I have a custom view derived from View. I'd like to be notified when the view is clicked, and the x,y location of where the click happened. Same for long-clicks.
Looks like to do this, I need to override onTouchEvent()
. Is there no way to get the x,y location of the event from an OnClickListener
instead, though?
If not, what's a good way of telling if a motion event is a 'real' click vs a long-click etc? The onTouchEvent
generates many events in rapid s开发者_JS百科uccession etc.
Thank you. That was exactly what I was looking for. My code now is:
imageView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN){
textView.setText("Touch coordinates : " +
String.valueOf(event.getX()) + "x" + String.valueOf(event.getY()));
}
return true;
}
});
which does precisely what Mark asked for...
Full example
The other answers are missing some details. Here is a full example.
public class MainActivity extends AppCompatActivity {
// class member variable to save the X,Y coordinates
private float[] lastTouchDownXY = new float[2];
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// add both a touch listener and a click listener
View myView = findViewById(R.id.my_view);
myView.setOnTouchListener(touchListener);
myView.setOnClickListener(clickListener);
}
// the purpose of the touch listener is just to store the touch X,Y coordinates
View.OnTouchListener touchListener = new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
// save the X,Y coordinates
if (event.getActionMasked() == MotionEvent.ACTION_DOWN) {
lastTouchDownXY[0] = event.getX();
lastTouchDownXY[1] = event.getY();
}
// let the touch event pass on to whoever needs it
return false;
}
};
View.OnClickListener clickListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
// retrieve the stored coordinates
float x = lastTouchDownXY[0];
float y = lastTouchDownXY[1];
// use the coordinates for whatever
Log.i("TAG", "onLongClick: x = " + x + ", y = " + y);
}
};
}
Summary
- Add a class variable to store the coordinates
- Save the X,Y coordinates using an
OnTouchListener
- Access the X,Y coordinates in the
OnClickListener
Override onTouchEvent(MotionEvent ev)
Then you can do:
ev.getXLocation()
Or something like that. Have a butches.
You can make an extension function in Kotlin, like this:
fun View.setOnClickListenerWithPoint(action: (Point) -> Unit) {
val coordinates = Point()
val screenPosition = IntArray(2)
setOnTouchListener { v, event ->
if (event.action == MotionEvent.ACTION_DOWN) {
v.getLocationOnScreen(screenPosition)
coordinates.set(event.x.toInt() + screenPosition[0], event.y.toInt() + screenPosition[1])
}
false
}
setOnClickListener {
action.invoke(coordinates)
}
}
If you need a long click - just replace setOnClickListener
I use getLocationOnScreen()
because I need coordinates for RecyclerView's ViewHolder
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