Develop Reference

Android handle swipe on parent view and click on child

I am following the google developer documentation:
https://developer.android.com/training/gestures/viewgroup.html
I am doing the exact same case as their example code, where I have a swipe gesture on a parent, but if I am not swiping, then I will handle the click on the child as opposed to intercepting on the parent.
However the current flow is like this:
Action.DOWN - > Hits Parent's onInterceptTouchEvent I return false since I am not waiting for this case
Action.DOWN - > Hits Child's onTouch Handler, I return false since I still want to possibly use the parents code
Action.DOWN -> Hits Parents' onTouch Handler, I return true because i want to get the rest of the notifications for the gesture and then pass on to the child when appropriate. If I return false at this point, then the event will die and I wont get Action.UP
At this point in the gesture I am strictly relegated to the Parent's onTouchListener and feel pigeonholed there since there are conditions where I would like to go back down to the child's onTouch handler. Particularly confounding are the following stipulations in the Android documentation:
The down event will be handled either by a child of this view group, or given to your own onTouchEvent() method to handle; this means you should implement onTouchEvent() to return true, so you will continue to see the rest of the gesture (instead of looking for a parent view to handle it). Also, by returning true from onTouchEvent(), you will not receive any following events in onInterceptTouchEvent() and all touch processing must happen in onTouchEvent() like normal.
For as long as you return false from this function, each following event (up to and including the final up) will be delivered first here and then to the target's onTouchEvent().
So my desire is to get at least up until the point of Action.MOVE within the parent's onInterceptTouchEvent so that I can determine whether or not this gesture is the childs click/touch or the parent's swipe. I can only seem to get to ACTION_UP in my parent's onTouchEvent since I return true at Action.DOWN which relegates my entirely, as the documentation says, to my parents onTouch method.
How can i keep the onInterceptTouchEvent spinning while also implmenting the onTouchEvent never return true until the moment I want the parent to do something in lieu of the child?
That is my logical idea, but when I do that, I have to make my parent's onTouch return false for the ActionDown which then kills the event from both onTouch and onInterceptTouchEvent paradigms.
Parent's on touch listner:
binding.linLayoutWrapper.setOnTouchListener(new View.OnTouchListener() {
int downX, moveX, upX;
int downY, moveY;
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_DOWN) {
//binding.linLayoutWrapper.getParent().requestDisallowInterceptTouchEvent(true);
downX = (int) motionEvent.getX();
downY = (int) motionEvent.getY();
return false;
} else if (motionEvent.getAction() == MotionEvent.ACTION_UP) {
return false;
} else if (motionEvent.getAction() == MotionEvent.ACTION_MOVE) {
moveY = (int) motionEvent.getY();
moveX = (int) motionEvent.getX();
if (Math.abs(downX - moveX) > Math.abs(downY - moveY)){
upX = (int) motionEvent.getX();
if (upX - downX > 100) {
// swipe right
CalendarDay cal = binding.calendarView.getCurrentDate();
Calendar cal1 = Calendar.getInstance();
cal1.setTime(cal.getDate());
cal1.add(Calendar.WEEK_OF_YEAR, -1);
binding.calendarView.setCurrentDate(cal1.getTime());
binding.linLayoutWrapper.getParent().requestDisallowInterceptTouchEvent(true);
return true;
} else if (downX - upX > 100) {
CalendarDay cal = binding.calendarView.getCurrentDate();
Calendar cal1 = Calendar.getInstance();
cal1.setTime(cal.getDate());
cal1.add(Calendar.WEEK_OF_YEAR, 1);
binding.calendarView.setCurrentDate(cal1.getTime());
binding.linLayoutWrapper.getParent().requestDisallowInterceptTouchEvent(true);
return true;
}
} else {
binding.linLayoutWrapper.getParent().requestDisallowInterceptTouchEvent(false);
}
}
return false;
}
});
Parents onInterceptTouchListener:
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
final int action = MotionEventCompat.getActionMasked(ev);
if (action == MotionEvent.ACTION_CANCEL || action == MotionEvent.ACTION_UP) {
Log.d("HELP", " in parent action up");
mIsScrolling = false;
return false;
}
switch (action) {
case MotionEvent.ACTION_MOVE: {
if (mIsScrolling) {
return true;
}
final int xDiff = calculateDistanceX(ev);
if (xDiff > mTouchSlop) {
// Start scrolling!
mIsScrolling = true;
return true;
}
break;
}
case MotionEvent.ACTION_DOWN: {
xNot = ev.getX();
return false;
}
}
return false;
}
Finally my child's onTouch listener:
relativeLayout.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_UP) {
Intent intent = new Intent(getContext(), EditAvailabilityActivity.class);
if (event != null) {
int nurseId = AccountManager.sharedManager().getCurrentAccount().getId();
Conflict conflict = new Conflict();
conflict.setNurseId(nurseId);
conflict.setId(event.getConflictId());
conflict.setEndDate(event.getParentEnd());
conflict.setStartDate(event.getParentStart());
conflict.setStartTime(event.getStartTime());
conflict.setEndTime(event.getEndTime());
conflict.setIsAllDay(event.getAllDay() == 1);
intent.putExtra(EditAvailabilityActivity.EXTRA_CONFLICT, Parcels.wrap(conflict));
}
intent.putExtra(EditAvailabilityActivity.EXTRA_MODE, true);
((Activity) getContext()).startActivityForResult(intent, EDIT_AVAILABILITY_REQUEST_CODE);
return true;
}
return false;
}
});
UPDATE:
If I return true from the child's onTouchListener then it goes to the parent's onInterceptTouchEvent. I am not sure how that jives with what android says when they say " Also, by returning true from onTouchEvent(), you will not receive any following events in onInterceptTouchEvent() and all touch processing must happen in onTouchEvent() like normal." It seems like a flagrant contradiction, but maybe they mean "when you return true from the PARENT's onTouchListener" IS that accurate?
When I change my childs onTouchListener to this:
relativeLayout.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (motionEvent.getAction() == MotionEvent.ACTION_UP) {
Intent intent = new Intent(getContext(), EditAvailabilityActivity.class);
if (event != null) {
int nurseId = AccountManager.sharedManager().getCurrentAccount().getId();
Conflict conflict = new Conflict();
conflict.setNurseId(nurseId);
conflict.setId(event.getConflictId());
conflict.setEndDate(event.getParentEnd());
conflict.setStartDate(event.getParentStart());
conflict.setStartTime(event.getStartTime());
conflict.setEndTime(event.getEndTime());
conflict.setIsAllDay(event.getAllDay() == 1);
intent.putExtra(EditAvailabilityActivity.EXTRA_CONFLICT, Parcels.wrap(conflict));
}
intent.putExtra(EditAvailabilityActivity.EXTRA_MODE, true);
((Activity) getContext()).startActivityForResult(intent, EDIT_AVAILABILITY_REQUEST_CODE);
return true;
}
return true; //this makes it behave strangely
}
});
It effectively handles the click but it seems to do so in a weird way. It violates the android documentation by going back to the parent's oninterceptTouchEvent all the way through Action_UP. This seemed promising because if i could get that far along the gesture and still get the right outcome from the target's onTouch method then I would get what i was looking for. Sadly in this case, when I try to do a swipe gesture I only get the following rapartee between parent and child:
Action.DOWN - > Parent's onInterceptTouchEvent
Action.Down -> Hits Child's OnTouchListener which is returning "true"
Action.Cancel -> Hits Parent's onInterceptTouchEvent
This is the expected flow, so it was wishful thinking that it work but it was not in line with the earlier contradiction I noticed.

