Factory methods for heap-allocated SkImageFilter objects.

This is part of an effort to ensure that all SkPaint effects can only be
allocated on the heap.

This patch makes the constructors of SkImageFilter and its subclasses non-public
and instead provides factory methods for creating these objects on the heap. We
temporarily keep constructor of publicly visible classes public behind a flag.

BUG=skia:2187
R=scroggo@google.com, mtklein@chromium.org, reed@google.com, senorblanco@google.com, senorblanco@chromium.org, bsalomon@google.com, sugoi@chromium.org, zork@chromium.org

Author: dominikg@chromium.org

Review URL: https://codereview.chromium.org/182983003

git-svn-id: http://skia.googlecode.com/svn/trunk@13718 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 11 insertions, 3 deletions

diff --git a/include/effects/SkTileImageFilter.h b/include/effects/SkTileImageFilter.h
index 390e00c9a4..4bc2a20091 100644
--- a/include/effects/SkTileImageFilter.h
+++ b/include/effects/SkTileImageFilter.h
@@ -14,13 +14,15 @@ class SK_API SkTileImageFilter : public SkImageFilter {
     typedef SkImageFilter INHERITED;
 
 public:
-    /** Tile image filter constructor
+    /** Create a tile image filter
         @param srcRect  Defines the pixels to tile
         @param dstRect  Defines the pixels where tiles are drawn
         @param input    Input from which the subregion defined by srcRect will be tiled
     */
-    SkTileImageFilter(const SkRect& srcRect, const SkRect& dstRect, SkImageFilter* input)
-        : INHERITED(input), fSrcRect(srcRect), fDstRect(dstRect) {}
+    static SkTileImageFilter* Create(const SkRect& srcRect, const SkRect& dstRect,
+                                     SkImageFilter* input) {
+        return SkNEW_ARGS(SkTileImageFilter, (srcRect, dstRect, input));
+    }
 
     virtual bool onFilterImage(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
                                SkBitmap* dst, SkIPoint* offset) const SK_OVERRIDE;
@@ -32,6 +34,12 @@ protected:
 
     virtual void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE;
 
+#ifdef SK_SUPPORT_LEGACY_PUBLICEFFECTCONSTRUCTORS
+public:
+#endif
+    SkTileImageFilter(const SkRect& srcRect, const SkRect& dstRect, SkImageFilter* input)
+        : INHERITED(input), fSrcRect(srcRect), fDstRect(dstRect) {}
+
 private:
     SkRect fSrcRect;
     SkRect fDstRect;