Use BlendComposite for advanced PorterDuff Modes. [DO NOT MERGE]

Not all PorterDuff modes are supported by Java's AlphaComposite. Use
BlendComposite for such modes.

Change-Id: I51486a40f09186cf8a87ce1e6a3d1cfcf39fb2d3
(cherry picked from commit b15709cd36d28c47660b0ae30918642bfd3d85f7)

4 files changed, 75 insertions, 95 deletions

diff --git a/tools/layoutlib/bridge/src/android/graphics/Canvas_Delegate.java b/tools/layoutlib/bridge/src/android/graphics/Canvas_Delegate.java
index 7c8ef70..2ff0fc1 100644
--- a/tools/layoutlib/bridge/src/android/graphics/Canvas_Delegate.java
+++ b/tools/layoutlib/bridge/src/android/graphics/Canvas_Delegate.java
@@ -20,6 +20,7 @@ import com.android.ide.common.rendering.api.LayoutLog;
 import com.android.layoutlib.bridge.Bridge;
 import com.android.layoutlib.bridge.impl.DelegateManager;
 import com.android.layoutlib.bridge.impl.GcSnapshot;
+import com.android.layoutlib.bridge.impl.PorterDuffUtility;
 import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
 
 import android.graphics.Bitmap.Config;
@@ -534,7 +535,8 @@ public final class Canvas_Delegate {
                 // set the color
                 graphics.setColor(new Color(color, true /*alpha*/));
 
-                Composite composite = PorterDuffXfermode_Delegate.getComposite(mode, 0xFF);
+                Composite composite = PorterDuffUtility.getComposite(
+                        PorterDuffUtility.getPorterDuffMode(mode), 0xFF);
                 if (composite != null) {
                     graphics.setComposite(composite);
                 }
diff --git a/tools/layoutlib/bridge/src/android/graphics/PorterDuffColorFilter_Delegate.java b/tools/layoutlib/bridge/src/android/graphics/PorterDuffColorFilter_Delegate.java
index ee90595..4ac376c 100644
--- a/tools/layoutlib/bridge/src/android/graphics/PorterDuffColorFilter_Delegate.java
+++ b/tools/layoutlib/bridge/src/android/graphics/PorterDuffColorFilter_Delegate.java
@@ -21,11 +21,10 @@ import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
 
 import android.graphics.PorterDuff.Mode;
 
-import java.awt.AlphaComposite;
 import java.awt.Graphics2D;
 import java.awt.image.BufferedImage;
 
-import static com.android.layoutlib.bridge.impl.PorterDuffUtility.getAlphaCompositeRule;
+import static com.android.layoutlib.bridge.impl.PorterDuffUtility.getComposite;
 import static com.android.layoutlib.bridge.impl.PorterDuffUtility.getPorterDuffMode;
 
 /**
@@ -57,7 +56,7 @@ public class PorterDuffColorFilter_Delegate extends ColorFilter_Delegate {
 
     @Override
     public boolean isSupported() {
-        return getAlphaCompositeRule(mMode) != -1;
+        return true;
     }
 
     @Override
@@ -68,7 +67,7 @@ public class PorterDuffColorFilter_Delegate extends ColorFilter_Delegate {
     @Override
     public void applyFilter(Graphics2D g, int width, int height) {
         BufferedImage image = createFilterImage(width, height);
-        g.setComposite(getComposite());
+        g.setComposite(getComposite(mMode, 0xFF));
         g.drawImage(image, 0, 0, null);
     }
 
@@ -101,49 +100,36 @@ public class PorterDuffColorFilter_Delegate extends ColorFilter_Delegate {
         return image;
     }
 
