athena/content/content_proxy.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 ATHENA_CONTENT_CONTENT_PROXY_H_
   6 #define ATHENA_CONTENT_CONTENT_PROXY_H_
   7
   8 #include "base/macros.h"
   9 #include "base/memory/ref_counted_memory.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "ui/gfx/image/image_skia.h"
  13
  14 namespace views {
  15 class WebView;
  16 }
  17
  18 namespace athena {
  19
  20 class ProxyImageData;
  21
  22 // This object creates and holds proxy content which gets shown instead of the
  23 // actual web content, generated from the passed |web_view|.
  24 // The created |proxy_content_| will be destroyed with the destruction of this
  25 // object.
  26 // Calling EvictContent() will release the rendered content.
  27 // When ContentGetsDestroyed() gets called, the old view will be made visible
  28 // and then the link to the |web_view_| will get severed.
  29 class ContentProxy {
  30  public:
  31   // Creates the object by creating a sized down |web_view| layer.
  32   explicit ContentProxy(views::WebView* web_view);
  33   // TODO(skuhne): Add a function to create this object from a passed PNG, so
  34   // that we can create it from a session restore.
  35
  36   // With the destruction of the object, the layer should get destroyed and the
  37   // content should become visible again.
  38   virtual ~ContentProxy();
  39
  40   // Called when the content will get unloaded.
  41   void ContentWillUnload();
  42
  43   // Can be called to save resources by creating a layer with a solid color
  44   // instead of creating a content image layer.
  45   // Note: Currently the GPU does create a full size texture and fills it with
  46   // the given color - so there isn't really memory savings yet.
  47   void EvictContent();
  48
  49   // Get the image of the content. If there is no image known, an empty image
  50   // will be returned.
  51   gfx::ImageSkia GetContentImage();
  52
  53   // The content is about to get destroyed by its creator.
  54   // Note: This function should only be used by AppActivity.
  55   void OnPreContentDestroyed();
  56
  57  private:
  58   // Make the original (web)content visible. This call should only be paired
  59   // with HideOriginalContent.
  60   void ShowOriginalContent();
  61
  62   // Make the content invisible. This call should only be paired with
  63   // MakeVisible.
  64   void HideOriginalContent();
  65
  66   // Creates proxy content from |web_view_|.
  67   void CreateProxyContent();
  68
  69   // Creates an image from the current content.
  70   bool CreateContentImage();
  71
  72   // Called once the content was read back.
  73   void OnContentImageRead(bool success, const SkBitmap& bitmap);
  74
  75   // Called once the image content has been converted to PNG.
  76   void OnContentImageEncodeComplete(scoped_refptr<ProxyImageData> image);
  77
  78   // The web view which was passed on creation and is associated with this
  79   // object. It will be shown when OnPreContentDestroyed() gets called and then
  80   // set to NULL. The ownership remains with the creator.
  81   views::WebView* web_view_;
  82
  83   // While we are doing our PNG encode, we keep the read back image to have
  84   // something which we can pass back to the overview mode. (It would make no
  85   // sense to the user to see that more recent windows get painted later than
  86   // older ones).
  87   gfx::ImageSkia raw_image_;
  88
  89   // True if the content is visible.
  90   bool content_visible_;
  91
  92   // True if the content is loaded and needs a re-layout when it gets shown
  93   // again.
  94   bool content_loaded_;
  95
  96   // True if a content creation was kicked off once. This ensures that the
  97   // function is never called twice.
  98   bool content_creation_called_;
  99
 100   // The PNG image data.
 101   scoped_refptr<base::RefCountedBytes> png_data_;
 102
 103   // Creating an encoded image from the content will be asynchronous. Use a
 104   // weakptr for the callback to make sure that the read back / encoding image
 105   // completion callback does not trigger on a destroyed ContentProxy.
 106   base::WeakPtrFactory<ContentProxy> proxy_content_to_image_factory_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(ContentProxy);
 109 };
 110
 111 }  // namespace athena
 112
 113 #endif  // ATHENA_CONTENT_CONTENT_PROXY_H_