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_
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"
23 namespace extensions
{
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
{
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;
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
,
74 const gfx::ImageSkia
& image_skia() const { return image_skia_
; }
79 // Loads an image representation for the scale factor.
80 // If the representation gets loaded synchronously, it is returned by this
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_
;
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_