ash/utility/partial_screenshot_controller.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef ASH_UTILITY_PARTIAL_SCREENSHOT_CONTROLLER_H_
   6 #define ASH_UTILITY_PARTIAL_SCREENSHOT_CONTROLLER_H_
   7
   8 #include <map>
   9
  10 #include "ash/ash_export.h"
  11 #include "ash/shell_observer.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "ui/events/event_handler.h"
  14 #include "ui/gfx/display_observer.h"
  15 #include "ui/gfx/point.h"
  16
  17 namespace aura {
  18 class Window;
  19 }
  20
  21 namespace ui {
  22 class LocatedEvent;
  23 }
  24
  25 namespace ash {
  26 class ScreenshotDelegate;
  27
  28 // This class controls a session of taking partial screenshot, i.e.: drawing
  29 // region rectangles during drag, and changing the mouse cursor to indicate
  30 // the current mode.
  31 // This class does not use aura::Window / views::Widget intentionally to avoid
  32 // the conflicts of window manager features like mouse captures or window focus.
  33 class ASH_EXPORT PartialScreenshotController : public ui::EventHandler,
  34                                                public ShellObserver,
  35                                                public gfx::DisplayObserver {
  36  public:
  37   // Starts the UI for taking partial screenshot; dragging to select a region.
  38   // PartialScreenshotController manage their own lifetime so caller must not
  39   // delete the returned values.
  40   static void StartPartialScreenshotSession(
  41       ScreenshotDelegate* screenshot_delegate);
  42
  43   ~PartialScreenshotController() override;
  44
  45  private:
  46   friend class PartialScreenshotControllerTest;
  47
  48   class ScopedCursorSetter;
  49   class PartialScreenshotLayer;
  50
  51   static PartialScreenshotController* GetInstanceForTest();
  52
  53   PartialScreenshotController(ScreenshotDelegate* screenshot_delegate);
  54
  55   // Starts, ends, cancels, or updates the region selection.
  56   void MaybeStart(const ui::LocatedEvent& event);
  57   void Complete();
  58   void Cancel();
  59   void Update(const ui::LocatedEvent& event);
  60
  61   // ui::EventHandler:
  62   void OnKeyEvent(ui::KeyEvent* event) override;
  63   void OnMouseEvent(ui::MouseEvent* event) override;
  64   void OnTouchEvent(ui::TouchEvent* event) override;
  65
  66   // ShellObserver:
  67   void OnAppTerminating() override;
  68
  69   // gfx::DisplayObserver:
  70   void OnDisplayAdded(const gfx::Display& new_display) override;
  71   void OnDisplayRemoved(const gfx::Display& old_display) override;
  72   void OnDisplayMetricsChanged(const gfx::Display& display,
  73                                uint32_t changed_metrics) override;
  74
  75   // The data to build the screenshot region.
  76   gfx::Point start_position_;
  77   aura::Window* root_window_;
  78
  79   // Layers to create the visual effect of region selection.
  80   std::map<aura::Window*, PartialScreenshotLayer*> layers_;
  81
  82   // The object to specify the crosshair cursor.
  83   scoped_ptr<ScopedCursorSetter> cursor_setter_;
  84
  85   // ScreenshotDelegate to take the actual screenshot. No ownership.
  86   ScreenshotDelegate* screenshot_delegate_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(PartialScreenshotController);
  89 };
  90
  91 }  // namespace ash
  92
  93 #endif  // #ifndef ASH_WM_PARTIAL_SCREENSHOT_VIEW_H_