Develop Reference

Select other buttons on touch move

I'm writing a test which options are placed in buttons. I have a selector for buttons that displays normal and pressed state and everything works great.
What i want is that when user touches an option and moves to next option, the next button get focus and select. And when user takes the hand, perform the selected button click.
In images above you can see exactly what i mean.

You need to write a custom touch event management that will trigger setPressed(true) on MotionEvent.ACTION_DOWN OR MotionEvent.ACTION_MOVE (the default implementation expects to always receive MotionEvent.ACTION_DOWN).
Code like this should work (add it to all your buttons):
button.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_MOVE:
if (!v.isPressed()) {
v.setPressed(true);
}
return true;
case MotionEvent.ACTION_UP:
// perform action ON CLICK
break;
}
v.setPressed(false);
return false;
}
});

Using of MotionEvent (ACTION_MOVE)

So I have special question to you:
How can I catch buttons when I use move action? How can I handle moves on my screen for buttons(or other elements)?
I used MotionEvent (ACTION_MOVE) but by using that fragment of code i don't get the desired result
in OnCreate
btn1.setOnTouchListener(this); //for all of buttons on Activity
in onTouch
switch(event.getAction()) {
case MotionEvent.ACTION_MOVE:
//actions
break;
}
actions will be occur for first button from which the movement starts. In other case nothing will occur
At this time I think that I can use ACTION_MOVE for my Activity not for each button or other elements and save coordinates of buttons(top left and bottom right) to arraylist.
And when movement starts I could compare this coordinates and real coordinates of movement.
So by that way I could know on which buttons movement was.
Probably I reinvent the wheel. That why I ask for your help)

Would you explain more clear? From what I see you need probably do two things:
First add listener to all buttons and let your activity implement onTouchListener.
Second you need to save initial coordinate for each button in MotionEvent.ACTION_DOWN(if I'm right about syntax).
This way you will have access to all buttons of yours and you can save their coordinates correctly

You will get the view inside the touch listener, using which you can identify.
Button btn1 = (Button) findViewById(R.id.btn1);
Button btn2 = (Button) findViewById(R.id.btn2);
Button btn3 = (Button) findViewById(R.id.btn3);
btn1.setOnTouchListener(touchListener);
btn2.setOnTouchListener(touchListener);
btn3.setOnTouchListener(touchListener);
private OnTouchListener touchListener = new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_MOVE) {
switch (v.getId()) {
case R.id.btn1:
//Button 1
break;
case R.id.btn2:
//Button 2
break;
case R.id.btn3:
//Button 3
break;
}
}
return false;
}
};

How to perform an action as long as a Button is kept pressed

Hi and Thanks for your help.
I need a button to perform the following behavior:
when the button is pressed an action begins (in this case a view scrolls)
as long as the button is kept pressed the action continues (the view continues scrolling)
when the button is released the action (the scrolling) stops.
I have tried this, but does not work:
Button left = (Button) findViewById(R.id.left);
left.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
Log.e("","left");
return false;
}
});

I think you are looking for a combination of OnTouchListener and MotionEvent.ACTION_DOWN
Edit:
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// TODO start scroll
break;
case MotionEvent.ACTION_UP:
// TODO stop scroll
break;
default:
break;
}
return false;
Hope this helps.. :)

Button button = (Button) findViewById(R.id.button);
button.setOnTouchListener(new View.OnTouchListener() {
#Override public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()) {
case MotionEvent.ACTION_DOWN:
//Start your work
break;
case MotionEvent.ACTION_UP:
// stop the work
break;
case MotionEvent.ACTION_CANCEL:
// stop the work
break;
}
return false;
}
});

Use MotionEvent.ACTION_DOWN and MotionEvent.ACTION_UP for detecting action up as well as down
#Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
//start action here
break;
}
return super.onTouchEvent(event);
}

By default you can use onlongclick listener, But in your case it won't give effect as its max time 1-2 sec, so apply motion event on button and apply your logic..

You can use MotionEvent.ACTION_DOWN and MotionEvent.ACTION_UP for detecting action up and down
#Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
//start action
break;
case MotionEvent.ACTION_UP:
//stop action
break;
}
return super.onTouchEvent(event);
}

make new scroll view
ScrollView sv=new ScrollView(this);
and when you click/start button. then start thread which increment int value and scroll, and on key action down. stop the thread.
//start thread which incrment value one by one
sv.scrollBy(x, y); //x the amount of pixels to scroll by horizontally
//y the amount of pixels to scroll by vertically

Android Listener to detect when the screen is being pressed

I have a view in my Android app that should be updated constantly when the screen is being pressed. Most listeners I found only invalidate the view once when the user touches the screen for the first time, or when the user removes his hand from the screen.
Is there such a thing as a listener that is constantly triggered as long as the screen is touched ? Or is there any other way to do this ? I know, that sounds like something really simple, but I haven't found a way to do it.

Override onTouch() and set a flag in ACTION_DOWN. As long as ACTION_UP isn't called after that, the user is touching the screen.
boolean pressed = false;
#Override
public boolean onTouch(View v, MotionEvent event) {
//int action = event.getAction();
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
pressed = true;
break;
case MotionEvent.ACTION_MOVE:
//User is moving around on the screen
break;
case MotionEvent.ACTION_UP:
pressed = false;
break;
}
return pressed;
}

Dragging and pressing buttons - android

I have several buttons and I would like to press on one of them and drag through another presing them. Could you tell me which MotionEvent or another functionality should I use. I'm using onTouchListener.
There is an image where you can see what I want to do (first ACTION_DOWN on 1st button and drag through 2nd-7th buttons still pressing the screen) and finally press every white buttons:
Below is my onTouch button code:
button1 = (Button) findViewById(R.id.button1);
button1.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
soundIDs[0] = sound.play(R.raw.sample1);
button1.setBackgroundResource(R.drawable.white_clicked);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
sound.stop(soundIDs[0]);
button1.setBackgroundResource(R.drawable.white);
break;
}
return false;
}
});

You are setting the OnTouchListener on just the one button. That's not going to help you know when the pointer moves (e.g. user drags his finger) into another button.
You could set an OnTouchListener on the view that contains the buttons. Then check for ACTION_DOWN, ACTION_MOVE, and ACTION_UP events. You would then have to do some simple hit detection to figure out which button to activate.
Something along the lines of:
getWindow().getDecorView()
.findViewById(android.R.id.content)
.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View arg0, MotionEvent event) {
int action = event.getAction();
if (action != MotionEvent.ACTION_DOWN
&& action != MotionEvent.ACTION_MOVE
&& action != MotionEvent.ACTION_UP) return false;
Rect hitRect = new Rect();
Button button;
for(int i = 0; i < myButtons.size(); i++) {
button = myButtons.get(i);
button.getHitRect(hitRect);
if (hitRect.contains((int)event.getX(), (int)event.getY())) {
button.setText("hit!");
}
}
return true;
}
});
Where myButtons is an ArrayList of your buttons (piano keys in your example).
Also, you'd probably want to modify this to properly deactivate the currently active button if the user's touch leaves the button, but doesn't hit another button.
I tested the above code on an android device with a layout that has 3 buttons in a row. Dragging your finger across all the buttons causes each button's text to change to "hit!"
Like I said above, you were setting the touch listener on the just one button, that will not work. In this example I have set the touch listener on the entire view for the activity.