Android: add playOnce()

Summary:
Add `playOnce()` that will play the animation only once and stops at the end
Closes #94

Differential Revision: D4385175

Pulled By: lozzle

fbshipit-source-id: 8b2f65003bfb9a3cfc040e90385369d13e1025c5

Author: m1ga

README.md

@@ -149,6 +149,9 @@ kfDrawable.stopAnimation();
 
 // Stops the animation when the current animation ends.
 kfDrawable.stopAnimationAtLoopEnd();
+
+// Starts the animation and plays it once. Will stop at the end
+kfDrawable.playOnce();
 ```
 
 ### Mobile Frameworks

android/keyframes/src/main/java/com/facebook/keyframes/KeyframesDrawable.java

@@ -290,6 +290,13 @@ public void startAnimation() {
     mKeyframesDrawableAnimationCallback.start();
   }
 
+  /**
+   * Starts the animation and plays it once
+   */
+  public void playOnce() {
+    mKeyframesDrawableAnimationCallback.playOnce();
+  }
+
   /**
    * Stops the animation callbacks for this drawable immediately.
    */

android/keyframes/src/main/java/com/facebook/keyframes/KeyframesDrawableAnimationCallback.java

@@ -104,6 +104,17 @@ public void start() {
     postCallback();
   }
 
+  /**
+   * Starts the animation and plays it once
+   */
+  public void playOnce() {
+    mStopAtLoopEnd = true;
+    mStartTimeMillis = 0;
+    mCurrentLoopNumber = 0;
+    cancelCallback();
+    postCallback();
+  }
+
   /**
    * Stops the callbacks animation and resets the start time.
    */