Develop Reference

MotionEvent.ACTION_DOWN in Android is too sensitive. This event is received even if the screen is simply touched for a moment

I have a layout(A table layout). Whenever the user performs a "down" gesture, a specific function needs to be called. However,the ontouchlistener captures the event immediately instead of waiting until the user performs a proper "pull down" gesture.
My code is :
homePageTableLayout.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View view, MotionEvent event) {
if ((event.getAction() == MotionEvent.ACTION_DOWN)) {
startSyncData();
}
return true;
}
});
Currently, what's happening is that the startSyncData() function gets called immediately.
The end result should be somewhat similar to the commonly used "pulltorefresh" library for android but in this usecase, I don't have to update the view. I just have to post some data to the server.
I can't use the "pulltorefresh" library because it does not support "pulling" a tablelayout. I tried putting the tablelayout inside a scrollview but that only spoiled the UI.

You can try doing it in ACTION_MOVE or ACTION_UP - if you need it to be done exclusively on swipe down gesture, this should help, introduce four global floats: x, y, x1, y1, then in ACTION_DOWN:
x = event.getX();
y = event.getY();
ACTION_MOVE or ACTION_UP:
x1 = event.getX();
y1 = event.getY();
and then in ACTION_UP:
if (y1 > y) { //pointer moved down (y = 0 is at the top of the screen)
startSyncData();
}

Its not that easy. It works properly since you are catching MotionEvent.ACTION_DOWN. It doesn't mean a gesture like swipe down it means that user touched the screen (finger down, the touch or gesture just started). Now you need to catch MotionEvent.ACTION_UP (finger up, gesture or touch ends here) and decide if there was a gesture you need. http://developer.android.com/training/gestures/detector.html
http://developer.android.com/training/gestures/index.html

MotionEvent.ACTION_MOVE repeatedly gets called. So if you want startSyncData() to run after moving a certain distance, calculate how much you want the user to move before running the method.
The key is that ACTION_DOWN is not a downwards movement on the screen, but it means the user pressed down onto the screen.
homePageTableLayout.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View view, MotionEvent event) {
if ((event.getAction() == MotionEvent.ACTION_DOWN)) {
startFlg = 1;
} else if ((event.getAction() == MotionEvent.ACTION_MOVE)) {
if (startFlg==1){
// Calculate distance moved by using event.getRawX() and event.getRawX() and THEN run your method
startSyncData();
}
}
return true;
}
});

Update the position of textview/imageview at relative layout after moving it by touch

