chromium/extensions/browser/extension_icon_image.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_
#define EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_

#include "base/memory/raw_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/scoped_observation.h"
#include "extensions/browser/extension_registry.h"
#include "extensions/browser/extension_registry_observer.h"
#include "extensions/common/icons/extension_icon_set.h"
#include "ui/gfx/image/image.h"
#include "ui/gfx/image/image_skia.h"

namespace content {
class BrowserContext;
}

namespace extensions {
class Extension;
}

namespace gfx {
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. In painting code, UI code paints with
// the ImageSkia provided by this class. If the 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 a 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 ExtensionRegistryObserver { … };

}  // namespace extensions

#endif  // EXTENSIONS_BROWSER_EXTENSION_ICON_IMAGE_H_