Simple elevator-like animation android

Question

 private void moveViewToScreenCenter(final ImageView img, int x) {
    DisplayMetrics dm = new DisplayMetrics();
    this.getWindowManager().getDefaultDisplay().getMetrics(dm);

    img.animate()
            .translationX(0)
            .withEndAction(new Runnable() {
                @Override
                public void run() {
                    enableAll();
                    showDialog();
                }
            })
            .translationY(-x * dm.heightPixels / 6)
            .setDuration(2000)
            .setInterpolator(new LinearInterpolator())
            .setStartDelay(0);
}

public void showDialog()
{
    final CharSequence[] items = {"0", "1", "2","3","4","5"};

    AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);

    alertDialogBuilder.setTitle("which floor is your destination");

    alertDialogBuilder.setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int item) {

            if (items[item].equals("0")) {

                moveViewToScreen(img, 0);
            } else if (items[item].equals("1")) {

                moveViewToScreen(img, 1);
            } else if (items[item].equals("2")) {

                moveViewToScreen(img, 2);
            } else if (items[item].equals("3")) {

                moveViewToScreen(img, 3);
            } else if (items[item].equals("4")) {

                moveViewToScreen(img,4);
            }else if (items[item].equals("5")) {

                moveViewToScreen(img,5);
            }

            dialog.dismiss();
        }
    });
    alertDialogBuilder.show();

}

private void moveViewToScreen(final ImageView img, int x) {
    DisplayMetrics dm = new DisplayMetrics();
    this.getWindowManager().getDefaultDisplay().getMetrics(dm);

    img.animate()
            .translationX(0)
            .withEndAction(new Runnable() {
                @Override
                public void run() {
                    enableAll();

                }
            })
            .translationY(-x * dm.heightPixels / 6)
            .setDuration(2000)
            .setInterpolator(new LinearInterpolator())
            .setStartDelay(0);
}

Buttons are disabled (disableALL()) during animation but animation seems fast between far floors and slow between consecutive ones . i'm still new to android and simple animation stuff like this

Answer 1

Janos' advice is applying DRY principle to your code. It can be extended to also cover moveViewToScreenCenter and moveViewToScreen functions, since they are almost identical:

private void moveViewToScreenCenter(final ImageView img, int x, boolean center) {
    DisplayMetrics dm = new DisplayMetrics();
    this.getWindowManager().getDefaultDisplay().getMetrics(dm);

    img.animate()
            .translationX(0)
            .withEndAction(new Runnable() {
                @Override
                public void run() {
                    enableAll();
                    if (center)
                       showDialog();
                }
            })
            .translationY(-x * dm.heightPixels / 6)
            .setDuration(2000)
            .setInterpolator(new LinearInterpolator())
            .setStartDelay(0);
}

and call this function by providing true/false to your center parameter.

Also, functional scalability might be an issue: what if you have to handle 11 eleven floors in the future? (0 -> 10). You will be forced make several changes to handle a simple request like this.

In order to accommodate larger values, I would dynamically define your array and not base my condition on char (which allows only one character). Something like this (not tested):

// place this in some generic place
List<Integer> makeSequence(int begin, int end) {
  List<Integer> ret = new ArrayList(end - begin + 1);
  for(int i = begin; i <= end; i++, ret.add(i));
  return ret;  
}

int maxFloors = 5;
List<Integer> items = makeSequence(0, 5);

public void onClick(DialogInterface dialog, int item) {
    moveViewToScreen(img, items[item]);
    dialog.dismiss();
}