Fire event till touched android - android

I want to increase the width of a line dynamically as long as the user touches the screen. I used the following code :-
#Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
stopX++;
}
return true;//EDITED (FORGOT TO PASTE THIS LINE)
}
I make the line from 0 to stopX and y-axis is constant as long as the screen is touched. But, I failed. The line increases in width(as required). BUT, the line increases in width only when the screen is touched, i.e., when I touch the screen, the line increases by 1 BUT THE GROWTH DOES NOT CONTINUE AS LONG AS I TOUCH IT. I hope that I was able to make you understand my problem. Any help will be appreciated. Thanks in advance for any help.


This is because MotionEvent.ACTION_DOWN is fired once when you touch the View. You will need it for e.g. to start a loop that increments stopX in event MotionEvent.ACTION_DOWN and stop it in MotionEvent.ACTION_UP. For e.g.:
Thread t;
#Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
t=new Thread(new Runnable(){
#Override run(){
while(true){
try{
stopX++;
Thread.sleep(500);
}catch(ThreadInterruptedException e){
break;
}
}
}
});
t.start();
}
return true;
case MotionEvent.ACTION_UP:
t.interrupt();
return true;
}


Try doing something like this (just make sure to add the relevant lock where needed in order to keep the m_Task safe).
I would also consider running the task with a timer in order to prevent some busy waiting.
#Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
// Start an async task
// Add a lock
m_Task = new LineIncreamentTask(...);
task.Start();
}
case MotionEvent.ACTION_UP:
// Cancel the task
// Add a lock
if (m_Task != null) m_Task.cancel();
}
return true;//EDITED (FORGOT TO PASTE THIS LINE)
}
private class LineIncreamentTask
{
public void doInBackground(...)
{
// Increase the line width
// Update the UI & whatever
}
public void onPostExecute(...)
{
if (!isCanceled())
{
// Add a lock
// Consider using a timer to prevent busy waiting
m_Task = new LineIncreamentTask(...);
m_Task.start();
}
}
}

Related

Android - How to hold a button for some time to repeat an action?

I want to create a countdown timer in my app. There will be two buttons, one for increasing time and other for decreasing time. When the user holds down the button i want to get the app to repeat to add time.
I have already tried
this
but i got errors

You need to use onTouchListener
button.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()) {
case MotionEvent.ACTION_DOWN:
// PRESSED
// You can call a thread here which will keep increasing the time
return true;
case MotionEvent.ACTION_UP:
// RELEASED
// Stop the thread here
return true;
}
return false;
}
});

Touching the screen while onTouch() is already being called

When I touch the screen and move my finger I do something (pullanimation1 and 2) and when I release the screen I do something else (fireanimation1 and 2). Sometimes, the user might touch the screen while pullAnimation or fireAnimation is running, I get errors as the animation then run several times. I would like to make sure the animations won't run more then once when the user touch again the screen.
NB: pullAnimation1 and 2, fireAnimation 1 and 2 are AnimationDrawable
Here is what I've done :
image2.setOnTouchListener(new OnTouchListener(){
#Override
public boolean onTouch(View arg0, MotionEvent arg1) {
boolean bool=false;
boolean bool2=true;
int action = arg1.getAction() & MotionEvent.ACTION_MASK;
switch (action) {
case MotionEvent.ACTION_DOWN:
if (bool2) {
startAnimation(pullAnimation1,pullAnimation2);
bool=true;
}
break;
case MotionEvent.ACTION_MOVE:
if (bool2==true){
Log.w("GAMEACTIVITY","move");
bool=true;
bool2=false;
}
break;
case MotionEvent.ACTION_UP:
startAnimation(fireAnimation1,fireAnimation2);
bool=false;
doPhotoTask();
bool2=false;
break;
}
return bool;
}
});

I think you should be able to use the hasStarted() and hasEnded() methods to determine if your animation is currently going. See the docs for more
Some if statement like this might work:
if((fireAnimation1.hasStarted() == false) || (fireAnimation1.hasEnded == true()){
startAnimation(fireAnimation1, fireAnimation2);
}
I imagine you may also need to use reset() after it is done playing in order or the methods to return proper values next time touch happens.
EDIT:
AnimationDrawable has an isRunning() method, which makes it even easier than View animations.
if(fireAnimation1.isRunning() == false){
startAnimation(fireAnimation1, fireAnimation2);
}

Android: Long touch on Button while MotionEvent.ACTION_MOVE

Ok... in my app i update the layout on MotionEvent.ACTION_DOWN and then i check the motion event coordinates to locate my buttons. I can show a toast when finger is released on different buttons. The problem is i need a long touch on my buttons to call another action without conflicting with the MotionEvent.ACTION_UP. Implemented a long click handler but since i don't 'click' its not working. Hope you guys understand my problem.
Whats the best way to get my app working as intended?
My class implements OnTouchListener, OnGestureListener
#Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()){
case MotionEvent.ACTION_DOWN:
// UPDATE LAYOUT
break;
case MotionEvent.ACTION_UP:
// GET BUTTON X Y
if (x and y match the button location){
// DO ACTION
}else{
// DO NOTHING
}
// CHANGE LAYOUT TO INITIAL STATE
break;
case MotionEvent.ACTION_MOVE:
break;
}
return false;
mybutton.setOnLongClickListener(new OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
// DO STUFF
return true;
}
});
}

just try to return false in your onTouch(...) method and use onLongClickListener(...) as usual

Android to detect when you are holding down a button

I need to be able to tell when the user is holding a button down and when the user lets go. This is different from onClickListener and onLongClickListener. How would i go about doing something like this?
For example I press a button that starts a chronometer.(pseudo code)
if ButtonIsBeingPressed
{
chronometer start(); //and keep going
}
else chronometer stop();
//or on release or something
}

Look into the OnTouchListener it has MotionEvents for Down (press) and Up (release):
view.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction()) {
case MotionEvent.ACTION_DOWN:
// Start
break;
case MotionEvent.ACTION_UP:
// End
break;
}
return false;
}
});

How to get a continuous Touch Event?