I want to have possibility to change position of items(textviews/imageview) on the screen by using touch. So I made OnTouchListener which looks like this:
float x = 0,y = 0 ;
private void clickOnObjectTaker() {
cream.setOnTouchListener(new OnTouchListener(){
#Override
public boolean onTouch(View v, MotionEvent event) {
boolean touched= false;
if(event.getAction()==MotionEvent.ACTION_DOWN)
{
messageMaker("touched");
x= event.getX();
y= event.getY();
}
if(event.getAction()==MotionEvent.ACTION_MOVE )
{
Animation anim =
new TranslateAnimation(x, event.getX(), y, event.getY());
anim.setFillAfter(true);
anim.setFillEnabled(true);
cream.startAnimation(anim);
x= event.getX();
y= event.getY();
}
if(event.getAction()== MotionEvent.ACTION_CANCEL)
{
cream.setX(x);
cream.setY(y);
}
return true;
}});
}
My problem is that when i change the position of object, the listener don't get new position, so I see the object in different place on the screen, but when I want to move it I must click on old position. I thought i solve it by adding this lines:
if(event.getAction()== MotionEvent.ACTION_CANCEL)
{
cream.setX(x);
cream.setY(y);
}
but nothing changed.
UPDATE: I tried with this code. There |I haven't any problems with updating position element of layout, everything works properly except the process of moving object by touch.
What I don't like it in this method:
touched object vibrate when I move it (it doesn't look nice),
object doesn't follow perfectly my finger, like somewhere I should scale the coordinates ( for example I moved object from right to left side of screen, when my finger stops at the brink of screen, the object is lag behind of it.)
this two things makes this method useless for me.
#Override
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction()== MotionEvent.ACTION_DOWN){
dx = event.getX()-v.getX();
dy = event.getY()-v.getY();
}
if(event.getAction()== MotionEvent.ACTION_MOVE)
{
v.setX(event.getX()-dx);
v.setY(event.getY()-dy);
}
return true;
}
}
The moving of oobject in method with animation looks great for me, everything works fluently. Only problem is connected with update layout, when I add code like this
if(event.getAction()==MotionEvent.ACTION_UP )
{
v.setX(event.getX());
v.setY(event.getY());
}
It put object at random position (I can't figure out, from what place he take this position), If somebody can give me any advice I would be grateful
EDITED
This code almost perfectly I could make repeatedly moves on view. It have two flaws:
small reallocation after Move gesture ends
During moving the view if I stop the finger on the screen, I can see the flashes of view at old position.
the code
OnTouchListener dealingwithproblems = new OnTouchListener()
{
#Override
public boolean onTouch( View v, MotionEvent event) {
if(event.getActionMasked()== MotionEvent.ACTION_DOWN){
//values for
dx = event.getX()-v.getX();
dy = event.getY()-v.getY();
x= event.getX();
y= event.getY();
}
if(event.getActionMasked()== MotionEvent.ACTION_MOVE)
{
Animation anim =
new TranslateAnimation(x, event.getX() , y, event.getY());
//anim.setFillAfter(true);
anim.setFillEnabled(true);
v.startAnimation(anim);
x= event.getX();
y= event.getY();
}
if(event.getActionMasked() == MotionEvent.ACTION_UP)
{
v.setX(event.getX()-dx);
v.setY(event.getY()-dy);
}
return true;
}
};
If somebody knew how to improve it, leave the answer pliz

it maybe animation problem, you are using ViewAnimation try to use change that in Object animator. it supports form API 11.
ObjectAnimator.ofFloat(view,"Translate",x,y,toX,toY);

I had a similar problem (touched object vibrates on move) and resolved it by using getRawX() and getRawY() instead of getX() and getY()

MotionEvent.ACTION_CANCEL is not triggered during onTouch

I am having this problem where ACTION_CANCEL is not triggered, I have implemented it in my other project and it's working fine. It seems that ACTION_UP is the only MotionEvent that is called after ACTION_DOWN. I wanted to trigger ACTION_CANCEL once my finger is not anymore in the view or outside the screen.
Sample scenario: I click on the view which is a LinearLayout btw, on ACTION_DOWN its background is changed to a "clicked/dimmed" version of the image and when ACTION_UP is triggered its background changes back to the default image only if the finger is within the LinearLayout. Now the problem is when I press it and kept my finger on the screen, and drag my finger outside the LinearLayout, ACTION_UP is still triggered where it shouldn't have.
Here's my code:
dimView.setOnTouchListener(new OnTouchListener() {
public boolean onTouch(final View view,
final MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
Log.d("TAG", "DOWN");
return true;
} else if (motionEvent.getAction() == MotionEvent.ACTION_UP) {
Log.d("TAG", "UP");
return true;
} else if (motionEvent.getAction() == MotionEvent.ACTION_CANCEL) {
Log.d("TAG", "CANCEL");
return true;
}
return false;
}
});
where: dimView is a LinearLayout

