Refactor Drawable outline production, flesh out Outline methods

Change-Id: I1b8c25384b5f123e86cf5e0b2270eb741bc3159b

3 files changed, 77 insertions, 51 deletions

diff --git a/graphics/java/android/graphics/Outline.java b/graphics/java/android/graphics/Outline.java
index 4ea7ec7..d3aac79 100644
--- a/graphics/java/android/graphics/Outline.java
+++ b/graphics/java/android/graphics/Outline.java
@@ -16,18 +16,19 @@
 
 package android.graphics;
 
+import android.graphics.drawable.Drawable;
 import android.view.View;
 
 /**
  * Defines an area of content.
  *
- * Can be used with a View or Drawable to drive the shape of shadows cast by a
+ * Can be used with a View, or computed by a Drawable, to drive the shape of shadows cast by a
  * View, and allowing Views to clip inner content.
  *
  * @see View#setOutline(Outline)
- * @see View#setClipToOutline(boolean)
+ * @see Drawable#getOutline(Outline)
  */
-public class Outline {
+public final class Outline {
     /** @hide */
     public Rect mRect;
 
@@ -44,19 +45,26 @@ public class Outline {
     public Outline() {}
 
     /**
-     * Returns whether the Outline is valid for use with a View.
-     * <p>
-     * Outlines are invalid when constructed until a setter method is called.
+     * Constructs an Outline with a copy of the data in src.
      */
-    public final boolean isValid() {
-        return mRect != null || mPath != null;
+    public Outline(Outline src) {
+        set(src);
+    }
+
+    /** @hide */
+    public void markInvalid() {
+        mRadius = 0;
+        mRect = null;
+        mPath = null;
     }
 
     /**
-     * @hide
+     * Returns whether the Outline is valid for use with a View.
+     * <p>
+     * Outlines are invalid when constructed until a setter method is called.
      */
-    public final boolean canClip() {
-        return mPath == null;
+    public boolean isValid() {
+        return mRect != null || mPath != null;
     }
 
     /**
@@ -81,9 +89,20 @@ public class Outline {
 
     /**
      * Sets the Outline to the rounded rect defined by the input rect, and corner radius.
-     * <p>
-     * Outlines produced by this method support
-     * {@link View#setClipToOutline(boolean) View clipping.}
+     */
+    public void setRect(int left, int top, int right, int bottom) {
+        setRoundRect(left, top, right, bottom, 0.0f);
+    }
+
+    /**
+     * Convenience for {@link #setRect(int, int, int, int)}
+     */
+    public void setRect(Rect rect) {
+        setRect(rect.left, rect.top, rect.right, rect.bottom);
+    }
+
+    /**
+     * Sets the Outline to the rounded rect defined by the input rect, and corner radius.
      */
     public void setRoundRect(int left, int top, int right, int bottom, float radius) {
         if (mRect == null) mRect = new Rect();
@@ -93,9 +112,16 @@ public class Outline {
     }
 
     /**
+     * Convenience for {@link #setRoundRect(int, int, int, int, float)}
+     * @param rect
+     * @param radius
+     */
+    public void setRoundRect(Rect rect, float radius) {
+        setRoundRect(rect.left, rect.top, rect.right, rect.bottom, radius);
+    }
+
+    /**
      * Sets the Constructs an Outline from a {@link android.graphics.Path#isConvex() convex path}.
-     *
-     * @hide
      */
     public void setConvexPath(Path convexPath) {
         if (!convexPath.isConvex()) {
diff --git a/graphics/java/android/graphics/drawable/Drawable.java b/graphics/java/android/graphics/drawable/Drawable.java
index 74d1219..b9d5e19 100644
--- a/graphics/java/android/graphics/drawable/Drawable.java
+++ b/graphics/java/android/graphics/drawable/Drawable.java
@@ -864,22 +864,21 @@ public abstract class Drawable {
     }
 
     /**
-     * Returns the outline for this drawable if defined, null if not.
+     * Called to get the drawable to populate the Outline.
      * <p>
-     * This method will be called by a View on its background Drawable after
-     * bounds change, if the View's Outline isn't set explicitly. This allows
-     * the background Drawable to provide the shape of the shadow casting
-     * portion of the View. It can also serve to clip the area of the View if
-     * if {@link View#setClipToOutline(boolean)} is set on the View.
-     * <p>
-     * The Outline queried by the View will not be modified, and is treated as
-     * a static shape that only needs to be requeried when the drawable's bounds
-     * change.
+     * This method will be called by a View on its background Drawable after bounds change, or its
+     * Drawable is invalidated, if the View's Outline isn't set explicitly. This allows the
+     * background Drawable to define the shape of the shadow cast by the View.
+     *
+     * The default behavior defines the outline to be the bounding rectangle. Subclasses that wish
+     * to convey a different shape must override this method.
      *
-     * @see View#setOutline(android.view.Outline)
-     * @see View#setClipToOutline(boolean)
+     * @see View#setOutline(android.graphics.Outline)
      */
-    public Outline getOutline() { return null; }
+    public boolean getOutline(Outline outline) {
+        outline.setRect(getBounds());
+        return true;
+    }
 
