Linux: server side backing stores

chrome/common/x11_util.h

+// Copyright (c) 2009 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_COMMON_X11_UTIL_H_
+#define CHROME_COMMON_X11_UTIL_H_
+
+// This file declares utility functions for X11 (Linux only).
+//
+// These functions do not require the Xlib headers to be included (which is why
+// we use a void* for Visual*). The Xlib headers are highly polluting so we try
+// hard to limit their spread into the rest of the code.
+
+typedef struct _GtkWidget GtkWidget;
+typedef unsigned long XID;
+typedef struct _XDisplay Display;
+
+namespace gfx {
+class Size;
+}
+
+namespace x11_util {
+  // These functions cache their results and must be called from the UI thread.
+  // Currently they don't support multiple screens/displays.
+
+  // Return an X11 connection for the current, primary display.
+  Display* GetXDisplay();
+  // Return true iff the connection supports X shared memory
+  bool QuerySharedMemorySupport(Display* dpy);
+
+  // These functions do not cache their results
+
+  // Get the X window id for the given GTK widget.
+  XID GetX11WindowFromGtkWidget(GtkWidget*);
+  // Get a Visual from the given widget. Since we don't include the Xlib
+  // headers, this is returned as a void*.
+  void* GetVisualFromGtkWidget(GtkWidget*);
+
+  // Return a handle to a server side pixmap. |shared_memory_key| is a SysV
+  // IPC key. The shared memory region must contain 32-bit pixels.
+  XID AttachSharedMemory(Display* display, int shared_memory_support);
+  void DetachSharedMemory(Display* display, XID shmseg);
+
+  // Return a handle to an XRender picture where |pixmap| is a handle to a
+  // pixmap containing Skia ARGB data.
+  XID CreatePictureFromSkiaPixmap(Display* display, XID pixmap);
+
+  void FreePicture(Display* display, XID picture);
+  void FreePixmap(Display* display, XID pixmap);
+};
+
+#endif  // CHROME_COMMON_X11_UTIL_H_