-    private AlphaComposite getComposite() {
-        return AlphaComposite.getInstance(getAlphaCompositeRule(mMode));
-    }
-
     // For filtering the colors, the src image should contain the "color" only for pixel values
     // which are not transparent in the target image. But, we are using a simple rectangular image
-    // completely filled with color. Hence some AlphaComposite rules do not apply as intended.
-    // However, in such cases, they can usually be mapped to some other mode, which produces an
+    // completely filled with color. Hence some Composite rules do not apply as intended. However,
+    // in such cases, they can usually be mapped to some other mode, which produces an
     // equivalent result.
     private Mode getCompatibleMode(Mode mode) {
         Mode m = mode;
+        // Modes that are directly supported:
+        // CLEAR, DST, SRC_IN, DST_IN, DST_OUT, SRC_ATOP, DARKEN, LIGHTEN, MULTIPLY, SCREEN,
+        // ADD, OVERLAY
         switch (mode) {
-            // Modes that are directly supported.
-            case CLEAR:
-            case DST:
-            case SRC_IN:
-            case DST_IN:
-            case DST_OUT:
-            case SRC_ATOP:
-                break;
-            // Modes that can be mapped to one of the supported modes.
-            case SRC:
-                m = Mode.SRC_IN;
-                break;
-            case SRC_OVER:
-                m = Mode.SRC_ATOP;
-                break;
-            case DST_OVER:
-                m = Mode.DST;
-                break;
-            case SRC_OUT:
-                m = Mode.CLEAR;
-                break;
-            case DST_ATOP:
-                m = Mode.DST_IN;
-                break;
-            case XOR:
-                m = Mode.DST_OUT;
-                break;
-            // This mode is not supported, but used by Action Bar Overflow Popup Menus. We map this
-            // to the closest supported mode, to prevent showing excessive warnings to the user.
-            case MULTIPLY:
-                m = Mode.SRC_IN;
+        // Modes that can be mapped to one of the supported modes.
+        case SRC:
+            m = Mode.SRC_IN;
+            break;
+        case SRC_OVER:
+            m = Mode.SRC_ATOP;
+            break;
+        case DST_OVER:
+            m = Mode.DST;
+            break;
+        case SRC_OUT:
+            m = Mode.CLEAR;
+            break;
+        case DST_ATOP:
+            m = Mode.DST_IN;
+            break;
+        case XOR:
+            m = Mode.DST_OUT;
+            break;
         }
         return m;
     }
diff --git a/tools/layoutlib/bridge/src/android/graphics/PorterDuffXfermode_Delegate.java b/tools/layoutlib/bridge/src/android/graphics/PorterDuffXfermode_Delegate.java
index f6c36b6..8825f84 100644
--- a/tools/layoutlib/bridge/src/android/graphics/PorterDuffXfermode_Delegate.java
+++ b/tools/layoutlib/bridge/src/android/graphics/PorterDuffXfermode_Delegate.java
@@ -16,17 +16,14 @@
 
 package android.graphics;
 
-import com.android.ide.common.rendering.api.LayoutLog;
-import com.android.layoutlib.bridge.Bridge;
 import com.android.layoutlib.bridge.impl.DelegateManager;
+import com.android.layoutlib.bridge.impl.PorterDuffUtility;
 import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
 
 import android.graphics.PorterDuff.Mode;
 
-import java.awt.AlphaComposite;
 import java.awt.Composite;
 
-import static com.android.layoutlib.bridge.impl.PorterDuffUtility.getAlphaCompositeRule;
 import static com.android.layoutlib.bridge.impl.PorterDuffUtility.getPorterDuffMode;
 
 /**
@@ -58,7 +55,7 @@ public class PorterDuffXfermode_Delegate extends Xfermode_Delegate {
 
     @Override
     public Composite getComposite(int alpha) {
-        return getComposite(mMode, alpha);
+        return PorterDuffUtility.getComposite(mMode, alpha);
     }
 
     @Override
@@ -72,9 +69,6 @@ public class PorterDuffXfermode_Delegate extends Xfermode_Delegate {
         return null;
     }
 
-    public static Composite getComposite(int mode, int alpha) {
-        return getComposite(getPorterDuffMode(mode), alpha);
-    }
 
     // ---- native methods ----
 
@@ -90,17 +84,4 @@ public class PorterDuffXfermode_Delegate extends Xfermode_Delegate {
         mMode = getPorterDuffMode(mode);
     }
 
-    private static Composite getComposite(Mode mode, int alpha255) {
-        float alpha1 = alpha255 != 0xFF ? alpha255 / 255.f : 1.f;
-        int rule = getAlphaCompositeRule(mode);
-        if (rule >= 0) {
-            return AlphaComposite.getInstance(rule, alpha1);
-        }
-
-        Bridge.getLog().fidelityWarning(LayoutLog.TAG_BROKEN,
-                String.format("Unsupported PorterDuff Mode: %1$s", mode.name()),
-                null, null /*data*/);
-
-        return AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha1);
-    }
 }
diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/PorterDuffUtility.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/PorterDuffUtility.java
index bc53e93..9588035 100644
--- a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/PorterDuffUtility.java
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/impl/PorterDuffUtility.java
@@ -19,11 +19,14 @@ package com.android.layoutlib.bridge.impl;
 import com.android.ide.common.rendering.api.LayoutLog;
 import com.android.layoutlib.bridge.Bridge;
 