     /**
      * Make this drawable mutable. This operation cannot be reversed. A mutable
diff --git a/graphics/java/android/graphics/drawable/GradientDrawable.java b/graphics/java/android/graphics/drawable/GradientDrawable.java
index 1b5cefe..708c8b0 100644
--- a/graphics/java/android/graphics/drawable/GradientDrawable.java
+++ b/graphics/java/android/graphics/drawable/GradientDrawable.java
@@ -139,8 +139,7 @@ public class GradientDrawable extends Drawable {
 
     private final Path mPath = new Path();
     private final RectF mRect = new RectF();
-    private Outline mOutline;
-    
+
     private Paint mLayerPaint;    // internal, used if we use saveLayer()
     private boolean mRectIsDirty;   // internal state
     private boolean mMutated;
@@ -573,15 +572,11 @@ public class GradientDrawable extends Drawable {
                 mStrokePaint.setColorFilter(mColorFilter);
             }
         }
-        
+
         switch (st.mShape) {
             case RECTANGLE:
                 if (st.mRadiusArray != null) {
-                    if (mPathIsDirty || mRectIsDirty) {
-                        mPath.reset();
-                        mPath.addRoundRect(mRect, st.mRadiusArray, Path.Direction.CW);
-                        mPathIsDirty = mRectIsDirty = false;
-                    }
+                    buildPathIfDirty();
                     canvas.drawPath(mPath, mFillPaint);
                     if (haveStroke) {
                         canvas.drawPath(mPath, mStrokePaint);
@@ -638,7 +633,16 @@ public class GradientDrawable extends Drawable {
             }
         }
     }
-    
+
+    private void buildPathIfDirty() {
+        final GradientState st = mGradientState;
+        if (mPathIsDirty || mRectIsDirty) {
+            mPath.reset();
+            mPath.addRoundRect(mRect, st.mRadiusArray, Path.Direction.CW);
+            mPathIsDirty = mRectIsDirty = false;
+        }
+    }
+
     private Path buildRing(GradientState st) {
         if (mRingPath != null && (!st.mUseLevelForShape || !mPathIsDirty)) return mRingPath;
         mPathIsDirty = false;
@@ -1428,42 +1432,39 @@ public class GradientDrawable extends Drawable {
     }
 
     @Override
-    public Outline getOutline() {
+    public boolean getOutline(Outline outline) {
         final GradientState st = mGradientState;
         final Rect bounds = getBounds();
 
         switch (st.mShape) {
             case RECTANGLE:
                 if (st.mRadiusArray != null) {
-                    return null;
+                    buildPathIfDirty();
+                    outline.setConvexPath(mPath);
+                    return true;
                 }
+
                 float rad = 0;
                 if (st.mRadius > 0.0f) {
                     // clamp the radius based on width & height, matching behavior in draw()
                     rad = Math.min(st.mRadius,
                             Math.min(bounds.width(), bounds.height()) * 0.5f);
                 }
-                if (mOutline == null) {
-                    mOutline = new Outline();
-                }
-                mOutline.setRoundRect(bounds.left, bounds.top,
+                outline.setRoundRect(bounds.left, bounds.top,
                         bounds.right, bounds.bottom, rad);
-                return mOutline;
+                return true;
             case LINE: {
                 float halfStrokeWidth = mStrokePaint.getStrokeWidth() * 0.5f;
                 float centerY = bounds.centerY();
                 int top = (int) Math.floor(centerY - halfStrokeWidth);
                 int bottom = (int) Math.ceil(centerY + halfStrokeWidth);
 
-                if (mOutline == null) {
-                    mOutline = new Outline();
-                }
-                mOutline.setRoundRect(bounds.left, top, bounds.right, bottom, 0);
-                return mOutline;
+                outline.setRect(bounds.left, top, bounds.right, bottom);
+                return true;
             }
             default:
                 // TODO: investigate
-                return null;
+                return false;
         }
     }