Removal of dependencies on PlatformDevice classes.

skia/ext/platform_device.cc

+// Copyright (c) 2011 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.
+
+#include "skia/ext/platform_device.h"
+
+#include "third_party/skia/include/core/SkMetaData.h"
+
+namespace skia {
+
+namespace {
+const char* kDevicePlatformBehaviour = "CrDevicePlatformBehaviour";
+}
+
+void SetPlatformDevice(SkDevice* device, PlatformDevice* platform_behaviour) {
+  SkMetaData& meta_data = device->getMetaData();

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

This is still a bit confusing but OK for the first iteration. I think the
meta-data should really be BitmapPlatformDeviceData.

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

The reason I place the meta-data here is so that all of the overrides of
PlatformDevice behaviour in the VectorPlatformDevice classes.  

If we want to call BeginPlatformPaint on a SkDevice* (that's 
 really a VectorPlaformDevice), then it needs to somehow lookup the correct
functions to call.  The VectorPlatformDevice classes have no equivalent of
BitmapPlatformDevice data.

Reviewing the code, I see that there could be a common PlatformData class that
could provide a union of the data housed in VectorPlatformDevice and
BitmapPlatformDevice.

[alokp, 2011/05/19 21:52:27]

Yes. A PlatformData class would be perfect.

+  meta_data.setPtr(kDevicePlatformBehaviour, platform_behaviour);
+}
+
+PlatformDevice* GetPlatformDevice(SkDevice* device) {
+  SkMetaData& meta_data = device->getMetaData();
+  PlatformDevice* device_behaviour = NULL;
+  if (meta_data.findPtr(kDevicePlatformBehaviour,
+                        reinterpret_cast<void**>(&device_behaviour)))
+    return device_behaviour;
+
+  return NULL;
+}
+
+PlatformSurface BeginPlatformPaint(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->BeginPlatformPaint();
+
+  return 0;
+}
+
+void EndPlatformPaint(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->EndPlatformPaint();
+}
+
+bool IsVectorial(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->IsVectorial();
+
+  return device->getDeviceCapabilities() & SkDevice::kVector_Capability;
+}
+
+bool IsNativeFontRenderingAllowed(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->IsNativeFontRenderingAllowed();
+
+  return false;
+}
+
+void DrawToNativeContext(SkDevice* device, PlatformSurface context,
+                         int x, int y, const PlatformRect* src_rect) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    platform_device->DrawToNativeContext(context, x, y, src_rect);
+}
+
+}  // namespace skia
+