Implement off-screen rendering support using delegated rendering (issue #1257).

This implementation supports both GPU compositing and software compositing (used when GPU is not supported or when passing `--disable-gpu --disable-gpu-compositing` command-line flags). GPU-accelerated features (WebGL and 3D CSS) that did not work with the previous off-screen rendering implementation do work with this implementation when GPU support is available.

Rendering now operates on a per-frame basis. The frame rate is configurable via CefBrowserSettings.windowless_frame_rate up to a maximum of 60fps (potentially limited by how fast the system can generate new frames). CEF generates a bitmap from the compositor backing and passes it to CefRenderHandler::OnPaint.

The previous CefRenderHandler/CefBrowserHost API for off-screen rendering has been restored mostly as-is with some minor changes:

- CefBrowserHost::Invalidate no longer accepts a CefRect region argument. Instead of invalidating a specific region it now triggers generation of a new frame.
- The |dirtyRects| argument to CefRenderHandler::OnPaint will now always be a single CefRect representing the whole view (frame) size. Previously, invalidated regions were listed separately.
- Linux: CefBrowserHost::SendKeyEvent now expects X11 event information instead of GTK event information. See cefclient for an example of converting GTK events to the necessary format.
- Sizes passed to the CefRenderHandler OnPaint and OnPopupSize methods are now already DPI scaled. Previously, the client had to perform DPI scaling.
- Includes drag&drop implementation from issue #1032.
- Includes unit test fixes from issue #1245.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1751 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

include/internal/cef_linux.h

@@ -72,6 +72,7 @@ class CefCriticalSection {
 #define CefCursorHandle cef_cursor_handle_t
 #define CefEventHandle cef_event_handle_t
 #define CefWindowHandle cef_window_handle_t
+#define CefTextInputContext cef_text_input_context_t
 
 struct CefMainArgsTraits {
   typedef cef_main_args_t struct_type;
@@ -113,6 +114,8 @@ struct CefWindowInfoTraits {
     target->width = src->width;
     target->height = src->height;
     target->parent_window = src->parent_window;
+    target->windowless_rendering_enabled = src->windowless_rendering_enabled;
+    target->transparent_painting_enabled = src->transparent_painting_enabled;
     target->window = src->window;
   }
 };
@@ -137,6 +140,24 @@ class CefWindowInfo : public CefStructBase<CefWindowInfoTraits> {
     width = windowRect.width;
     height = windowRect.height;
   }
+
+  ///
+  // Create the browser using windowless (off-screen) rendering. No window
+  // will be created for the browser and all rendering will occur via the
+  // CefRenderHandler interface. The |parent| value will be used to identify
+  // monitor info and to act as the parent window for dialogs, context menus,
+  // etc. If |parent| is not provided then the main screen monitor will be used
+  // and some functionality that requires a parent window may not function
+  // correctly. If |transparent| is true a transparent background color will be
+  // used (RGBA=0x00000000). If |transparent| is false the background will be
+  // white and opaque. In order to create windowless browsers the
+  // CefSettings.windowless_rendering_enabled value must be set to true.
+  ///
+  void SetAsWindowless(CefWindowHandle parent, bool transparent) {
+    windowless_rendering_enabled = true;
+    parent_window = parent;
+    transparent_painting_enabled = transparent;
+  }
 };
 
 #endif  // OS_LINUX

include/internal/cef_mac.h

@@ -72,6 +72,7 @@ class CefCriticalSection {
 #define CefCursorHandle cef_cursor_handle_t
 #define CefEventHandle cef_event_handle_t
 #define CefWindowHandle cef_window_handle_t
+#define CefTextInputContext cef_text_input_context_t
 
 struct CefMainArgsTraits {
   typedef cef_main_args_t struct_type;
@@ -119,6 +120,8 @@ struct CefWindowInfoTraits {
     target->height = src->height;
     target->hidden = src->hidden;
     target->parent_view = src->parent_view;
+    target->windowless_rendering_enabled = src->windowless_rendering_enabled;
+    target->transparent_painting_enabled = src->transparent_painting_enabled;
     target->view = src->view;
   }
 };
@@ -144,6 +147,24 @@ class CefWindowInfo : public CefStructBase<CefWindowInfoTraits> {
     this->height = height;
     hidden = false;
   }
+
+  ///
+  // Create the browser using windowless (off-screen) rendering. No view
+  // will be created for the browser and all rendering will occur via the
+  // CefRenderHandler interface. The |parent| value will be used to identify
+  // monitor info and to act as the parent view for dialogs, context menus,
+  // etc. If |parent| is not provided then the main screen monitor will be used
+  // and some functionality that requires a parent view may not function
+  // correctly. If |transparent| is true a transparent background color will be
+  // used (RGBA=0x00000000). If |transparent| is false the background will be
+  // white and opaque. In order to create windowless browsers the
+  // CefSettings.windowless_rendering_enabled value must be set to true.
+  ///
+  void SetAsWindowless(CefWindowHandle parent, bool transparent) {
+    windowless_rendering_enabled = true;
+    parent_view = parent;
+    transparent_painting_enabled = transparent;
+  }
 };
 
