1 // Copyright (c) 2011 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_UI_GTK_CAIRO_CACHED_SURFACE_H_ 6 #define CHROME_BROWSER_UI_GTK_CAIRO_CACHED_SURFACE_H_ 7 #pragma once 8 9 typedef struct _GdkPixbuf GdkPixbuf; 10 typedef struct _cairo cairo_t; 11 typedef struct _cairo_surface cairo_surface_t; 12 13 // A helper class that takes a GdkPixbuf* and renders it to the screen. Unlike 14 // gdk_cairo_set_source_pixbuf(), CairoCachedSurface assumes that the pixbuf is 15 // immutable after UsePixbuf() is called and can be sent to the X server 16 // once. From then on, that cached version is used so we don't upload the same 17 // image each and every time we expose. 18 // 19 // Most cached surfaces are owned by the GtkThemeService, which associates 20 // them with a certain XDisplay. Some users of surfaces (CustomDrawButtonBase, 21 // for example) own their surfaces instead since they interact with the 22 // ResourceBundle instead of the GtkThemeService. 23 class CairoCachedSurface { 24 public: 25 CairoCachedSurface(); 26 ~CairoCachedSurface(); 27 28 // Whether this CairoCachedSurface owns a GdkPixbuf. 29 bool valid() const { 30 return pixbuf_; 31 } 32 33 // The dimensions of the underlying pixbuf/surface. (or -1 if invalid.) 34 int Width() const; 35 int Height() const; 36 37 // Sets the pixbuf that we pass to cairo. Calling UsePixbuf() only derefs the 38 // current pixbuf and surface (if they exist). Actually transfering data to 39 // the X server occurs at SetSource() time. Calling UsePixbuf() should only 40 // be done once as it clears cached data from the X server. 41 void UsePixbuf(GdkPixbuf* pixbuf); 42 43 // Sets our pixbuf as the active surface starting at (x, y), uploading it in 44 // case we don't have an X backed surface cached. 45 void SetSource(cairo_t* cr, int x, int y); 46 47 // Raw access to the pixbuf. May be NULL. Used for a few gdk operations 48 // regarding window shaping. 49 GdkPixbuf* pixbuf() { return pixbuf_; } 50 51 private: 52 // The source pixbuf. 53 GdkPixbuf* pixbuf_; 54 55 // Our cached surface. This should be a xlib surface so the data lives on the 56 // server instead of on the client. 57 cairo_surface_t* surface_; 58 }; 59 60 #endif // CHROME_BROWSER_UI_GTK_CAIRO_CACHED_SURFACE_H_ 61
