mus Window Server: implement event capture

components/mus/public/interfaces/window_tree.mojom

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module mus.mojom;
 
 import "components/mus/public/interfaces/compositor_frame.mojom";
 import "components/mus/public/interfaces/cursor.mojom";
 import "components/mus/public/interfaces/input_events.mojom";
 import "components/mus/public/interfaces/mus_constants.mojom";
@@ skipping 87 matching lines @@
   // TODO(sky): this likely needs context, maybe in |properties|.
   NewTopLevelWindow(uint32 change_id,
                     uint32 window_id,
                     map<string, array<uint8>> properties);
 
   // Deletes a window. This does not recurse. No hierarchy change notifications
   // are sent as a result of this. Only the connection that created the window
   // can delete it.
   DeleteWindow(uint32 change_id, uint32 window_id);
 
+  // Requests input event capture for the given |window_id|. Capture is only
+  // allowed if the window is processing an event. When a window gains capture,
+  // current input events are canceled. The given window will receive all
+  // subsequent input until an alternate window is set via SetCapture, or
+  // ReleaseCapture is called for |window_id|. OnLostCapture is called to notify
+  // of capture ending.
+  SetCapture(uint32 change_id, uint32 window_id);
+
+  // Releases input event capture for the given |window_id|.

[sky, 2016/02/08 16:57:11]

Document this does nothing if |window_id| does not currently have capture.

[jonross, 2016/02/10 15:57:56]

Done.

+  ReleaseCapture(uint32 change_id, uint32 window_id);
+
   // Sets the specified bounds of the specified window.
   SetWindowBounds(uint32 change_id, uint32 window_id, mojo.Rect bounds);
 
   // Sets the client area of the specified window. The client area is specified
   // by way of insets. Everything outside of the insets, and not in
   // |additional_client_areas| is considered non-client area.
   // TODO(sky): convert additional_client_areas to a path.
   SetClientArea(uint32 window_id,
                 mojo.Insets insets,
                 array<mojo.Rect>? additional_client_areas);
@@ skipping 140 matching lines @@
   // Invoked when the application embedded at |window| is disconnected. In other
   // words the embedded app closes the connection to the server. This is called
   // on the connection that created |window| as well as any ancestors that have
   // the embed root policy.
   OnEmbeddedAppDisconnected(uint32 window);
 
   // Sent when another connection is embedded in the Window this connection was
   // previously embedded in. See Embed() for more information.
   OnUnembed(uint32 window);
 
+  // Sent when a window loses capture.
+  OnLostCapture(uint32 window);
+
   // Called in response to NewTopLevelWindow() successfully completing.
   OnTopLevelCreated(uint32 change_id, WindowData data);
 
   // Invoked when a window's bounds have changed.
   OnWindowBoundsChanged(uint32 window,
                         mojo.Rect old_bounds,
                         mojo.Rect new_bounds);
 
   OnClientAreaChanged(uint32 window_id,
                       mojo.Insets new_client_area,
@@ skipping 73 matching lines @@
   // client allows the change it should delete the window.
   RequestClose(uint32 window_id);
 
   // See description of WindowManager for details.
   GetWindowManager(associated WindowManager& internal);
 };
 
 interface WindowTreeFactory {
   CreateWindowTree(WindowTree& tree_request, WindowTreeClient client);
 };