboardItem, CursorStyle,
-    DisplayId, ForegroundExecutor, Keymap, Menu, MenuItem, OwnedMenu, PathPromptOptions, Platform,
-    PlatformDisplay, PlatformKeyboardLayout, PlatformKeyboardMapper, PlatformTextSystem,
-    PlatformWindow, Result, RunnableVariant, Task, ThermalState, WindowAppearance,
-    WindowButtonLayout, WindowParams,
+    DisplayId, ForegroundExecutor, GlobalCursorState, Keymap, Menu, MenuItem, OwnedMenu,
+    PathPromptOptions, Platform, PlatformDisplay, PlatformKeyboardLayout, PlatformKeyboardMapper,
+    PlatformTextSystem, PlatformWindow, Result, RunnableVariant, Task, ThermalState,
+    WindowAppearance, WindowButtonLayout, WindowParams,
 };
 #[cfg(any(feature = "wayland", feature = "x11"))]
 use gpui::{Pixels, Point, px};
@@ -101,6 +101,7 @@ pub(crate) trait LinuxClient {
     fn read_from_clipboard(&self) -> Option<ClipboardItem>;
     fn active_window(&self) -> Option<AnyWindowHandle>;
     fn window_stack(&self) -> Option<Vec<AnyWindowHandle>>;
+    fn global_cursor_state(&self) -> Option<GlobalCursorState>;
     fn run(&self);
 
     #[cfg(any(feature = "wayland", feature = "x11"))]
@@ -436,6 +437,10 @@ impl<P: LinuxClient + 'static> Platform for LinuxPlatform<P> {
         self.inner.window_stack()
     }
 
+    fn global_cursor_state(&self) -> Option<GlobalCursorState> {
+        self.inner.global_cursor_state()
+    }
+
     fn open_window(
         &self,
         handle: AnyWindowHandle,

crates/gpui_linux/src/linux/wayland/client.rs

@@ -97,9 +97,9 @@ use crate::linux::{
 };
 use gpui::{
     AnyWindowHandle, Bounds, Capslock, CursorStyle, DevicePixels, DisplayId, ExternalDragPayload,
-    FileDragPaths, FileDropEvent, ForegroundExecutor, KeyDownEvent, KeyUpEvent, Keystroke,
-    Modifiers, ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseExitEvent, MouseMoveEvent,
-    MouseUpEvent, NavigationDirection, Pixels, PlatformDisplay, PlatformInput,
+    FileDragPaths, FileDropEvent, ForegroundExecutor, GlobalCursorState, KeyDownEvent, KeyUpEvent,
+    Keystroke, Modifiers, ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseExitEvent,
+    MouseMoveEvent, MouseUpEvent, NavigationDirection, Pixels, PlatformDisplay, PlatformInput,
     PlatformKeyboardLayout, PlatformWindow, Point, ScrollDelta, ScrollWheelEvent, SharedString,
     Size, TouchPhase, WindowButtonLayout, WindowKind, WindowParams, point, profiler, px, size,
 };
@@ -1368,6 +1368,10 @@ impl LinuxClient for WaylandClient {
         None
     }
 
+    fn global_cursor_state(&self) -> Option<GlobalCursorState> {
+        None
+    }
+
     fn compositor_name(&self) -> &'static str {
         "Wayland"
     }

crates/gpui_linux/src/linux/x11/client.rs

@@ -60,10 +60,11 @@ use crate::linux::{
 use crate::linux::{LinuxCommon, LinuxKeyboardLayout, X11Window, modifiers_from_xinput_info};
 
 use gpui::{
-    AnyWindowHandle, Bounds, ClipboardItem, CursorStyle, DisplayId, FileDropEvent, Keystroke,
-    Modifiers, ModifiersChangedEvent, MouseButton, Pixels, PlatformDisplay, PlatformInput,
-    PlatformKeyboardLayout, PlatformWindow, Point, RequestFrameOptions, ScrollDelta, Size,
-    TouchPhase, WindowButtonLayout, WindowParams, WindowVisibility, point, px,
+    AnyWindowHandle, Bounds, ClipboardItem, CursorStyle, DisplayId, FileDropEvent,
+    GlobalCursorState, Keystroke, Modifiers, ModifiersChangedEvent, MouseButton, Pixels,
+    PlatformDisplay, PlatformInput, PlatformKeyboardLayout, PlatformWindow, Point,
+    RequestFrameOptions, ScrollDelta, Size, TouchPhase, WindowButtonLayout, WindowParams,
+    WindowVisibility, point, px,
 };
 use gpui_wgpu::{CompositorGpuHint, GpuContext};
 
@@ -1878,6 +1879,24 @@ impl LinuxClient for X11Client {
         Some(handles)
     }
 
+    fn global_cursor_state(&self) -> Option<GlobalCursorState> {
+        let state = self.0.borrow();
+        let root = state.xcb_connection.setup().roots[state.x_root_index].root;
+        let scale_factor = state.scale_factor;
+        let reply = get_reply(
+            || "Failed to query pointer position",
+            state.xcb_connection.query_pointer(root),
+        )
+        .log_err()?;
+        Some(GlobalCursorState {
+            position: point(
+                px(reply.root_x as f32 / scale_factor),
+                px(reply.root_y as f32 / scale_factor),
+            ),
+            left_button_pressed: reply.mask.contains(xproto::KeyButMask::BUTTON1),
+        })
+    }
+
     fn window_identifier(&self) -> impl Future<Output = Option<WindowIdentifier>> + Send + 'static {
         let state = self.0.borrow();
         state

crates/gpui_windows/src/display.rs

@@ -201,7 +201,7 @@ fn generate_uuid(device_name: &[u16]) -> Uuid {
     Uuid::new_v5(&Uuid::NAMESPACE_DNS, &name)
 }
 
