1 files changed, 64 insertions, 0 deletions
diff --git a/libs/hwui/utils/PaintUtils.h b/libs/hwui/utils/PaintUtils.h
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+++ b/libs/hwui/utils/PaintUtils.h
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+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef PAINT_UTILS_H
+#define PAINT_UTILS_H
+
+namespace android {
+namespace uirenderer {
+
+class PaintUtils {
+public:
+
+   /**
+     * Safely retrieves the mode from the specified xfermode. If the specified
+     * xfermode is null, the mode is assumed to be SkXfermode::kSrcOver_Mode.
+     */
+    static inline SkXfermode::Mode getXfermode(SkXfermode* mode) {
+        SkXfermode::Mode resultMode;
+        if (!SkXfermode::AsMode(mode, &resultMode)) {
+            resultMode = SkXfermode::kSrcOver_Mode;
+        }
+        return resultMode;
+    }
+
+    // TODO: move to a method on android:Paint? replace with SkPaint::nothingToDraw()?
+    static inline bool paintWillNotDraw(const SkPaint& paint) {
+        return paint.getAlpha() == 0
+                && !paint.getColorFilter()
+                && getXfermode(paint.getXfermode()) == SkXfermode::kSrcOver_Mode;
+    }
+
+    // TODO: move to a method on android:Paint? replace with SkPaint::nothingToDraw()?
+    static inline bool paintWillNotDrawText(const SkPaint& paint) {
+        return paint.getAlpha() == 0
+                && paint.getLooper() == NULL
+                && !paint.getColorFilter()
+                && getXfermode(paint.getXfermode()) == SkXfermode::kSrcOver_Mode;
+    }
+
+    static bool isBlendedColorFilter(const SkColorFilter* filter) {
+        if (filter == NULL) {
+            return false;
+        }
+        return (filter->getFlags() & SkColorFilter::kAlphaUnchanged_Flag) == 0;
+    }
+
+}; // class PaintUtils
+
+} /* namespace uirenderer */
+} /* namespace android */
+
+#endif /* PAINT_UTILS_H */