Utils.java

package com.example.termproject;

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatDelegate;
import android.view.View;
import android.widget.ImageView;


public class Utils
{
    public final static int sREQUEST_CODE_SETTINGS = 100, sREQUEST_CODE_LOCATION_PERMISSION = 100;

    // background
    // ----------

    public static void showHideBackground (boolean usePicBackground, ImageView background)
    {
        int visibilityMode = usePicBackground ? View.VISIBLE : View.INVISIBLE;

        // Set the ImageView's visibility to be show or hidden as per the user preference
        assert background != null;
        background.setVisibility (visibilityMode);
    }

    // Location
    public static void promptToAllowPermissionRequest (Activity activity)
    {
        DialogInterface.OnClickListener okListener =
                getLocationPromptOkOnClickListener (activity);
        DialogInterface.OnClickListener cancelListener =
                Utils.getNewEmptyOnClickListener ();

        Utils.showYesNoDialog (activity, "Permission Denied",
                "The Location Permission is requested for Night Mode " +
                        "display purposes.\n\nWould you like to again " +
                        "be prompted to allow this permission?",
                okListener, cancelListener);
    }

    @NonNull private static DialogInterface.OnClickListener getLocationPromptOkOnClickListener
            (final Activity activity)
    {
        return new DialogInterface.OnClickListener ()
        {
            @Override public void onClick (DialogInterface dialog, int which)
            {
                Utils.getLocationPermission (activity, sREQUEST_CODE_LOCATION_PERMISSION);
            }
        };
    }


    // Night Mode
    // ----------
    public static void getLocationPermission (Activity activity, int code)
    {
// Here, activity is the current activity
        if (ContextCompat.checkSelfPermission (activity, Manifest.permission.ACCESS_COARSE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions
                    (activity, new String[] {Manifest.permission.ACCESS_COARSE_LOCATION}, code);
        }
    }

    public static void applyNightModePreference (Activity activity, boolean useNightMode)
    {
        int defaultNightMode = AppCompatDelegate.getDefaultNightMode ();
        int userPrefNightMode = useNightMode
                ? AppCompatDelegate.MODE_NIGHT_AUTO
                : AppCompatDelegate.MODE_NIGHT_NO;

        if ((useNightMode && (defaultNightMode != userPrefNightMode)) ||
                (!useNightMode && defaultNightMode == AppCompatDelegate.MODE_NIGHT_AUTO)) {

            applyNightMode (activity, userPrefNightMode);
        }
    }

    private static void applyNightMode (final Activity activity, int userPrefNightMode)
    {
        // Inform the user so they're not staring at a white screen while the Activity is recreated
        //Toast.makeText (activity, "Applying Night Mode Preference", Toast.LENGTH_SHORT).show ();

        // Set the Default Night Mode to match the User's Preference
        AppCompatDelegate.setDefaultNightMode (userPrefNightMode);

        // recreate the Activity to make the Night Mode Setting active
        activity.recreate ();
    }


    // AlertDialog
    // -----------

    @NonNull public static DialogInterface.OnClickListener getNewEmptyOnClickListener ()
    {
        return new DialogInterface.OnClickListener ()
        {
            @Override public void onClick (DialogInterface dialog, int which)
            {

            }
        };
    }

    /**
     * Shows an Android (nicer) equivalent to JOptionPane
     *
     * @param strTitle Title of the Dialog box
     * @param strMsg   Message (body) of the Dialog box
     */
    public static void showYesNoDialog (Context context, String strTitle, String strMsg,
                                        DialogInterface.OnClickListener okListener,
                                        DialogInterface.OnClickListener cancelListener)
    {
        // create the listener for the dialog
        final DialogInterface.OnClickListener emptyOnClickListener = getNewEmptyOnClickListener ();

        // Create the AlertDialog.Builder object
        AlertDialog.Builder ADBuilder = new AlertDialog.Builder (context);

        // Use the AlertDialog's Builder Class methods to set the title, icon, message, et al.
        // These could all be chained as one long statement, if desired
        ADBuilder.setTitle (strTitle);
        ADBuilder.setIcon (android.R.drawable.ic_dialog_alert);
        ADBuilder.setMessage (strMsg);
        ADBuilder.setCancelable (true);
        ADBuilder.setPositiveButton (context.getString (R.string.yes),
                okListener != null ? okListener : emptyOnClickListener);
        ADBuilder.setNegativeButton (context.getString (R.string.no),
                cancelListener != null ? cancelListener : emptyOnClickListener);

        // Create and Show the Dialog
        ADBuilder.show ();
    }

    /**
     * Shows an Android (nicer) equivalent to JOptionPane
     *
     * @param strTitle Title of the Dialog box
     * @param strMsg   Message (body) of the Dialog box
     */
    public static void showInfoDialog (Context context, String strTitle, String strMsg)
    {
        // create the listener for the dialog
        final DialogInterface.OnClickListener emptyOnClickListener = getNewEmptyOnClickListener ();

        // Create the AlertDialog.Builder object
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder (context);

        // Use the AlertDialog's Builder Class methods to set the title, icon, message, et al.
        // These could all be chained as one long statement, if desired
        alertDialogBuilder.setTitle (strTitle);
        alertDialogBuilder.setIcon (android.R.drawable.ic_dialog_info);
        alertDialogBuilder.setMessage (strMsg);
        alertDialogBuilder.setCancelable (true);
        alertDialogBuilder.setNeutralButton (context.getString (android.R.string.ok),
                emptyOnClickListener);

        // Create and Show the Dialog
        alertDialogBuilder.show ();
    }

    /**
     * Overloaded XML version of showInfoDialog(String, String) method
     *
     * @param titleID Title stored in XML resource (e.g. strings.xml)
     * @param msgID   Message (body) stored in XML resource (e.g. strings.xml)
     */
    public static void showInfoDialog (Context context, int titleID, int msgID)
    {
        showInfoDialog (context, context.getString (titleID), context.getString (msgID));
    }

}