Simplify flattening to just write enough to call the factory/public-constructor for the class. We want to *not* rely on private constructors, and not rely on calling through the inheritance hierarchy for either flattening or unflattening(CreateProc).

Refactoring pattern:

1. guard the existing constructor(readbuffer) with the legacy build-flag
2. If you are a instancable subclass, implement CreateProc(readbuffer) to create a new instances from the buffer params (or return NULL).

If you're a shader subclass
1. You must read/write the local matrix if your class accepts that in its factory/constructor, else ignore it.

R=robertphillips@google.com, mtklein@google.com, senorblanco@google.com, senorblanco@chromium.org, sugoi@chromium.org

Author: reed@google.com

Review URL: https://codereview.chromium.org/395603002

1 files changed, 8 insertions, 18 deletions

diff --git a/src/effects/SkComposeImageFilter.cpp b/src/effects/SkComposeImageFilter.cpp
index 645d63372a..c0556749ac 100644
--- a/src/effects/SkComposeImageFilter.cpp
+++ b/src/effects/SkComposeImageFilter.cpp
@@ -21,14 +21,6 @@ bool SkComposeImageFilter::onFilterImage(Proxy* proxy,
     SkImageFilter* outer = getInput(0);
     SkImageFilter* inner = getInput(1);
 
-    if (!outer && !inner) {
-        return false;
-    }
-
-    if (!outer || !inner) {
-        return (outer ? outer : inner)->filterImage(proxy, src, ctx, result, offset);
-    }
-
     SkBitmap tmp;
     return inner->filterImage(proxy, src, ctx, &tmp, offset) &&
            outer->filterImage(proxy, tmp, ctx, result, offset);
@@ -40,19 +32,17 @@ bool SkComposeImageFilter::onFilterBounds(const SkIRect& src,
     SkImageFilter* outer = getInput(0);
     SkImageFilter* inner = getInput(1);
 
-    if (!outer && !inner) {
-        return false;
-    }
-
-    if (!outer || !inner) {
-        return (outer ? outer : inner)->filterBounds(src, ctm, dst);
-    }
-
     SkIRect tmp;
-    return inner->filterBounds(src, ctm, &tmp) &&
-           outer->filterBounds(tmp, ctm, dst);
+    return inner->filterBounds(src, ctm, &tmp) && outer->filterBounds(tmp, ctm, dst);
+}
+
+SkFlattenable* SkComposeImageFilter::CreateProc(SkReadBuffer& buffer) {
+    SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 2);
+    return SkComposeImageFilter::Create(common.getInput(0), common.getInput(1));
 }
 
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
 SkComposeImageFilter::SkComposeImageFilter(SkReadBuffer& buffer)
   : INHERITED(2, buffer) {
 }
+#endif