Fix Volume slider is captured in screenshot done in touchview mode

ash/wm/power_button_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/wm/power_button_controller.h"
 
 #include "ash/common/accelerators/accelerator_controller.h"
 #include "ash/common/ash_switches.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shell_window_ids.h"
+#include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "ash/wm/lock_state_controller.h"
 #include "ash/wm/session_state_animator.h"
 #include "base/command_line.h"
+#include "base/task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/display/types/display_snapshot.h"
 #include "ui/events/event_handler.h"
 #include "ui/wm/core/compound_event_filter.h"
 
 #if defined(OS_CHROMEOS)
+#include "chromeos/audio/cras_audio_handler.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #endif
 
 namespace ash {
 
+namespace {
+const int kWaitVolumeSliderHiddenInMs = 200;
+}  // namespace
+
 PowerButtonController::PowerButtonController(LockStateController* controller)
     : power_button_down_(false),
       lock_button_down_(false),
       volume_down_pressed_(false),
+      first_pressed_volume_percent_(0),
+      volume_down_first_(false),
       brightness_is_zero_(false),
       internal_display_off_and_external_display_on_(false),
       has_legacy_power_button_(
           base::CommandLine::ForCurrentProcess()->HasSwitch(
               switches::kAuraLegacyPowerButton)),
 #if defined(OS_CHROMEOS)
       enable_quick_lock_(base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kAshEnableTouchView)),
 #else
       enable_quick_lock_(false),
@@ skipping 31 matching lines @@
   // Avoid starting the lock/shutdown sequence if the power button is pressed
   // while the screen is off (http://crbug.com/128451), unless an external
   // display is still on (http://crosbug.com/p/24912).
   if (brightness_is_zero_ && !internal_display_off_and_external_display_on_)
     return;
 
   if (volume_down_pressed_ && down &&
       WmShell::Get()
           ->maximize_mode_controller()
           ->IsMaximizeModeWindowManagerEnabled()) {
-    WmShell::Get()->accelerator_controller()->PerformActionIfEnabled(
-        TAKE_SCREENSHOT);
+    WmShell::Get()->system_tray_notifier()->NotifyWillTakeScreenshot(
+        first_pressed_volume_percent_);
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+        FROM_HERE, base::Bind(&PowerButtonController::TakingScreenshot,
+                              base::Unretained(this)),
+        base::TimeDelta::FromMilliseconds(kWaitVolumeSliderHiddenInMs));
     return;
   }
 
   const SessionStateDelegate* session_state_delegate =
       WmShell::Get()->GetSessionStateDelegate();
   if (has_legacy_power_button_) {
     // If power button releases won't get reported correctly because we're not
     // running on official hardware, just lock the screen or shut down
     // immediately.
     if (down) {
@@ skipping 49 matching lines @@
   if (power_button_down_)
     return;
 
   if (down)
     controller_->StartLockAnimation(false);
   else
     controller_->CancelLockAnimation();
 }
 
 void PowerButtonController::OnKeyEvent(ui::KeyEvent* event) {
-  if (event->key_code() == ui::VKEY_VOLUME_DOWN)
+  if (event->key_code() == ui::VKEY_VOLUME_DOWN) {
     volume_down_pressed_ = event->type() == ui::ET_KEY_PRESSED;
+#if defined(OS_CHROMEOS)
+    if (event->type() == ui::ET_KEY_RELEASED) {
+      volume_down_first_ = false;
+      return;
+    }
+    // We should avoid saving volume to |first_pressed_volume_percent_| if that
+    // is continuous press.
+    if (!volume_down_first_) {

[Daniel Erat, 2016/07/27 23:51:31]

can't you use event->is_repeat() to determine if this is a repeated event?

[Qiang(Joe) Xu, 2016/07/28 00:15:39]

Yes. Just find it. I will update it later.

+      chromeos::CrasAudioHandler* audio_handler =
+          chromeos::CrasAudioHandler::Get();
+      DCHECK(audio_handler->IsInitialized());
+      first_pressed_volume_percent_ = audio_handler->GetOutputVolumePercent();
+      volume_down_first_ = true;
+    }
+#endif
+  }
 }
 
 #if defined(OS_CHROMEOS)
 void PowerButtonController::OnDisplayModeChanged(
     const ui::DisplayConfigurator::DisplayStateList& display_states) {
   bool internal_display_off = false;
   bool external_display_on = false;
   for (const ui::DisplaySnapshot* display : display_states) {
     if (display->type() == ui::DISPLAY_CONNECTION_TYPE_INTERNAL) {
       if (!display->current_mode())
         internal_display_off = true;
     } else if (display->current_mode()) {
       external_display_on = true;
     }
   }
   internal_display_off_and_external_display_on_ =
       internal_display_off && external_display_on;
 }
 
 void PowerButtonController::PowerButtonEventReceived(
     bool down,
     const base::TimeTicks& timestamp) {
   OnPowerButtonEvent(down, timestamp);
 }
 #endif  // defined(OS_CHROMEOS)
 
+void PowerButtonController::TakingScreenshot() {
+  WmShell::Get()->accelerator_controller()->PerformActionIfEnabled(
+      TAKE_SCREENSHOT);
+}
+
 }  // namespace ash