Refuse to show Alt+Tab UI concurrently with virtual keyboard.

ash/common/accelerators/accelerator_controller.cc

 // Copyright (c) 2012 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 "ash/common/accelerators/accelerator_controller.h"
 
 #include "ash/common/accelerators/accelerator_commands.h"
 #include "ash/common/accelerators/accelerator_controller_delegate.h"
 #include "ash/common/accelerators/debug_commands.h"
 #include "ash/common/accessibility_delegate.h"
@@ skipping 15 matching lines @@
 #include "ash/common/wm/window_cycle_controller.h"
 #include "ash/common/wm/window_positioning_utils.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm/wm_event.h"
 #include "ash/common/wm_shell.h"
 #include "ash/common/wm_window.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "ui/base/accelerators/accelerator.h"
 #include "ui/base/accelerators/accelerator_manager.h"
+#include "ui/keyboard/keyboard_controller.h"
 
 #if defined(OS_CHROMEOS)
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/power_manager_client.h"
 #include "ui/base/ime/chromeos/ime_keyboard.h"
 #include "ui/base/ime/chromeos/input_method_manager.h"
 #endif  // defined(OS_CHROMEOS)
 
 namespace ash {
 namespace {
@@ skipping 77 matching lines @@
 
 void HandleNewWindow() {
   base::RecordAction(UserMetricsAction("Accel_New_Window"));
   WmShell::Get()->new_window_delegate()->NewWindow(false /* is_incognito */);
 }
 
 bool CanHandleNextIme(ImeControlDelegate* ime_control_delegate) {
   return ime_control_delegate && ime_control_delegate->CanCycleIme();
 }
 
+bool CanHandleCycleMru(const ui::Accelerator& accelerator) {
+  // Don't do anything when Alt+Tab comes from a virtual keyboard. Touchscreen
+  // users have better window switching options. See http://crbug.com/638269
+  keyboard::KeyboardController* keyboard_controller =
+      keyboard::KeyboardController::GetInstance();
+  return !(keyboard_controller && keyboard_controller->keyboard_visible() &&
+           (accelerator.modifiers() & ui::EF_IS_SYNTHESIZED));

[sadrul, 2016/08/24 14:22:19]

Are you sure you need to look at whether the keyboard is visible? Just the
SYNTHESIZED flag should be sufficient, I think?

[Evan Stade, 2016/08/26 14:17:55]

Since I don't really know all the things that could make an event "synthesized"
this seems less likely to cause issues.

[bshe, 2016/08/26 15:01:33]

Sorry, I am not sure about other cases either. But adding a visibility check
doesn't look like harmful.

+}
+
 // We must avoid showing the Deprecated NEXT_IME notification erronously.
 bool ShouldShowDeprecatedNextImeNotification(
     const ui::Accelerator& previous_accelerator) {
   // We only show the deprecation notification if the previous accelerator key
   // is ONLY either Shift, or Alt.
   const ui::KeyboardCode previous_key_code = previous_accelerator.key_code();
   switch (previous_key_code) {
     case ui::VKEY_SHIFT:
     case ui::VKEY_LSHIFT:
     case ui::VKEY_RSHIFT:
@@ skipping 497 matching lines @@
   if (restriction != RESTRICTION_NONE)
     return restriction == RESTRICTION_PREVENT_PROCESSING_AND_PROPAGATION;
 
   const ui::Accelerator& previous_accelerator =
       accelerator_history_->previous_accelerator();
 
   // True should be returned if running |action| does something. Otherwise,
   // false should be returned to give the web contents a chance at handling the
   // accelerator.
   switch (action) {
+    case CYCLE_BACKWARD_MRU:
+    case CYCLE_FORWARD_MRU:
+      return CanHandleCycleMru(accelerator);
     case DEBUG_PRINT_LAYER_HIERARCHY:
     case DEBUG_PRINT_VIEW_HIERARCHY:
     case DEBUG_PRINT_WINDOW_HIERARCHY:
       return debug::DebugAcceleratorsEnabled();
     case NEW_INCOGNITO_WINDOW:
       return CanHandleNewIncognitoWindow();
     case NEXT_IME:
       return CanHandleNextIme(ime_control_delegate_.get());
     case PREVIOUS_IME:
       return CanHandlePreviousIme(ime_control_delegate_.get());
@@ skipping 15 matching lines @@
     case DISABLE_CAPS_LOCK:
       return CanHandleDisableCapsLock(previous_accelerator);
     case LOCK_SCREEN:
       return CanHandleLock();
     case SWITCH_TO_PREVIOUS_USER:
     case SWITCH_TO_NEXT_USER:
       return CanHandleCycleUser();
     case TOGGLE_CAPS_LOCK:
       return CanHandleToggleCapsLock(accelerator, previous_accelerator);
 #endif
-    case CYCLE_BACKWARD_MRU:
-    case CYCLE_FORWARD_MRU:
     case EXIT:
     case FOCUS_NEXT_PANE:
     case FOCUS_PREVIOUS_PANE:
     case MEDIA_NEXT_TRACK:
     case MEDIA_PLAY_PAUSE:
     case MEDIA_PREV_TRACK:
     case NEW_TAB:
     case NEW_WINDOW:
     case OPEN_FEEDBACK_PAGE:
     case PRINT_UI_HIERARCHIES:
@@ skipping 220 matching lines @@
 }
 
 bool AcceleratorController::ShouldActionConsumeKeyEvent(
     AcceleratorAction action) {
   // Adding new exceptions is *STRONGLY* discouraged.
   return true;
 }
 
 AcceleratorController::AcceleratorProcessingRestriction
 AcceleratorController::GetAcceleratorProcessingRestriction(int action) {
-  if (WmShell::Get()->IsPinned() &&
+  WmShell* wm_shell = WmShell::Get();
+  if (wm_shell->IsPinned() &&
       actions_allowed_in_pinned_mode_.find(action) ==
           actions_allowed_in_pinned_mode_.end()) {
     return RESTRICTION_PREVENT_PROCESSING_AND_PROPAGATION;
   }
-  WmShell* wm_shell = WmShell::Get();
   if (!wm_shell->GetSessionStateDelegate()->IsActiveUserSessionStarted() &&
       actions_allowed_at_login_screen_.find(action) ==
           actions_allowed_at_login_screen_.end()) {
     return RESTRICTION_PREVENT_PROCESSING;
   }
   if (wm_shell->GetSessionStateDelegate()->IsScreenLocked() &&
       actions_allowed_at_lock_screen_.find(action) ==
           actions_allowed_at_lock_screen_.end()) {
     return RESTRICTION_PREVENT_PROCESSING;
   }
@@ skipping 14 matching lines @@
   if (wm_shell->mru_window_tracker()->BuildMruWindowList().empty() &&
       actions_needing_window_.find(action) != actions_needing_window_.end()) {
     wm_shell->accessibility_delegate()->TriggerAccessibilityAlert(
         A11Y_ALERT_WINDOW_NEEDED);
     return RESTRICTION_PREVENT_PROCESSING_AND_PROPAGATION;
   }
   return RESTRICTION_NONE;
 }
 
 }  // namespace ash