Add new ResourceBundle::Delegate interface.

ui/base/resource/resource_bundle.h

Index: ui/base/resource/resource_bundle.h
===================================================================
--- ui/base/resource/resource_bundle.h	(revision 134688)
+++ ui/base/resource/resource_bundle.h	(working copy)
@@ -19,6 +19,8 @@
 #include "base/string16.h"
 #include "base/string_piece.h"
 #include "ui/base/ui_export.h"
+#include "ui/gfx/font.h"

[tony, 2012/05/03 20:35:42]

Nit: I think we can still forward declare gfx::Font.

[Marshall, 2012/05/04 14:41:03]

When using scoped_ptr with a forward declared type on Windows I get errors in
other header files that include resource_bundle.h but not font.h:

scoped_ptr.h(161): error C2027: use of undefined type 'gfx::Font'

So I think it's probably better to include font.h in resource_bundle.h instead
of modifying all of the other header files.

[tony, 2012/05/04 17:10:51]

Which header files did you see this in?  Should they be including font.h
directly?  We should fix that in a separate change, but it's OK to include
font.h here for now.

[Marshall, 2012/05/04 17:28:41]

Here is the complete error message:

1>C:\svn\chromium_writable\src\base/memory/scoped_ptr.h(161): error C2027: use
of undefined type 'gfx::Font'
1>          C:\svn\chromium_writable\src\ui/base/resource/resource_bundle.h(33)
: see declaration of 'gfx::Font'
1>          C:\svn\chromium_writable\src\base/memory/scoped_ptr.h(160) : while
compiling class template member function 'scoped_ptr<C>::~scoped_ptr(void)'
1>          with
1>          [
1>              C=gfx::Font
1>          ]
1>          C:\svn\chromium_writable\src\ui/base/resource/resource_bundle.h(274)
: see reference to class template instantiation 'scoped_ptr<C>' being compiled
1>          with
1>          [
1>              C=gfx::Font
1>          ]
1>C:\svn\chromium_writable\src\base/memory/scoped_ptr.h(162): warning C4150:
deletion of pointer to incomplete type 'gfx::Font'; no destructor called
1>          C:\svn\chromium_writable\src\ui/base/resource/resource_bundle.h(33)
: see declaration of 'gfx::Font'
1>

So I misspoke earlier. It appears to be an error reported in resource_bundle.h
itself when using a forward declaration of gfx::Font.

+#include "ui/gfx/image/image.h"
 #include "ui/gfx/native_widget_types.h"
 
 class SkBitmap;
@@ -28,11 +30,6 @@
 class RefCountedStaticMemory;
 }
 
-namespace gfx {
-class Font;
-class Image;
-}
-
 namespace ui {
 
 class ResourceHandle;
@@ -63,12 +60,60 @@
     RTL_DISABLED,
   };
 
-  // Initialize the ResourceBundle for this process.  Returns the language
-  // selected.
+  // Delegate class that allows interception of pack file loading and resource
+  // requests. The methods of this class may be called on multiple threads.
+  class Delegate {
+   public:
+    // Called before a resource pack file is loaded. Return the full path for
+    // the pack file to continue loading or an empty value to cancel loading.
+    // |pack_path| will contain the complete default path for the pack file if
+    // known or just the pack file name otherwise.
+    virtual FilePath GetPathForResourcePack(const FilePath& pack_path,
+                                            float scale_factor) = 0;
+
+    // Called before a locale pack file is loaded. Return the full path for
+    // the pack file to continue loading or an empty value to cancel loading.
+    // |pack_path| will contain the complete default path for the pack file if
+    // known or just the pack file name otherwise.
+    virtual FilePath GetPathForLocalePack(const FilePath& pack_path,
+                                          const std::string& locale) = 0;
+
+    // Return an image resource or an empty value to attempt retrieval of the
+    // default resource.
+    virtual gfx::Image GetImageNamed(int resource_id) = 0;
+
+    // Return an image resource or an empty value to attempt retrieval of the
+    // default resource.
+    virtual gfx::Image GetNativeImageNamed(int resource_id, ImageRTL rtl) = 0;
+
+    // Return a static memory resource or NULL to attempt retrieval of the
+    // default resource.
+    virtual base::RefCountedStaticMemory* LoadDataResourceBytes(
+        int resource_id) = 0;
+
+    // Retrieve a raw data resource. Return true if a resource was provided or
+    // false to attempt retrieval of the default resource.
+    virtual bool GetRawDataResource(int resource_id,
+                                    base::StringPiece* value) = 0;
+
+    // Retrieve a localized string. Return true if a string was provided or
+    // false to attempt retrieval of the default string.
+    virtual bool GetLocalizedString(int message_id, string16* value) = 0;
+
+    // Return a font resource or NULL to attempt retrieval of the default
+    // resource.
+    virtual scoped_ptr<gfx::Font> GetFont(FontStyle style) = 0;
+
+   protected:
+    virtual ~Delegate() {}
+  };
+
+  // Initialize the ResourceBundle for this process. Does not take ownership of
+  // the |delegate| value. Returns the language selected.
   // NOTE: Mac ignores this and always loads up resources for the language
   // defined by the Cocoa UI (i.e., NSBundle does the language work).
   static std::string InitSharedInstanceWithLocale(
-      const std::string& pref_locale);
+      const std::string& pref_locale, Delegate* delegate);
 