I've been debugging this for a really long time and it bothered me a lot since this came up very randomly. I then tested my code on different devices and realized the API implementation changed with Android 4.2.
The expected behaviour and code work absolutely fine with Android 4.1.2 (tested on Galaxy Tab 2) but the bug you describe can be seen on a Nexus 7 (Android 4.2).
Apparently Android changed the way MotionEvents are handled in API 17.
One particular case when the bug does not occur is when the view is located in a GroupLayout under a ScrollView. When scrolling is possible the ACTION_CANCEL gets fired. However when no scrolling is possible the bug persists.
At first I tried combining an OnClickListener and OnTouchListener so that the last can handle just the animations but to no avail. Dispatching the Events from parents also doesn't work.
One workaround is to capture ACTION_MOVE events and check if the finger is located outside of the view's boundaries using v.getX() and v.getY() and comparing them to event.getX() and event.getY() respectably. A global boolean variable (isOutside) can be used to store the most current information. Before firing up the ACTION_UP you can check the latest state of isOutside and perform your animations and action accordingly. You can also return true or false depending on whether you captured the event or not.
Update: After digging a bit here i found this solution:
Android: Detect if user touches and drags out of button region? and compiled this code. The idea is the same except that it creates a rectangle and checks if the event boundaries are within the rectangle of the view.
someView.setOnTouchListener(new View.OnTouchListener() {
private Rect rect;
#Override
public boolean onTouch(View v, MotionEvent event) {
Log.d(TAG,"Touched: "+event.getAction());
if (event.getAction() == MotionEvent.ACTION_DOWN) {
Log.d(TAG,"ACTION_DOWN");
animateImageButtonOnClick(v, event);
rect = new Rect(v.getLeft(), v.getTop(), v.getRight(), v.getBottom());
}
if (event.getAction() == MotionEvent.ACTION_UP) {
Log.d(TAG,"ACTION_UP");
if (!rect.contains(v.getLeft() + (int) event.getX(), v.getTop() + (int) event.getY())) {
Log.d(TAG,"ACTION_UP - outside");
animateImageButtonOnRelease(v, event);
} else {
Log.d(TAG,"ACTION_UP - inside");
// do your stuff here
}
}
if(event.getAction() == MotionEvent.ACTION_MOVE){
if(!rect.contains(v.getLeft() + (int) event.getX(), v.getTop() + (int) event.getY())){
animateImageButtonOnReleaseWithLowDuration(v, event);
}
}
if (event.getAction() == MotionEvent.ACTION_CANCEL){
Log.d(TAG,"ACTION_CANCEL");
animateImageButtonOnRelease(v, event);
return true;
}
return true;
}
});

Override dispatchTouchEvent method maybe deal with it;
dimView.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
// to call super touch method
return false;
}
});
#Override
public boolean dispatchTouchEvent(MotionEvent motionEvent) {
// TODO Auto-generated method stub
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
Log.d("TAG", "DOWN");
return true;
} else if (motionEvent.getAction() == MotionEvent.ACTION_UP) {
Log.d("TAG", "UP");
return true;
} else if (motionEvent.getAction() == MotionEvent.ACTION_CANCEL) {
Log.d("TAG", "CANCEL");
return true;
}
return super.dispatchTouchEvent(motionEvent);
}

What's the correct way to determine when a MapView's Lat/Lon window has changed?

I'm developing an Android application that uses a MapView. I'd like to run a procedure whenever the visible portion of the map changes (due to zooming/panning/rotating the phone/etc), and I'd like to pass the new latitude and longitude values to the procedure.
I thought I could override onInterceptTouchEvent to do this, but then the procedure only seems to run when you first touch the screen (so, for example, panning by dragging your finger only calls the procedure at the beginning of the dragging motion). Which means the procedure is never called with the new coordinates.
So -- what's the correct way to do it?

You probably have to combine several techniques to achieve what you want.
To catch the panning, I'd try overriding your MapViews onTouchEvent(), or maybe dispatchTouchEvent(), and listen for the MotionEvent.ACTION_UP event. This is triggered when the user lifts his finger from the screen:
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction()==MotionEvent.ACTION_UP) {
// Call your procedure here
}
return super.onTouchEvent(ev);
}
If you wanted to call your procedure during the panning, I think you'd have to look for the panning motion overriding one of the two same methods. Something like this:
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_MOVE) {
if (event.getHistorySize() < 1)
return; // First call, no history
// Get difference in position since previous move event
float diffX = event.getX() - event.getHistoricalX(event.getHistorySize() - 1);
float diffY = event.getY() - event.getHistoricalY(event.getHistorySize() - 1);
if (Math.abs(diffX) > 0.5f || Math.abs(diffY) > 0.5f) {
/* Position has changed substantially, so this is probably a drag action.
Call your procedure here. */
}
}
}
To detect a change in zoom level you can override dispatchDraw:
int oldZoomLevel=-1;
public void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
if (getZoomLevel() != oldZoomLevel) {
// Call your procedure here
oldZoomLevel = getZoomLevel();
}
}

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;
}
});