API Review: Improve javadoc.

Bug 17189781
Also rename PatternMotion to PatternPathMotion

Change-Id: I1c4dcbdd65e33cf9de1504277e31f9f7ede0380d
diff --git a/api/current.txt b/api/current.txt
index d7ddcf1..616b192 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -968,6 +968,7 @@
     field public static final int pathData = 16843807; // 0x101041f
     field public static final int pathPattern = 16842796; // 0x101002c
     field public static final int pathPrefix = 16842795; // 0x101002b
+    field public static final int patternPathData = 16843979; // 0x10104cb
     field public static final int permission = 16842758; // 0x1010006
     field public static final int permissionFlags = 16843719; // 0x10103c7
     field public static final int permissionGroup = 16842762; // 0x101000a
@@ -31493,13 +31494,13 @@
     method public abstract android.graphics.Path getPath(float, float, float, float);
   }
 
-  public class PatternMotion extends android.transition.PathMotion {
-    ctor public PatternMotion();
-    ctor public PatternMotion(android.content.Context, android.util.AttributeSet);
-    ctor public PatternMotion(android.graphics.Path);
+  public class PatternPathMotion extends android.transition.PathMotion {
+    ctor public PatternPathMotion();
+    ctor public PatternPathMotion(android.content.Context, android.util.AttributeSet);
+    ctor public PatternPathMotion(android.graphics.Path);
     method public android.graphics.Path getPath(float, float, float, float);
-    method public android.graphics.Path getPattern();
-    method public void setPattern(android.graphics.Path);
+    method public android.graphics.Path getPatternPath();
+    method public void setPatternPath(android.graphics.Path);
   }
 
   public final class Scene {
diff --git a/core/java/android/transition/ArcMotion.java b/core/java/android/transition/ArcMotion.java
index a27063d..f95fb49 100644
--- a/core/java/android/transition/ArcMotion.java
+++ b/core/java/android/transition/ArcMotion.java
@@ -41,9 +41,9 @@
  * {@code
  * <changeBounds>
  *   <arcMotion android:minimumHorizontalAngle="15"
- *     android:minimumVerticalAngle="0" android:maximumAngle="90"/>
- * </changeBounds>
- * }
+ *              android:minimumVerticalAngle="0"
+ *              android:maximumAngle="90"/>
+ * </changeBounds>}
  * </pre>
  */
 public class ArcMotion extends PathMotion {
diff --git a/core/java/android/transition/ChangeTransform.java b/core/java/android/transition/ChangeTransform.java
index cb0a875..1b8d57c 100644
--- a/core/java/android/transition/ChangeTransform.java
+++ b/core/java/android/transition/ChangeTransform.java
@@ -99,6 +99,7 @@
      * @return <code>true</code> when a changed parent should execute the transition
      * inside the scene root's overlay or <code>false</code> if a parent change only
      * affects the transform of the transitioning view.
+     * @attr ref android.R.styleable#ChangeTransform_reparentWithOverlay
      */
     public boolean getReparentWithOverlay() {
         return mUseOverlay;
@@ -120,6 +121,7 @@
      * @return <code>true</code> when a changed parent should execute the transition
      * inside the scene root's overlay or <code>false</code> if a parent change only
      * affects the transform of the transitioning view.
+     * @attr ref android.R.styleable#ChangeTransform_reparentWithOverlay
      */
     public void setReparentWithOverlay(boolean reparentWithOverlay) {
         mUseOverlay = reparentWithOverlay;
@@ -132,6 +134,7 @@
      * view will be tracked. Default is true.
      *
      * @return whether parent changes will be tracked by the ChangeTransform.
+     * @attr ref android.R.styleable#ChangeTransform_reparent
      */
     public boolean getReparent() {
         return mReparent;
@@ -145,6 +148,7 @@
      *
      * @param reparent Set to true to track parent changes or false to only track changes
      *                 of the transitioning view without considering the parent change.
+     * @attr ref android.R.styleable#ChangeTransform_reparent
      */
     public void setReparent(boolean reparent) {
         mReparent = reparent;
diff --git a/core/java/android/transition/PatternMotion.java b/core/java/android/transition/PatternPathMotion.java
similarity index 68%
rename from core/java/android/transition/PatternMotion.java
rename to core/java/android/transition/PatternPathMotion.java
index e4045b4..a609df6 100644
--- a/core/java/android/transition/PatternMotion.java
+++ b/core/java/android/transition/PatternPathMotion.java
@@ -34,36 +34,35 @@
  * <pre>
  * {@code
  * &lt;changeBounds>
- *     &lt;patternMotion android:pathData="M0 0 L0 100 L100 100"/>
- * &lt;/changeBounds>
- * }
+ *     &lt;patternPathMotion android:patternPathData="M0 0 L0 100 L100 100"/>
+ * &lt;/changeBounds>}
  * </pre>
  */
-public class PatternMotion extends PathMotion {
+public class PatternPathMotion extends PathMotion {
 