-fn get_scale_factor_for_monitor(monitor: HMONITOR) -> Result<f32> {
+pub(crate) fn get_scale_factor_for_monitor(monitor: HMONITOR) -> Result<f32> {
     let mut dpi_x = 0;
     let mut dpi_y = 0;
     unsafe { GetDpiForMonitor(monitor, MDT_EFFECTIVE_DPI, &mut dpi_x, &mut dpi_y) }?;

crates/gpui_windows/src/platform.rs

@@ -636,6 +636,27 @@ impl Platform for WindowsPlatform {
             .map(|inner| inner.handle)
     }
 
+    fn global_cursor_state(&self) -> Option<GlobalCursorState> {
+        let mut point: POINT = unsafe { std::mem::zeroed() };
+        unsafe { GetCursorPos(&mut point) }
+            .context("unable to get cursor position")
+            .log_err()?;
+        let scale_factor = unsafe {
+            let monitor = MonitorFromPoint(point, MONITOR_DEFAULTTONEAREST);
+            if monitor.is_invalid() {
+                1.0
+            } else {
+                get_scale_factor_for_monitor(monitor).log_err()?
+            }
+        };
+        let left_button_pressed =
+            unsafe { GetAsyncKeyState(VK_LBUTTON.0 as i32) } as u16 & 0x8000 != 0;
+        Some(GlobalCursorState {
+            position: logical_point(point.x as f32, point.y as f32, scale_factor),
+            left_button_pressed,
+        })
+    }
+
     fn open_window(
         &self,
         handle: AnyWindowHandle,

crates/pdf_viewer/README.md

@@ -52,8 +52,9 @@ A native, high performance PDF viewing engine and GPUI workspace item engineered
 ## 2. Scope Boundaries
 
 - **Continuous Scroll & Text Selection**: Supports fluid high frame rate document browsing and visual text selection.
-- **Excluded from initial scope**:
+- **Excluded from scope**:
   - Interactive PDF form field editing.
+  - Annotation authoring, editing and deletion.
 - *Rationale*: Delivering an ultra fast, stutter free viewing experience with zero UI locks takes precedence.
 
 ---

crates/pdf_viewer/src/cache.rs

@@ -191,6 +191,26 @@ impl<T: CacheablePage> PageLruCache<T> {
         false
     }
 
+    /// Returns true if an entry with exactly this key is currently cached.
+    pub fn contains(&self, key: &CacheKey) -> bool {
+        self.entries.contains_key(key)
+    }
+
+    /// Returns the cached page for `page_index` whose zoom is closest to `zoom_factor`,
+    /// ignoring LRU order, so a zoom change can keep showing the previous bitmap while a
+    /// fresh one renders.
+    pub fn closest_to_zoom(&self, page_index: usize, zoom_factor: f32) -> Option<&T> {
+        self.entries
+            .iter()
+            .filter(|(key, _)| key.page_index == page_index)
+            .min_by(|(a, _), (b, _)| {
+                let distance_a = (a.zoom_bucket as f32 - zoom_factor * 100.0).abs();
+                let distance_b = (b.zoom_bucket as f32 - zoom_factor * 100.0).abs();
+                distance_a.total_cmp(&distance_b)
+            })
+            .map(|(_, value)| value)
+    }
+
     /// Clears all entries from the cache and resets memory tracking.
     pub fn clear(&mut self) {
         self.entries.clear();

crates/pdf_viewer/src/pdf_viewer.rs

@@ -22,9 +22,8 @@ pub mod watcher;
 pub use cache::{CacheKey, CacheablePage, DEFAULT_MEMORY_BUDGET_BYTES, PageLruCache, RenderedPage};
 pub use document::{PageDimensions, PdfDocument};
 pub use pdfium::{
-    PdfAnnotationColor, PdfAnnotationInfo, PdfAnnotationKind, PdfCharBox, PdfDocumentDetails,
-    PdfFormEdit, PdfFormWidget, PdfFormWidgetKind, PdfLinkAnnotation, PdfMetadata, PdfOutlineItem,
-    PdfPageDetails, PdfTextSegment, PdfiumEngine,
+    PdfCharBox, PdfDocumentDetails, PdfLinkAnnotation, PdfMetadata, PdfOutlineItem, PdfPageDetails,
+    PdfTextSegment, PdfiumEngine,
 };
 pub use rasterizer::{LuminosityToneMapper, PageRasterizer, RasterizerOptions};
 pub use settings::{DefaultZoomPolicy, PageLayoutMode, PdfViewerSettings};

crates/pdf_viewer/src/rasterizer.rs

@@ -5,6 +5,7 @@
 
 use crate::cache::RenderedPage;
 use crate::document::PageDimensions;
+use crate::pdfium::compute_target_dimensions;
 use anyhow::Result;
 
 /// Rendering and tone mapping configuration.
@@ -160,7 +161,16 @@ impl PageRasterizer {
         dimensions: PageDimensions,
         options: RasterizerOptions,
     ) -> Result<RenderedPage> {
-        let (width, height) = dimensions.to_pixel_size(options.zoom_factor, options.target_dpi);
+        // Mirror the native renderer's clamp: an unclamped frame at high zoom can grow
+        // past the page cache budget, which would make the cache refuse the entry and
+        // the caller re-render it forever.
+        let (width, height) = compute_target_dimensions(
+            dimensions.width,
+            dimensions.height,
+            options.target_dpi,
+            options.zoom_factor,
+        );
+        let (width, height) = (width.max(1) as u32, height.max(1) as u32);
         let total_bytes = (width as usize) * (height as usize) * 4;
 
