Redman Redman - 19 days ago 7
Android Question

WebView TextSelection gone after adding MotionEvent

Hello guys i am creating an epubreader and loading the book in a webview, i made the webview scroll horizontal adding some css rule , now i added swipe left and right to turn pages based on screen width, i got the screen to detect the swipe left and right feature by using this class

public class OnSwipeTouchListener implements OnTouchListener {

private final GestureDetector gestureDetector;

public OnSwipeTouchListener(Context context) {
gestureDetector = new GestureDetector(context, new GestureListener());
}

public void onSwipeLeft() {
}

public void onSwipeRight() {
}

public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}

private final class GestureListener extends SimpleOnGestureListener {

private static final int SWIPE_DISTANCE_THRESHOLD = 100;
private static final int SWIPE_VELOCITY_THRESHOLD = 100;

@Override
public boolean onDown(MotionEvent e) {
return true;
}

@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
float distanceX = e2.getX() - e1.getX();
float distanceY = e2.getY() - e1.getY();
if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
if (distanceX > 0)
onSwipeRight();
else
onSwipeLeft();
return true;
}
return false;
}

}
}


and in my Main Activity implemented like this

webView.setOnTouchListener(new OnSwipeTouchListener(this) {
@Override
public void onSwipeLeft() {
// Whatever
if(TotalPages>PresentPage){
PresentPage++;
forward.start();
webView.scrollTo(PresentPage*ScreenWidth, 0);

}
else{
Toast.makeText(getApplicationContext(), "The End", 100).show();
}
}
@Override
public void onSwipeRight() {

if(PresentPage>0)
{
PresentPage--;
back.start();
webView.scrollTo(PresentPage*ScreenWidth, 0);
}
}
});


now the gestures left and right are working fine but the default text selection feature(i.e on long press selecting text) is gone , i want the default text selection with swipe detection ,How can i get it ? thanks in advance

Answer

solve it using this class

public class OnSwipeTouchListener implements OnTouchListener {

private final GestureDetector gestureDetector;
private static final int MAX_CLICK_DURATION = 1000;
private static final int MAX_CLICK_DISTANCE = 15;
static Context mcontext;
private long pressStartTime;
private float pressedX;
private float pressedY;
private boolean stayedWithinClickDistance;

public OnSwipeTouchListener(Context context) {
    gestureDetector = new GestureDetector(context, new GestureListener());
    this.mcontext=context;
}

public void onSwipeLeft() {
}

public void onSwipeRight() {
}
public void newTouch(){

}
public boolean onTouch(View v, MotionEvent event) {
      gestureDetector.onTouchEvent(event);

     if(event.getAction()== MotionEvent.ACTION_MOVE)
     {
          if (stayedWithinClickDistance && distance(pressedX, pressedY, event.getX(), event.getY()) > MAX_CLICK_DISTANCE) {
              stayedWithinClickDistance = false;
          }
         return true;
     }

     else if (event.getAction()== MotionEvent.ACTION_DOWN) {
         pressStartTime = System.currentTimeMillis();                
         pressedX = event.getX();
         pressedY = event.getY();
         stayedWithinClickDistance = true;

         return v.onTouchEvent(event);
     }
     else if(event.getAction()== MotionEvent.ACTION_UP) {

         long pressDuration = System.currentTimeMillis() - pressStartTime;
         if (pressDuration < MAX_CLICK_DURATION && stayedWithinClickDistance) {
            newTouch();
         }

         return v.onTouchEvent(event);
     }
     else{
         return v.onTouchEvent(event);
     }

}
private static float distance(float x1, float y1, float x2, float y2) {
    float dx = x1 - x2;
    float dy = y1 - y2;
    float distanceInPx = (float) Math.sqrt(dx * dx + dy * dy);
    return pxToDp(distanceInPx);
}

private static float pxToDp(float px) {
    return px / mcontext.getResources().getDisplayMetrics().density;
}


private final class GestureListener extends SimpleOnGestureListener {

    private static final int SWIPE_DISTANCE_THRESHOLD = 100;
    private static final int SWIPE_VELOCITY_THRESHOLD = 100;

    @Override
    public boolean onDown(MotionEvent e) {
        return true;
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        float distanceX = e2.getX() - e1.getX();
        float distanceY = e2.getY() - e1.getY();
        if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
            if (distanceX > 0)
                onSwipeRight();
            else
                onSwipeLeft();
            return true;
        }
        return false;
    }

}


}

and in main activity

 webView.setOnTouchListener(new OnSwipeTouchListener(this) {
                        @Override
                        public void onSwipeLeft() {
                            // Whatever
                             // for swiping left action
                            }

                        @Override
                        public void onSwipeRight() {
                            // TODO Auto-generated method stub

                            //for swiping right action

                        }
                        @Override
                        public void newTouch() {

                           // for single tap action

                        }

                    });

after this you will still have default text selection option

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