content/browser/web_contents/aura/overscroll_window_delegate.h

   1 // Copyright 2015 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 CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_DELEGATE_H_
   6 #define CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_DELEGATE_H_
   7
   8 #include "content/browser/renderer_host/overscroll_controller.h"
   9 #include "content/browser/web_contents/aura/overscroll_navigation_overlay.h"
  10 #include "content/browser/web_contents/web_contents_impl.h"
  11 #include "ui/aura_extra/image_window_delegate.h"
  12
  13 namespace content {
  14
  15 // The window delegate for the overscroll window. This processes UI trackpad and
  16 // touch events and converts them to overscroll event. The delegate destroys
  17 // itself when the window is destroyed.
  18 class CONTENT_EXPORT OverscrollWindowDelegate
  19     : public aura_extra::ImageWindowDelegate {
  20  public:
  21   OverscrollWindowDelegate(OverscrollControllerDelegate* delegate,
  22                            const gfx::Image& image);
  23
  24  private:
  25   FRIEND_TEST_ALL_PREFIXES(OverscrollWindowDelegateTest, BasicOverscrollModes);
  26
  27   ~OverscrollWindowDelegate() override;
  28
  29   // Starts the overscroll gesture.
  30   void StartOverscroll();
  31
  32   // Resets the overscroll state.
  33   void ResetOverscroll();
  34
  35   // Completes or resets the overscroll from the current state.
  36   void CompleteOrResetOverscroll();
  37
  38   // Updates the current horizontal overscroll.
  39   void UpdateOverscroll(float delta_x);
  40
  41   // Overridden from ui::EventHandler.
  42   void OnKeyEvent(ui::KeyEvent* event) override;
  43   void OnMouseEvent(ui::MouseEvent* event) override;
  44   void OnScrollEvent(ui::ScrollEvent* event) override;
  45   void OnGestureEvent(ui::GestureEvent* event) override;
  46
  47   // Delegate to which we forward overscroll events.
  48   OverscrollControllerDelegate* delegate_;
  49
  50   // The current overscroll mode.
  51   OverscrollMode overscroll_mode_;
  52
  53   // The latest delta_x scroll update.
  54   float delta_x_;
  55
  56   // The ratio of overscroll at which we consider the overscroll completed.
  57   const float complete_threshold_ratio_;
  58
  59   // The threshold for starting the overscroll gesture, for touchscreen or
  60   // touchpads.
  61   const float start_threshold_touchscreen_;
  62   const float start_threshold_touchpad_;
  63
  64   // The threshold for starting the overscroll gesture for the current touch
  65   // input.
  66   float active_start_threshold_;
  67
  68   DISALLOW_COPY_AND_ASSIGN(OverscrollWindowDelegate);
  69 };
  70
  71 }  // namespace content
  72
  73 #endif  // CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_WINDOW_DELEGATE_H_