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 EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_ 6 #define EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_ 7 8 #include <map> 9 #include <string> 10 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" 18 19 namespace content { 20 class BrowserContext; 21 } 22 23 namespace extensions { 24 class Extension; 25 } 26 27 namespace gfx { 28 class Size; 29 class Image; 30 } 31 32 namespace extensions { 33 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; 58 59 protected: ~Observer()60 virtual ~Observer() {} 61 }; 62 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(); 73 image_skia()74 const gfx::ImageSkia& image_skia() const { return image_skia_; } 75 76 private: 77 class Source; 78 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); 86 87 void OnImageLoaded(float scale_factor, const gfx::Image& image); 88 89 // content::NotificationObserver overrides: 90 virtual void Observe(int type, 91 const content::NotificationSource& source, 92 const content::NotificationDetails& details) OVERRIDE; 93 94 content::BrowserContext* browser_context_; 95 const Extension* extension_; 96 const ExtensionIconSet& icon_set_; 97 const int resource_size_in_dip_; 98 99 Observer* observer_; 100 101 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_; 106 107 content::NotificationRegistrar registrar_; 108 109 base::WeakPtrFactory<IconImage> weak_ptr_factory_; 110 111 DISALLOW_COPY_AND_ASSIGN(IconImage); 112 }; 113 114 } // namespace extensions 115 116 #endif // EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_ 117