SkClipStack::Element tweaks.

(
This is intended to facilitate efficient kMatrix_SaveFlags emulation
on restore():

  * collect all clip stack elements for the current save count into a
    side clip stack
  * canvas.restore(everything)
  * replay the collected clip ops to restore the initial clip state
  => we restored the matrix but the clip state is unchanged
)

Two main changes:

  * expose the save count for SkClipStack::Element
  * expose a replay method for the same (logic relocated from
    SkCanvas::replayClips)

The SkCanvas::ClipVisitor shuffling is to enable forward decl
in SkClipStack.h (cannot fwdecl a nested class).

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

Author: fmalita@chromium.org

Review URL: https://codereview.chromium.org/269693003

1 files changed, 9 insertions, 8 deletions

diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index ee8ad250d..b92b1460f 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -24,6 +24,7 @@
     #define SK_LEGACY_DRAWTEXT_VIRTUAL
 #endif
 
+class SkCanvasClipVisitor;
 class SkBaseDevice;
 class SkDraw;
 class SkDrawFilter;
@@ -1134,14 +1135,7 @@ public:
         return &fClipStack;
     }
 
-    class ClipVisitor {
-    public:
-        virtual ~ClipVisitor();
-        virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0;
-        virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0;
-        virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0;
-    };
-
+    typedef SkCanvasClipVisitor ClipVisitor;
     /**
      *  Replays the clip operations, back to front, that have been applied to
      *  the canvas, calling the appropriate method on the visitor for each
@@ -1504,5 +1498,12 @@ static inline SkCanvas::SaveFlags& operator|=(SkCanvas::SaveFlags& lhs,
     return lhs;
 }
 
+class SkCanvasClipVisitor {
+public:
+    virtual ~SkCanvasClipVisitor();
+    virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0;
+    virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0;
+    virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0;
+};
 
 #endif