java - Android MultiTouch does not work -

 @override  public boolean ontouchevent(motionevent event) {      synchronized (getholder())     {            int aktion = event.getaction();         if (aktion == motionevent.action_down)         {             touched = true;             bar.sharetouch(event.getx(), event.gety(), touched);         }         else if (aktion == motionevent.action_up)         {             touched = false;             bar.sharetouch(event.getx(), event.gety(), touched);         }             if (aktion == motionevent.action_pointer_down)         {             touched2 = true;             bar.sharetouch2(event.getx(), event.gety(), touched2);         }         else if (aktion == motionevent.action_pointer_up)          {             touched2 = false;             bar.sharetouch2(event.getx(), event.gety(), touched2);         }     }     return true; } 

this code chech if first finger going onto screen or leaving it. same finger.

public void sharetouch2(float xtouch2, float ytouch2, boolean touched2) {     if (xtouch2 <= gameviewwidth/2) {         if (touched2 == true) {             touchedleft2 = true;         }         else if(touched2 == false) {             touchedleft2 = false;         }     }     else if (xtouch2 > gameviewwidth/2) {         if (touched2 == true) {             touchedright2 = true;         }         else if(touched2 == false) {             touchedright2 = false;         }     } } 

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public void sharetouch(float xtouch, float ytouch, boolean touched) {     if (xtouch <= gameviewwidth/2) {         if (touched == true) {         touchedleft = true;         }         else if(touched == false) {             touchedleft = false;         }     }     else if (xtouch > gameviewwidth/2) {         if (touched == true) {             touchedright = true;         }         else if(touched == false) {             touchedright = false;         }     }  }  private void moveright() {     x += 3; }  private void moveleft() {     x -= 3; } 

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private void checktouch() {     if ((touchedleft == true && touchedright2 == false) || (touchedleft2 == true && touchedright == false)) {         moveleft();     }     else if ((touchedleft == false && touchedright2 == true) || (touchedleft2 == false && touchedright == true)) {         moveright();     }     else if ((touchedleft == true && touchedright2 == true) || (touchedleft2 == true && touchedright == true)) {      } } 

the checktouch() called in ondraw() method. if place finger on right side of screen moves right. same left. if touch left , right without removing left finger object still moves left although should stop. when leave left finger still moves left although should move right.

i hope understand problem.

hope can help

you can't assume action_pointer_up event sent same finger action_pointer_down sent.

just action_down event fired first finger touch down, action_up event fired last finger lift (i.e. when there no more fingers on screen). others action_pointer_up event, if it's finger started gesture.

however, android documentation specify

each pointer has unique id assigned when first goes down [and] remains valid until pointer goes up.

so in theory, first , second finger should still have same id, regardless whether event reports them.

the solution simple, then: use getpointercount() , getpointerid() keep track of fingers.

this may easier if refactor code account more 2 fingers replacing booleans touchedleft , touchedleft2 single counter, e.g. fingersonleftside - has neat side effect of needing 1 sharetouch() method , otherwise reducing redundancy in code.

edit:

disclaimer: off top of head, untested , written without knowledge of of code other posted. not best way solve problem, shortest think of.

this event handler:

public boolean ontouchevent(motionevent event) {     synchronized (getholder())     {            int aktion = event.getaction();         if (aktion == motionevent.action_down || aktion == motionevent.action_pointer_down         || aktion == motionevent.action_up || aktion == motionevent.action_pointer_up)         {             bar.cleartouches();             (int = 0; < event.getpointercount(); i++) {                 bar.sharetouch(event.getx(i)); // don't need y coordinate anyway             }         }     }     return true; } 

the rewritten sharetouch() go along it, cleartouches() introduced make simpler:

private void sharetouch(float x)  {     if (x < gameviewwidth/2) {         fingersleft++;     } else {         fingersright++;     } }  private void cleartouches()  {     fingersleft = 0;     fingersright = 0; } 

and finally, new checktouch():

public void checktouch() {     if (fingersleft > fingersright) {         moveleft();     } else if (fingersright > fingersleft) {         moveright();     } }