title: Adding Fling Gesture to an image view - Android
body: <p>Okay I have been referencing the code here: <a href="https://stackoverflow.com/questions/937313/android-basic-gesture-detection">Fling gesture detection on grid layout</a> </p>
  
  <p>but just can not get it to work. In my main activity I have a simple image defined. I want to detect a fling on the image. Here is my code below. The onclick method at the bottom is empty. Is it because of this? I left it blank because in the other code sample its not what I want. I just want a simple toast to pop up saying fling right or fling left.</p>
  
  <pre><code>public class GestureRightLeft extends Activity implements OnClickListener  {
  
      ImageView peek;
  
      private static final int SWIPE_MIN_DISTANCE = 120;
      private static final int SWIPE_MAX_OFF_PATH = 250;
      private static final int SWIPE_THRESHOLD_VELOCITY = 200;
      private GestureDetector gestureDetector;
      View.OnTouchListener gestureListener;
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.main);
  
          peek =(ImageView) findViewById(R.id.peek);
          peek.setImageResource(R.drawable.bluestrip);
  
          gestureDetector = new GestureDetector(new MyGestureDetector());
          gestureListener = new View.OnTouchListener() {
              public boolean onTouch(View v, MotionEvent event) {
                  if (gestureDetector.onTouchEvent(event)) {
                      return true;
                  }
                  return false;
              }
          };
      }
  
      class MyGestureDetector extends SimpleOnGestureListener {
          @Override
          public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
              try {
                  if (Math.abs(e1.getY() - e2.getY()) &gt; SWIPE_MAX_OFF_PATH)
                      return false;
                  // right to left swipe
                  if(e1.getX() - e2.getX() &gt; SWIPE_MIN_DISTANCE &amp;&amp; Math.abs(velocityX) &gt; SWIPE_THRESHOLD_VELOCITY) {
                      Toast.makeText(GestureRightLeft.this, "Left Swipe", Toast.LENGTH_SHORT).show();
                  }  else if (e2.getX() - e1.getX() &gt; SWIPE_MIN_DISTANCE &amp;&amp; Math.abs(velocityX) &gt; SWIPE_THRESHOLD_VELOCITY) {
                      Toast.makeText(GestureRightLeft.this, "Right Swipe", Toast.LENGTH_SHORT).show();
                  }
              } catch (Exception e) {
                  // nothing
              }
              return false;
          }
      }
  
      @Override
      public void onClick(View v) {}
  }
  </code></pre>