content/browser/web_contents/aura/overscroll_navigation_overlay.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 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
  14 struct ViewHostMsg_UpdateRect_Params;
  15
  16 namespace content {
  17
  18 class ImageLayerDelegate;
  19 class ImageWindowDelegate;
  20 class 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.
  27 class 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   // Resets state and starts observing |web_contents_| for page load/paint
  37   // updates. This function makes sure that the screenshot window is stacked
  38   // on top, so that it hides the content window behind it, and destroys the
  39   // screenshot window when the page is done loading/painting.
  40   // This should be called immediately after initiating the navigation,
  41   // otherwise the overlay may be dismissed prematurely.
  42   void StartObserving();
  43
  44   // Sets the screenshot window and the delegate. This takes ownership of
  45   // |window|.
  46   // Note that ImageWindowDelegate manages its own lifetime, so this function
  47   // does not take ownership of |delegate|.
  48   void SetOverlayWindow(scoped_ptr<aura::Window> window,
  49                         ImageWindowDelegate* delegate);
  50
  51  private:
  52   friend class OverscrollNavigationOverlayTest;
  53   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  54                            FirstVisuallyNonEmptyPaint_NoImage);
  55   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  56                            FirstVisuallyNonEmptyPaint_WithImage);
  57   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  58                            LoadUpdateWithoutNonEmptyPaint);
  59   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  60                            MultiNavigation_LoadingUpdate);
  61   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  62                            MultiNavigation_PaintUpdate);
  63
  64   enum SlideDirection {
  65     SLIDE_UNKNOWN,
  66     SLIDE_BACK,
  67     SLIDE_FRONT
  68   };
  69
  70   // Stop observing the page and start the final overlay fade-out animation if
  71   // a window-slide isn't in progress and either the page has been painted or
  72   // the page-load has completed.
  73   void StopObservingIfDone();
  74
  75   // Creates a layer to be used for window-slide. |offset| is the offset of the
  76   // NavigationEntry for the screenshot image to display.
  77   ui::Layer* CreateSlideLayer(int offset);
  78
  79   // Overridden from WindowSlider::Delegate:
  80   virtual ui::Layer* CreateBackLayer() override;
  81   virtual ui::Layer* CreateFrontLayer() override;
  82   virtual void OnWindowSlideCompleting() override;
  83   virtual void OnWindowSlideCompleted(scoped_ptr<ui::Layer> layer) override;
  84   virtual void OnWindowSlideAborted() override;
  85   virtual void OnWindowSliderDestroyed() override;
  86
  87   // Overridden from WebContentsObserver:
  88   virtual void DidFirstVisuallyNonEmptyPaint() override;
  89   virtual void DidStopLoading(RenderViewHost* host) override;
  90
  91   // The WebContents which is being navigated.
  92   WebContentsImpl* web_contents_;
  93
  94   // The screenshot overlay window.
  95   scoped_ptr<aura::Window> window_;
  96
  97   // This is the WindowDelegate of |window_|. The delegate manages its own
  98   // lifetime (destroys itself when |window_| is destroyed).
  99   ImageWindowDelegate* image_delegate_;
 100
 101   bool loading_complete_;
 102   bool received_paint_update_;
 103
 104   // URL of the NavigationEntry we are navigating to. This is needed to
 105   // filter on WebContentsObserver callbacks and is used to dismiss the overlay
 106   // when the relevant page loads and paints.
 107   GURL pending_entry_url_;
 108
 109   // The |WindowSlider| that allows sliding history layers while the page is
 110   // being reloaded.
 111   scoped_ptr<WindowSlider> window_slider_;
 112
 113   // Layer to be used for the final overlay fadeout animation when the overlay
 114   // is being dismissed.
 115   scoped_ptr<ui::Layer> overlay_dismiss_layer_;
 116
 117   // The direction of the in-progress slide (if any).
 118   SlideDirection slide_direction_;
 119
 120   // The LayerDelegate used for the back/front layers during a slide.
 121   scoped_ptr<ImageLayerDelegate> layer_delegate_;
 122
 123   DISALLOW_COPY_AND_ASSIGN(OverscrollNavigationOverlay);
 124 };
 125
 126 }  // namespace content
 127
 128 #endif  // CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_NAVIGATION_OVERLAY_H_