Helper Utility for Android

Util.java

import android.content.Context;
import android.graphics.Point;
import android.view.Display;
import android.view.WindowManager;
import android.widget.Toast;

/**
 * A collection of utility methods, all static.
 */
public class Utils {

    /*
     * Making sure public utility methods remain static
     */
    private Utils() {
    }

    /**
     * Returns the screen/display size
     *
     * @param context
     * @return
     */
    public static Point getDisplaySize(Context context) {
        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Display display = wm.getDefaultDisplay();
        Point size = new Point();
        display.getSize(size);
        int width = size.x;
        int height = size.y;
        return new Point(width, height);
    }

//    /**
//     * Shows an error dialog with a given text message.
//     *
//     * @param context
//     * @param errorString
//     */
//
//    public static final void showErrorDialog(Context context, String errorString) {
//        new AlertDialog.Builder(context).setTitle(R.string.error)
//                .setMessage(errorString)
//                .setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
//                    @Override
//                    public void onClick(DialogInterface dialog, int id) {
//                        dialog.cancel();
//                    }
//                })
//                .create()
//                .show();
//    }

    /**
     * Shows a (long) toast
     *
     * @param context
     * @param msg
     */
    public static void showToast(Context context, String msg) {
        Toast.makeText(context, msg, Toast.LENGTH_LONG).show();
    }

    /**
     * Shows a (long) toast.
     *
     * @param context
     * @param resourceId
     */
    public static void showToast(Context context, int resourceId) {
        Toast.makeText(context, context.getString(resourceId), Toast.LENGTH_LONG).show();
    }

    /**
     * Formats time in milliseconds to hh:mm:ss string format.
     *
     * @param millis
     * @return
     */
    public static String formatMillis(int millis) {
        String result = "";
        int hr = millis / 3600000;
        millis %= 3600000;
        int min = millis / 60000;
        millis %= 60000;
        int sec = millis / 1000;
        if (hr > 0) {
            result += hr + ":";
        }
        if (min >= 0) {
            if (min > 9) {
                result += min + ":";
            } else {
                result += "0" + min + ":";
            }
        }
        if (sec > 9) {
            result += sec;
        } else {
            result += "0" + sec;
        }
        return result;
    }

    public static int dpToPx(int dp, Context ctx) {
        float density = ctx.getResources().getDisplayMetrics().density;
        return Math.round((float) dp * density);
    }
}