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      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 Activity;
     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 and making it
     33   // visible inside |activity|'s window.
     34   ContentProxy(views::WebView* web_view, Activity* activity);
     35   // TODO(skuhne): Add a function to create this object from a passed PNG, so
     36   // that we can create it from a session restore.
     37 
     38   // With the destruction of the object, the layer should get destroyed and the
     39   // content should become visible again.
     40   virtual ~ContentProxy();
     41 
     42   // Called when the content will get unloaded.
     43   void ContentWillUnload();
     44 
     45   // Can be called to save resources by creating a layer with a solid color
     46   // instead of creating a content image layer.
     47   // Note: Currently the GPU does create a full size texture and fills it with
     48   // the given color - so there isn't really memory savings yet.
     49   void EvictContent();
     50 
     51   // Get the image of the content. If there is no image known, an empty image
     52   // will be returned.
     53   gfx::ImageSkia GetContentImage();
     54 
     55   // The content is about to get destroyed by its creator.
     56   // Note: This function should only be used by AppActivity.
     57   void OnPreContentDestroyed();
     58 
     59  private:
     60   // Make the original (web)content visible. This call should only be paired
     61   // with HideOriginalContent.
     62   void ShowOriginalContent();
     63 
     64   // Make the content invisible. This call should only be paired with
     65   // MakeVisible.
     66   void HideOriginalContent();
     67 
     68   // Creates proxy content from |web_view_|.
     69   void CreateProxyContent();
     70 
     71   // Creates an image from the current content.
     72   bool CreateContentImage();
     73 
     74   // Called once the content was read back.
     75   void OnContentImageRead(bool success, const SkBitmap& bitmap);
     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 NULL. 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_
    116