I have created a mini Android game. The aim is to catch aliens in space. You score points for each aliens, there is a pause function and you can change the level of difficulty and change spaceships.
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.view.MotionEventCompat;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import java.util.Random;
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
public void onItemSelected(AdapterView<?> parent, View view,
int pos, long id) {
// An item was selected. You can retrieve the selected item using
Log.d("myTag", "This is my message" + parent.getItemAtPosition(pos));
String name = "Purple";
String str = parent.getItemAtPosition(pos).toString();
if (str.equals("Rookie")) {
mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout menuLayout = new LinearLayout(this);
menuLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
textView = new TextView(this);
textView.setVisibility(View.VISIBLE);
str = "Score: 0";
textView.setText(str);
menuLayout.addView(textView);
Button button = new Button(this);
button.setText("Pause");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
togglePausePlay();
}
});
menuLayout.addView(button);
Spinner spinner2 = new Spinner(this);
spinner2.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue);
spinner2.setAdapter(adapter);
menuLayout.addView(spinner2);
mainLayout.addView(menuLayout);
cg = new CatchGame(this, 3, "Purple", onScoreListener);
cg.setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
mainLayout.addView(cg);
getSupportActionBar().hide();
setContentView(mainLayout);
Log.d("game", "Started Advanced game");
} else if (str.equals("Advanced")) {
mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout menuLayout = new LinearLayout(this);
menuLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
textView = new TextView(this);
textView.setVisibility(View.VISIBLE);
str = "Score: 0";
textView.setText(str);
menuLayout.addView(textView);
Button button = new Button(this);
button.setText("Pause");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
togglePausePlay();
}
});
menuLayout.addView(button);
Spinner spinner2 = new Spinner(this);
spinner2.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue);
spinner2.setAdapter(adapter);
menuLayout.addView(spinner2);
mainLayout.addView(menuLayout);
cg = new CatchGame(this, 5, "Purple", onScoreListener);
cg.setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
mainLayout.addView(cg);
getSupportActionBar().hide();
setContentView(mainLayout);
Log.d("game", "Started Advanced game");
} else if (str.equals("Expert")) {
mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout menuLayout = new LinearLayout(this);
menuLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
textView = new TextView(this);
textView.setVisibility(View.VISIBLE);
str = "Score: 0";
textView.setText(str);
menuLayout.addView(textView);
Button button = new Button(this);
button.setText("Pause");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
togglePausePlay();
}
});
menuLayout.addView(button);
Spinner spinner2 = new Spinner(this);
spinner2.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue);
spinner2.setAdapter(adapter);
menuLayout.addView(spinner2);
mainLayout.addView(menuLayout);
cg = new CatchGame(this, 7, "Purple", onScoreListener);
cg.setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
mainLayout.addView(cg);
getSupportActionBar().hide();
setContentView(mainLayout);
Log.d("game", "Started Advanced game");
} else if (str.equals("Master")) {
mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout menuLayout = new LinearLayout(this);
menuLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
textView = new TextView(this);
textView.setVisibility(View.VISIBLE);
str = "Score: 0";
textView.setText(str);
menuLayout.addView(textView);
Button button = new Button(this);
button.setText("Pause");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
togglePausePlay();
}
});
menuLayout.addView(button);
Spinner spinner2 = new Spinner(this);
spinner2.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue);
spinner2.setAdapter(adapter);
menuLayout.addView(spinner2);
mainLayout.addView(menuLayout);
cg = new CatchGame(this, 9, "Purple", onScoreListener);
cg.setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
mainLayout.addView(cg);
getSupportActionBar().hide();
setContentView(mainLayout);
Log.d("game", "Started Advanced game");
} else if (str.equals("Orange")) {
mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout menuLayout = new LinearLayout(this);
menuLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
textView = new TextView(this);
textView.setVisibility(View.VISIBLE);
str = "Score: 0";
textView.setText(str);
menuLayout.addView(textView);
Button button = new Button(this);
button.setText("Pause");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
togglePausePlay();
}
});
menuLayout.addView(button);
Spinner spinner2 = new Spinner(this);
spinner2.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue);