         // Create standard white paper background with an inner border

crates/pdf_viewer/tests/integration_tests.rs

@@ -1,4 +1,5 @@
-use pdf_viewer::{PageLayoutMode, PdfToolbarState, PdfView, PdfViewerSettings};
+use pdf_viewer::rasterizer::RasterizerOptions;
+use pdf_viewer::{PageLayoutMode, PdfToolbarState, PdfView, PdfViewerSettings, PdfiumEngine};
 use std::time::Duration;
 
 const MINIMAL_PDF: &[u8] = b"%PDF-1.7\n1 0 obj\n<< /Type /Catalog /Pages 2 0 R >>\nendobj\n2 0 obj\n<< /Type /Pages /Kids [3 0 R] /Count 1 >>\nendobj\n3 0 obj\n<< /Type /Page /Parent 2 0 R /MediaBox [0 0 612 792] >>\nendobj\nxref\n0 4\n0000000000 65535 f \n0000000010 00000 n \n0000000060 00000 n \n0000000117 00000 n \ntrailer\n<< /Size 4 /Root 1 0 R >>\nstartxref\n185\n%%EOF\n";
@@ -105,3 +106,83 @@ fn test_toolbar_synchronization_with_view_state() {
     assert!(toolbar_state.dark_mode);
     assert_eq!(toolbar_state.layout_mode, PageLayoutMode::Continuous);
 }
+
+/// Builds a single-page PDF whose entire canvas is filled pure red, with a fully
+/// computed xref table so no repair parsing is involved.
+fn red_page_pdf() -> Vec<u8> {
+    let content = b"1 0 0 rg 0 0 612 792 re f";
+    let objects: Vec<Vec<u8>> = vec![
+        b"<< /Type /Catalog /Pages 2 0 R >>".to_vec(),
+        b"<< /Type /Pages /Kids [3 0 R] /Count 1 >>".to_vec(),
+        b"<< /Type /Page /Parent 2 0 R /MediaBox [0 0 612 792] /Resources << >> /Contents 4 0 R >>"
+            .to_vec(),
+        format!(
+            "<< /Length {} >>\nstream\n{}\nendstream",
+            content.len(),
+            String::from_utf8_lossy(content)
+        )
+        .into_bytes(),
+    ];
+
+    let mut out = b"%PDF-1.7\n".to_vec();
+    let mut offsets = Vec::with_capacity(objects.len());
+    for (index, object) in objects.iter().enumerate() {
+        offsets.push(out.len() as u32);
+        out.extend_from_slice(format!("{} 0 obj\n", index + 1).as_bytes());
+        out.extend_from_slice(object);
+        out.extend_from_slice(b"\nendobj\n");
+    }
+
+    let xref_offset = out.len() as u32;
+    out.extend_from_slice(format!("xref\n0 {}\n", objects.len() + 1).as_bytes());
+    out.extend_from_slice(b"0000000000 65535 f \n");
+    for offset in &offsets {
+        out.extend_from_slice(format!("{offset:010} 00000 n \n").as_bytes());
+    }
+    out.extend_from_slice(
+        format!(
+            "trailer\n<< /Size {} /Root 1 0 R >>\nstartxref\n{}\n%%EOF",
+            objects.len() + 1,
+            xref_offset
+        )
+        .as_bytes(),
+    );
+    out
+}
+
+/// Guards against PDFium's native BGRA bitmap order leaking through: the rasterizer
+/// must hand out RGBA buffers, so a red page must read as high-R/low-B. The mock
+/// renderer also draws red, so this only proves something when a native engine
+/// bound; without libpdfium the test cannot exercise the real byte order.
+#[test]
+fn test_native_render_outputs_rgba_channel_order() {
+    let engine = PdfiumEngine::new();
+    if !engine.is_native_available() {
+        eprintln!("skipping: native libpdfium not available on this machine");
+        return;
+    }
+
+    let rendered = engine
+        .render_page_from_bytes(&red_page_pdf(), 0, RasterizerOptions::default())
+        .expect("native render should succeed");
+
+    let stride = rendered.width as usize * 4;
+    assert_eq!(rendered.rgba_buffer.len(), stride * rendered.height as usize);
+
+    for (x, y) in [
+        (rendered.width as usize / 2, rendered.height as usize / 2),
+        (rendered.width as usize / 4, rendered.height as usize / 4),
+        (
+            rendered.width as usize * 3 / 4,
+            rendered.height as usize * 3 / 4,
+        ),
+    ] {
+        let pixel = &rendered.rgba_buffer[y * stride + x * 4..y * stride + x * 4 + 4];
+        let (r, g, b, a) = (pixel[0], pixel[1], pixel[2], pixel[3]);
+        assert!(
+            r > 200 && b < 60,
+            "buffer is not RGBA-ordered at ({x},{y}): R={r} G={g} B={b} A={a}"
+        );
+        assert_eq!(a, 255, "opaque page should carry alpha 255");
+    }
+}

crates/workspace/src/background_image.rs

@@ -7,16 +7,16 @@ use std::{
 
 use fs::Fs;
 use gpui::{
-    point, px, relative, size, BackgroundExecutor, Bounds, Context, Corners, Element,
-    ElementId, Empty, GlobalElementId, InspectorElementId, IntoElement, LayoutId,
-    ParentElement, Pixels, Render, RenderImage, Style, Styled, Subscription, Task, Window,
+    BackgroundExecutor, Bounds, Context, Corners, Element, ElementId, Empty, GlobalElementId,
+    InspectorElementId, IntoElement, LayoutId, ParentElement, Pixels, Render, RenderImage, Style,
+    Styled, Subscription, Task, Window, point, px, relative, size,
 };
-use util::ResultExt;
 use image::Frame;
 use settings::{
     BackgroundImageFit, BackgroundImagePosition, RegisterSetting, Settings, SettingsStore,
 };
 use smallvec::SmallVec;
+use util::ResultExt;
 
