This is the demo game I created in class on 4/1 with the bunny and the food pellet.

Images used

Download these into your res/drawable-mdpi folder.

go_down.png

go_next.png

go_previous.png

go_up.png

rabbit_animal_green.png

red_ball.png

XML layout

I created a horizontal LinearLayout to hold the arrow images, then a RelativeLayout below that with a white background.

The corresponding XML code is below.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
        >
    <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Hello World, GameActivity"
            android:id="@+id/textView" android:textSize="24dp"/>
    <LinearLayout
            android:orientation="horizontal"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content">
        <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/leftControl"
                android:src="@drawable/go_previous"
                android:onClick="onClick"/>
        <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/rightControl" android:src="@drawable/go_next"
                android:onClick="onClick"/>
        <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/upControl" android:src="@drawable/go_up"
                android:onClick="onClick"/>
        <ImageView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/downControl" android:src="@drawable/go_down"
                android:onClick="onClick"/>
    </LinearLayout>
    <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" android:background="#dfdfd8"
            android:id="@+id/fieldLayout">
        <ImageView
                android:layout_width="64dp"
                android:layout_height="64dp"
                android:id="@+id/bunnyView"
                android:layout_alignParentLeft="true"
                android:layout_marginLeft="41dp"
                android:layout_alignParentTop="true"
                android:layout_marginTop="37dp"
                android:src="@drawable/rabbit_animal_green"
                />
        <ImageView
                android:layout_width="35dp"
                android:layout_height="35dp"
                android:id="@+id/pellet1"
                android:layout_alignParentLeft="true"
                android:layout_marginLeft="131dp"
                android:layout_alignParentTop="true"
                android:layout_marginTop="140dp"
                android:src="@drawable/red_ball"/>
    </RelativeLayout>
</LinearLayout>

Activity code

package com.example.bunny2;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class GameActivity extends Activity {

    /* Game state */
    int playerX, playerY;
    int pelletX, pelletY;
    int score;
    final int bunnyVelocity = 8;

    /* UI elements */
    TextView tv;
    ImageView bunny, pellet;
    RelativeLayout field;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        tv = (TextView) findViewById(R.id.textView);
        bunny = (ImageView) findViewById(R.id.bunnyView);
        field = (RelativeLayout) findViewById(R.id.fieldLayout);
        int h = field.getHeight();
        Log.i("bunny2", "field height " + h);
        if(savedInstanceState != null) {
            playerX = savedInstanceState.getInt("playerX");
            playerY = savedInstanceState.getInt("playerY");
            score = 0;
        } else {
            playerX = playerY = 0;
            score = 0;
        }
//        ImageView pellet = new ImageView(this, null);
//        pellet.setImageResource(R.drawable.red_ball);
//        RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(this, null);
//        lp.leftMargin = pelletX;
//        lp.rightMargin = pelletY;
//        lp.width = 35;
//        lp.height = 35;
        pellet = (ImageView) findViewById(R.id.pellet1);
        chooseRandomPelletLocation();
        updatePosition();
    }

    public void setPositionOfImageView(ImageView v, int x, int y) {
        int h = field.getHeight();
        Log.i("bunny2", "field height now " + h);
        RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) v.getLayoutParams();
        lp.leftMargin = x;
        lp.topMargin = y;
        v.setLayoutParams(lp);
    }

    private void chooseRandomPelletLocation() {
        pelletX = (int)(Math.random() * 600);
        pelletY = (int)(Math.random() * 400);
        setPositionOfImageView(pellet,  pelletX, pelletY);
    }

    public void updatePosition() {
        setPositionOfImageView(bunny, playerX, playerY);
        double dist = distanceFromPellet();
        if(dist < 25) {
            score++;
            chooseRandomPelletLocation();
        }
        tv.setText("You are at: " + playerX + ", " + playerY + "; score is " + score);
    }

    private double distanceFromPellet()
    {
        // Euclidean distance = square root of sum of squared differences
        double dx = playerX - pelletX;
        double dy = playerY - pelletY;
        return Math.sqrt(dx*dx + dy*dy);
    }


    public void onClick(View v) {
        switch(v.getId()) {
            case R.id.leftControl:
                playerX -= bunnyVelocity;
                break;
            case R.id.rightControl:
                playerX += bunnyVelocity;
                break;
            case R.id.upControl:
                playerY -= bunnyVelocity;
                break;
            case R.id.downControl:
                // Don't go off screen
                if(playerY < field.getHeight() - bunny.getHeight()) {
                    playerY += bunnyVelocity;
                }
                break;
        }
        updatePosition();
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt("playerX", playerX);
        outState.putInt("playerY", playerY);
    }
}