My class extends View and I need to get continuous touch events on it.
If I use:
public boolean onTouchEvent(MotionEvent me) {
if(me.getAction()==MotionEvent.ACTION_DOWN) {
myAction();
}
return true;
}
... the touch event is captured once.
What if I need to get continuous touches without moving the finger?
Please, tell me I don't need to use threads or timers. My app is already too much heavy.
Thanks.

Use if(me.getAction() == MotionEvent.ACTION_MOVE). It's impossible to keep a finger 100% completely still on the screen so Action_Move will get called every time the finger moves, even if it's only a pixel or two.
You could also listen for me.getAction() == MotionEvent.ACTION_UP - until that happens, the user must still have their finger on the screen.

You need to set this properties for the element
android:focusable="true"
android:clickable="true"
if not, just produce the down action.

Her is the simple code snippet which shows that how you can handle the continues touch event. When you touch the device and hold the touch and move your finder, the Touch Move action performed.
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
if(isTsunami){
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// Write your code to perform an action on down
break;
case MotionEvent.ACTION_MOVE:
// Write your code to perform an action on contineus touch move
break;
case MotionEvent.ACTION_UP:
// Write your code to perform an action on touch up
break;
}
}
return true;
}

Try this. It works to me:
public static OnTouchListener loadContainerOnTouchListener() {
OnTouchListener listener = new OnTouchListener(){
#Override
public boolean onTouch(View v, MotionEvent event) {
LinearLayout layout = (LinearLayout)v;
for(int i =0; i< layout.getChildCount(); i++)
{
View view = layout.getChildAt(i);
Rect outRect = new Rect(view.getLeft(), view.getTop(), view.getRight(), view.getBottom());
if(outRect.contains((int)event.getX(), (int)event.getY()))
{
Log.d(this.getClass().getName(), String.format("Over view.id[%d]", view.getId()));
}
}
}
Remember: the listener you´ll set must be a container layout (Grid, Relative, Linear).
LinearLayout layout = findViewById(R.id.yourlayoutid);
layout.setOnTouchListener(HelperClass.loadContainerOnTouchListener());

This might help,
requestDisallowInterceptTouchEvent(true);
on the parent view, like this -
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
view.getParent().requestDisallowInterceptTouchEvent(true);
switch(motionEvent.getAction()){
}
return false;
}

I was making a game with a custom view used as a thumb control. . . here is what I did
float x = 0, y = 0;
#Override
public boolean onTouchEvent(MotionEvent event) {
x = event.getX();
y = event.getY();
// handle touch events with
switch( event.getActionMasked() ) {
case MotionEvent.ACTION_DOWN :
if(cont)
{
// remove any previous callbacks
removeCallbacks(contin);
// post new runnable
postDelayed(contin, 10);
}
invalidate();
return true;
case MotionEvent.ACTION_MOVE :
if(!cont && thumbing != null)
{
// do non-continuous operations here
}
invalidate();
return true;
case MotionEvent.ACTION_UP :
// set runnable condition to false
x = 0;
// remove the callbacks to the thread
removeCallbacks(contin);
invalidate();
return true;
default :
return super.onTouchEvent(event);
}
}
public boolean cont = false;
// sets input to continuous
public void set_continuous(boolean b) { cont = b; }
public Runnable contin = new Runnable()
{
#Override
public void run() {
if(x != 0)
{
// do continuous operations here
postDelayed(this, 10);
}
}
};
A quick note however, make sure in your main activity that is calling this view removes the callbacks manually via the onPause method as follows
#Override
protected void onPause() {
if(left.cont) left.removeCallbacks(left.contin);
if(right.cont) right.removeCallbacks(left.contin);
super.onPause();
}
That way if you pause and come back touch events aren't being handled twice and the view is free from it's thread's overhead.
** tested on Samsung Galaxy S3 with hardware acceleration on **

All these answer are partially correct but they do not resolve in the right way the problem.
First of all, for everyone out there that decide to track when the event is ACTION_MOVE. Well that works only guess when? When user move his finger, so could if you decide to implement a custom thumb control is okay but for a normal custom button that's not the case.
Second, using a flag inside ACTION_DOWN and check it in ACTION_UP seems the logic way to do it, but as Clusterfux find out if you implement a while(!up_flag) logic you get stuck into troubles ;)
So the proper way to do it is mentioned here:
Continuous "Action_DOWN" in Android
Just keep in mind that if the logic you're going to write during the continuous press has to modify the UI in some way, you have to do it from the main thread in all the other cases it's better use another thread.

You can use the below code snippet as a reference in which I used the background to detect if the screen is held or not...
Main_Layout.setOnTouchListener(new View.OnTouchListener() {
#SuppressLint("ResourceAsColor")
#Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_MOVE:
Main_Layout.setBackgroundColor(R.color.green);
event.setAction(MotionEvent.ACTION_DOWN);
break;
default:
Main_Layout.setBackgroundColor(R.color.blue);
break;
}
return false;
}
});

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