title: ACTION_CANCEL while touching
body: <p>I has the following class that represents a View that is touchable and draw a Slide Bar.</p>
  
  <pre><code>public class SlideBar extends View {
  private int progress;
  private int max;
  
  private Paint background;
  private Paint upground;
  
  private RectF bar;
  
  private boolean firstDraw;
  
  public SlideBar(Context context, AttributeSet attrs) {
      super(context, attrs);
      progress = 0;
  
      upground = new Paint();
      upground.setColor(Color.parseColor("#C2296C"));
  
      background = new Paint();
      background.setColor(Color.parseColor("#777777"));
  }
  
  private void onFirstDraw() {
      max = getWidth();
      bar = new RectF(0, 19, max, 21);
  }
  
  public void onDraw(Canvas canvas) {
      if (!firstDraw) {
          onFirstDraw();
          progress = max;
          firstDraw = true;
      }
  
      canvas.save();
      canvas.drawRoundRect(bar, 5, 5, background);
      canvas.drawCircle(progress, 20, 9, upground);
      canvas.restore();
  }
  
  public void setValue(int value) {
      progress = value;
  }
  
  public boolean onTouchEvent(MotionEvent evt) {
      System.out.println(evt.getAction());
      progress = (int) evt.getX();
      invalidate();
      return false;
  }
  }
  </code></pre>
  
  <p>But when touching and dragging it, I receive a ACTION_DOWN, some ACTION_MOVEs then receive a ACTION_CANCEL and no further events.</p>
  
  <p>Why it's happens? I don't want to cancel the event and enable it to keep dragging bar.</p>