De-virtualize SkCanvas save/restore.

This moves the state management logic into non-virtual SkCanvas methods,
and turns the virtuals into protected notifiers.

R=robertphillips@google.com, reed@google.com

Review URL: https://codereview.chromium.org/194713008

git-svn-id: http://skia.googlecode.com/svn/trunk@13747 2bbb7eff-a529-9590-31e7-b0007b416f81

8 files changed, 69 insertions, 67 deletions

diff --git a/src/utils/SkDeferredCanvas.cpp b/src/utils/SkDeferredCanvas.cpp
index efe750188e..8b617b30e8 100644
--- a/src/utils/SkDeferredCanvas.cpp
+++ b/src/utils/SkDeferredCanvas.cpp
@@ -739,28 +739,25 @@ bool SkDeferredCanvas::isFullFrame(const SkRect* rect,
         SkIntToScalar(canvasSize.fWidth), SkIntToScalar(canvasSize.fHeight)));
 }
 
-int SkDeferredCanvas::save(SaveFlags flags) {
+void SkDeferredCanvas::onSave(SaveFlags flags) {
     this->drawingCanvas()->save(flags);
-    int val = this->INHERITED::save(flags);
     this->recordedDrawCommand();
-
-    return val;
+    this->INHERITED::onSave(flags);
 }
 
-int SkDeferredCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
-                                SaveFlags flags) {
+bool SkDeferredCanvas::onSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                                   SaveFlags flags) {
     this->drawingCanvas()->saveLayer(bounds, paint, flags);
-    int count = this->INHERITED::save(flags);
-    this->clipRectBounds(bounds, flags, NULL);
     this->recordedDrawCommand();
-
-    return count;
+    this->INHERITED::onSaveLayer(bounds, paint, flags);
+    // No need for a full layer.
+    return false;
 }
 
-void SkDeferredCanvas::restore() {
+void SkDeferredCanvas::onRestore() {
     this->drawingCanvas()->restore();
-    this->INHERITED::restore();
     this->recordedDrawCommand();
+    this->INHERITED::onRestore();
 }
 
 bool SkDeferredCanvas::isDrawingToLayer() const {
diff --git a/src/utils/SkDumpCanvas.cpp b/src/utils/SkDumpCanvas.cpp
index 4805d6287c..ccc5124f30 100644
--- a/src/utils/SkDumpCanvas.cpp
+++ b/src/utils/SkDumpCanvas.cpp
@@ -192,13 +192,13 @@ void SkDumpCanvas::dump(Verb verb, const SkPaint* paint,
 
 ///////////////////////////////////////////////////////////////////////////////
 
-int SkDumpCanvas::save(SaveFlags flags) {
+void SkDumpCanvas::onSave(SaveFlags flags) {
     this->dump(kSave_Verb, NULL, "save(0x%X)", flags);
-    return this->INHERITED::save(flags);
+    this->INHERITED::onSave(flags);
 }
 
-int SkDumpCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
-                             SaveFlags flags) {
+bool SkDumpCanvas::onSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                               SaveFlags flags) {
     SkString str;
     str.printf("saveLayer(0x%X)", flags);
     if (bounds) {
@@ -214,12 +214,12 @@ int SkDumpCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
         }
     }
     this->dump(kSave_Verb, paint, str.c_str());
-    return this->INHERITED::saveLayer(bounds, paint, flags);
+    return this->INHERITED::onSaveLayer(bounds, paint, flags);
 }
 
-void SkDumpCanvas::restore() {
-    this->INHERITED::restore();
+void SkDumpCanvas::onRestore() {
     this->dump(kRestore_Verb, NULL, "restore");
+    this->INHERITED::onRestore();
 }
 
 bool SkDumpCanvas::translate(SkScalar dx, SkScalar dy) {
diff --git a/src/utils/SkLuaCanvas.cpp b/src/utils/SkLuaCanvas.cpp
index 0f13073049..2679fd25bd 100644
--- a/src/utils/SkLuaCanvas.cpp
+++ b/src/utils/SkLuaCanvas.cpp
@@ -81,13 +81,13 @@ SkLuaCanvas::SkLuaCanvas(int width, int height, lua_State* L, const char func[])
 
 SkLuaCanvas::~SkLuaCanvas() {}
 
-int SkLuaCanvas::save(SaveFlags flags) {
+void SkLuaCanvas::onSave(SaveFlags flags) {
     AUTO_LUA("save");
-    return this->INHERITED::save(flags);
+    this->INHERITED::onSave(flags);
 }
 