 #endif  // OS_MACOSX

include/internal/cef_types.h

@@ -223,6 +223,13 @@ typedef struct _cef_settings_t {
   ///
   int multi_threaded_message_loop;
 
+  ///
+  // Set to true (1) to enable windowless (off-screen) rendering support. Do not
+  // enable this value if the application does not use windowless rendering as
+  // it may reduce rendering performance on some systems.
+  ///
+  int windowless_rendering_enabled;
+
   ///
   // Set to true (1) to disable configuration of browser process features using
   // standard CEF and Chromium command-line arguments. Configuration can still
@@ -393,6 +400,14 @@ typedef struct _cef_browser_settings_t {
   ///
   size_t size;
 
+  ///
+  // The maximum rate in frames per second (fps) that CefRenderHandler::OnPaint
+  // will be called for a windowless browser. The actual fps may be lower if
+  // the browser cannot generate frames at the requested rate. The minimum
+  // value is 1 and the maximum value is 60 (default 30).
+  ///
+  int windowless_frame_rate;
+
   // The below values map to WebPreferences settings.
 
   ///
@@ -1306,6 +1321,14 @@ typedef struct _cef_mouse_event_t {
   uint32 modifiers;
 } cef_mouse_event_t;
 
+///
+// Paint element types.
+///
+typedef enum {
+  PET_VIEW  = 0,
+  PET_POPUP,
+} cef_paint_element_type_t;
+
 ///
 // Supported event bit flags.
 ///

include/internal/cef_types_linux.h

@@ -60,6 +60,7 @@ extern "C" {
 // thread-safe and must only be accessed on the browser process UI thread.
 ///
 CEF_EXPORT XDisplay* cef_get_xdisplay();
+#define cef_text_input_context_t void*
 
 ///
 // Structure representing CefExecuteProcess arguments.
@@ -83,6 +84,26 @@ typedef struct _cef_window_info_t {
   ///
   cef_window_handle_t parent_window;
 
+  ///
+  // Set to true (1) to create the browser using windowless (off-screen)
+  // rendering. No window will be created for the browser and all rendering will
+  // occur via the CefRenderHandler interface. The |parent_window| value will be
+  // used to identify monitor info and to act as the parent window for dialogs,
+  // context menus, etc. If |parent_window| is not provided then the main screen
+  // monitor will be used and some functionality that requires a parent window
+  // may not function correctly. In order to create windowless browsers the
+  // CefSettings.windowless_rendering_enabled value must be set to true.
+  ///
+  int windowless_rendering_enabled;
+
+  ///
+  // Set to true (1) to enable transparent painting in combination with
+  // windowless rendering. When this value is true a transparent background
+  // color will be used (RGBA=0x00000000). When this value is false the
+  // background will be white and opaque.
+  ///
+  int transparent_painting_enabled;
+
   ///
   // Pointer for the new browser window. Only used with windowed rendering.
   ///

include/internal/cef_types_mac.h

@@ -43,18 +43,22 @@
 @class NSCursor;
 @class NSEvent;
 @class NSView;
+@class NSTextInputContext;
 #else
 class NSCursor;
 class NSEvent;
 struct NSView;
+class NSTextInputContext;
 #endif
 #define cef_cursor_handle_t NSCursor*
 #define cef_event_handle_t NSEvent*
 #define cef_window_handle_t NSView*
+#define cef_text_input_context_t NSTextInputContext*
 #else
 #define cef_cursor_handle_t void*
 #define cef_event_handle_t void*
 #define cef_window_handle_t void*
+#define cef_text_input_context_t void*
 #endif
 
 #define kNullCursorHandle NULL
@@ -93,6 +97,26 @@ typedef struct _cef_window_info_t {
   ///
   cef_window_handle_t parent_view;
 