+import android.graphics.BlendComposite;
+import android.graphics.BlendComposite.BlendingMode;
 import android.graphics.PorterDuff.Mode;
 import android.graphics.PorterDuffColorFilter_Delegate;
 import android.graphics.PorterDuffXfermode_Delegate;
 
 import java.awt.AlphaComposite;
+import java.awt.Composite;
 
 /**
  * Provides various utility methods for {@link PorterDuffColorFilter_Delegate} and {@link
@@ -51,46 +54,54 @@ public final class PorterDuffUtility {
     }
 
     /**
-     * A utility method to convert the porterDuffMode to an int to be used as a rule for {@link
-     * AlphaComposite}. If {@code AlphaComposite} doesn't support the mode, -1 is returned.
+     * A utility method to get the {@link Composite} that represents the filter for the given
+     * PorterDuff mode and the alpha. Defaults to {@link Mode#SRC_OVER} for invalid modes.
      */
-    public static int getAlphaCompositeRule(Mode porterDuffMode) {
-        switch (porterDuffMode) {
+    public static Composite getComposite(Mode mode, int alpha255) {
+        float alpha1 = alpha255 != 0xFF ? alpha255 / 255.f : 1.f;
+        switch (mode) {
             case CLEAR:
-                return AlphaComposite.CLEAR;
-            case DARKEN:
-                break;
+                return AlphaComposite.getInstance(AlphaComposite.CLEAR, alpha1);
+            case SRC:
+                return AlphaComposite.getInstance(AlphaComposite.SRC, alpha1);
             case DST:
-                return AlphaComposite.DST;
-            case DST_ATOP:
-                return AlphaComposite.DST_ATOP;
+                return AlphaComposite.getInstance(AlphaComposite.DST, alpha1);
+            case SRC_OVER:
+                return AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha1);
+            case DST_OVER:
+                return AlphaComposite.getInstance(AlphaComposite.DST_OVER, alpha1);
+            case SRC_IN:
+                return AlphaComposite.getInstance(AlphaComposite.SRC_IN, alpha1);
             case DST_IN:
-                return AlphaComposite.DST_IN;
+                return AlphaComposite.getInstance(AlphaComposite.DST_IN, alpha1);
+            case SRC_OUT:
+                return AlphaComposite.getInstance(AlphaComposite.SRC_OUT, alpha1);
             case DST_OUT:
-                return AlphaComposite.DST_OUT;
-            case DST_OVER:
-                return AlphaComposite.DST_OVER;
+                return AlphaComposite.getInstance(AlphaComposite.DST_OUT, alpha1);
+            case SRC_ATOP:
+                return AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha1);
+            case DST_ATOP:
+                return AlphaComposite.getInstance(AlphaComposite.DST_ATOP, alpha1);
+            case XOR:
+                return AlphaComposite.getInstance(AlphaComposite.XOR, alpha1);
+            case DARKEN:
+                return BlendComposite.getInstance(BlendingMode.DARKEN, alpha1);
             case LIGHTEN:
-                break;
+                return BlendComposite.getInstance(BlendingMode.LIGHTEN, alpha1);
             case MULTIPLY:
-                break;
+                return BlendComposite.getInstance(BlendingMode.MULTIPLY, alpha1);
             case SCREEN:
-                break;
-            case SRC:
-                return AlphaComposite.SRC;
-            case SRC_ATOP:
-                return AlphaComposite.SRC_ATOP;
-            case SRC_IN:
-                return AlphaComposite.SRC_IN;
-            case SRC_OUT:
-                return AlphaComposite.SRC_OUT;
-            case SRC_OVER:
-                return AlphaComposite.SRC_OVER;
-            case XOR:
-                return AlphaComposite.XOR;
-        }
-        // This is an unsupported mode.
-        return -1;
+                return BlendComposite.getInstance(BlendingMode.SCREEN, alpha1);
+            case ADD:
+                return BlendComposite.getInstance(BlendingMode.ADD, alpha1);
+            case OVERLAY:
+                return BlendComposite.getInstance(BlendingMode.OVERLAY, alpha1);
+            default:
+                Bridge.getLog().fidelityWarning(LayoutLog.TAG_BROKEN,
+                        String.format("Unsupported PorterDuff Mode: %1$s", mode.name()),
+                        null, null /*data*/);
 
+                return AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha1);
+        }
     }
 }