 /// Default opacity of the editor and terminal surfaces drawn on top of
 /// the background image. Lower values let the image show through more.
@@ -125,11 +125,9 @@ impl BackgroundImage {
             let path = path.clone();
             let path_for_check = path.clone();
             let cache_dir = cache_dir.clone();
-            let load_task = executor
-                .clone()
-                .spawn(async move {
-                    load_background_image(&fs, &path, &cache_dir, executor.clone()).await
-                });
+            let load_task = executor.clone().spawn(async move {
+                load_background_image(&fs, &path, &cache_dir, executor.clone()).await
+            });
             let image = load_task.await;
 
             this.update(cx, |this, cx| {
@@ -335,7 +333,7 @@ async fn load_background_image(
                 );
                 load_from_cache(fs, path, cache_dir).await
             }
-        }
+        },
         futures::future::Either::Left((Err(error), _)) => {
             log::info!(
                 "failed to load background image at {}: {error}",
@@ -441,9 +439,7 @@ mod tests {
         cx: &mut TestAppContext,
         fs: Arc<FakeFs>,
     ) -> gpui::Entity<BackgroundImage> {
-        cx.update(|cx| {
-            cx.new(|cx| BackgroundImage::new(fs, Arc::from(Path::new(CACHE_DIR)), cx))
-        })
+        cx.update(|cx| cx.new(|cx| BackgroundImage::new(fs, Arc::from(Path::new(CACHE_DIR)), cx)))
     }
 
     /// A minimal 2x2 PNG of the given color.
@@ -523,7 +519,8 @@ mod tests {
         settings_store(cx);
 
         let fs = FakeFs::new(cx.executor());
-        fs.insert_file("/background.png", png_bytes(image::Rgba([255, 0, 0, 255]))).await;
+        fs.insert_file("/background.png", png_bytes(image::Rgba([255, 0, 0, 255])))
+            .await;
 
         let background_image = new_background_image(cx, fs.clone());
         cx.run_until_parked();
@@ -581,11 +578,10 @@ mod tests {
         settings_store(cx);
 
         let fs = FakeFs::new(cx.executor());
-        let cache_path = cache_path_for(
-            Path::new("/remote/background.png"),
-            Path::new(CACHE_DIR),
-        );
-        fs.write(&cache_path, &png_bytes(image::Rgba([255, 0, 0, 255]))).await.unwrap();
+        let cache_path = cache_path_for(Path::new("/remote/background.png"), Path::new(CACHE_DIR));
+        fs.write(&cache_path, &png_bytes(image::Rgba([255, 0, 0, 255])))
+            .await
+            .unwrap();
 
         let background_image = new_background_image(cx, fs);
         set_background_path(cx, Some("/remote/background.png"));
@@ -618,7 +614,8 @@ mod tests {
         settings_store(cx);
 
         let fs = FakeFs::new(cx.executor());
-        fs.insert_file("/broken.png", b"not an image".to_vec()).await;
+        fs.insert_file("/broken.png", b"not an image".to_vec())
+            .await;
 
         let background_image = new_background_image(cx, fs);
         set_background_path(cx, Some("/broken.png"));
@@ -634,7 +631,8 @@ mod tests {
         settings_store(cx);
 
         let fs = FakeFs::new(cx.executor());
-        fs.insert_file("/background.png", png_bytes(image::Rgba([255, 0, 0, 255]))).await;
+        fs.insert_file("/background.png", png_bytes(image::Rgba([255, 0, 0, 255])))
+            .await;
 
         let background_image = new_background_image(cx, fs);
         set_background_path(cx, Some("/background.png"));

crates/workspace/src/pane.rs

@@ -1,7 +1,8 @@
 use crate::{
     CloseWindow, NewCenterTerminal, NewFile, NewTerminal, OpenInTerminal, OpenOptions,
-    OpenTerminal, OpenVisible, SplitDirection, ToggleFileFinder, ToggleProjectSymbols, ToggleZoom,
-    Workspace, WorkspaceItemBuilder, ZoomIn, ZoomOut,
+    OpenTerminal, OpenVisible, SerializableItemRegistry, SplitDirection, ToggleFileFinder,
+    ToggleProjectSymbols, ToggleZoom, Workspace, WorkspaceId, WorkspaceItemBuilder, ZoomIn,
+    ZoomOut,
     focus_follows_mouse::FocusFollowsMouse as _,
     invalid_item_view::InvalidItemView,
     item::{
@@ -14,7 +15,7 @@ use crate::{
     toolbar::Toolbar,
     workspace_settings::{AutosaveSetting, FocusFollowsMouse, TabBarSettings, WorkspaceSettings},
 };
-use anyhow::Result;
+use anyhow::{Result, anyhow};
 use collections::{BTreeSet, HashMap, HashSet, VecDeque};
 use futures::{StreamExt, stream::FuturesUnordered};
 use git::{CopyFilePermalink, OpenFilePermalink};
@@ -3884,9 +3885,27 @@ impl Pane {
 
         let from_pane = dragged_tab.pane.clone();
 