-int SkLuaCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
-                             SaveFlags flags) {
+bool SkLuaCanvas::onSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                              SaveFlags flags) {
     AUTO_LUA("saveLayer");
     if (bounds) {
         lua.pushRect(*bounds, "bounds");
@@ -95,12 +95,15 @@ int SkLuaCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
     if (paint) {
         lua.pushPaint(*paint, "paint");
     }
-    return this->INHERITED::save(flags);
+
+    this->INHERITED::onSaveLayer(bounds, paint, flags);
+    // No need for a layer.
+    return false;
 }
 
-void SkLuaCanvas::restore() {
+void SkLuaCanvas::onRestore() {
     AUTO_LUA("restore");
-    this->INHERITED::restore();
+    this->INHERITED::onRestore();
 }
 
 bool SkLuaCanvas::translate(SkScalar dx, SkScalar dy) {
diff --git a/src/utils/SkNWayCanvas.cpp b/src/utils/SkNWayCanvas.cpp
index a9543f9c02..6fbec96204 100644
--- a/src/utils/SkNWayCanvas.cpp
+++ b/src/utils/SkNWayCanvas.cpp
@@ -57,29 +57,33 @@ private:
     SkCanvas* fCanvas;
 };
 
-int SkNWayCanvas::save(SaveFlags flags) {
+void SkNWayCanvas::onSave(SaveFlags flags) {
     Iter iter(fList);
     while (iter.next()) {
         iter->save(flags);
     }
-    return this->INHERITED::save(flags);
+
+    this->INHERITED::onSave(flags);
 }
 
-int SkNWayCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
-                                    SaveFlags flags) {
+bool SkNWayCanvas::onSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                               SaveFlags flags) {
     Iter iter(fList);
     while (iter.next()) {
         iter->saveLayer(bounds, paint, flags);
     }
-    return this->INHERITED::saveLayer(bounds, paint, flags);
+
+    this->INHERITED::onSaveLayer(bounds, paint, flags);
+    // No need for a layer.
+    return false;
 }
 
-void SkNWayCanvas::restore() {
+void SkNWayCanvas::onRestore() {
     Iter iter(fList);
     while (iter.next()) {
         iter->restore();
     }
-    this->INHERITED::restore();
+    this->INHERITED::onRestore();
 }
 
 bool SkNWayCanvas::translate(SkScalar dx, SkScalar dy) {
diff --git a/src/utils/SkNoSaveLayerCanvas.h b/src/utils/SkNoSaveLayerCanvas.h
index 60fad87237..037fcecab5 100644
--- a/src/utils/SkNoSaveLayerCanvas.h
+++ b/src/utils/SkNoSaveLayerCanvas.h
@@ -18,21 +18,13 @@ class SkNoSaveLayerCanvas : public SkCanvas {
 public:
     SkNoSaveLayerCanvas(SkBaseDevice* device) : INHERITED(device) {}
 
-    // turn saveLayer() into save() for speed, should not affect correctness.
-    virtual int saveLayer(const SkRect* bounds,
-                          const SkPaint* paint,
-                          SaveFlags flags) SK_OVERRIDE {
-
-        // Like SkPictureRecord, we don't want to create layers, but we do need
-        // to respect the save and (possibly) its rect-clip.
-        int count = this->INHERITED::save(flags);
-        if (NULL != bounds) {
-            this->INHERITED::clipRectBounds(bounds, flags, NULL);
-        }
-        return count;
+protected:
+    virtual bool onSaveLayer(const SkRect* bounds, const SkPaint* paint, SaveFlags flags)
+        SK_OVERRIDE {
+        this->INHERITED::onSaveLayer(bounds, paint, flags);
+        return false;
     }
 
-protected:
     // disable aa for speed
     virtual void onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle) SK_OVERRIDE {
         this->INHERITED::onClipRect(rect, op, kHard_ClipEdgeStyle);
diff --git a/src/utils/SkProxyCanvas.cpp b/src/utils/SkProxyCanvas.cpp
index 0a9d7a80c2..f61a31d9b3 100644
--- a/src/utils/SkProxyCanvas.cpp
+++ b/src/utils/SkProxyCanvas.cpp
@@ -21,17 +21,22 @@ void SkProxyCanvas::setProxy(SkCanvas* proxy) {
 
