LayoutLib: Misc rendering fixes.

- always set up the stroke. Paint may not have the proper
  style when drawing lines. stroke should still be setup.

- Fixed vertical linear gradient. Old code generated
  a gradient ratio of NaN

- Fixed alpha rendering when using shaders. In that
  case the alpha channel from the paint color should be
  used in conjunction with the shader.

- Fixed miter limit. Java expects the value to be multiplied
  by the stroke width

- Fixed support for drawing ALPHA_8 bitmaps. Java2D doesn't
  have bitmaps with only alpha channels, so we keep using
  ARGB bitmaps but when drawing them into a bitmap we erase
  the color information.

Change-Id: I4f04341fc843e3f7dadd1fdbf709b11a4f1e24b9

1 files changed, 31 insertions, 31 deletions

diff --git a/tools/layoutlib/bridge/src/android/graphics/PorterDuffXfermode_Delegate.java b/tools/layoutlib/bridge/src/android/graphics/PorterDuffXfermode_Delegate.java
index 3e9a346..097dfce 100644
--- a/tools/layoutlib/bridge/src/android/graphics/PorterDuffXfermode_Delegate.java
+++ b/tools/layoutlib/bridge/src/android/graphics/PorterDuffXfermode_Delegate.java
@@ -46,8 +46,8 @@ public class PorterDuffXfermode_Delegate extends Xfermode_Delegate {
     // ---- Public Helper methods ----
 
     @Override
-    public Composite getComposite() {
-        return getComposite(mMode);
+    public Composite getComposite(int alpha) {
+        return getComposite(getPorterDuffMode(mMode), alpha);
     }
 
     @Override
@@ -61,23 +61,35 @@ public class PorterDuffXfermode_Delegate extends Xfermode_Delegate {
         return null;
     }
 
-    public static Composite getComposite(int mode) {
-        PorterDuff.Mode m = getMode(mode);
-        switch (m) {
+    public static PorterDuff.Mode getPorterDuffMode(int mode) {
+        for (PorterDuff.Mode m : PorterDuff.Mode.values()) {
+            if (m.nativeInt == mode) {
+                return m;
+            }
+        }
+
+        Bridge.getLog().error(null, String.format("Unknown PorterDuff.Mode: %d", mode));
+        assert false;
+        return PorterDuff.Mode.SRC_OVER;
+    }
+
+    public static Composite getComposite(PorterDuff.Mode mode, int alpha) {
+        float falpha = alpha != 0xFF ? (float)alpha / 255.f : 1.f;
+        switch (mode) {
             case CLEAR:
-                return AlphaComposite.getInstance(AlphaComposite.CLEAR, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.CLEAR, falpha);
             case DARKEN:
                 break;
             case DST:
-                return AlphaComposite.getInstance(AlphaComposite.DST, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.DST, falpha);
             case DST_ATOP:
-                return AlphaComposite.getInstance(AlphaComposite.DST_ATOP, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.DST_ATOP, falpha);
             case DST_IN:
-                return AlphaComposite.getInstance(AlphaComposite.DST_IN, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.DST_IN, falpha);
             case DST_OUT:
-                return AlphaComposite.getInstance(AlphaComposite.DST_OUT, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.DST_OUT, falpha);
             case DST_OVER:
-                return AlphaComposite.getInstance(AlphaComposite.DST_OVER, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.DST_OVER, falpha);
             case LIGHTEN:
                 break;
             case MULTIPLY:
@@ -85,24 +97,24 @@ public class PorterDuffXfermode_Delegate extends Xfermode_Delegate {
             case SCREEN:
                 break;
             case SRC:
-                return AlphaComposite.getInstance(AlphaComposite.SRC, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.SRC, falpha);
             case SRC_ATOP:
-                return AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, falpha);
             case SRC_IN:
-                return AlphaComposite.getInstance(AlphaComposite.SRC_IN, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.SRC_IN, falpha);
             case SRC_OUT:
-                return AlphaComposite.getInstance(AlphaComposite.SRC_OUT, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.SRC_OUT, falpha);
             case SRC_OVER:
-                return AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.SRC_OVER, falpha);
             case XOR:
-                return AlphaComposite.getInstance(AlphaComposite.XOR, 1.0f /*alpha*/);
+                return AlphaComposite.getInstance(AlphaComposite.XOR, falpha);
         }
 
         Bridge.getLog().fidelityWarning(null,
-                String.format("Unsupported PorterDuff Mode: %s", m.name()),
+                String.format("Unsupported PorterDuff Mode: %s", mode.name()),
                 null);
 
-        return AlphaComposite.getInstance(AlphaComposite.SRC_OVER);
+        return AlphaComposite.getInstance(AlphaComposite.SRC_OVER, falpha);
     }
 
     // ---- native methods ----
@@ -117,16 +129,4 @@ public class PorterDuffXfermode_Delegate extends Xfermode_Delegate {
     private PorterDuffXfermode_Delegate(int mode) {
         mMode = mode;
     }
-
-    private static PorterDuff.Mode getMode(int mode) {
-        for (PorterDuff.Mode m : PorterDuff.Mode.values()) {
-            if (m.nativeInt == mode) {
-                return m;
-            }
-        }
-
-        Bridge.getLog().error(null, String.format("Unknown PorterDuff.Mode: %d", mode));
-        assert false;
-        return PorterDuff.Mode.SRC_OVER;
-    }
 }