Spin the Bottle

[embedyt] https://www.youtube.com/watch?v=bqgseI9pHwE[/embedyt]

In this video we are going to build a simple spin the bottle game in Android Studio. We will display the bottle in an ImageView on which we set an onClickListener with the onClick xml attribute. When we click this image, we start a RotateAnimation which ends at a random direction. We will get this random direction as a number with the Random class and it’s nextInt method. For pivotX and pivotY we will set the middle of the ImageView which we get by dividing getWidth and getHeight by 2. With setDuration we set the length of the animation and with setFillAfter(true) we make sure that the ImageView ends up pointing to the direction at which the rotation ends.
We will also set an AnimationListener on our animation to lock and unlock the spinning method in onAnimationStart and onAnimationEnd.

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Downloadsactivity_main.xmlMainActivity.java

Image files:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/floor"
    tools:context="com.codinginflow.spinthebottle.MainActivity">

    <ImageView
        android:id="@+id/bottle"
        android:layout_width="300dp"
        android:layout_height="300dp"
        android:src="@drawable/bottle"
        android:layout_centerInParent="true" 
        android:onClick="spinBottle"/>

</RelativeLayout>

package com.codinginflow.spinthebottle;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;

import java.util.Random;

public class MainActivity extends AppCompatActivity {
    private ImageView bottle;
    private Random random = new Random();
    private int lastDir;
    private boolean spinning;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        bottle = findViewById(R.id.bottle);
    }
    
    public void spinBottle(View v) {
        if (!spinning) {
            int newDir = random.nextInt(1800);
            float pivotX = bottle.getWidth() / 2;
            float pivotY = bottle.getHeight() / 2;

            Animation rotate = new RotateAnimation(lastDir, newDir, pivotX, pivotY);
            rotate.setDuration(2500);
            rotate.setFillAfter(true);
            rotate.setAnimationListener(new Animation.AnimationListener() {
                @Override
                public void onAnimationStart(Animation animation) {
                    spinning = true;
                }

                @Override
                public void onAnimationEnd(Animation animation) {
                    spinning = false;
                }

                @Override
                public void onAnimationRepeat(Animation animation) {

                }
            });

            lastDir = newDir;
            bottle.startAnimation(rotate);
        }
    }
}