CL removing inheritance of SkDevice from PlatformDevice. Flavours of PlatformDevice classes now ...

skia/ext/bitmap_platform_device_win.cc

Index: skia/ext/bitmap_platform_device_win.cc
===================================================================
--- skia/ext/bitmap_platform_device_win.cc	(revision 97282)
+++ skia/ext/bitmap_platform_device_win.cc	(working copy)
@@ -8,6 +8,7 @@
 #include "skia/ext/bitmap_platform_device_win.h"
 
 #include "skia/ext/bitmap_platform_device_data.h"
+#include "skia/ext/platform_device.h"
 #include "third_party/skia/include/core/SkMatrix.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 #include "third_party/skia/include/core/SkRegion.h"
@@ -144,18 +145,20 @@
 
   // The device object will take ownership of the HBITMAP. The initial refcount
   // of the data object will be 1, which is what the constructor expects.
-  return new BitmapPlatformDevice(new BitmapPlatformDeviceData(hbitmap),
-                                  bitmap);
+  BitmapPlatformDevice* bitmap_platform_device =
+      new BitmapPlatformDevice(new BitmapPlatformDeviceData(hbitmap),
+                               bitmap);
+  return bitmap_platform_device;
 }
 
 // static
 BitmapPlatformDevice* BitmapPlatformDevice::create(int width,
-                                                   int height,
-                                                   bool is_opaque,
-                                                   HANDLE shared_section) {
+                                       int height,

[vandebo (ex-Chrome), 2011/08/19 21:54:22]

nit: indent

[Jeff Timanus, 2011/08/20 02:31:04]

Done.

+                                       bool is_opaque,
+                                       HANDLE shared_section) {
   HDC screen_dc = GetDC(NULL);
-  BitmapPlatformDevice* device = BitmapPlatformDevice::create(
-      screen_dc, width, height, is_opaque, shared_section);
+  SkDevice* device = BitmapPlatformDevice::create(screen_dc, width, height,
+                                                  is_opaque, shared_section);
   ReleaseDC(NULL, screen_dc);
   return device;
 }
@@ -165,10 +168,16 @@
 BitmapPlatformDevice::BitmapPlatformDevice(
     BitmapPlatformDeviceData* data,
     const SkBitmap& bitmap)
-    : PlatformDevice(bitmap),
+    : PlatformDevice(this),
+      SkDevice(bitmap),
       data_(data) {
   // The data object is already ref'ed for us by create().
   SkDEBUGCODE(begin_paint_count_ = 0);
+
+  // Pass false, because BitmapPlatformDevice inherits both SkDevice, and
+  // PlatformDevice, so there is no need to explicitly bind the lifetime of the
+  // two classes.
+  SetPlatformDevice(this, this, false);

[vandebo (ex-Chrome), 2011/08/19 21:54:22]

This generally seems pretty fragile, is there any to do this automagically?

[Jeff Timanus, 2011/08/20 02:31:04]

Yes, I was also worried about the fragile requirement to register the
PlatformDevice properly.

After thinking about your suggestion to allow VectorPlatformDeviceSkia to also
inherit from SkDevice, the need to specify the ownership is no longer required. 

I pondered having the PlatformDevice constructor also register itself with the
bound SkDevice's meta-data, but that is a problem due to multiple inheritance. 
The style guide is inherit in alphabetical order, but that means that the
SkDevice is constructed AFTER the PlatformDevice, which means that the
PlatformDevice would try to package itself in the metadata of a
yet-to-be-constructed SkDevice.  

I think it's best if these classes still explicitly call SetPlatformDevice in
their constructors.

 }
 
 BitmapPlatformDevice::~BitmapPlatformDevice() {
@@ -262,4 +271,3 @@
 }
 
 }  // namespace skia
-