How can I make it possible that when someone slides their finger into or over a button, the button acts as if it were getting pushed?
An example of what i'm looking for would be a keyboard app. Where you slide your fingers over all the keys to play sounds.
You can use an OnTouchListener like this:
boolean firstTime = true;
OnTouchListener testTouchListener = new OnTouchListener(){
public boolean onTouch(View v, MotionEvent me){
Rect r = new Rect();
secondButton.getDrawingRect(r);
if(r.contains((int)me.getX(),(int)me.getY())){
//Log.i(myTag, "Moved to button 2");
if(firstTime == true){
firstTime = false;
secondButton.performClick();
}
}
if(me.getAction() == MotionEvent.ACTION_UP){
//When we lift finger reset the firstTime flag
firstTime = true;
}
return false;
}
};
firstButton.setOnTouchListener(testTouchListener);
With this approach though you are going to get a flood of touch events because onTouch() gets called a lot with MotionEvent.ACTION_MOVE. So you'll have to keep a boolean that tells you if its the first time you've gotten onTouch() call. Then you can reset that boolean in onTouch() for MotionEvent.ACTION_UP so it works again the next time. However this could get kind of complicated if you are trying to do more than just 2 buttons. I think you'd have to keep a boolean for each of them seperately (or perhaps an array of booleans to hold them all). and you'd need an additional if(r.contains(x,y) statements for every button. This should get you started on the right path though.
Related
As title suggests, I want a new screen to appear after 7 ACTION_DOWN events are logged by my OnTouchEvent.
Can get it working for a single ACTION_DOWN, but not sure how to make it pop after 7 of them.
public boolean onTouchEvent(MotionEvent event) {
int count = event.getPointerCount();
if (event.getAction() == MotionEvent.ACTION_DOWN) {
count++;
}
if (count == 7) {
Intent intent = new Intent(this, UsersList.class);
startActivity(intent);
}
return true;
}
}
That's a variable scope problem you have there. That variable count only lives for the duration of the onTouchEvent method. You'll have to put that variable into a bigger scope, like your class for exemple.
Also, I suggest you to look at the getPointerCount method documentation. This might not be want you think...
Hi I'm using AndEngine in my Android app. I'm wondering if there is a method that detects when an object (in this case an object of AnalogOnScreenControls) goes from being touched to untouched? I want to set a specific command that executes only when someone lets go of the "analog stick" entity. The controls also use float values to detect what position they're in, so it could also be a method for when the values go from some value other than zero to zero, since the variables are set to zero when the controls are idle. Thanks for any help in advance!
There is a flag in the TouchEvent that you can check.
Most times I do something like this:
#Override
public boolean onAreaTouched(final TouchEvent touchEvent, ITouchArea touchArea, float touchAreaLocalX, float touchAreaLocalY) {
switch(touchEvent.getAction()){
case TouchEvent.ACTION_MOVE:{
// do stuff when finger moves
return true; // don't forget to break, or return true directly if the event was handled
}
case TouchEvent.ACTION_DOWN:{
// do stuff, the first time the finger touches the display
return true;
}
case TouchEvent.ACTION_UP:{
// do stuff when the finger goes up again and ends the touch event (your case)
return true;
}
case TouchEvent.ACTION_CANCEL:{
// If the event is somehow canceled - e.g. the finger leaves the display
return true;
}
default:{
// none of the above
return false;
}
}
}
Something like that. If you need more information about the event than theses simple actions, get the MotionEvent with touchEvent.getMotionEvent() and check out the additional options there.
BTW: I prefer to use the return true statement directly instead of a break here, just to make sure that the touch event won't get used otherwise in the app. But you can change that of course.
hope this helps
Christoph
You could create a field (global variable) named isTouched and set it initially to false. Then inside onControlChange() you do this:
if(pValueX == 0 && pValueY == 0 && isTouched){ //means knob has recently been touched
isTouched = false; //set to false so that being idle does not come here
//do your thing here
}
else{
isTouched = true;
//do normal stuff here
}
I want handle a gesture in my activity. To do this i have override the public boolean onTouchEvent(MotionEvent MEvent) method on my Activity. The content looks like this:
motionaction = MEvent.getAction();
if(motionaction == MotionEvent.ACTION_DOWN)
{
...
return true;
}
if(motionaction == MotionEvent.ACTION_UP)
{
...
return true;
}
if(motionaction == MotionEvent.ACTION_MOVE)
{
...
return true;
}
motionaction = MEvent.getActionMasked();
if(motionaction == MotionEvent.ACTION_POINTER_DOWN)
{
...
return true;
}
if(motionaction == MotionEvent.ACTION_POINTER_UP)
{
...
return true;
}
return true;
The gesture it's the follow:
-finger1 on the screen hold its position (virtually because there is always a little movement)
-finger2 move on the screen. This is the movement that i want to grab.
I can grab the 5 action but the problem it's that when two fingers are on the screen the ACTION_MOVE grabs the movement of both first and second finger. The method MEvent.getActionIndex() don't works for the ACTION_MOVE that is return always 0; The only thing that i can do it's to save the position of the finger1 and to discard the movement near to that point. The result it's not perfect indeed sometime the movement of the finger2 it's "tainted" by the little finger1 movement because though the finger holds it's position on the screen the listener feels each minimal movement.
How can i improve this ?
Referring to the answer of Quintin Balsdon:
I have a similar thing in my code. I save the position of the finger1 in the ACTION_DOWN case, then when the finger2 move i see if the Y coordinate of the move is over the saved finger1 Y coordinate. If so the movement it's referred to the finger2 otherwise is referred to finger1 and i discard that in two finger mode.
