Enable keyboard accelerators while a menu is open

ui/views/controls/menu/menu_event_handler.cc

Index: ui/views/controls/menu/menu_event_handler.cc
diff --git a/ui/views/controls/menu/menu_event_handler.cc b/ui/views/controls/menu/menu_event_handler.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f4200d7b6d11435269f5f59f5a6c5643ad2cfead
--- /dev/null
+++ b/ui/views/controls/menu/menu_event_handler.cc
@@ -0,0 +1,80 @@
+// Copyright 2015 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.
+
+#include "ui/views/controls/menu/menu_event_handler.h"
+
+#include "ui/aura/env.h"
+#include "ui/events/keycodes/keyboard_code_conversion.h"
+#include "ui/views/controls/menu/menu_controller.h"
+#include "ui/views/views_delegate.h"
+
+namespace views {
+
+namespace {
+
+const int kKeyFlagsMask = ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN;
+
+}  // namespace
+
+MenuEventHandler::MenuEventHandler() {
+  aura::Env::GetInstanceDontCreate()->PrependPreTargetHandler(this);
+}
+
+MenuEventHandler::~MenuEventHandler() {
+  aura::Env::GetInstanceDontCreate()->RemovePreTargetHandler(this);
+}
+
+void MenuEventHandler::OnKeyEvent(ui::KeyEvent* event) {
+  MenuController* menu_controller = MenuController::GetActiveInstance();
+  if (!menu_controller)

[sky, 2015/09/09 00:01:59]

Can this really happen?
DCHECK?

[afakhry, 2015/09/09 02:31:34]

DCHECK()ed

+    return;
+
+  if (menu_controller->exit_type() == MenuController::EXIT_ALL ||
+      menu_controller->exit_type() == MenuController::EXIT_DESTROYED) {
+    // If the event has arrived after the menu's exit type had changed but
+    // before its message loop terminated, the event will continue its normal
+    // propagation for the following reason:
+    // If the user accepts a menu item in a nested menu, the menu item action is
+    // run after the base::RunLoop for the innermost menu has quit but before
+    // the base::RunLoop for the outermost menu has quit. If the menu item
+    // action starts a base::RunLoop, the outermost menu's base::RunLoop will
+    // not quit till the action's base::RunLoop ends. IDC_BOOKMARK_BAR_OPEN_ALL
+    // sometimes opens a modal dialog. The modal dialog starts a base::RunLoop
+    // and keeps the base::RunLoop running for the duration of its lifetime.
+    menu_controller->TerminateNestedMessageLoop();
+    return;
+  } else {
+    if (event->type() == ui::ET_KEY_PRESSED) {
+      menu_controller->OnKeyDown(event->key_code());
+
+      // Below we'll handle the mnemonics only if neither Alt nor Ctrl is
+      // pressed.
+      const int flags = event->flags();
+      if (menu_controller->exit_type() == MenuController::EXIT_NONE &&
+          (flags & kKeyFlagsMask) == 0) {

[oshima, 2015/09/08 23:51:59]

You can look into this in a follow up CL, but I think this probably should check
against IsSystemKeyModifier & CONTROL_DOWN ?

+        char c = ui::DomCodeToUsLayoutCharacter(event->code(), flags);
+        menu_controller->SelectByChar(c);
+      }
+    }
+  }
+
+  ViewsDelegate::GetInstance()->HandleKeyEventOnMenu(event);
+
+  if (menu_controller->exit_type() != MenuController::EXIT_NONE)
+    menu_controller->TerminateNestedMessageLoop();
+
+  event->StopPropagation();
+}
+
+void MenuEventHandler::OnTouchEvent(ui::TouchEvent* event) {
+  if (event->type() == ui::ET_TOUCH_RELEASED ||
+      event->type() == ui::ET_TOUCH_CANCELLED) {
+    // Don't allow the event copy to clear the native touch id
+    // mapping, or we'll lose the mapping before the initial event
+    // has finished being dispatched.
+    event->set_should_remove_native_touch_id_mapping(false);
+  }
+}
+
+}  // namespace views