+        let dragged_item = dragged_tab.item.boxed_clone();
+
         self.workspace
             .update(cx, |_, cx| {
                 cx.defer_in(window, move |workspace, window, cx| {
+                    let from_workspace_id =
+                        from_pane.read_with(cx, |pane, _| pane.workspace.entity_id());
+                    if from_workspace_id != cx.entity_id() {
+                        let to_pane = to_pane.downgrade();
+                        if let Some(transfer) =
+                            prepare_item_transfer(&*dragged_item, &from_pane, cx)
+                        {
+                            cx.spawn_in(window, async move |_, cx| {
+                                complete_item_transfer(transfer, to_pane, ix, cx)
+                                    .await
+                                    .log_err();
+                            })
+                            .detach();
+                        }
+                        return;
+                    }
                     if let Some(split_direction) = split_direction {
                         to_pane = workspace.split_pane(to_pane, split_direction, window, cx);
                     }
@@ -5080,18 +5099,108 @@ impl Render for DraggedTab {
     }
 }
 
+/// The pieces needed to recreate an item in another workspace by round
+/// tripping it through the workspace database. Item entities are bound to
+/// their workspace's project, so moves across windows cannot move the entity
+/// itself.
+pub(crate) struct ItemTransfer {
+    kind: Arc<str>,
+    source_workspace_id: WorkspaceId,
+    item_id: EntityId,
+    source_pane: Entity<Pane>,
+    serialize_task: Task<Result<()>>,
+}
+
+/// Prepares to recreate `item` in another workspace. Returns `None` when the
+/// item has unsaved changes or is not serializable, in which case the drag
+/// snaps back instead of moving the entity across projects.
+pub(crate) fn prepare_item_transfer(
+    item: &dyn ItemHandle,
+    source_pane: &Entity<Pane>,
+    cx: &mut App,
+) -> Option<ItemTransfer> {
+    if item.is_dirty(cx) {
+        return None;
+    }
+    let serializable =
+        SerializableItemRegistry::view_to_serializable_item_handle(item.to_any_view(), cx)?;
+    let source_workspace = source_pane.read(cx).workspace.upgrade()?;
+    let source_workspace_id = source_workspace.read(cx).database_id()?;
+    let serialize_task = source_workspace.update(cx, |workspace, cx| {
+        serializable.serialize(workspace, false, cx)
+    })?;
+    Some(ItemTransfer {
+        kind: Arc::from(serializable.serialized_item_kind()),
+        source_workspace_id,
+        item_id: item.item_id(),
+        source_pane: source_pane.clone(),
+        serialize_task,
+    })
+}
+
+/// Recreates a transferred item at index `ix` of `to_pane`, then closes the
+/// source item in its own window.
+pub(crate) async fn complete_item_transfer(
+    transfer: ItemTransfer,
+    to_pane: WeakEntity<Pane>,
+    ix: usize,
+    cx: &mut AsyncWindowContext,
+) -> Result<()> {
+    transfer.serialize_task.await.log_err();
+    let project = to_pane
+        .update(cx, |pane, _| pane.project.upgrade())?
+        .ok_or_else(|| anyhow!("target pane's project was dropped"))?;
+    let workspace = to_pane.update(cx, |pane, _| pane.workspace.clone())?;
+    let item = to_pane
+        .update_in(cx, |_, window, cx| {
+            SerializableItemRegistry::deserialize(
+                &transfer.kind,
+                project,
+                workspace,
+                transfer.source_workspace_id,
+                transfer.item_id.as_u64(),
+                window,
+                cx,
+            )
+        })?
+        .await?;
+    let to_pane = to_pane
+        .upgrade()
+        .ok_or_else(|| anyhow!("target pane was dropped"))?;
+    to_pane.update_in(cx, |pane, window, cx| {
+        pane.add_item(item, true, true, None, window, cx);
+    })?;
+    let last_index = to_pane.read_with(cx, |pane, _| pane.items.len().saturating_sub(1));
+    if ix < last_index {
+        to_pane.update_in(cx, |_, window, cx| {
+            move_item(&to_pane, &to_pane, transfer.item_id, ix, true, window, cx);
+        })?;
+    }
+    let source_workspace = transfer
+        .source_pane
+        .read_with(cx, |pane, _| pane.workspace.clone());
+    source_workspace
+        .update_in(cx, |_, window, cx| {
+            transfer.source_pane.update(cx, |pane, cx| {
+                pane.close_item_by_id(transfer.item_id, SaveIntent::Close, window, cx)
+            })
+        })?
+        .await
+        .log_err();
+    Ok(())
+}
 #[cfg(test)]
 mod tests {
-    use std::{cell::Cell, iter::zip, num::NonZero, rc::Rc};
+    use std::{cell::Cell, iter::zip, num::NonZero, rc::Rc, sync::Arc};
 