-    private Path mOriginalPattern;
+    private Path mOriginalPatternPath;
 
-    private final Path mPattern = new Path();
+    private final Path mPatternPath = new Path();
 
     private final Matrix mTempMatrix = new Matrix();
 
     /**
-     * Constructs a PatternMotion with a straight-line pattern.
+     * Constructs a PatternPathMotion with a straight-line pattern.
      */
-    public PatternMotion() {
-        mPattern.lineTo(1, 0);
-        mOriginalPattern = mPattern;
+    public PatternPathMotion() {
+        mPatternPath.lineTo(1, 0);
+        mOriginalPatternPath = mPatternPath;
     }
 
-    public PatternMotion(Context context, AttributeSet attrs) {
-        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.PatternMotion);
+    public PatternPathMotion(Context context, AttributeSet attrs) {
+        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.PatternPathMotion);
         try {
-            String pathData = a.getString(R.styleable.PatternMotion_pathData);
+            String pathData = a.getString(R.styleable.PatternPathMotion_patternPathData);
             if (pathData == null) {
-                throw new RuntimeException("pathData must be supplied for patternMotion");
+                throw new RuntimeException("pathData must be supplied for patternPathMotion");
             }
             Path pattern = PathParser.createPathFromPathData(pathData);
-            setPattern(pattern);
+            setPatternPath(pattern);
         } finally {
             a.recycle();
         }
@@ -71,14 +70,15 @@
     }
 
     /**
-     * Creates a PatternMotion with the Path defining a pattern of motion between two coordinates.
-     * The pattern will be translated, rotated, and scaled to fit between the start and end points.
-     * The pattern must not be empty and must have the end point differ from the start point.
+     * Creates a PatternPathMotion with the Path defining a pattern of motion between two
+     * coordinates. The pattern will be translated, rotated, and scaled to fit between the start
+     * and end points. The pattern must not be empty and must have the end point differ from the
+     * start point.
      *
-     * @param pattern A Path to be used as a pattern for two-dimensional motion.
+     * @param patternPath A Path to be used as a pattern for two-dimensional motion.
      */
-    public PatternMotion(Path pattern) {
-        setPattern(pattern);
+    public PatternPathMotion(Path patternPath) {
+        setPatternPath(patternPath);
     }
 
     /**
@@ -87,10 +87,10 @@
      * The pattern must not be empty and must have the end point differ from the start point.
      *
      * @return the Path defining a pattern of motion between two coordinates.
-     * @attr ref android.R.styleable#PatternMotion_pathData
+     * @attr ref android.R.styleable#PatternPathMotion_patternPathData
      */
-    public Path getPattern() {
-        return mOriginalPattern;
+    public Path getPatternPath() {
+        return mOriginalPatternPath;
     }
 
     /**
@@ -98,11 +98,11 @@
      * The pattern will be translated, rotated, and scaled to fit between the start and end points.
      * The pattern must not be empty and must have the end point differ from the start point.
      *
-     * @param pattern A Path to be used as a pattern for two-dimensional motion.
-     * @attr ref android.R.styleable#PatternMotion_pathData
+     * @param patternPath A Path to be used as a pattern for two-dimensional motion.
+     * @attr ref android.R.styleable#PatternPathMotion_patternPathData
      */
-    public void setPattern(Path pattern) {
-        PathMeasure pathMeasure = new PathMeasure(pattern, false);
+    public void setPatternPath(Path patternPath) {
+        PathMeasure pathMeasure = new PathMeasure(patternPath, false);
         float length = pathMeasure.getLength();
         float[] pos = new float[2];
         pathMeasure.getPosTan(length, pos, null);
@@ -124,8 +124,8 @@
         mTempMatrix.postScale(scale, scale);
         double angle = Math.atan2(dy, dx);
         mTempMatrix.postRotate((float) Math.toDegrees(-angle));
-        pattern.transform(mTempMatrix, mPattern);
-        mOriginalPattern = pattern;
+        patternPath.transform(mTempMatrix, mPatternPath);
+        mOriginalPatternPath = patternPath;
     }
 
     @Override
@@ -139,7 +139,7 @@
         mTempMatrix.postRotate((float) Math.toDegrees(angle));
         mTempMatrix.postTranslate(startX, startY);
         Path path = new Path();
-        mPattern.transform(mTempMatrix, path);
+        mPatternPath.transform(mTempMatrix, path);
         return path;
     }
 
