Take a screenshot in maximize mode when volume down and power are pressed.

ash/wm/maximize_mode/maximize_mode_controller.cc

 // Copyright 2014 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/maximize_mode/maximize_mode_controller.h"
 
+#include "ash/accelerators/accelerator_controller.h"
+#include "ash/accelerators/accelerator_table.h"
 #include "ash/accelerometer/accelerometer_controller.h"
 #include "ash/ash_switches.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
 #include "ash/wm/maximize_mode/maximize_mode_event_blocker.h"
 #include "base/command_line.h"
+#include "ui/base/accelerators/accelerator.h"
+#include "ui/events/event.h"
+#include "ui/events/event_handler.h"
+#include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/gfx/vector3d_f.h"
 
 namespace ash {
 
 namespace {
 
 // The hinge angle at which to enter maximize mode.
 const float kEnterMaximizeModeAngle = 200.0f;
 
 // The angle at which to exit maximize mode, this is specifically less than the
@@ skipping 51 matching lines @@
   gfx::Vector3dF cross(base);
   cross.Cross(other);
   // If the dot product of this cross product is normal, it means that the
   // shortest angle between |base| and |other| was counterclockwise with respect
   // to the surface represented by |normal| and this angle must be reversed.
   if (gfx::DotProduct(cross, normal) > 0.0f)
     angle = 360.0f - angle;
   return angle;
 }
 
+#if defined(OS_CHROMEOS)
+
+// An event handler which listens for a volume down + power keypress and
+// triggers a screenshot when this is seen.
+class ScreenshotActionHandler : public ui::EventHandler {
+ public:
+  ScreenshotActionHandler();
+  virtual ~ScreenshotActionHandler();
+
+  // ui::EventHandler:
+  virtual void OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
+
+ private:
+  bool volume_down_pressed_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScreenshotActionHandler);
+};
+
+ScreenshotActionHandler::ScreenshotActionHandler()
+    : volume_down_pressed_(false) {
+  Shell::GetInstance()->PrependPreTargetHandler(this);
+}
+
+ScreenshotActionHandler::~ScreenshotActionHandler() {
+  Shell::GetInstance()->RemovePreTargetHandler(this);
+}
+
+void ScreenshotActionHandler::OnKeyEvent(ui::KeyEvent* event) {
+  if (event->key_code() == ui::VKEY_VOLUME_DOWN) {
+    volume_down_pressed_ = event->type() == ui::ET_KEY_PRESSED ||
+                           event->type() == ui::ET_TRANSLATED_KEY_PRESS;
+  } else if (volume_down_pressed_ &&
+             event->key_code() == ui::VKEY_POWER &&
+             event->type() == ui::ET_KEY_PRESSED) {
+    Shell::GetInstance()->accelerator_controller()->PerformAction(
+        ash::TAKE_SCREENSHOT, ui::Accelerator());
+  }
+}
+
+#endif  // OS_CHROMEOS
+
 }  // namespace
 
 MaximizeModeController::MaximizeModeController()
     : rotation_locked_(false),
       have_seen_accelerometer_data_(false) {
   Shell::GetInstance()->accelerometer_controller()->AddObserver(this);
 }
 
 MaximizeModeController::~MaximizeModeController() {
   Shell::GetInstance()->accelerometer_controller()->RemoveObserver(this);
@@ skipping 57 matching lines @@
 
   // Toggle maximize mode on or off when corresponding thresholds are passed.
   // TODO(flackr): Make MaximizeModeController own the MaximizeModeWindowManager
   // such that observations of state changes occur after the change and shell
   // has fewer states to track.
   if (maximize_mode_engaged &&
       angle > kFullyOpenAngleErrorTolerance &&
       angle < kExitMaximizeModeAngle) {
     Shell::GetInstance()->EnableMaximizeModeWindowManager(false);
     event_blocker_.reset();
+    event_handler_.reset();
   } else if (!maximize_mode_engaged &&
       angle > kEnterMaximizeModeAngle) {
     Shell::GetInstance()->EnableMaximizeModeWindowManager(true);
     event_blocker_.reset(new MaximizeModeEventBlocker);
+#if defined(OS_CHROMEOS)
+    event_handler_.reset(new ScreenshotActionHandler);
+#endif
   }
 }
 
 void MaximizeModeController::HandleScreenRotation(const gfx::Vector3dF& lid) {
   bool maximize_mode_engaged =
       Shell::GetInstance()->IsMaximizeModeWindowManagerEnabled();
 
   DisplayManager* display_manager =
       Shell::GetInstance()->display_manager();
   gfx::Display::Rotation current_rotation = display_manager->GetDisplayInfo(
@@ skipping 67 matching lines @@
   // When exiting maximize mode return rotation to 0. When entering, rotate to
   // match screen orientation.
   if (new_rotation == gfx::Display::ROTATE_0 ||
       maximize_mode_engaged) {
     display_manager->SetDisplayRotation(gfx::Display::InternalDisplayId(),
                                         new_rotation);
   }
 }
 
 }  // namespace ash