     use super::*;
     use crate::{
-        Member,
+        Member, MultiWorkspace,
         item::test::{TestItem, TestProjectItem},
     };
     use gpui::{
-        AppContext, Axis, Modifiers, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent,
-        TestAppContext, VisualTestContext, size,
+        AnyDrag, AppContext, Axis, Empty, Modifiers, MouseButton, MouseDownEvent, MouseMoveEvent,
+        MouseUpEvent, TestAppContext, VisualTestContext, point, px, size,
     };
     use project::FakeFs;
     use settings::SettingsStore;
@@ -9664,4 +9773,150 @@ mod tests {
             }
         }
     }
+
+    #[gpui::test]
+    async fn test_tab_drop_across_workspaces_transfers_item(cx: &mut TestAppContext) {
+        init_test(cx);
+        let fs = FakeFs::new(cx.executor());
+        let project_a = Project::test(fs.clone(), None, cx).await;
+        let project_b = Project::test(fs.clone(), None, cx).await;
+        cx.update(crate::register_serializable_item::<TestItem>);
+
+        let (workspace_a, cx_a) =
+            cx.add_window_view(|window, cx| Workspace::test_new(project_a.clone(), window, cx));
+        workspace_a.update(cx_a, |workspace, _| {
+            workspace.database_id = Some(WorkspaceId(1))
+        });
+        let pane_a = workspace_a.read_with(cx_a, |workspace, _| workspace.active_pane().clone());
+        let item = cx_a.new(|cx| TestItem::new(cx).with_serialize(|| Some(Task::ready(Ok(())))));
+        pane_a.update_in(cx_a, |pane, window, cx| {
+            pane.add_item(Box::new(item.clone()), true, false, None, window, cx)
+        });
+        let source_workspace_id =
+            workspace_a.read_with(cx_a, |workspace, _| workspace.database_id());
+
+        let window_b =
+            cx_a.add_window(|window, cx| Workspace::test_new(project_b.clone(), window, cx));
+        let cx_b = &mut VisualTestContext::from_window(window_b.into(), cx_a);
+        cx_b.run_until_parked();
+        let pane_b = window_b
+            .update(cx_b, |workspace, _, _| workspace.active_pane().clone())
+            .unwrap();
+
+        let dragged_tab = DraggedTab {
+            pane: pane_a.clone(),
+            item: Box::new(item.clone()),
+            ix: 0,
+            detail: 0,
+            is_active: true,
+        };
+        pane_b.update_in(cx_b, |pane, window, cx| {
+            pane.handle_tab_drop(&dragged_tab, 0, false, window, cx)
+        });
+        cx_a.run_until_parked();
+
+        assert_eq!(pane_a.read_with(cx_a, |pane, _| pane.items_len()), 0);
+        let transferred = pane_b
+            .read_with(cx_b, |pane, _| pane.items().next().cloned())
+            .expect("item moved to the other workspace")
+            .downcast::<TestItem>()
+            .expect("transferred item is a test item");
+        assert_eq!(
+            transferred.read_with(cx_b, |item, _| item.workspace_id),
+            source_workspace_id
+        );
+    }
+
+    #[allow(clippy::arc_with_non_send_sync)]
+    #[gpui::test]
+    async fn test_tab_dropped_outside_opens_new_window(cx: &mut TestAppContext) {
+        init_test(cx);
+        let fs = FakeFs::new(cx.executor());
+        let project = Project::test(fs.clone(), None, cx).await;
+        cx.update(crate::register_serializable_item::<TestItem>);
+        let (workspace, cx) =
+            cx.add_window_view(|window, cx| Workspace::test_new(project.clone(), window, cx));
+        workspace.update(cx, |workspace, _| {
+            workspace.database_id = Some(WorkspaceId(1))
+        });
+        let pane = workspace.read_with(cx, |workspace, _| workspace.active_pane().clone());
+        let item = cx.new(|cx| TestItem::new(cx).with_serialize(|| Some(Task::ready(Ok(())))));
+        pane.update_in(cx, |pane, window, cx| {
+            pane.add_item(Box::new(item.clone()), true, false, None, window, cx)
+        });
+        let source_workspace_id = workspace.read_with(cx, |workspace, _| workspace.database_id());
+
+        let dragged_tab = DraggedTab {
+            pane: pane.clone(),
+            item: Box::new(item.clone()),
+            ix: 0,
+            detail: 0,
+            is_active: true,
+        };
+        let drag = AnyDrag {
+            value: Arc::new(dragged_tab),
+            view: cx.new(|_| Empty).into(),
+            cursor_offset: point(px(0.), px(0.)),
+            cursor_style: None,
+            external_payload_source: None,
+        };
+        cx.update(|_, cx| crate::handle_tab_dropped_outside(&drag, point(px(400.), px(300.)), cx));
+        cx.run_until_parked();
+
+        let mut transferred_workspace_id = None;
+        for window in cx.windows() {
+            let Some(handle) = window.downcast::<MultiWorkspace>() else {
+                continue;
+            };
+            let workspace = handle
+                .update(cx, |multi_workspace, _, _| {
+                    multi_workspace.workspace().clone()
+                })
+                .unwrap();
+            let pane = workspace.read_with(cx, |workspace, _| workspace.active_pane().clone());
+            if let Some(item) = pane.read_with(cx, |pane, _| pane.items().next().cloned()) {
+                transferred_workspace_id = item
+                    .downcast::<TestItem>()
+                    .map(|item| item.read_with(cx, |item, _| item.workspace_id));
+            }
+        }
+        assert_eq!(transferred_workspace_id, Some(source_workspace_id));
+        assert_eq!(pane.read_with(cx, |pane, _| pane.items_len()), 0);
+    }
+
+    #[allow(clippy::arc_with_non_send_sync)]
+    #[gpui::test]
+    async fn test_dirty_tab_dropped_outside_keeps_item(cx: &mut TestAppContext) {
+        init_test(cx);
+        cx.update(crate::register_serializable_item::<TestItem>);
+        let fs = FakeFs::new(cx.executor());
+        let project = Project::test(fs.clone(), None, cx).await;
+        let (workspace, cx) =
+            cx.add_window_view(|window, cx| Workspace::test_new(project.clone(), window, cx));
+        let pane = workspace.read_with(cx, |workspace, _| workspace.active_pane().clone());
+        let item = cx.new(|cx| TestItem::new(cx).with_dirty(true));
+        pane.update_in(cx, |pane, window, cx| {
+            pane.add_item(Box::new(item.clone()), true, false, None, window, cx)
+        });
+
+        let dragged_tab = DraggedTab {
+            pane: pane.clone(),
+            item: Box::new(item.clone()),
+            ix: 0,
+            detail: 0,
+            is_active: true,
+        };
+        let drag = AnyDrag {
+            value: Arc::new(dragged_tab),
+            view: cx.new(|_| Empty).into(),
+            cursor_offset: point(px(0.), px(0.)),
+            cursor_style: None,
+            external_payload_source: None,
+        };
+        cx.update(|_, cx| crate::handle_tab_dropped_outside(&drag, point(px(400.), px(300.)), cx));
+        cx.run_until_parked();
+
+        assert_eq!(cx.windows().len(), 1);
+        assert_eq!(pane.read_with(cx, |pane, _| pane.items_len()), 1);
+    }
 }

