Sending key events through script task before processing them in the compositor.

Fixes #4163

components/compositing/compositor.rs

@@ -4,6 +4,7 @@
 
 use compositor_layer::{CompositorData, CompositorLayer, DoesntWantScrollEvents};
 use compositor_layer::{WantsScrollEvents};
+use compositor_task;
 use compositor_task::{ChangePageLoadData, ChangePageTitle, ChangePaintState, ChangeReadyState};
 use compositor_task::{CompositorEventListener, CompositorProxy, CompositorReceiver};
 use compositor_task::{CompositorTask, CreateOrUpdateDescendantLayer, CreateOrUpdateRootLayer};
@@ -336,6 +337,10 @@ impl<Window: WindowMethods> IOCompositor<Window> {
                 }
             }
 
+            (compositor_task::KeyEvent(key, modified), NotShuttingDown) => {
+                self.window.handle_key(key, modified);
+            }
+
             // When we are shutting_down, we need to avoid performing operations
             // such as Paint that may crash because we have begun tearing down
             // the rest of our resources.

components/compositing/compositor_task.rs

@@ -20,6 +20,7 @@ use layers::layers::LayerBufferSet;
 use servo_msg::compositor_msg::{Epoch, LayerId, LayerMetadata, ReadyState};
 use servo_msg::compositor_msg::{PaintListener, PaintState, ScriptListener, ScrollPolicy};
 use servo_msg::constellation_msg::{ConstellationChan, LoadData, PipelineId};
+use servo_msg::constellation_msg::{Key, KeyState, KeyModifiers, Pressed};
 use servo_util::memory::MemoryProfilerChan;
 use servo_util::time::TimeProfilerChan;
 use std::comm::{channel, Sender, Receiver};
@@ -85,6 +86,12 @@ impl ScriptListener for Box<CompositorProxy+'static+Send> {
     fn set_title(&mut self, pipeline_id: PipelineId, title: Option<String>) {
         self.send(ChangePageTitle(pipeline_id, title))
     }
+
+    fn send_key_event(&mut self, key: Key, state: KeyState, modifiers: KeyModifiers) {
+        if state == Pressed {
+            self.send(KeyEvent(key, modifiers));
+        }
+    }
 }
 
 /// Information about each layer that the compositor keeps.
@@ -204,6 +211,8 @@ pub enum Msg {
     /// Indicates that the scrolling timeout with the given starting timestamp has happened and a
     /// composite should happen. (See the `scrolling` module.)
     ScrollTimeout(u64),
+    /// Sends an unconsumed key event back to the compositor.
+    KeyEvent(Key, KeyModifiers),
 }
 
 impl Show for Msg {
@@ -226,6 +235,7 @@ impl Show for Msg {
             FrameTreeUpdateMsg(..) => write!(f, "FrameTreeUpdateMsg"),
             LoadComplete => write!(f, "LoadComplete"),
             ScrollTimeout(..) => write!(f, "ScrollTimeout"),
+            KeyEvent(..) => write!(f, "KeyEvent"),
         }
     }
 }

components/compositing/headless.rs

@@ -6,7 +6,7 @@ use compositor_task::{GetGraphicsMetadata, CreateOrUpdateRootLayer, CreateOrUpda
 use compositor_task::{Exit, ChangeReadyState, LoadComplete, Paint, ScrollFragmentPoint, SetIds};
 use compositor_task::{SetLayerOrigin, ShutdownComplete, ChangePaintState, PaintMsgDiscarded};
 use compositor_task::{CompositorEventListener, CompositorReceiver, ScrollTimeout, ChangePageTitle};
-use compositor_task::{ChangePageLoadData, FrameTreeUpdateMsg};
+use compositor_task::{ChangePageLoadData, FrameTreeUpdateMsg, KeyEvent};
 use windowing::WindowEvent;
 
 use geom::scale_factor::ScaleFactor;
@@ -106,7 +106,7 @@ impl CompositorEventListener for NullCompositor {
             SetLayerOrigin(..) | Paint(..) |
             ChangeReadyState(..) | ChangePaintState(..) | ScrollFragmentPoint(..) |
             LoadComplete | PaintMsgDiscarded(..) | ScrollTimeout(..) | ChangePageTitle(..) |
-            ChangePageLoadData(..) => ()
+            ChangePageLoadData(..) | KeyEvent(..) => ()
         }
         true
     }

components/compositing/windowing.rs

@@ -123,5 +123,7 @@ pub trait WindowMethods {
     /// some type of platform-specific graphics context current. Returns true if the composite may
     /// proceed and false if it should not.
     fn prepare_for_composite(&self) -> bool;
-}
 
+    /// Process a key event.
+    fn handle_key(&self, key: Key, mods: KeyModifiers);
+}