Android: can't seem to use MotionEvent.ACTION_MOVE correctly
Solution 1
I was having the same problem while using MotionEvent.ACTION_MOVE
.
For MotionEvent.ACTION_MOVE
to work, return true instead of false.
Solution 2
For me Solution was
return true
in the onTouch function as you should use this
public boolean onTouch(View v, MotionEvent event){
float x;
float y;
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN: // gets called
{
x = event.getX();
y = event.getY();
circle c = new circle(this, x, y, 10, 0xFFFFFF);
_main.addView(c, tapCount++);
break;
}
case MotionEvent.ACTION_MOVE: // doesnt seem to do anything
{
x = event.getX();
y = event.getY();
circle c = new circle(this, x, y, 10, 0xFFFFFF);
_main.addView(c, tapCount++);
break;
}
}
return true; //the problem was here
}
when you return false from onTouch(View v, MotionEvent event) then only MotionEvent.ACTION_DOWN will be called. so you should return true from this function
Hope this is helps
Solution 3
Had the same problems too, I don't know if it's a bug or not, but I managed to make it work by adding OnClickListener
to the implementation, and implementing public void onClick(View v)
then also adding setOnClickListener(this)
on the constructor.
Stijnn
Updated on March 16, 2021Comments
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Stijnn over 3 years
I am quite new to Android programming and Java (though I have some experience with C#, so that helps).
At this moment I'm goofing around with a couple of things to get to know how everything works. I've made an activity which implements onTouchListener. I've overridden onTouch and have a switch on event.getAction():
public boolean onTouch(View v, MotionEvent event) { float x; float y; switch (event.getAction()) { case MotionEvent.ACTION_DOWN: // gets called { x = event.getX(); y = event.getY(); circle c = new circle(this, x, y, 10, 0xFFFFFF); _main.addView(c, tapCount++); break; } case MotionEvent.ACTION_MOVE: // doesnt seem to do anything { x = event.getX(); y = event.getY(); circle c = new circle(this, x, y, 10, 0xFFFFFF); _main.addView(c, tapCount++); break; } } return false; }
Where "circle" is a class which draws a circle.
What I expected to see was a trail of circles as I dragged my finger over the screen. In stead, the circle is only being drawn when I start touching.
I have compared my code to examples (for example: this blogpost by Google: http://android-developers.blogspot.com/2010/06/making-sense-of-multitouch.html ) and I can't find my mistake.
EDIT: Link to the full class: http://pastebin.com/tVDQjQhu
EDIT: Fixed. One has to return true in the onTouch() function. d'oh!
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Admin over 4 yearswhy would you return false from onTouch?
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Lzh over 12 years+1 Do you have any idea why this is how it works? Could you point us in the direction where this is documented, a place where there would be an explanation? Thanks!
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stealthcopter almost 12 yearsWhen you override onTouchEvent the boolean your return boolean indicates if the event was consumed or not.