crates/workspace/src/workspace.rs

@@ -62,13 +62,13 @@ use futures::{
     future::{Shared, try_join_all},
 };
 use gpui::{
-    Action, AnyEntity, AnyView, AnyWeakView, App, AppContext, AsyncApp, AsyncWindowContext, Axis,
-    Bounds, ClipboardItem, Context, CursorStyle, Decorations, DragMoveEvent, Entity, EntityId,
-    EventEmitter, FocusHandle, Focusable, Global, HitboxBehavior, Hsla, KeyContext, Keystroke,
-    ManagedView, MouseButton, PathPromptOptions, Point, PromptLevel, Render, ResizeEdge, Size,
-    Stateful, Subscription, SystemWindowTabController, Task, TaskExt, Tiling, WeakEntity,
-    WindowBounds, WindowHandle, WindowId, WindowOptions, actions, canvas, point, relative, size,
-    transparent_black,
+    Action, AnyDrag, AnyEntity, AnyView, AnyWeakView, App, AppContext, AsyncApp,
+    AsyncWindowContext, Axis, Bounds, ClipboardItem, Context, CursorStyle, Decorations,
+    DragMoveEvent, Entity, EntityId, EventEmitter, FocusHandle, Focusable, Global, HitboxBehavior,
+    Hsla, KeyContext, Keystroke, ManagedView, MouseButton, PathPromptOptions, Pixels, Point,
+    PromptLevel, Render, ResizeEdge, Size, Stateful, Subscription, SystemWindowTabController, Task,
+    TaskExt, Tiling, WeakEntity, WindowBounds, WindowHandle, WindowId, WindowOptions, actions,
+    canvas, point, px, relative, size, transparent_black,
 };
 pub use history_manager::*;
 pub use item::{
@@ -166,8 +166,8 @@ pub use workspace_settings::{
 };
 use zed_actions::{Spawn, feedback::FileBugReport, theme::ToggleMode};
 
-use crate::{dock::PanelSizeState, item::ItemBufferKind, notifications::NotificationId};
 use crate::background_image::BackgroundImage;
+use crate::{dock::PanelSizeState, item::ItemBufferKind, notifications::NotificationId};
 use crate::{
     persistence::{
         SerializedAxis,
@@ -999,6 +999,10 @@ pub fn init(app_state: Arc<AppState>, cx: &mut App) {
 
     cx.on_app_quit(flush_windows_serialization_on_quit).detach();
 
+    cx.set_drag_dropped_outside_handler(|drag, position, cx| {
+        handle_tab_dropped_outside(drag, position, cx);
+    });
+
     cx.on_action(|_: &CloseWindow, cx| Workspace::close_global(cx))
         .on_action(|_: &Reload, cx| reload(cx))
         .on_action(|action: &Open, cx: &mut App| {
@@ -2178,6 +2182,30 @@ impl Workspace {
         init: Option<Box<dyn FnOnce(&mut Workspace, &mut Window, &mut Context<Workspace>) + Send>>,
         open_mode: OpenMode,
         cx: &mut App,
+    ) -> Task<anyhow::Result<OpenResult>> {
+        Self::new_local_with_bounds(
+            abs_paths,
+            app_state,
+            requesting_window,
+            env,
+            init,
+            open_mode,
+            None,
+            cx,
+        )
+    }
+
+    /// Same as [`Workspace::new_local`], but places a newly created window at
+    /// `window_bounds_override` instead of the persisted or cascaded defaults.
+    pub fn new_local_with_bounds(
+        abs_paths: Vec<PathBuf>,
+        app_state: Arc<AppState>,
+        requesting_window: Option<WindowHandle<MultiWorkspace>>,
+        env: Option<HashMap<String, String>>,
+        init: Option<Box<dyn FnOnce(&mut Workspace, &mut Window, &mut Context<Workspace>) + Send>>,
+        open_mode: OpenMode,
+        window_bounds_override: Option<Bounds<Pixels>>,
+        cx: &mut App,
     ) -> Task<anyhow::Result<OpenResult>> {
         let project_handle = Project::local(
             app_state.client.clone(),
@@ -2315,7 +2343,8 @@ impl Workspace {
                     })?;
                     (window, workspace)
                 } else {
-                    let window_bounds_override = window_bounds_env_override();
+                    let window_bounds_override =
+                        window_bounds_override.or_else(window_bounds_env_override);
 
                     let (window_bounds, display) = if let Some(bounds) = window_bounds_override {
                         (Some(WindowBounds::Windowed(bounds)), None)
@@ -12290,6 +12319,82 @@ pub fn clone_active_item(
         .detach();
 }
 