   // Initialize the ResourceBundle using given data pack path for testing.
   static void InitSharedInstanceWithPakFile(const FilePath& path);
@@ -83,11 +128,13 @@
   static ResourceBundle& GetSharedInstance();
 
   // Check if the .pak for the given locale exists.
-  static bool LocaleDataPakExists(const std::string& locale);
+  bool LocaleDataPakExists(const std::string& locale);
 
-  // Registers additional data pack files with the global ResourceBundle.  When
+  // Registers additional data pack files with this ResourceBundle.  When
   // looking for a DataResource, we will search these files after searching the
-  // main module. |scale_factor| is the scale of images in this resource pak
+  // main module. |path| should be the complete path to the pack file if known
+  // or just the pack file name otherwise (the delegate may optionally override
+  // this value). |scale_factor| is the scale of images in this resource pak
   // relative to the images in the 1x resource pak. This method is not thread
   // safe! You should call it immediately after calling InitSharedInstance.
   void AddDataPack(const FilePath& path, float scale_factor);
@@ -109,7 +156,7 @@
 
   // Gets an image resource from the current module data. This will load the
   // image in Skia format by default. The ResourceBundle owns this.
-  gfx::Image& GetImageNamed(int resource_id);
+  const gfx::Image& GetImageNamed(int resource_id);
 
   // Similar to GetImageNamed, but rather than loading the image in Skia format,
   // it will load in the native platform type. This can avoid conversion from
@@ -120,10 +167,10 @@
   // loading code of ResourceBundle.
   //
   // If |rtl| is RTL_ENABLED then the image is flipped in RTL locales.
-  gfx::Image& GetNativeImageNamed(int resource_id, ImageRTL rtl);
+  const gfx::Image& GetNativeImageNamed(int resource_id, ImageRTL rtl);
 
   // Same as GetNativeImageNamed() except that RTL is not enabled.
-  gfx::Image& GetNativeImageNamed(int resource_id);
+  const gfx::Image& GetNativeImageNamed(int resource_id);
 
   // Loads the raw bytes of a data resource into |bytes|,
   // without doing any processing or interpretation of
@@ -149,10 +196,19 @@
   void OverrideLocalePakForTest(const FilePath& pak_path);
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetPathForResourcePack);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetPathForLocalePack);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetImageNamed);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetNativeImageNamed);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateLoadDataResourceBytes);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetRawDataResource);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetLocalizedString);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetFont);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, LoadDataResourceBytes);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, LocaleDataPakExists);
 
   // Ctor/dtor are private, since we're a singleton.
-  ResourceBundle();
+  explicit ResourceBundle(Delegate* delegate);
   ~ResourceBundle();
 
   // Free skia_images_.
@@ -177,7 +233,7 @@
 
   // Returns the full pathname of the locale file to load.  May return an empty
   // string if no locale data files are found.
-  static FilePath GetLocaleFilePath(const std::string& app_locale);
+  FilePath GetLocaleFilePath(const std::string& app_locale);
 
   // Creates and returns a new SkBitmap given the data file to look in and the
   // resource id.  It's up to the caller to free the returned bitmap when
@@ -186,10 +242,14 @@
 
   // Returns an empty image for when a resource cannot be loaded. This is a
   // bright red bitmap.
-  gfx::Image* GetEmptyImage();
+  const gfx::Image& GetEmptyImage();
 
   const FilePath& GetOverriddenPakPath();
 
+  // This pointer is guaranteed to outlive the ResourceBundle instance and may
+  // be NULL.
+  Delegate* delegate_;
+
   // Protects |images_| and font-related members.
   scoped_ptr<base::Lock> images_and_fonts_lock_;
 
@@ -202,7 +262,7 @@
 
   // Cached images. The ResourceBundle caches all retrieved images and keeps
   // ownership of the pointers.
-  typedef std::map<int, gfx::Image*> ImageMap;
+  typedef std::map<int, gfx::Image> ImageMap;
   ImageMap images_;
 
   // The various fonts used. Cached to avoid repeated GDI creation/destruction.