Implement outline support for nine patches

b/15856895

Nine patches now have outline round rect metadata stored as optional
png tags. aapt generates these automatically by inspecting the bitmap
pixels to estimate outline bounds and round rect radius, based on
opacity.

Change-Id: I226e328a97873010d9e1adb797ac48f93a31183c

1 files changed, 33 insertions, 1 deletions

diff --git a/graphics/java/android/graphics/NinePatch.java b/graphics/java/android/graphics/NinePatch.java
index befac92..335bce0 100644
--- a/graphics/java/android/graphics/NinePatch.java
+++ b/graphics/java/android/graphics/NinePatch.java
@@ -16,7 +16,6 @@
 
 package android.graphics;
 
-
 /**
  * The NinePatch class permits drawing a bitmap in nine or more sections.
  * Essentially, it allows the creation of custom graphics that will scale the
@@ -32,6 +31,39 @@ package android.graphics;
  * </p>
  */
 public class NinePatch {
+    /**
+     * Struct of inset information attached to a 9 patch bitmap.
+     *
+     * Present on a 9 patch bitmap if it optical insets were manually included,
+     * or if outline insets were automatically included by aapt.
+     *
+     * @hide
+     */
+    public static class InsetStruct {
+        @SuppressWarnings({"UnusedDeclaration"}) // called from JNI
+        InsetStruct(int opticalLeft, int opticalTop, int opticalRight, int opticalBottom,
+                int outlineLeft, int outlineTop, int outlineRight, int outlineBottom,
+                float outlineRadius, boolean outlineFilled, float decodeScale) {
+            opticalRect = new Rect(opticalLeft, opticalTop, opticalRight, opticalBottom);
+            outlineRect = new Rect(outlineLeft, outlineTop, outlineRight, outlineBottom);
+
+            if (decodeScale != 1.0f) {
+                // if bitmap was scaled when decoded, scale the insets from the metadata values
+                opticalRect.scale(decodeScale);
+
+                // round inward while scaling outline, as the outline should always be conservative
+                outlineRect.scaleRoundIn(decodeScale);
+            }
+            this.outlineRadius = outlineRadius * decodeScale;
+            this.outlineFilled = outlineFilled;
+        }
+
+        public final Rect opticalRect;
+        public final Rect outlineRect;
+        public final float outlineRadius;
+        public final boolean outlineFilled;
+    }
+
     private final Bitmap mBitmap;
 
     /**