| // 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_ICON_LOADER_H_ |
| #define CHROME_BROWSER_ICON_LOADER_H_ |
| |
| #include <memory> |
| #include <string> |
| |
| #include "base/callback.h" |
| #include "base/files/file_path.h" |
| #include "base/macros.h" |
| #include "base/single_thread_task_runner.h" |
| #include "build/build_config.h" |
| #include "content/public/browser/browser_thread.h" |
| #include "ui/gfx/image/image.h" |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // |
| // A facility to read a file containing an icon asynchronously in the IO |
| // thread. Returns the icon in the form of an ImageSkia. |
| // |
| //////////////////////////////////////////////////////////////////////////////// |
| class IconLoader { |
| public: |
| // An IconGroup is a class of files that all share the same icon. For all |
| // platforms but Windows, and for most files on Windows, it is the file type |
| // (e.g. all .mp3 files share an icon, all .html files share an icon). On |
| // Windows, for certain file types (.exe, .dll, etc), each file of that type |
| // is assumed to have a unique icon. In that case, each of those files is a |
| // group to itself. |
| using IconGroup = base::FilePath::StringType; |
| |
| enum IconSize { |
| SMALL = 0, // 16x16 |
| NORMAL, // 32x32 |
| LARGE, // Windows: 32x32, Linux: 48x48, Mac: Unsupported |
| ALL, // All sizes available |
| }; |
| |
| // The callback invoked when an icon has been read. The parameters are: |
| // - The icon that was loaded, or null if there was a failure to load it. |
| // - The determined group from the original requested path. |
| using IconLoadedCallback = |
| base::Callback<void(std::unique_ptr<gfx::Image>, const IconGroup&)>; |
| |
| // Creates an IconLoader, which owns itself. If the IconLoader might outlive |
| // the caller, be sure to use a weak pointer in the |callback|. |
| static IconLoader* Create(const base::FilePath& file_path, |
| IconSize size, |
| IconLoadedCallback callback); |
| |
| // Starts the process of reading the icon. When the reading of the icon is |
| // complete, the IconLoadedCallback callback will be fulfilled, and the |
| // IconLoader will delete itself. |
| void Start(); |
| |
| private: |
| IconLoader(const base::FilePath& file_path, |
| IconSize size, |
| IconLoadedCallback callback); |
| |
| ~IconLoader(); |
| |
| // Given a file path, get the group for the given file. |
| static IconGroup GroupForFilepath(const base::FilePath& file_path); |
| |
| // The thread ReadIcon() should be called on. |
| static content::BrowserThread::ID ReadIconThreadID(); |
| |
| void ReadGroup(); |
| void OnReadGroup(); |
| void ReadIcon(); |
| |
| // The task runner object of the thread in which we notify the delegate. |
| scoped_refptr<base::SingleThreadTaskRunner> target_task_runner_; |
| |
| base::FilePath file_path_; |
| |
| IconGroup group_; |
| |
| IconSize icon_size_; |
| |
| IconLoadedCallback callback_; |
| |
| DISALLOW_COPY_AND_ASSIGN(IconLoader); |
| }; |
| |
| #endif // CHROME_BROWSER_ICON_LOADER_H_ |