diff --git a/core/java/android/transition/Transition.java b/core/java/android/transition/Transition.java
index bd52e71..0d1b568 100644
--- a/core/java/android/transition/Transition.java
+++ b/core/java/android/transition/Transition.java
@@ -1989,8 +1989,33 @@
      *     by extending PathMotion and implementing
      *     {@link android.transition.PathMotion#getPath(float, float, float, float)}.
      * </p>
+     * <p>
+     *     When describing in XML, use a nested XML tag for the path motion. It can be one of
+     *     the built-in tags <code>arcMotion</code> or <code>patternPathMotion</code> or it can
+     *     be a custom PathMotion using <code>pathMotion</code> with the <code>class</code>
+     *     attributed with the fully-described class name. For example:</p>
+     * <pre>
+     * {@code
+     * &lt;changeBounds>
+     *     &lt;pathMotion class="my.app.transition.MyPathMotion"/>
+     * &lt;/changeBounds>
+     * }
+     * </pre>
+     * <p>or</p>
+     * <pre>
+     * {@code
+     * &lt;changeBounds>
+     *   &lt;arcMotion android:minimumHorizontalAngle="15"
+     *     android:minimumVerticalAngle="0" android:maximumAngle="90"/>
+     * &lt;/changeBounds>
+     * }
+     * </pre>
+     *
      * @param pathMotion Algorithm object to use for determining how to interpolate in two
      *                   dimensions. If null, a straight-path algorithm will be used.
+     * @see android.transition.ArcMotion
+     * @see PatternPathMotion
+     * @see android.transition.PathMotion
      */
     public void setPathMotion(PathMotion pathMotion) {
         if (pathMotion == null) {
@@ -2004,7 +2029,31 @@
      * Returns the algorithm object used to interpolate along two dimensions. This is typically
      * used to determine the View motion between two points.
      *
+     * <p>
+     *     When describing in XML, use a nested XML tag for the path motion. It can be one of
+     *     the built-in tags <code>arcMotion</code> or <code>patternPathMotion</code> or it can
+     *     be a custom PathMotion using <code>pathMotion</code> with the <code>class</code>
+     *     attributed with the fully-described class name. For example:</p>
+     * <pre>
+     * {@code
+     * &lt;changeBounds>
+     *     &lt;pathMotion class="my.app.transition.MyPathMotion"/>
+     * &lt;/changeBounds>}
+     * </pre>
+     * <p>or</p>
+     * <pre>
+     * {@code
+     * &lt;changeBounds>
+     *   &lt;arcMotion android:minimumHorizontalAngle="15"
+     *              android:minimumVerticalAngle="0"
+     *              android:maximumAngle="90"/>
+     * &lt;/changeBounds>}
+     * </pre>
+     *
      * @return The algorithm object used to interpolate along two dimensions.
+     * @see android.transition.ArcMotion
+     * @see PatternPathMotion
+     * @see android.transition.PathMotion
      */
     public PathMotion getPathMotion() {
         return mPathMotion;
diff --git a/core/java/android/transition/TransitionInflater.java b/core/java/android/transition/TransitionInflater.java
index 760ffe1..9009d6a 100644
--- a/core/java/android/transition/TransitionInflater.java
+++ b/core/java/android/transition/TransitionInflater.java
@@ -171,8 +171,8 @@
                 parent.setPathMotion(new ArcMotion(mContext, attrs));
             } else if ("pathMotion".equals(name)) {
                 parent.setPathMotion((PathMotion)createCustom(attrs, PathMotion.class, "pathMotion"));
-            } else if ("patternMotion".equals(name)) {
-                parent.setPathMotion(new PatternMotion(mContext, attrs));
+            } else if ("patternPathMotion".equals(name)) {
+                parent.setPathMotion(new PatternPathMotion(mContext, attrs));
             } else {
                 throw new RuntimeException("Unknown scene name: " + parser.getName());
             }
diff --git a/core/res/res/values/attrs.xml b/core/res/res/values/attrs.xml
index 3629cbb..d1cc1fd 100644
--- a/core/res/res/values/attrs.xml
+++ b/core/res/res/values/attrs.xml
@@ -5686,12 +5686,12 @@
         <attr name="maximumAngle" format="float" />
     </declare-styleable>
 
-    <!-- Use <code>patternMotion</code> as the root tag of the XML resource that
-         describes a {@link android.transition.PatternMotion}. This must be used
+    <!-- Use <code>patternPathMotion</code> as the root tag of the XML resource that
+         describes a {@link android.transition.PatternPathMotion}. This must be used
          within a transition with which the PathMotion should be associated. -->
-    <declare-styleable name="PatternMotion">
-        <!-- The path string describing the pattern to use for the PathMotion. -->
-        <attr name="pathData" />
+    <declare-styleable name="PatternPathMotion">
+        <!-- The path string describing the pattern to use for the PathPathMotion. -->
+        <attr name="patternPathData" format="string" />
     </declare-styleable>
 
     <!-- ========================== -->
diff --git a/core/res/res/values/public.xml b/core/res/res/values/public.xml
index 4bf4531..a4c3474 100644
--- a/core/res/res/values/public.xml
+++ b/core/res/res/values/public.xml
@@ -2290,6 +2290,7 @@
   <public type="attr" name="fragmentReenterTransition" />
   <public type="attr" name="fragmentAllowEnterTransitionOverlap" />
   <public type="attr" name="fragmentAllowReturnTransitionOverlap" />
+  <public type="attr" name="patternPathData" />
 
   <public-padding type="dimen" name="l_resource_pad" end="0x01050010" />