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 "content/public/browser/readback_types.h"
  13 #include "ui/gfx/image/image_skia.h"
  14
  15 namespace views {
  16 class WebView;
  17 }
  18
  19 namespace athena {
  20
  21 class ProxyImageData;
  22
  23 // This object creates and holds proxy content which gets shown instead of the
  24 // actual web content, generated from the passed |web_view|.
  25 // The created |proxy_content_| will be destroyed with the destruction of this
  26 // object.
  27 // Calling EvictContent() will release the rendered content.
  28 // When ContentGetsDestroyed() gets called, the old view will be made visible
  29 // and then the link to the |web_view_| will get severed.
  30 class ContentProxy {
  31  public:
  32   // Creates the object by creating a sized down |web_view| layer.
  33   explicit ContentProxy(views::WebView* web_view);
  34   // TODO(skuhne): Add a function to create this object from a passed PNG, so
  35   // that we can create it from a session restore.
  36
  37   // With the destruction of the object, the layer should get destroyed and the
  38   // content should become visible again.
  39   virtual ~ContentProxy();
  40
  41   // Called when the content will get unloaded.
  42   void ContentWillUnload();
  43
  44   // Can be called to save resources by creating a layer with a solid color
  45   // instead of creating a content image layer.
  46   // Note: Currently the GPU does create a full size texture and fills it with
  47   // the given color - so there isn't really memory savings yet.
  48   void EvictContent();
  49
  50   // Get the image of the content. If there is no image known, an empty image
  51   // will be returned.
  52   gfx::ImageSkia GetContentImage();
  53
  54   // The content is about to get destroyed by its creator.
  55   // Note: This function should only be used by AppActivity.
  56   void OnPreContentDestroyed();
  57
  58  private:
  59   // Make the original (web)content visible. This call should only be paired
  60   // with HideOriginalContent.
  61   void ShowOriginalContent();
  62
  63   // Make the content invisible. This call should only be paired with
  64   // MakeVisible.
  65   void HideOriginalContent();
  66
  67   // Creates proxy content from |web_view_|.
  68   void CreateProxyContent();
  69
  70   // Creates an image from the current content.
  71   bool CreateContentImage();
  72
  73   // Called once the content was read back.
  74   void OnContentImageRead(const SkBitmap& bitmap,
  75                           content::ReadbackResponse response);
  76
  77   // Called once the image content has been converted to PNG.
  78   void OnContentImageEncodeComplete(scoped_refptr<ProxyImageData> image);
  79
  80   // The web view which was passed on creation and is associated with this
  81   // object. It will be shown when OnPreContentDestroyed() gets called and then
  82   // set to nullptr. The ownership remains with the creator.
  83   views::WebView* web_view_;
  84
  85   // While we are doing our PNG encode, we keep the read back image to have
  86   // something which we can pass back to the overview mode. (It would make no
  87   // sense to the user to see that more recent windows get painted later than
  88   // older ones).
  89   gfx::ImageSkia raw_image_;
  90
  91   // True if the content is visible.
  92   bool content_visible_;
  93
  94   // True if the content is loaded and needs a re-layout when it gets shown
  95   // again.
  96   bool content_loaded_;
  97
  98   // True if a content creation was kicked off once. This ensures that the
  99   // function is never called twice.
 100   bool content_creation_called_;
 101
 102   // The PNG image data.
 103   scoped_refptr<base::RefCountedBytes> png_data_;
 104
 105   // Creating an encoded image from the content will be asynchronous. Use a
 106   // weakptr for the callback to make sure that the read back / encoding image
 107   // completion callback does not trigger on a destroyed ContentProxy.
 108   base::WeakPtrFactory<ContentProxy> proxy_content_to_image_factory_;
 109
 110   DISALLOW_COPY_AND_ASSIGN(ContentProxy);
 111 };
 112
 113 }  // namespace athena
 114
 115 #endif  // ATHENA_CONTENT_CONTENT_PROXY_H_