 ///////////////////////////////// Overrides ///////////
 
-int SkProxyCanvas::save(SaveFlags flags) {
-    return fProxy->save(flags);
+void SkProxyCanvas::onSave(SaveFlags flags) {
+    fProxy->save(flags);
+    this->INHERITED::onSave(flags);
 }
 
-int SkProxyCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
-                             SaveFlags flags) {
-    return fProxy->saveLayer(bounds, paint, flags);
+bool SkProxyCanvas::onSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                                SaveFlags flags) {
+    fProxy->saveLayer(bounds, paint, flags);
+    this->INHERITED::onSaveLayer(bounds, paint, flags);
+    // No need for a layer.
+    return false;
 }
 
-void SkProxyCanvas::restore() {
+void SkProxyCanvas::onRestore() {
     fProxy->restore();
+    this->INHERITED::onRestore();
 }
 
 bool SkProxyCanvas::translate(SkScalar dx, SkScalar dy) {
diff --git a/src/utils/debugger/SkDebugCanvas.cpp b/src/utils/debugger/SkDebugCanvas.cpp
index 08e6d94f9e..67ecc65b08 100644
--- a/src/utils/debugger/SkDebugCanvas.cpp
+++ b/src/utils/debugger/SkDebugCanvas.cpp
@@ -530,8 +530,9 @@ void SkDebugCanvas::onPopCull() {
     this->addDrawCommand(new SkPopCullCommand());
 }
 
-void SkDebugCanvas::restore() {
-    addDrawCommand(new SkRestoreCommand());
+void SkDebugCanvas::onRestore() {
+    this->addDrawCommand(new SkRestoreCommand());
+    this->INHERITED::onRestore();
 }
 
 bool SkDebugCanvas::rotate(SkScalar degrees) {
@@ -539,15 +540,17 @@ bool SkDebugCanvas::rotate(SkScalar degrees) {
     return true;
 }
 
-int SkDebugCanvas::save(SaveFlags flags) {
-    addDrawCommand(new SkSaveCommand(flags));
-    return true;
+void SkDebugCanvas::onSave(SaveFlags flags) {
+    this->addDrawCommand(new SkSaveCommand(flags));
+    this->INHERITED::onSave(flags);
 }
 
-int SkDebugCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint,
-        SaveFlags flags) {
-    addDrawCommand(new SkSaveLayerCommand(bounds, paint, flags));
-    return true;
+bool SkDebugCanvas::onSaveLayer(const SkRect* bounds, const SkPaint* paint,
+                                SaveFlags flags) {
+    this->addDrawCommand(new SkSaveLayerCommand(bounds, paint, flags));
+    this->INHERITED::onSaveLayer(bounds, paint, flags);
+    // No need for a full layer.
+    return false;
 }
 
 bool SkDebugCanvas::scale(SkScalar sx, SkScalar sy) {
diff --git a/src/utils/debugger/SkDebugCanvas.h b/src/utils/debugger/SkDebugCanvas.h
index 0bbb640a98..24824c964d 100644
--- a/src/utils/debugger/SkDebugCanvas.h
+++ b/src/utils/debugger/SkDebugCanvas.h
@@ -206,14 +206,8 @@ public:
                               const uint16_t indices[], int indexCount,
                               const SkPaint&) SK_OVERRIDE;
 
-    virtual void restore() SK_OVERRIDE;
-
     virtual bool rotate(SkScalar degrees) SK_OVERRIDE;
 
-    virtual int save(SaveFlags) SK_OVERRIDE;
-
-    virtual int saveLayer(const SkRect* bounds, const SkPaint*, SaveFlags) SK_OVERRIDE;
-
     virtual bool scale(SkScalar sx, SkScalar sy) SK_OVERRIDE;
 
     virtual void setMatrix(const SkMatrix& matrix) SK_OVERRIDE;
@@ -248,6 +242,10 @@ public:
     }
 
 protected:
+    virtual void onSave(SaveFlags) SK_OVERRIDE;
+    virtual bool onSaveLayer(const SkRect*, const SkPaint*, SaveFlags) SK_OVERRIDE;
+    virtual void onRestore() SK_OVERRIDE;
+
     virtual void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&) SK_OVERRIDE;
     virtual void onPushCull(const SkRect& cullRect) SK_OVERRIDE;
     virtual void onPopCull() SK_OVERRIDE;