1 // Copyright (c) 2012 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 CHROME_BROWSER_ICON_LOADER_H_ 6 #define CHROME_BROWSER_ICON_LOADER_H_ 7 8 #include "build/build_config.h" 9 10 #include <string> 11 12 #include "base/basictypes.h" 13 #include "base/files/file_path.h" 14 #include "base/memory/ref_counted.h" 15 #include "base/memory/scoped_ptr.h" 16 #include "base/message_loop/message_loop_proxy.h" 17 #include "content/public/browser/browser_thread.h" 18 #include "ui/gfx/image/image.h" 19 20 #if defined(OS_WIN) 21 // On Windows, we group files by their extension, with several exceptions: 22 // .dll, .exe, .ico. See IconManager.h for explanation. 23 typedef std::wstring IconGroupID; 24 #elif defined(OS_POSIX) 25 // On POSIX, we group files by MIME type. 26 typedef std::string IconGroupID; 27 #endif 28 29 //////////////////////////////////////////////////////////////////////////////// 30 // 31 // A facility to read a file containing an icon asynchronously in the IO 32 // thread. Returns the icon in the form of an ImageSkia. 33 // 34 //////////////////////////////////////////////////////////////////////////////// 35 class IconLoader : public base::RefCountedThreadSafe<IconLoader> { 36 public: 37 enum IconSize { 38 SMALL = 0, // 16x16 39 NORMAL, // 32x32 40 LARGE, // Windows: 32x32, Linux: 48x48, Mac: Unsupported 41 ALL, // All sizes available 42 }; 43 44 class Delegate { 45 public: 46 // Invoked when an icon group has been read, but before the icon data 47 // is read. If the icon is already cached, this method should call and 48 // return the results of OnImageLoaded with the cached image. 49 virtual bool OnGroupLoaded(IconLoader* source, 50 const IconGroupID& group) = 0; 51 // Invoked when an icon has been read. |source| is the IconLoader. If the 52 // icon has been successfully loaded, result is non-null. This method must 53 // return true if it is taking ownership of the returned image. 54 virtual bool OnImageLoaded(IconLoader* source, 55 gfx::Image* result, 56 const IconGroupID& group) = 0; 57 58 protected: ~Delegate()59 virtual ~Delegate() {} 60 }; 61 62 IconLoader(const base::FilePath& file_path, 63 IconSize size, 64 Delegate* delegate); 65 66 // Start reading the icon on the file thread. 67 void Start(); 68 69 private: 70 friend class base::RefCountedThreadSafe<IconLoader>; 71 72 virtual ~IconLoader(); 73 74 // Get the identifying string for the given file. The implementation 75 // is in icon_loader_[platform].cc. 76 static IconGroupID ReadGroupIDFromFilepath(const base::FilePath& path); 77 78 // Some icons (exe's on windows) can change as they're loaded. 79 static bool IsIconMutableFromFilepath(const base::FilePath& path); 80 81 // The thread ReadIcon() should be called on. 82 static content::BrowserThread::ID ReadIconThreadID(); 83 84 void ReadGroup(); 85 void OnReadGroup(); 86 void ReadIcon(); 87 88 void NotifyDelegate(); 89 90 // The message loop object of the thread in which we notify the delegate. 91 scoped_refptr<base::MessageLoopProxy> target_message_loop_; 92 93 base::FilePath file_path_; 94 95 IconGroupID group_; 96 97 IconSize icon_size_; 98 99 scoped_ptr<gfx::Image> image_; 100 101 Delegate* delegate_; 102 103 DISALLOW_COPY_AND_ASSIGN(IconLoader); 104 }; 105 106 #endif // CHROME_BROWSER_ICON_LOADER_H_ 107