Wires up registering accelerators from mash with the wm

ash/mus/accelerators/accelerator_controller_registrar.h

+// Copyright 2016 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.
+
+#ifndef ASH_MUS_ACCELERATORS_ACCELERATOR_CONTROLLER_REGISTRAR_H_
+#define ASH_MUS_ACCELERATORS_ACCELERATOR_CONTROLLER_REGISTRAR_H_
+
+#include <stdint.h>
+
+#include <map>
+
+#include "ash/mus/accelerators/accelerator_handler.h"
+#include "base/macros.h"
+#include "ui/base/accelerators/accelerator.h"
+#include "ui/base/accelerators/accelerator_manager_delegate.h"
+#include "ui/events/mojo/event_constants.mojom.h"
+
+namespace ash {
+
+class AcceleratorRouter;
+
+namespace mus {
+
+class WindowManager;
+
+// Responsible for registering accelerators created by AcceleratorController
+// with the WindowManager, as well as routing handling of accelerators to
+// the right place.
+class AcceleratorControllerRegistrar : public AcceleratorHandler,
+                                       public ui::AcceleratorManagerDelegate {
+ public:
+  AcceleratorControllerRegistrar(WindowManager* window_manager,
+                                 uint16_t id_namespace);
+  ~AcceleratorControllerRegistrar() override;
+
+  // AcceleratorHandler:
+  ui::mojom::EventResult OnAccelerator(uint32_t id,
+                                       const ui::Event& event) override;
+
+  // ui::AcceleratorManagerDelegate:
+  void OnAcceleratorRegistered(const ui::Accelerator& accelerator) override;
+  void OnAcceleratorUnregistered(const ui::Accelerator& accelerator) override;
+
+ private:
+  // The flow of accelerators in ash is:
+  // . wm::AcceleratorFilter() sees events first as it's a pre-target handler.
+  // . AcceleratorFilter forwards to its delegate, which indirectly is
+  //   implemented by AcceleratorRouter.
+  // . AcceleratorRouter may early out, if not it calls through to
+  //   AcceleratorController. This stop may stop propagation entirely.
+  // . If focus is on a Widget, then NativeWidgetAura gets the key event, calls
+  //   to Widget::OnKeyEvent(), which calls to FocusManager::OnKeyEvent(), which
+  //   calls to AshFocusManagerFactory::Delegate::ProcessAccelerator() finally
+  //   ending up in AcceleratorController::Process().
+  // . OTOH if focus is on a content, then
+  //   RenderWidgetHostViewAura::OnKeyEvent() is called and may end up consuming
+  //   the event.
+  //
+  // To get this behavior for mash we register accelerators for both pre and
+  // post. Pre gives the behavior of AcceleratorRouter and post that of
+  // AshFocusManagerFactory.

[sadrul, 2016/07/27 17:20:00]

This seems a bit unfortunate :(

We may be able to avoid installing post- accelerators for some of these. e.g.
looks like we always process accelerators with cmd-down in the pre-target phase,
and a number of 'reserved' accelerators. We probably don't need to install
post-accelerators for these.

[sky, 2016/07/27 17:39:03]

Once we make it so that all are registered in a single IPC there likely isn't
much value in the optimization.

+  //
+  // These ids all use the namespace |id_namespace_|.
+  struct Ids {
+    uint16_t pre_id;
+    uint16_t post_id;
+  };
+
+  // Returns the next local id for an accelerator, or false if the max number of
+  // accelerators have been registered.
+  bool GenerateIds(Ids* ids);
+
+  // Used internally by GenerateIds(). Returns the next local id (as well as
+  // updating |ids_|). This *must* be called from GenerateIds().
+  uint16_t GetNextLocalAcceleratorId();
+
+  WindowManager* window_manager_;
+
+  const uint16_t id_namespace_;
+
+  // Id to use for the next accelerator.
+  uint16_t next_id_;
+
+  std::unique_ptr<AcceleratorRouter> router_;
+
+  // Set of registered local ids.
+  std::set<uint16_t> ids_;
+
+  // Maps from accelerator to the two ids registered for it.
+  std::map<ui::Accelerator, Ids> accelerator_to_ids_;
+
+  DISALLOW_COPY_AND_ASSIGN(AcceleratorControllerRegistrar);
+};
+
+}  // namespace mus
+}  // namespace ash
+
+#endif  // ASH_MUS_ACCELERATORS_ACCELERATOR_CONTROLLER_REGISTRAR_H_