Detect ongoing touch event

I am currently trying to detect an ongoing touch event in my Android app.
In detail I want to recognize within a fragment whether the user touches any part of the app's screen.
Android's OnTouchListener works as expected except if the touch event lasts longer than a few seconds without moving.
For example the first 1-2 seconds of touch are being detected but everything after won't.
Is there something like an "OnPressListener" or a workaround?

If it's a well defined gesture you are trying to detect, have a look at GestureDetector.
http://developer.android.com/reference/android/view/GestureDetector.html

You can use
aButton.setOnLongClickListener(new OnLongClickListener() {
public boolean onLongClick(View arg0) {
Toast.makeText(getApplicationContext(), "Long Clicked " ,
Toast.LENGTH_SHORT).show();
return true; // <- set to true
}
});
on your aButton and if you are using API < 19 you have to add
android:longClickable="true"
Attribute to your aButton in layout xml.

I finally found it out.
The solution is to use a simple OnTouchListener:
private boolean pressed = false;
#Override
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
if (action == MotionEvent.ACTION_DOWN) {
pressed = true;
} else if ((action == MotionEvent.ACTION_UP)
|| (action == MotionEvent.ACTION_CANCEL)) {
pressed = false;
}
return true;
}

onTouch always shows Reaction to second event

in my App I have a Custom View in an Activity.
To detect touch events I have the method onTouchEvent() in both of them.
Custom View: The onTouchEvent()-method basically just marks the object which is touched.
#Override
public boolean onTouchEvent(MotionEvent event) {
int maskedAction = event.getActionMasked();
switch (maskedAction) {
case MotionEvent.ACTION_DOWN:
touchedXY[0] = event.getX();
touchedXY[1] = event.getY();
mMatrix.mapPoints(touchedXY); // this is just for
event.setLocation(touchedXY[0], touchedXY[1]); // rotation purposes
for(int i = 0; i < mPoints[i]; i++){
mPoints[i].isSelected(setIsSelected(touchedXY)); //using method to
//check if point
//is selected
}
break;
default:
return false;
}
invalidate();
return true;
}
Activity: If an Object is touched a LinearLayout should appear at the Bottom of the Activity with the number of touched Points.
int key = 0;
#Override
public boolean onTouch(View v, MotionEvent event) {
// get masked (not specific to a pointer) action
int maskedAction = event.getActionMasked();
switch (maskedAction) {
case MotionEvent.ACTION_DOWN:
List<AddressPoint> selectedPoints = Arrays.asList(mPoints);
if (key == 0) {
if (selectedPoints.size() > 0) {
key = 1;
test.setText(String.valueOf(selectedPoints.size()));
popup.setVisibility(View.VISIBLE);
} else {
test.setText(String.valueOf(selectedPoints.size()));
}
} else {
if (selectedPoints.size() > 0) {
test.setText(String.valueOf(selectedPoints.size()));
} else {
key = 0;
popup.setVisibility(View.GONE);
}
}
break;
default:
return false;
}
return false;
}
So, it is working but behaves not as desired. The Activity seems only to react to the second touchevent and refreshes every second touchevent.
Like for example:
TouchEvent = 4 Points --> Activity shows no popup.
TouchEvent = 3 Points --> Activity shows popup with the number "4"
TouchEvent = 1 Point --> Activity shows popup with the number "3"
.
. and so on
.
I hope you can help me and I appreciate your help!

The problem seems to occour because your view is redrawn before the points are saved.
Therefore it might be better to save the number of points in the onTouch onTouchEvent and then invoke another function to set the text accordingly.

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);
}

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;
}
});