mus: Introduce API for embedder to dispatch event to the embeded client.

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 "cc/ipc/surface_id.mojom";
 import "components/mus/public/interfaces/cursor.mojom";
 import "components/mus/public/interfaces/event_matcher.mojom";
 import "components/mus/public/interfaces/mus_constants.mojom";
 import "components/mus/public/interfaces/surface.mojom";
 import "components/mus/public/interfaces/window_manager.mojom";
 import "components/mus/public/interfaces/window_manager_constants.mojom";
 import "components/mus/public/interfaces/window_tree_constants.mojom";
 import "ui/events/mojo/event.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
 import "ui/platform_window/mojo/text_input_state.mojom";
 
+interface InputEventHandler {
+  OnInputEvent(uint32 window_id, ui.mojom.Event event) => (bool handled);
+};
+
 // Windows are identified by a uint32. The upper 16 bits are the connection id,
 // and the lower 16 the id assigned by the client.
 //
 // The root window is identified with a connection id of 0, and value of 1.
 //
 // Most functions to the WindowTree take a change_id parameter. When
 // WindowTree completes processing of a function WindowTree calls
 // WindowTreeClient::OnChangeCompleted() with the change_id supplied by the
 // client and the result of the function. This allows the client to track
 // whether the call succeeded or not. Calls are done via the client interface
@@ skipping 160 matching lines @@
   // Embed() for the same window result in the currently embedded
   // WindowTreeClient being removed. The embedded app is told this by way of
   // OnUnembed(), which is followed by OnWindowDeleted() (as the connection no
   // longer has access to the window).
   //
   // The embedder can detect when the embedded app disconnects by way of
   // OnEmbeddedAppDisconnected().
   //
   // The callback returns whether the embedding was successful.
   Embed(uint32 window_id, WindowTreeClient client, uint32 embed_flags)
-      => (bool success);
+      => (bool success, InputEventHandler? event_handler);
 
   // Sets focus to the specified window, use 0 to clear focus. For a window to
   // get focus the following has to happen: the window is drawn, the window has
   // been marked as focusable (see SetCanFocus()) and the window is in a
   // container the WindowManager has identified as allowing activation
   // (see WindowManagerClient::AddActivationParent()).
   SetFocus(uint32 change_id, uint32 window_id);
 
   // Marks the specified window as being able to receive focus.
   SetCanFocus(uint32 window_id, bool can_focus);
@@ skipping 145 matching lines @@
   // is 0. As with other functions this is only called if the client did not
   // initiate the change.
   OnWindowFocused(uint32 focused_window_id);
 
   OnWindowPredefinedCursorChanged(uint32 window_id, Cursor cursor_id);
 
   // A change initiated from the client has completed. See description of
   // change ids for details.
   OnChangeCompleted(uint32 change_id, bool success);
 
+  RequestInputEventHandler(InputEventHandler& handler);
+
   // The WindowManager is requesting the specified window to close. If the
   // client allows the change it should delete the window.
   RequestClose(uint32 window_id);
 
   // See description of WindowManager for details.
   GetWindowManager(associated WindowManager& internal);
 };
 
 // Mus provides this interface as a way for clients to connect and obtain a
 // WindowTree handle with a supplied WindowTreeClient handle. The
 // WindowTreeClient has no roots, use NewTopLevelWindow() to create one.
 interface WindowTreeFactory {
   CreateWindowTree(WindowTree& tree_request, WindowTreeClient client);
 };