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 aura_extra {
  17 class ImageWindowDelegate;
  18 }
  19
  20 namespace content {
  21
  22 class ImageLayerDelegate;
  23 class OverscrollNavigationOverlayTest;
  24
  25 // When a history navigation is triggered at the end of an overscroll
  26 // navigation, it is necessary to show the history-screenshot until the page is
  27 // done navigating and painting. This class accomplishes this by showing the
  28 // screenshot window on top of the page until the page has completed loading and
  29 // painting.
  30 class CONTENT_EXPORT OverscrollNavigationOverlay
  31     : public WebContentsObserver,
  32       public WindowSlider::Delegate {
  33  public:
  34   explicit OverscrollNavigationOverlay(WebContentsImpl* web_contents);
  35   ~OverscrollNavigationOverlay() override;
  36
  37   bool has_window() const { return !!window_.get(); }
  38
  39   // Resets state and starts observing |web_contents_| for page load/paint
  40   // updates. This function makes sure that the screenshot window is stacked
  41   // on top, so that it hides the content window behind it, and destroys the
  42   // screenshot window when the page is done loading/painting.
  43   // This should be called immediately after initiating the navigation,
  44   // otherwise the overlay may be dismissed prematurely.
  45   void StartObserving();
  46
  47   // Sets the screenshot window and the delegate. This takes ownership of
  48   // |window|.
  49   // Note that aura_extra::ImageWindowDelegate manages its own lifetime, so this
  50   // function does not take ownership of |delegate|.
  51   void SetOverlayWindow(scoped_ptr<aura::Window> window,
  52                         aura_extra::ImageWindowDelegate* delegate);
  53
  54  private:
  55   friend class OverscrollNavigationOverlayTest;
  56   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  57                            FirstVisuallyNonEmptyPaint_NoImage);
  58   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  59                            FirstVisuallyNonEmptyPaint_WithImage);
  60   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  61                            LoadUpdateWithoutNonEmptyPaint);
  62   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  63                            MultiNavigation_LoadingUpdate);
  64   FRIEND_TEST_ALL_PREFIXES(OverscrollNavigationOverlayTest,
  65                            MultiNavigation_PaintUpdate);
  66
  67   enum SlideDirection {
  68     SLIDE_UNKNOWN,
  69     SLIDE_BACK,
  70     SLIDE_FRONT
  71   };
  72
  73   // Stop observing the page and start the final overlay fade-out animation if
  74   // a window-slide isn't in progress and either the page has been painted or
  75   // the page-load has completed.
  76   void StopObservingIfDone();
  77
  78   // Creates a layer to be used for window-slide. |offset| is the offset of the
  79   // NavigationEntry for the screenshot image to display.
  80   ui::Layer* CreateSlideLayer(int offset);
  81
  82   // Overridden from WindowSlider::Delegate:
  83   ui::Layer* CreateBackLayer() override;
  84   ui::Layer* CreateFrontLayer() override;
  85   void OnWindowSlideCompleting() override;
  86   void OnWindowSlideCompleted(scoped_ptr<ui::Layer> layer) override;
  87   void OnWindowSlideAborted() override;
  88   void OnWindowSliderDestroyed() override;
  89
  90   // Overridden from WebContentsObserver:
  91   void DidFirstVisuallyNonEmptyPaint() override;
  92   void DidStopLoading() override;
  93
  94   // The WebContents which is being navigated.
  95   WebContentsImpl* web_contents_;
  96
  97   // The screenshot overlay window.
  98   scoped_ptr<aura::Window> window_;
  99
 100   // This is the WindowDelegate of |window_|. The delegate manages its own
 101   // lifetime (destroys itself when |window_| is destroyed).
 102   aura_extra::ImageWindowDelegate* image_delegate_;
 103
 104   bool loading_complete_;
 105   bool received_paint_update_;
 106
 107   // URL of the NavigationEntry we are navigating to. This is needed to
 108   // filter on WebContentsObserver callbacks and is used to dismiss the overlay
 109   // when the relevant page loads and paints.
 110   GURL pending_entry_url_;
 111
 112   // The |WindowSlider| that allows sliding history layers while the page is
 113   // being reloaded.
 114   scoped_ptr<WindowSlider> window_slider_;
 115
 116   // Layer to be used for the final overlay fadeout animation when the overlay
 117   // is being dismissed.
 118   scoped_ptr<ui::Layer> overlay_dismiss_layer_;
 119
 120   // The direction of the in-progress slide (if any).
 121   SlideDirection slide_direction_;
 122
 123   // The LayerDelegate used for the back/front layers during a slide.
 124   scoped_ptr<ImageLayerDelegate> layer_delegate_;
 125
 126   DISALLOW_COPY_AND_ASSIGN(OverscrollNavigationOverlay);
 127 };
 128
 129 }  // namespace content
 130
 131 #endif  // CONTENT_BROWSER_WEB_CONTENTS_AURA_OVERSCROLL_NAVIGATION_OVERLAY_H_