// 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_EXTENSIONS_EXTENSION_ICON_IMAGE_H_
#define CHROME_BROWSER_EXTENSIONS_EXTENSION_ICON_IMAGE_H_
#include <map>
#include <string>
#include "base/basictypes.h"
#include "base/memory/weak_ptr.h"
#include "chrome/common/extensions/extension_icon_set.h"
#include "content/public/browser/notification_observer.h"
#include "content/public/browser/notification_registrar.h"
#include "ui/base/layout.h"
#include "ui/gfx/image/image_skia.h"
namespace content {
class BrowserContext;
}
namespace extensions {
class Extension;
}
namespace gfx {
class Size;
class Image;
}
namespace extensions {
// A class that provides an ImageSkia for UI code to use. It handles extension
// icon resource loading, screen scale factor change etc. UI code that uses
// extension icon should host this class and be its observer. ExtensionIconImage
// should be outlived by the observer. In painting code, UI code paints with the
// ImageSkia provided by this class. If required extension icon resource is not
// already present, this class tries to load it and calls its observer interface
// when the image get updated. Until the resource is loaded, the UI code will be
// provided with blank, transparent image.
// If the requested resource doesn't exist or can't be loaded and a default
// icon was supplied in the constructor, icon image will be updated with the
// default icon's resource.
// The default icon doesn't need to be supplied, but in that case, icon image
// representation will be left blank if the resource loading fails.
// If default icon is supplied, it is assumed that it contains or can
// synchronously create (when |GetRepresentation| is called on it)
// representations for all the scale factors supported by the current platform.
// Note that |IconImage| is not thread safe.
class IconImage : public content::NotificationObserver {
public:
class Observer {
public:
// Invoked when a new image rep for an additional scale factor
// is loaded and added to |image|.
virtual void OnExtensionIconImageChanged(IconImage* image) = 0;
protected:
virtual ~Observer() {}
};
// |context| is required by the underlying implementation to retrieve the
// |ImageLoader| instance associated with the given context. |ImageLoader| is
// used to perform the asynchronous image load work.
IconImage(content::BrowserContext* context,
const Extension* extension,
const ExtensionIconSet& icon_set,
int resource_size_in_dip,
const gfx::ImageSkia& default_icon,
Observer* observer);
virtual ~IconImage();
const gfx::ImageSkia& image_skia() const { return image_skia_; }
private:
class Source;
// Loads an image representation for the scale factor.
// If the representation gets loaded synchronously, it is returned by this
// method.
// If representation loading is asynchronous, an empty image
// representation is returned. When the representation gets loaded the
// observer's |OnExtensionIconImageLoaded| will be called.
gfx::ImageSkiaRep LoadImageForScaleFactor(ui::ScaleFactor scale_factor);
void OnImageLoaded(float scale_factor, const gfx::Image& image);
// content::NotificationObserver overrides:
virtual void Observe(int type,
const content::NotificationSource& source,
const content::NotificationDetails& details) OVERRIDE;
content::BrowserContext* browser_context_;
const Extension* extension_;
const ExtensionIconSet& icon_set_;
const int resource_size_in_dip_;
Observer* observer_;
Source* source_; // Owned by ImageSkia storage.
gfx::ImageSkia image_skia_;
// The icon with whose representation |image_skia_| should be updated if
// its own representation load fails.
gfx::ImageSkia default_icon_;
content::NotificationRegistrar registrar_;
base::WeakPtrFactory<IconImage> weak_ptr_factory_;
DISALLOW_COPY_AND_ASSIGN(IconImage);
};
} // namespace extensions
#endif // CHROME_BROWSER_EXTENSIONS_EXTENSION_ICON_IMAGE_H_