Refactored-out the code of thumbnaling algorithm from thumbnail_tab_helper.

chrome/browser/thumbnails/thumbnail_tab_helper.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_
 #define CHROME_BROWSER_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_
 
 #include "base/basictypes.h"
-#include "chrome/common/thumbnail_score.h"
+#include "chrome/browser/thumbnails/thumbnailing_context.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
-class GURL;
-class Profile;
-class SkBitmap;
-
 namespace content {
 class RenderViewHost;
 class RenderWidgetHost;
 }
 
-namespace skia {
-class PlatformBitmap;
-}
-
 class ThumbnailTabHelper
     : public content::NotificationObserver,
       public content::WebContentsObserver,
       public content::WebContentsUserData<ThumbnailTabHelper> {
  public:
-  // The result of clipping. This can be used to determine if the
-  // generated thumbnail is good or not.
-  enum ClipResult {
-    // Clipping is not done yet.
-    kUnprocessed,
-    // The source image is smaller.
-    kSourceIsSmaller,
-    // Wider than tall by twice or more, clip horizontally.
-    kTooWiderThanTall,
-    // Wider than tall, clip horizontally.
-    kWiderThanTall,
-    // Taller than wide, clip vertically.
-    kTallerThanWide,
-    // The source and destination aspect ratios are identical.
-    kNotClipped,
-  };
-
-  // Holds the information needed for processing a thumbnail.
-  struct ThumbnailingContext : base::RefCountedThreadSafe<ThumbnailingContext> {
-    ThumbnailingContext(content::WebContents* web_contents,
-                        bool load_interrupted);
-
-    content::BrowserContext* browser_context;
-    GURL url;
-    ClipResult clip_result;
-    ThumbnailScore score;
-
-   private:
-    ~ThumbnailingContext();
-    friend class base::RefCountedThreadSafe<ThumbnailingContext>;
-  };
-
   virtual ~ThumbnailTabHelper();
 
   // Enables or disables the function of taking thumbnails.
   // A disabled ThumbnailTabHelper generates no thumbnails although it still
   // continues to receive the notifications from the web contents.
   void set_enabled(bool enabled) { enabled_ = enabled; }
 
-  // Calculates how "boring" a thumbnail is. The boring score is the
-  // 0,1 ranged percentage of pixels that are the most common
-  // luma. Higher boring scores indicate that a higher percentage of a
-  // bitmap are all the same brightness.
-  // Statically exposed for use by tests only.
-  static double CalculateBoringScore(const SkBitmap& bitmap);
-
-  // Gets the clipped bitmap from |bitmap| per the aspect ratio of the
-  // desired width and the desired height. For instance, if the input
-  // bitmap is vertically long (ex. 400x900) and the desired size is
-  // square (ex. 100x100), the clipped bitmap will be the top half of the
-  // input bitmap (400x400).
-  // Statically exposed for use by tests only.
-  static SkBitmap GetClippedBitmap(const SkBitmap& bitmap,
-                                   int desired_width,
-                                   int desired_height,
-                                   ClipResult* clip_result);
-
  private:
   explicit ThumbnailTabHelper(content::WebContents* contents);
   friend class content::WebContentsUserData<ThumbnailTabHelper>;
 
   // content::NotificationObserver overrides.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
   // content::WebContentsObserver overrides.
   virtual void DidStartLoading(
       content::RenderViewHost* render_view_host) OVERRIDE;
   virtual void StopNavigation() OVERRIDE;
 
   // Update the thumbnail of the given tab contents if necessary.
   void UpdateThumbnailIfNecessary(content::WebContents* web_contents);
 
-  // Update the thumbnail of the given tab.
-  static void UpdateThumbnail(ThumbnailingContext* context,
-                              const SkBitmap& bitmap);
-
-  // Asynchronously updates the thumbnail of the given tab. This must be called
-  // on the UI thread.
-  void AsyncUpdateThumbnail(content::WebContents* web_contents);
-
-  // Called when the bitmap for generating a thumbnail is ready after the
-  // AsyncUpdateThumbnail invocation. This runs on the UI thread.
-  static void UpdateThumbnailWithBitmap(ThumbnailingContext* context,
-                                        const SkBitmap& bitmap);
-
-  // Called when the canvas for generating a thumbnail is ready after the
-  // AsyncUpdateThumbnail invocation. This runs on the UI thread.
-  static void UpdateThumbnailWithCanvas(
-      ThumbnailingContext* context,
-      skia::PlatformBitmap* temp_bitmap,
-      bool result);
-
   // Called when a render view host was created for a WebContents.
   void RenderViewHostCreated(content::RenderViewHost* renderer);
 
   // Indicates that the given widget has changed is visibility.
   void WidgetHidden(content::RenderWidgetHost* widget);
 
   // Called when the given render view host was deleted.
   void RenderViewHostDeleted(content::RenderViewHost* renderer);
 
   bool enabled_;
 
   content::NotificationRegistrar registrar_;
 
   bool load_interrupted_;
 
   DISALLOW_COPY_AND_ASSIGN(ThumbnailTabHelper);
 };
 
 #endif  // CHROME_BROWSER_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_