Updating trunk VERSION from 2139.0 to 2140.0
[chromium-blink-merge.git] / extensions / browser / extension_icon_image.h
blob3f76ed3c5c4ce0a46a975b5abd1c5c7cff38e3a4
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.
5 #ifndef EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_
6 #define EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_
8 #include <map>
9 #include <string>
11 #include "base/basictypes.h"
12 #include "base/memory/weak_ptr.h"
13 #include "content/public/browser/notification_observer.h"
14 #include "content/public/browser/notification_registrar.h"
15 #include "extensions/common/extension_icon_set.h"
16 #include "ui/base/layout.h"
17 #include "ui/gfx/image/image_skia.h"
19 namespace content {
20 class BrowserContext;
23 namespace extensions {
24 class Extension;
27 namespace gfx {
28 class Size;
29 class Image;
32 namespace extensions {
34 // A class that provides an ImageSkia for UI code to use. It handles extension
35 // icon resource loading, screen scale factor change etc. UI code that uses
36 // extension icon should host this class and be its observer. ExtensionIconImage
37 // should be outlived by the observer. In painting code, UI code paints with the
38 // ImageSkia provided by this class. If required extension icon resource is not
39 // already present, this class tries to load it and calls its observer interface
40 // when the image get updated. Until the resource is loaded, the UI code will be
41 // provided with blank, transparent image.
42 // If the requested resource doesn't exist or can't be loaded and a default
43 // icon was supplied in the constructor, icon image will be updated with the
44 // default icon's resource.
45 // The default icon doesn't need to be supplied, but in that case, icon image
46 // representation will be left blank if the resource loading fails.
47 // If default icon is supplied, it is assumed that it contains or can
48 // synchronously create (when |GetRepresentation| is called on it)
49 // representations for all the scale factors supported by the current platform.
50 // Note that |IconImage| is not thread safe.
51 class IconImage : public content::NotificationObserver {
52 public:
53 class Observer {
54 public:
55 // Invoked when a new image rep for an additional scale factor
56 // is loaded and added to |image|.
57 virtual void OnExtensionIconImageChanged(IconImage* image) = 0;
59 protected:
60 virtual ~Observer() {}
63 // |context| is required by the underlying implementation to retrieve the
64 // |ImageLoader| instance associated with the given context. |ImageLoader| is
65 // used to perform the asynchronous image load work.
66 IconImage(content::BrowserContext* context,
67 const Extension* extension,
68 const ExtensionIconSet& icon_set,
69 int resource_size_in_dip,
70 const gfx::ImageSkia& default_icon,
71 Observer* observer);
72 virtual ~IconImage();
74 const gfx::ImageSkia& image_skia() const { return image_skia_; }
76 private:
77 class Source;
79 // Loads an image representation for the scale factor.
80 // If the representation gets loaded synchronously, it is returned by this
81 // method.
82 // If representation loading is asynchronous, an empty image
83 // representation is returned. When the representation gets loaded the
84 // observer's |OnExtensionIconImageLoaded| will be called.
85 gfx::ImageSkiaRep LoadImageForScaleFactor(ui::ScaleFactor scale_factor);
87 void OnImageLoaded(float scale_factor, const gfx::Image& image);
89 // content::NotificationObserver overrides:
90 virtual void Observe(int type,
91 const content::NotificationSource& source,
92 const content::NotificationDetails& details) OVERRIDE;
94 content::BrowserContext* browser_context_;
95 const Extension* extension_;
96 const ExtensionIconSet& icon_set_;
97 const int resource_size_in_dip_;
99 Observer* observer_;
101 Source* source_; // Owned by ImageSkia storage.
102 gfx::ImageSkia image_skia_;
103 // The icon with whose representation |image_skia_| should be updated if
104 // its own representation load fails.
105 gfx::ImageSkia default_icon_;
107 content::NotificationRegistrar registrar_;
109 base::WeakPtrFactory<IconImage> weak_ptr_factory_;
111 DISALLOW_COPY_AND_ASSIGN(IconImage);
114 } // namespace extensions
116 #endif // EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_