Correctly exchange text using Textswitcher

Question

I need to use a component TextSwitcher with the intention that when the user moves this TextSwitcher to the right as well as to the left the text of the same.

For this I created a variable of type String[] and stored 5 values, and used the event OnTouch on the type component TextSwitcher, but with the following code I will post below the text is not exchanged, remains the same, until give an error of ArrayOfBounds because I didn’t handle the size of the Strings array.

What would be the best way to exchange texts?

    tsIntroduction.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {

            switch (event.getActionMasked()) {

            case MotionEvent.ACTION_DOWN:
                // Variaveis declaradas no topo da aplicação
                initialX = event.getX();
                initialY = event.getY();

            case MotionEvent.ACTION_UP:
                float finalX = event.getX();
                float finalY = event.getY();

                if (initialX < finalX) {
                    pos =+ 1;
                }

                if (initialX > finalX) {
                    pos =- 1;
                }
            }

            // Varíavel pos declarada no inicio da aplicação para pegar a posição atual
            tsIntroduction.setText(descriptions[pos]);
            return true;
        }

Answer 1

I managed to solve the problem, the following was done:

I implemented the interface OnGestureListener package android.view.GestureDetector and used two main methods to make the logic:

 @Override
 public boolean onTouchEvent(MotionEvent event) {
  this.mDetector.onTouchEvent(event);
  return super.onTouchEvent(event);
 }

@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
        float velocityY) {
     float sensitvity = 50;

      if((e1.getX() - e2.getX()) > sensitvity){
          pos += 1;
          tsIntroduction.setText(descriptions[pos]);
      }else if((e2.getX() - e1.getX()) > sensitvity){
          pos -= 1;
          tsIntroduction.setText(descriptions[pos]);
      }

      return true;
}

Where the variable mDetector is the type GestureDetectorCompat and initializes as follows:

mDetector = new GestureDetectorCompat(this,this);

And tsIntroduction would be the ImageSwitcher and descriptions is the string array I created.

I didn’t implement the logic to treat the error ArrayOutOfBounds, but it’s not hard to create.