make SkDeviceFactory reference counted

git-svn-id: http://skia.googlecode.com/svn/trunk@1180 2bbb7eff-a529-9590-31e7-b0007b416f81

4 files changed, 29 insertions, 10 deletions

diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index 6b2ee10e75..b1222eb874 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -126,12 +126,15 @@ public:
     SkDevice* setBitmapDevice(const SkBitmap& bitmap, bool forLayer = false);
 
     /**
-     *  Return the current device factory, or NULL.
+     *  Return the current device factory, or NULL. The reference count of
+     *  the returned factory is not changed.
      */
     SkDeviceFactory* getDeviceFactory() const { return fDeviceFactory; }
 
     /**
-     *  Replace any existing factory with the specified factory.
+     *  Replace any existing factory with the specified factory, unrefing the
+     *  previous (if any), and refing the new one (if any). For convenience,
+     *  the factory parameter is also returned.
      */
     SkDeviceFactory* setDeviceFactory(SkDeviceFactory*);
 
diff --git a/include/core/SkDevice.h b/include/core/SkDevice.h
index 5755e955e0..d9a4fde4c2 100644
--- a/include/core/SkDevice.h
+++ b/include/core/SkDevice.h
@@ -36,8 +36,9 @@ class SkRegion;
     to pass into SkCanvas.  Doing so will eliminate the need to extend
     SkCanvas as well.
 */
-class SK_API SkDeviceFactory {
+class SK_API SkDeviceFactory : public SkRefCnt {
 public:
+    SkDeviceFactory();
     virtual ~SkDeviceFactory();
     virtual SkDevice* newDevice(SkCanvas*, SkBitmap::Config, int width,
                                 int height, bool isOpaque, bool isLayer) = 0;
@@ -65,9 +66,12 @@ public:
     SkDevice(SkCanvas*, const SkBitmap& bitmap, bool forOffscreen);
     virtual ~SkDevice();
 
-    virtual SkDeviceFactory* getDeviceFactory() {
-        return SkNEW(SkRasterDeviceFactory);
-    }
+    /**
+     *  Return the factory that will create this subclass of SkDevice.
+     *  The returned factory is cached by the device, and so its reference count
+     *  is not changed by this call.
+     */
+    SkDeviceFactory* getDeviceFactory();
 
     enum Capabilities {
         kGL_Capability     = 0x1,  //!< mask indicating GL support
@@ -247,6 +251,13 @@ public:
     virtual bool filterTextFlags(const SkPaint& paint, TextFlags*);
 
 protected:
+    /**
+     *  subclasses must override this to return a new (or ref'd) instance of
+     *  a device factory that will create this subclass of device. This value
+     *  is cached, so it should get called at most once for a given instance.
+     */
+    virtual SkDeviceFactory* onNewDeviceFactory();
+
     /** Update as needed the pixel value in the bitmap, so that the caller can access
         the pixels directly. Note: only the pixels field should be altered. The config/width/height/rowbytes
         must remain unchanged.
@@ -269,6 +280,8 @@ private:
     SkBitmap    fBitmap;
     SkIPoint    fOrigin;
     SkMetaData* fMetaData;
+
+    SkDeviceFactory* fCachedDeviceFactory;
 };
 
 #endif
diff --git a/include/gpu/SkGpuDevice.h b/include/gpu/SkGpuDevice.h
index ff1bb0d362..15def87942 100644
--- a/include/gpu/SkGpuDevice.h
+++ b/include/gpu/SkGpuDevice.h
@@ -121,6 +121,9 @@ public:
     virtual void makeRenderTargetCurrent();
 
 protected:
+    // override
+    virtual SkDeviceFactory* onNewDeviceFactory();
+
     class TexCache;
     TexCache* lockCachedTexture(const SkBitmap& bitmap,
                                 const GrSamplerState& sampler,
diff --git a/include/pdf/SkPDFDevice.h b/include/pdf/SkPDFDevice.h
index ac9ef20fc4..0d06fe6715 100644
--- a/include/pdf/SkPDFDevice.h
+++ b/include/pdf/SkPDFDevice.h
@@ -61,10 +61,6 @@ public:
     SkPDFDevice(int width, int height, const SkMatrix& initialTransform);
     virtual ~SkPDFDevice();
 
-    virtual SkDeviceFactory* getDeviceFactory() {
-        return SkNEW(SkPDFDeviceFactory);
-    }
-
     virtual uint32_t getDeviceCapabilities() { return kVector_Capability; }
 
     virtual int width() const { return fWidth; };
@@ -138,6 +134,10 @@ public:
      */
     SkStream* content() const;
 
+protected:
+    // override
+    virtual SkDeviceFactory* onNewDeviceFactory();
+
 private:
     int fWidth;
     int fHeight;