I have onLongPress and onDoubleTap actions placed on the button according to this code:
...
GestureDetector detector = new GestureDetector(this, new TapDetector());
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
detector = new GestureDetector(this, new TapDetector());
...
}
private class TapDetector extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onDoubleTap(MotionEvent e) {
// Do something
return true;
}
@Override
public void onLongPress(MotionEvent e) {
// Do something
}
}
Button incomeButton = (Button) findViewById(R.id.income);
button.setOnTouchListener(new OnTouchListener(){
@Override
public boolean onTouch(View v, MotionEvent event) {
detector.onTouchEvent(event);
return true;
}
});
I always see onLongPress fired after onDoubleClick fired and executed. What is the reason of such counterintuitive behavior and how to avoid it?
UPDATED
I have changed my source code to be more specific
public class MainActivity extends Activity {
private GestureDetector detector;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
detector = new GestureDetector(this, new TapDetector());
Button button = (Button) findViewById(R.id.button);
button.setOnTouchListener(new OnTouchListener(){
@Override
public boolean onTouch(View v, MotionEvent event) {
System.out.println("************* onTouch *************");
detector.onTouchEvent(event);
return true;
}
});
}
class TapDetector extends GestureDetector.SimpleOnGestureListener {
@Override
public void onLongPress(MotionEvent e) {
System.out.println("************* onLongPress *************");
}
@Override
public boolean onDoubleTap(MotionEvent e) {
System.out.println("************* onDoubleTap *************");
Intent intent = new Intent();
intent.setClass(getApplicationContext(), NewActivity.class);
intent.putExtra("parameterName", "parameter");
startActivity(intent);
return true;
}
}
}
This is a log after onDoubleTap I clicked. You can see onLongPress at the end – I never click it.
I/System.out( 1106): ************* onTouch *************
I/System.out( 1106): ************* onTouch *************
I/System.out( 1106): ************* onTouch *************
I/System.out( 1106): ************* onDoubleTap *************
I/ActivityManager( 59): Starting activity: Intent { cmp=my.tapdetector/.NewActivity (has extras) }
I/ActivityManager( 59): Displayed activity my.tapdetector/.NewActivity: 324 ms (total 324 ms)
I/System.out( 1106): ************* onLongPress *************
UPDATE I have found the solution. To avoid onLongPress firing two changes needs to be done:
First: detector.setIsLongpressEnabled(true); in onTouch(View v, MotionEvent event)
button.setOnTouchListener(new OnTouchListener(){
@Override
public boolean onTouch(View v, MotionEvent event) {
System.out.println("************* onTouch *************");
detector.onTouchEvent(event);
detector.setIsLongpressEnabled(true);
return true;
}
});
Second: add detector.setIsLongpressEnabled(false); in onDoubleTap(MotionEvent e)
public boolean onDoubleTap(MotionEvent e) {
detector.setIsLongpressEnabled(false);
System.out.println("************* onDoubleTap *************");
Intent intent = new Intent();
intent.setClass(getApplicationContext(), NewActivity.class);
intent.putExtra("parameterName", "parameter");
startActivity(intent);
return true;
}
Technically this shouldn’t happen
because on the ACTION_DOWN or ACTION_UP event, all of the LONG_PRESS messages events are removed from the queue. So on the second tap the following code will remove the long press events.