Tablet-like power button behavior on Convertible/Tablet ChromeOS devices

ash/wm/power_button_controller.cc

Index: ash/wm/power_button_controller.cc
diff --git a/ash/wm/power_button_controller.cc b/ash/wm/power_button_controller.cc
index 92ca9c12aabcd64eeb6996e10f6ab273b57e803c..1aa363ca748e30b5a78d6c8c5ace622972f1b013 100644
--- a/ash/wm/power_button_controller.cc
+++ b/ash/wm/power_button_controller.cc
@@ -18,10 +18,10 @@
 #include "base/command_line.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/display/types/display_snapshot.h"
-#include "ui/events/event_handler.h"

[Qiang(Joe) Xu, 2016/11/04 23:18:21]

it is included in head file.

 #include "ui/wm/core/compound_event_filter.h"
 
 #if defined(OS_CHROMEOS)
+#include "ash/wm/tablet_power_button_controller.h"
 #include "chromeos/audio/cras_audio_handler.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #endif
@@ -50,6 +50,7 @@ PowerButtonController::PowerButtonController(LockStateController* controller)
 #if defined(OS_CHROMEOS)
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(
       this);
+  tablet_controller_.reset(new TabletPowerButtonController(controller_));
   Shell::GetInstance()->display_configurator()->AddObserver(this);
 #endif
   Shell::GetInstance()->PrependPreTargetHandler(this);
@@ -59,6 +60,7 @@ PowerButtonController::~PowerButtonController() {
   Shell::GetInstance()->RemovePreTargetHandler(this);
 #if defined(OS_CHROMEOS)
   Shell::GetInstance()->display_configurator()->RemoveObserver(this);
+  tablet_controller_.reset();
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(
       this);
 #endif
@@ -76,16 +78,27 @@ void PowerButtonController::OnPowerButtonEvent(
   if (controller_->ShutdownRequested())
     return;
 
+  bool should_take_screenshot = down && volume_down_pressed_ &&
+                                WmShell::Get()
+                                    ->maximize_mode_controller()
+                                    ->IsMaximizeModeWindowManagerEnabled();

[Qiang(Joe) Xu, 2016/11/04 23:18:21]

Shall we make IsTabletModeActive and IsTabletModeSupported methods belong to
PowerButtonController?

They can be static method so that TabletPowerButtonController can also call
them.

+
+#if defined(OS_CHROMEOS)
+  if (!has_legacy_power_button_ && !should_take_screenshot &&
+      tablet_controller_->ShouldHandlePowerButtonEvents()) {
+    tablet_controller_->OnPowerButtonEvent(down, timestamp,
+                                           brightness_is_zero_);
+    return;
+  }
+#endif
+
   // 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()) {
+  if (should_take_screenshot) {
     SystemTray* system_tray = Shell::GetInstance()->GetPrimarySystemTray();
     if (system_tray && system_tray->GetTrayAudio())
       system_tray->GetTrayAudio()->HideDetailedView(false);