+  ///
+  // Set to true (1) to create the browser using windowless (off-screen)
+  // rendering. No view will be created for the browser and all rendering will
+  // occur via the CefRenderHandler interface. The |parent_view| value will be
+  // used to identify monitor info and to act as the parent view for dialogs,
+  // context menus, etc. If |parent_view| is not provided then the main screen
+  // monitor will be used and some functionality that requires a parent view
+  // may not function correctly. In order to create windowless browsers the
+  // CefSettings.windowless_rendering_enabled value must be set to true.
+  ///
+  int windowless_rendering_enabled;
+
+  ///
+  // Set to true (1) to enable transparent painting in combination with
+  // windowless rendering. When this value is true a transparent background
+  // color will be used (RGBA=0x00000000). When this value is false the
+  // background will be white and opaque.
+  ///
+  int transparent_painting_enabled;
+
   ///
   // NSView pointer for the new browser view. Only used with windowed rendering.
   ///

include/internal/cef_types_win.h

@@ -42,6 +42,7 @@
 #define cef_cursor_handle_t HCURSOR
 #define cef_event_handle_t MSG*
 #define cef_window_handle_t HWND
+#define cef_text_input_context_t void*
 
 #define kNullCursorHandle NULL
 #define kNullEventHandle NULL
@@ -73,6 +74,26 @@ typedef struct _cef_window_info_t {
   cef_window_handle_t parent_window;
   HMENU menu;
 
+  ///
+  // Set to true (1) to create the browser using windowless (off-screen)
+  // rendering. No window will be created for the browser and all rendering will
+  // occur via the CefRenderHandler interface. The |parent_window| value will be
+  // used to identify monitor info and to act as the parent window for dialogs,
+  // context menus, etc. If |parent_window| is not provided then the main screen
+  // monitor will be used and some functionality that requires a parent window
+  // may not function correctly. In order to create windowless browsers the
+  // CefSettings.windowless_rendering_enabled value must be set to true.
+  ///
+  int windowless_rendering_enabled;
+
+  ///
+  // Set to true (1) to enable transparent painting in combination with
+  // windowless rendering. When this value is true a transparent background
+  // color will be used (RGBA=0x00000000). When this value is false the
+  // background will be white and opaque.
+  ///
+  int transparent_painting_enabled;
+
   ///
   // Handle for the new browser window. Only used with windowed rendering.
   ///

include/internal/cef_types_wrappers.h

@@ -349,6 +349,7 @@ struct CefSettingsTraits {
         src->browser_subprocess_path.length,
         &target->browser_subprocess_path, copy);
     target->multi_threaded_message_loop = src->multi_threaded_message_loop;
+    target->windowless_rendering_enabled = src->windowless_rendering_enabled;
     target->command_line_args_disabled = src->command_line_args_disabled;
 
     cef_string_set(src->cache_path.str, src->cache_path.length,
@@ -405,6 +406,8 @@ struct CefBrowserSettingsTraits {
 
   static inline void set(const struct_type* src, struct_type* target,
       bool copy) {
+    target->windowless_frame_rate = src->windowless_frame_rate;
+
     cef_string_set(src->standard_font_family.str,
         src->standard_font_family.length, &target->standard_font_family, copy);
     cef_string_set(src->fixed_font_family.str, src->fixed_font_family.length,

include/internal/cef_win.h

@@ -71,6 +71,7 @@ class CefCriticalSection {
 #define CefCursorHandle cef_cursor_handle_t
 #define CefEventHandle cef_event_handle_t
 #define CefWindowHandle cef_window_handle_t
+#define CefTextInputContext cef_text_input_context_t
 
 struct CefMainArgsTraits {
   typedef cef_main_args_t struct_type;
@@ -118,6 +119,8 @@ struct CefWindowInfoTraits {
     target->height = src->height;
     target->parent_window = src->parent_window;
     target->menu = src->menu;
+    target->transparent_painting_enabled = src->transparent_painting_enabled;
+    target->windowless_rendering_enabled = src->windowless_rendering_enabled;
     target->window = src->window;
   }
 };
@@ -160,6 +163,24 @@ class CefWindowInfo : public CefStructBase<CefWindowInfoTraits> {
 
     cef_string_copy(windowName.c_str(), windowName.length(), &window_name);
   }
+
+  ///
+  // Create the browser using windowless (off-screen) rendering. No window
+  // will be created for the browser and all rendering will occur via the
+  // CefRenderHandler interface. The |parent| value will be used to identify
+  // monitor info and to act as the parent window for dialogs, context menus,
+  // etc. If |parent| is not provided then the main screen monitor will be used
+  // and some functionality that requires a parent window may not function
+  // correctly. If |transparent| is true a transparent background color will be
+  // used (RGBA=0x00000000). If |transparent| is false the background will be
+  // white and opaque. In order to create windowless browsers the
+  // CefSettings.windowless_rendering_enabled value must be set to true.
+  ///
+  void SetAsWindowless(CefWindowHandle parent, bool transparent) {
+    windowless_rendering_enabled = TRUE;
+    parent_window = parent;
+    transparent_painting_enabled = transparent;
+  }
 };
 
 #endif  // OS_WIN