+/// Opens a new window holding the dragged tab's item, for drags released
+/// outside of every application window.
+fn handle_tab_dropped_outside(drag: &AnyDrag, position: Point<Pixels>, cx: &mut App) {
+    let Some(dragged_tab) = drag.value.downcast_ref::<DraggedTab>() else {
+        return;
+    };
+    let source_pane = dragged_tab.pane.clone();
+    let Some(transfer) = prepare_item_transfer(&*dragged_tab.item, &source_pane, cx) else {
+        return;
+    };
+    let Some(source_workspace) = source_pane.read(cx).workspace.upgrade() else {
+        return;
+    };
+    let paths = source_workspace
+        .read(cx)
+        .root_paths(cx)
+        .into_iter()
+        .map(|path| path.to_path_buf())
+        .collect();
+    let app_state = source_workspace.read(cx).app_state.clone();
+    let window_bounds = tear_off_window_bounds(position, cx);
+    let open_task = Workspace::new_local_with_bounds(
+        paths,
+        app_state,
+        None,
+        None,
+        None,
+        OpenMode::NewWindow,
+        Some(window_bounds),
+        cx,
+    );
+    cx.spawn(async move |cx| {
+        let opened = open_task.await?;
+        let to_pane = opened
+            .workspace
+            .update(cx, |workspace, _| workspace.active_pane().downgrade());
+        opened.window.update(cx, |_, window, cx| {
+            window
+                .spawn(cx, async move |cx| {
+                    complete_item_transfer(transfer, to_pane, 0, cx)
+                        .await
+                        .log_err();
+                })
+                .detach();
+        })?;
+        anyhow::Ok(())
+    })
+    .detach_and_log_err(cx);
+}
+
+/// Bounds for a window torn off at `position`: the active window's size with
+/// its origin at the cursor, clamped inside the display's visible area.
+fn tear_off_window_bounds(position: Point<Pixels>, cx: &mut App) -> Bounds<Pixels> {
+    let size = cx
+        .active_window()
+        .and_then(|window| {
+            window
+                .update(cx, |_, window, _| window.window_bounds().get_bounds().size)
+                .ok()
+        })
+        .unwrap_or_else(|| size(px(1024.), px(768.)));
+    let Some(display) = cx.primary_display() else {
+        return Bounds::new(position, size);
+    };
+    let visible = display.visible_bounds();
+    let max_origin = point(
+        (visible.origin.x + visible.size.width - size.width).max(visible.origin.x),
+        (visible.origin.y + visible.size.height - size.height).max(visible.origin.y),
+    );
+    let origin = point(
+        position.x.clamp(visible.origin.x, max_origin.x),
+        position.y.clamp(visible.origin.y, max_origin.y),
+    );
+    Bounds::new(origin, size)
+}
+
 #[derive(Debug)]
 pub struct WorkspacePosition {
     pub window_bounds: Option<WindowBounds>,

script/bundle-mac

@@ -146,6 +146,7 @@ fi
 
 GIT_VERSION="v2.43.3"
 GIT_VERSION_SHA="fa29823"
+PDFIUM_TAG="chromium/8066"
 
 function download_and_unpack() {
     local url=$1
@@ -192,6 +193,42 @@ function download_git() {
     rm -rf "$tmp_dir"
 }
 
+function download_pdfium() {
+    local architecture=$1
+    local target_path=$2
+
+    case "$architecture" in
+        aarch64-apple-darwin)
+            pdfium_flavor="mac-arm64"
+            pdfium_sha256="336219e80580b93c6523f44db7dc1de59cc497b13a7390ddac84223f68ca162b"
+            ;;
+        x86_64-apple-darwin)
+            pdfium_flavor="mac-x64"
+            pdfium_sha256="841ecac278cdd46288dd065873522cf72f3996560d8978f473d336f01d59942c"
+            ;;
+        *)
+            echo "Unsupported architecture for pdfium: $architecture"
+            exit 1
+            ;;
+    esac
+
+    # sha256sum is not present on stock macOS, so checksums go through shasum.
+    pdfium_tgz="${target_dir}/pdfium-${pdfium_flavor}.tgz"
+    if ! echo "${pdfium_sha256}  ${pdfium_tgz}" | shasum -a 256 -c >/dev/null 2>&1; then
+        mkdir -p "${target_dir}"
+        curl --silent --fail --location --output "${pdfium_tgz}" \
+            "https://github.com/bblanchon/pdfium-binaries/releases/download/${PDFIUM_TAG}/pdfium-${pdfium_flavor}.tgz"
+        echo "${pdfium_sha256}  ${pdfium_tgz}" | shasum -a 256 -c
+    fi
+
+    pdfium_tmp=$(mktemp -d)
+    tar -xzf "${pdfium_tgz}" -C "${pdfium_tmp}" "lib/libpdfium.dylib" "LICENSE" "licenses"
+    cp "${pdfium_tmp}/lib/libpdfium.dylib" "${target_path}"
+    mkdir -p "${app_path}/Contents/Resources/pdfium-licenses"
+    cp "${pdfium_tmp}/LICENSE" "${pdfium_tmp}/licenses/"* "${app_path}/Contents/Resources/pdfium-licenses/"
+    rm -rf "${pdfium_tmp}"
+}
+
 function sign_app_binaries() {
     rm -rf "${app_path}/Contents/Frameworks"
     mkdir -p "${app_path}/Contents/Frameworks"
@@ -199,6 +236,10 @@ function sign_app_binaries() {
     echo "Downloading git binary"
     download_git "${target_triple}" "${app_path}/Contents/MacOS/git"
 
+    # PDFium is dlopen'd at runtime by the bundled pdf_viewer for native PDF viewing.
+    echo "Downloading pdfium library"
+    download_pdfium "${target_triple}" "${app_path}/Contents/Frameworks/libpdfium.dylib"
+
     # Note: The app identifier for our development builds is the same as the app identifier for nightly.
     cp crates/zed/contents/$channel/embedded.provisionprofile "${app_path}/Contents/"