make SkDeviceFactory reference counted

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

2 files changed, 52 insertions, 10 deletions

diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 07c2748a7a..dbd4852006 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -417,21 +417,27 @@ SkDevice* SkCanvas::init(SkDevice* device) {
 }
 
 SkCanvas::SkCanvas(SkDeviceFactory* factory)
-        : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage)),
-          fDeviceFactory(factory) {
+        : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage)) {
     inc_canvas();
 
-    if (!factory)
-        fDeviceFactory = SkNEW(SkRasterDeviceFactory);
+    if (factory) {
+        factory->ref();
+    } else {
+        factory = SkNEW(SkRasterDeviceFactory);
+    }
+    fDeviceFactory = factory;
 
     this->init(NULL);
 }
 
 SkCanvas::SkCanvas(SkDevice* device)
-        : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage)),
-          fDeviceFactory(device->getDeviceFactory()) {
+        : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage)) {
     inc_canvas();
 
+    fDeviceFactory = device->getDeviceFactory();
+    SkASSERT(fDeviceFactory);
+    fDeviceFactory->ref();
+              
     this->init(device);
 }
 
@@ -441,6 +447,9 @@ SkCanvas::SkCanvas(const SkBitmap& bitmap)
 
     SkDevice* device = SkNEW_ARGS(SkDevice, (this, bitmap, false));
     fDeviceFactory = device->getDeviceFactory();
+    SkASSERT(fDeviceFactory);
+    fDeviceFactory->ref();
+
     this->init(device)->unref();
 }
 
@@ -450,7 +459,7 @@ SkCanvas::~SkCanvas() {
     this->internalRestore();    // restore the last, since we're going away
 
     SkSafeUnref(fBounder);
-    SkDELETE(fDeviceFactory);
+    SkSafeUnref(fDeviceFactory);
 
     dec_canvas();
 }
@@ -560,8 +569,7 @@ bool SkCanvas::readPixels(const SkIRect& srcRect, SkBitmap* bitmap) {
 }
 
 SkDeviceFactory* SkCanvas::setDeviceFactory(SkDeviceFactory* factory) {
-    SkDELETE(fDeviceFactory);
-    fDeviceFactory = factory;
+    SkRefCnt_SafeAssign(fDeviceFactory, factory);
     return factory;
 }
 
diff --git a/src/core/SkDevice.cpp b/src/core/SkDevice.cpp
index 6305e190fe..850a53fd16 100644
--- a/src/core/SkDevice.cpp
+++ b/src/core/SkDevice.cpp
@@ -3,10 +3,31 @@
 #include "SkMetaData.h"
 #include "SkRect.h"
 
-SkDeviceFactory::~SkDeviceFactory() {}
+//#define TRACE_FACTORY_LIFETIME
+
+#ifdef TRACE_FACTORY_LIFETIME
+    static int gFactoryCounter;
+#endif
+
+SkDeviceFactory::SkDeviceFactory() {
+#ifdef TRACE_FACTORY_LIFETIME
+    SkDebugf("+++ factory index %d\n", gFactoryCounter);
+    ++gFactoryCounter;
+#endif
+}
+
+SkDeviceFactory::~SkDeviceFactory() {
+#ifdef TRACE_FACTORY_LIFETIME
+    --gFactoryCounter;
+    SkDebugf("--- factory index %d\n", gFactoryCounter);
+#endif
+}
+
+///////////////////////////////////////////////////////////////////////////////
 
 SkDevice::SkDevice(SkCanvas* canvas) : fCanvas(canvas), fMetaData(NULL) {
     fOrigin.setZero();
+    fCachedDeviceFactory = NULL;
 }
 
 SkDevice::SkDevice(SkCanvas* canvas, const SkBitmap& bitmap, bool isForLayer)
@@ -21,10 +42,23 @@ SkDevice::SkDevice(SkCanvas* canvas, const SkBitmap& bitmap, bool isForLayer)
             }
         }
     }
+    fCachedDeviceFactory = NULL;
 }
 
 SkDevice::~SkDevice() {
     delete fMetaData;
+    SkSafeUnref(fCachedDeviceFactory);
+}
+
+SkDeviceFactory* SkDevice::onNewDeviceFactory() {
+    return SkNEW(SkRasterDeviceFactory);
+}
+
+SkDeviceFactory* SkDevice::getDeviceFactory() {
+    if (NULL == fCachedDeviceFactory) {
+        fCachedDeviceFactory = this->onNewDeviceFactory();
+    }
+    return fCachedDeviceFactory;
 }
 
 SkMetaData& SkDevice::getMetaData() {