Removal of dependencies on PlatformDevice classes.

skia/ext/platform_device.h

Index: skia/ext/platform_device.h
===================================================================
--- skia/ext/platform_device.h	(revision 85672)
+++ skia/ext/platform_device.h	(working copy)
@@ -10,6 +10,78 @@
 // header file for your platform.
 
 #if defined(WIN32)

[alokp, 2011/05/19 18:15:15]

This is fine for the first iteration. But I would eventually like to get rid of
PlatformDevice. BitmapPlatformDevice could directly derive from SkDevice.
Likewise VectorPlatformDevice could directly derive from SkDevice.

[Jeff Timanus, 2011/05/19 20:38:29]

Noted.  Will start working on a follow-up CL that tries to implement your
suggestion more cleanly than my previous effort.

+#include <windows.h>
+#endif
+
+#include "third_party/skia/include/core/SkPreConfig.h"
+#include "third_party/skia/include/core/SkColor.h"
+
+
+class SkDevice;
+struct SkIRect;
+
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+typedef struct _cairo cairo_t;
+typedef struct _cairo_rectangle cairo_rectangle_t;
+#elif defined(__APPLE__)
+typedef struct CGContext* CGContextRef;
+typedef struct CGRect CGRect;
+#endif
+
+namespace skia {
+
+class PlatformDevice;
+
+#if defined(WIN32)
+typedef HDC PlatformSurface;
+typedef RECT PlatformRect;
+#elif defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+typedef cairo_t* PlatformSurface;
+typedef cairo_rectangle_t PlatformRect;
+#elif defined(__APPLE__)
+typedef CGContextRef PlatformSurface;
+typedef CGRect PlatformRect;
+#endif
+
+// The following routines provide accessor points for the functionality
+// exported by the various PlatformDevice ports.  The PlatformDevice, and
+// BitmapPlatformDevice classes inherit directly from SkDevice, which is no
+// longer a supported usage-pattern for skia.  In preparation of the removal of
+// these classes, all calls to PlatformDevice::* should be routed through these
+// helper functions.
+
+// Bind a PlatformDevice instance, |platform_device| to |device|.  Subsequent
+// calls to the functions exported below will forward the request to the
+// corresponding method on the bound PlatformDevice instance.    If no
+// PlatformDevice has been bound to the SkDevice passed, then the routines are
+// NOPS.
+SK_API void SetPlatformDevice(SkDevice* device,
+                              PlatformDevice* platform_device);
+SK_API PlatformDevice* GetPlatformDevice(SkDevice* device);
+
+// Returns if the preferred rendering engine is vectorial or bitmap based.
+// Forwards to PlatformDevice::IsVectorial, if a PlatformDevice is bound,
+// otherwise falls-back to the SkDevice::getDeviceCapabilities routine.
+SK_API bool IsVectorial(SkDevice* device);
+
+// Returns if the native font rendering engine is allowed to render text to
+// this device.
+SK_API bool IsNativeFontRenderingAllowed(SkDevice* device);
+
+// Returns the PlatformSurface used for native rendering into the device.
+SK_API PlatformSurface BeginPlatformPaint(SkDevice* device);
+
+// Finish a previous call to BeginPlatformPaint.
+SK_API void EndPlatformPaint(SkDevice* device);
+
+// Draws to the given PlatformSurface, |context|. Forwards to the
+// PlatformDevice bound to |device|.  Otherwise is a NOP.
+SK_API void DrawToNativeContext(SkDevice* device, PlatformSurface context,
+                                int x, int y, const PlatformRect* src_rect);
+
+}  // namespace skia
+
+#if defined(WIN32)
 #include "skia/ext/platform_device_win.h"
 #elif defined(__APPLE__)
 #include "skia/ext/platform_device_mac.h"