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// Copyright 2014 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.
#include <set>
#include "base/callback_forward.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "components/keyed_service/core/keyed_service.h"
#include "extensions/common/extension_resource.h"
#include "ui/base/layout.h"
#include "ui/gfx/geometry/size.h"
namespace content {
class BrowserContext;
namespace gfx {
class Image;
class ImageFamily;
namespace extensions {
class Extension;
typedef base::Callback<void(const gfx::Image&)> ImageLoaderImageCallback;
typedef base::Callback<void(gfx::ImageFamily)> ImageLoaderImageFamilyCallback;
// This class is responsible for asynchronously loading extension images and
// calling a callback when an image is loaded.
// The views need to load their icons asynchronously might be deleted before
// the images have loaded. If you pass your callback using a weak_ptr, this
// will make sure the callback won't be called after the view is deleted.
class ImageLoader : public KeyedService {
// Information about a singe image representation to load from an extension
// resource.
struct ImageRepresentation {
// Enum values to indicate whether to resize loaded bitmap when it is larger
// than |desired_size| or always resize it.
ImageRepresentation(const ExtensionResource& resource,
ResizeCondition resize_condition,
const gfx::Size& desired_size,
float scale_factor);
// Extension resource to load.
ExtensionResource resource;
ResizeCondition resize_condition;
// When |resize_method| is ALWAYS_RESIZE or when the loaded image is larger
// than |desired_size| it will be resized to these dimensions.
gfx::Size desired_size;
// |scale_factor| is used to construct the loaded gfx::ImageSkia.
float scale_factor;
struct LoadResult;
// Returns the instance for the given |context| or NULL if none. This is
// a convenience wrapper around ImageLoaderFactory::GetForBrowserContext.
static ImageLoader* Get(content::BrowserContext* context);
~ImageLoader() override;
// Specify image resource to load. If the loaded image is larger than
// |max_size| it will be resized to those dimensions. IMPORTANT NOTE: this
// function may call back your callback synchronously (ie before it returns)
// if the image was found in the cache.
// Note this method loads a raw bitmap from the resource. All sizes given are
// assumed to be in pixels.
// TODO(estade): remove this in favor of LoadImageAtEveryScaleFactorAsync,
// and rename the latter to LoadImageAsync.
void LoadImageAsync(const Extension* extension,
const ExtensionResource& resource,
const gfx::Size& max_size,
const ImageLoaderImageCallback& callback);
// Loads a gfx::Image that has representations at all scale factors we are
// likely to care about. That includes every scale for which we pack resources
// in ResourceBundle plus the scale for all currently attached displays. The
// image is returned via |callback|.
void LoadImageAtEveryScaleFactorAsync(
const Extension* extension,
const gfx::Size& dip_size,
const ImageLoaderImageCallback& callback);
// Same as LoadImageAsync() above except it loads multiple images from the
// same extension. This is used to load multiple resolutions of the same image
// type.
void LoadImagesAsync(const Extension* extension,
const std::vector<ImageRepresentation>& info_list,
const ImageLoaderImageCallback& callback);
// Same as LoadImagesAsync() above except it loads into an image family. This
// is used to load multiple images of different logical sizes as opposed to
// LoadImagesAsync() which loads different scale factors of the same logical
// image size.
// If multiple images of the same logical size are loaded, they will be
// combined into a single ImageSkia in the ImageFamily.
void LoadImageFamilyAsync(const Extension* extension,
const std::vector<ImageRepresentation>& info_list,
const ImageLoaderImageFamilyCallback& callback);
void ReplyBack(const ImageLoaderImageCallback& callback,
const std::vector<LoadResult>& load_result);
void ReplyBackWithImageFamily(const ImageLoaderImageFamilyCallback& callback,
const std::vector<LoadResult>& load_result);
base::WeakPtrFactory<ImageLoader> weak_ptr_factory_;
} // namespace extensions