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 +10,74 @@
 // header file for your platform.
 
 #if defined(WIN32)
+#include <windows.h>
+#endif
+
+#include "third_party/skia/include/core/SkPreConfig.h"
+#include "third_party/skia/include/core/SkColor.h"
+
+
+class SkDevice;
+
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+typedef struct _cairo cairo_t;
+#elif defined(__APPLE__)
+typedef struct CGContext* CGContextRef;
+typedef struct CGRect CGRect;
+#endif
+
+namespace skia {
+
+class PlatformDevice;
+
+namespace platform_util {

[alokp, 2011/05/18 03:25:42]

is this namespace required? can we keep things in skia namespace itself?

[Jeff Timanus, 2011/05/18 22:10:28]

No, it's not required.  I added it to further encapsulate these routines.

Removed.

+
+#if defined(WIN32)
+typedef HDC PlatformSurface;
+#elif defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+typedef cairo_t* PlatformSurface;
+#elif defined(__APPLE__)
+typedef CGContextRef PlatformSurface;
+#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, |behaviour| to |device|.  Subsequent calls
+// to the functions exported below will forward the request to the corresponding
+// method on the bound PlatformBehaviour instance.    If no PlatformDevice has
+// been bound to the SkDevice passed, then the routines are NOPS.
+SK_API void SetPlatformDevice(SkDevice* device, PlatformDevice* behaviour);

[alokp, 2011/05/18 03:25:42]

this is a little confusing. PlatformBehaviour and PlatformDevice are used
interchangeably.

[Jeff Timanus, 2011/05/18 22:10:28]

My mistake.  Corrected.

+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);
+
+// Returns the color value at the specified location. This does not
+// consider any transforms that may be set on the device.
+SK_API SkColor GetColorAt(SkDevice* device, int x, int y);

[alokp, 2011/05/18 03:25:42]

this function does not seem to be doing anything useful. I think SkBitmap has
functions that does exactly the same thing.

[Jeff Timanus, 2011/05/18 22:10:28]

Removed.  Turned out that there were only very few call-sites.

See src\chrome\browser\ui\views\theme_helpers.cc

+
+}  // namespace platform_util
+
+}  // namespace skia
+
+#if defined(WIN32)
 #include "skia/ext/platform_device_win.h"
 #elif defined(__APPLE__)
 #include "skia/ext/platform_device_mac.h"