If i try to draw a circle on my view in one finger mode i have got something like this:
http://img208.imageshack.us/img208/8113/onefingercircle.jpg
If i try to draw a circle on my view in two finger mode i have got something like this:
http://img256.imageshack.us/img256/6778/twofingercircle.jpg
So in one finger mode it work perfectly but not in two finger mode.
I don't know if it's related to the phone multitouch handler or the touch screen. It can be only hardware related also or my misunderstanding of the API.
This is managed by you as the developer. You are going to have to create some boolean variable to set (to true) when the "DOWN" action takes place and then unset (false) when the "UP" or "MOVE" motionevent occurs. In the code below, I maintain the coordinates when the "DOWN" even happens and make adjustments while the user moves around.
switch (e.Action) //e is a MotionEvent type
{
case MotionEvent.ACTION_DOWN:
{
_prevx = e.getX();
_prevy = e.getY();
}
break;
case MotionEvent.ACTION_MOVE:
{
_xoffset += e.GetX() - _prevx;
_yoffset += e.GetY() - _prevy;
Invalidate();
_prevx = e.GetX();
_prevy = e.GetY();
}
break;
}
If you want to do multi-finger dragging you need to implement ScaleGestureDetector.OnScaleGestureListener (http://developer.android.com/reference/android/view/ScaleGestureDetector.OnScaleGestureListener.html)
I am trying to accomplish following things
Suppose I have 5-6 TextViews with values S N A K E
Now, I want to press S textView then slide my finger over N to select it too and then move my way to E. I want to do that so that i can get "SNAKE" in my string or char sequence etc
If there is any idea do share me. I can't get it how to use onTouch here.
Also, i am adding textViews dynamically so i am setting their ids dynamically too
Best Regards
I've never done this, but here's a thought.
Assuming all your textviews are in some sort of layout, you could disable the focusability on your textview and create an onTouch listener on your underlying container.
Start tracking on Mouse Down events
#Override public boolean onTouch(View v, MotionEvent event) {
if(event.getAction == MotionEvent.ACTION_DOWN)
{
captureInput = true;
}
}
*On your ACTION_MOVE event, check if the current position is above a textview, if so, capture that value*
#Override public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
if(action == MotionEvent.ACTION_DOWN)
{
captureInput = true;
}
else if(action == MotionEvent.ACTION_MOVE
{
//get x/y of your finger
int X = (int)event.getX();
int Y = (int)event.getY();
//Somehow check if the x,y are overlapping with one of your textivews
// If so, add that textview's text to your list
// Below is pseudo code
/* for(TextView curTV: allTextViews)
{
if(isOverlapping(X,Y))
{
listOfSwipedCharacters.add(curTV.getText());
}
}
}
}
Lastly, when the user releases their finger, stop tracking and do something with the word list
#Override public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
if(action == MotionEvent.ACTION_DOWN)
{
captureInput = true;
}
else if(action == MotionEvent.ACTION_MOVE
{
//get x/y of your finger
int X = (int)event.getX();
int Y = (int)event.getY();
//Somehow check which textview the X,Y coords are overlapping
// Below is pseudo code
/* for(TextView curTV: allTextViews)
{
if(isOverlapping(X,Y))
{
listOfSwipedCharacters += (curTV.getText());
}
}*/
}
else if(action == MotionEvent.ACTION_UP)
{
captureInput = false;
//Do whatever you want with the string of information that you've captured
}
}
Once again, I have no idea if that will work, it's just a guess at an approach. I suspect performance of cycling through each textview to check for overlaps will be pretty crappy, so there may be a more efficient approach than running a for loop.
Since you know you can't jump over letters when swyping, you could create a short list of all the possible swipe locations (surrounding letters) whenever you add a new letter. Then on your mouse event, check if any of those letters have been hit by the mouse move event. For example, in a standard word search game, once you select a letter, there are only 9 other possible locations for you to swipe (the surrounding letters), so you should only bother checking if those 9 locations have been hit when you capture the mouse move event.
Edit: I suppose you could use the solution above if you attached an onTouch listener to each and every textview. The same premise in regards to touch would apply: Down = start capture, move = capture text, up = stop capture. It would save you from having to identify which textview is being hovered as the textview that fires the onTouch event will be the one that the user is swiping across.
When I use the method onTouch, I use the methon event.getY() to give the variable y2 the finger precision. But one problem apper when I use a if-statement:
public boolean onTouch(View v, MotionEvent event){
if(y2 <= knifeY){
//y2 = where the finger is, knifeY = where on the height a knife will be on.
knifeDown = false;
// The knife stops
point--;
// score - 1;
knife = BitmapFactory.decodeResource(getResources(),R.drawable.bloddyknife);
// change picture.
return true;
}
}
But the problem is that you must move your finger when you hold it on the screen, if you're holding it still, the knife just slip past. :(
Someone help?
Do you assign int y2=event.getY() ? Because I dont see it anywhere, it must be done inside the onTouch()
I'm not sure if this is good approach
public boolean onTouch(View v, MotionEvent event)
{
while(event.getAction()!=MotionEvent.ACTION_CANCEL) // or here measure the pressure applied on the screen surface
{
if(event.getY() <= knifeY)
{
knifeDOwn=false; // keep the knife down
point--;
knife = BitmapFactory.decodeResource(getResources(),R.drawable.bloddyknife); //
//maybe here you might stop the pointers collecting with using event.setAction(MotionEvent.ACTION_CANCEL) (or ACTION_UP) to exit the while loop, i dont know your idea for it, at this point i'm just guessing, but you still need to change the action of the event at anypoint at this code to exit the while loop.
}
}
return true;
}
I suggest you to use GestureListener and use onFling() for this purpose.
Read here more on constants of MotionEvent class:
http://developer.android.com/reference/android/view/MotionEvent.html#ACTION_DOWN