overscroll_navigation_overlay.h revision 5d1f7b1de12d16ceb2c938c56701a3e8bfa558f7 
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 CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_NAVIGATION_OVERLAY_H_
6#define CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_NAVIGATION_OVERLAY_H_
7
8#include "base/gtest_prod_util.h"
9#include "base/macros.h"
10#include "content/browser/web_contents/aura/window_slider.h"
11#include "content/common/content_export.h"
12#include "content/public/browser/web_contents_observer.h"
13
14struct ViewHostMsg_UpdateRect_Params;
15
16namespace content {
17
18class ImageLayerDelegate;
19class ImageWindowDelegate;
20class OverscrollNavigationOverlayTest;
21
22// When a history navigation is triggered at the end of an overscroll
23// navigation, it is necessary to show the history-screenshot until the page is
24// done navigating and painting. This class accomplishes this by showing the
25// screenshot window on top of the page until the page has completed loading and
26// painting.
27class CONTENT_EXPORT OverscrollNavigationOverlay
28    : public WebContentsObserver,
29      public WindowSlider::Delegate {
30 public:
31  explicit OverscrollNavigationOverlay(WebContentsImpl* web_contents);
32  virtual ~OverscrollNavigationOverlay();
33
34  bool has_window() const { return !!window_.get(); }
35
36  // Starts observing |web_contents_| for page load/paint updates. This function
37  // makes sure that the screenshot window is stacked on top, so that it hides
38  // the content window behind it, and destroys the screenshot window when the
39  // page is done loading/painting.
40  void StartObserving();
41
42  // Sets the screenshot window and the delegate. This takes ownership of
43  // |window|.
44  // Note that ImageWindowDelegate manages its own lifetime, so this function
45  // does not take ownership of |delegate|.
46  void SetOverlayWindow(scoped_ptr<aura::Window> window,
47                        ImageWindowDelegate* delegate);
48
49  // Sets up the overlay for tests.
50  void SetupForTesting();
51
52 private:
53  friend class OverscrollNavigationOverlayTest;
54  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
55                           FirstVisuallyNonEmptyPaint_NoImage);
56  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
57                           FirstVisuallyNonEmptyPaint_WithImage);
58  FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
59                           PaintUpdateWithoutNonEmptyPaint);
60
61  enum SlideDirection {
62    SLIDE_UNKNOWN,
63    SLIDE_BACK,
64    SLIDE_FRONT
65  };
66
67  // Stop observing the page if the page-load has completed and the page has
68  // been painted, and a window-slide isn't in progress.
69  void StopObservingIfDone();
70
71  // Creates a layer to be used for window-slide. |offset| is the offset of the
72  // NavigationEntry for the screenshot image to display.
73  ui::Layer* CreateSlideLayer(int offset);
74
75  // IPC message callbacks.
76  void OnUpdateRect(const ViewHostMsg_UpdateRect_Params& params);
77
78  // Overridden from WindowSlider::Delegate:
79  virtual ui::Layer* CreateBackLayer() OVERRIDE;
80  virtual ui::Layer* CreateFrontLayer() OVERRIDE;
81  virtual void OnWindowSlideComplete() OVERRIDE;
82  virtual void OnWindowSlideAborted() OVERRIDE;
83  virtual void OnWindowSliderDestroyed() OVERRIDE;
84
85  // Overridden from WebContentsObserver:
86  virtual void DidFirstVisuallyNonEmptyPaint(int32 page_id) OVERRIDE;
87  virtual void DidStopLoading(RenderViewHost* host) OVERRIDE;
88  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
89
90  // The WebContents which is being navigated.
91  WebContentsImpl* web_contents_;
92
93  // The screenshot overlay window.
94  scoped_ptr<aura::Window> window_;
95
96  // This is the WindowDelegate of |window_|. The delegate manages its own
97  // lifetime (destroys itself when |window_| is destroyed).
98  ImageWindowDelegate* image_delegate_;
99
100  bool loading_complete_;
101  bool received_paint_update_;
102
103  // The |WindowSlider| that allows sliding history layers while the page is
104  // being reloaded.
105  scoped_ptr<WindowSlider> window_slider_;
106
107  // The direction of the in-progress slide (if any).
108  SlideDirection slide_direction_;
109
110  // The LayerDelegate used for the back/front layers during a slide.
111  scoped_ptr<ImageLayerDelegate> layer_delegate_;
112
113  // During tests, the aura windows don't get any paint updates. So the overlay
114  // container keeps waiting for a paint update it never receives, causing a
115  // timeout. So during tests, disable the wait for paint updates.
116  bool need_paint_update_;
117
118  DISALLOW_COPY_AND_ASSIGN(OverscrollNavigationOverlay);
119};
120
121}  // namespace content
122
123#endif  // CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_NAVIGATION_OVERLAY_H_
124