spinner2.setAdapter(adapter);
menuLayout.addView(spinner2);
Spinner spinner3 = new Spinner(this);
spinner3.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter2 = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue2);
spinner3.setAdapter(adapter2);
menuLayout.addView(spinner3);
mainLayout.addView(menuLayout);
cg = new CatchGame(this, 7, "Orange", onScoreListener);
cg.setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
mainLayout.addView(cg);
getSupportActionBar().hide();
setContentView(mainLayout);
Log.d("game", "Started Advanced game");
} else if (str.equals("Yellow")) {
mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout menuLayout = new LinearLayout(this);
menuLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
textView = new TextView(this);
textView.setVisibility(View.VISIBLE);
str = "Score: 0";
textView.setText(str);
menuLayout.addView(textView);
Button button = new Button(this);
button.setText("Pause");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
togglePausePlay();
}
});
menuLayout.addView(button);
Spinner spinner2 = new Spinner(this);
spinner2.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue);
spinner2.setAdapter(adapter);
menuLayout.addView(spinner2);
Spinner spinner3 = new Spinner(this);
spinner3.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter2 = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue2);
spinner3.setAdapter(adapter2);
menuLayout.addView(spinner3);
mainLayout.addView(menuLayout);
cg = new CatchGame(this, 7, "Yellow", onScoreListener);
cg.setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
mainLayout.addView(cg);
getSupportActionBar().hide();
setContentView(mainLayout);
Log.d("game", "Started Advanced game");
}else if (str.equals("Purple")) {
mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout menuLayout = new LinearLayout(this);
menuLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
textView = new TextView(this);
textView.setVisibility(View.VISIBLE);
str = "Score: 0";
textView.setText(str);
menuLayout.addView(textView);
Button button = new Button(this);
button.setText("Pause");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
togglePausePlay();
}
});
menuLayout.addView(button);
Spinner spinner2 = new Spinner(this);
spinner2.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue);
spinner2.setAdapter(adapter);
menuLayout.addView(spinner2);
Spinner spinner3 = new Spinner(this);
spinner3.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter2 = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue2);
spinner3.setAdapter(adapter2);
menuLayout.addView(spinner3);
mainLayout.addView(menuLayout);
cg = new CatchGame(this, 7, "Purple", onScoreListener);
cg.setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
mainLayout.addView(cg);
getSupportActionBar().hide();
setContentView(mainLayout);
Log.d("game", "Started Advanced game");
}
}
public void onNothingSelected(AdapterView<?> parent) {
// Another interface callback
}
CatchGame cg;
public TextView textView;
public LinearLayout mainLayout;
String[] spinnerValue = {"Difficulty", "Rookie", "Advanced", "Expert", "Master"};
String[] spinnerValue2 = {"Ship", "Purple", "Orange", "Yellow"};
// start app
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mainLayout = new LinearLayout(this);
mainLayout.setOrientation(LinearLayout.VERTICAL);
LinearLayout menuLayout = new LinearLayout(this);
menuLayout.setBackgroundColor(Color.parseColor("#FFFFFF"));
textView = new TextView(this);
textView.setVisibility(View.VISIBLE);
String str = "Score: 0";
textView.setText(str);
menuLayout.addView(textView);
Button button = new Button(this);
button.setText("Pause");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
togglePausePlay();
}
});
menuLayout.addView(button);
Spinner spinner2 = new Spinner(this);
spinner2.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue);
spinner2.setAdapter(adapter);
menuLayout.addView(spinner2);
Spinner spinner3 = new Spinner(this);
spinner3.setOnItemSelectedListener(this);
ArrayAdapter<String> adapter2 = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, spinnerValue2);
spinner3.setAdapter(adapter2);
menuLayout.addView(spinner3);
mainLayout.addView(menuLayout);
cg = new CatchGame(this, 7, "Purple", onScoreListener);
cg.setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
mainLayout.addView(cg);
getWindow().requestFeature(Window.FEATURE_ACTION_BAR);
getSupportActionBar().hide();
setContentView(mainLayout);
}
private void togglePausePlay() {
if (cg.paused) {
// play
// getSupportActionBar().hide();
Toast.makeText(MainActivity.this, "Play", Toast.LENGTH_SHORT).show();
} else {
// pause
// getSupportActionBar().show();
Toast.makeText(MainActivity.this, "Pause", Toast.LENGTH_SHORT).show();
}
cg.paused = !cg.paused;
}
private OnScoreListener onScoreListener = new OnScoreListener() {
@Override
public void onScore(int score) {
textView.setText("Score: " + score);
}
};
interface OnScoreListener {
void onScore(int score);
}
class CatchGame extends View {
int NBRSTEPS; // number of discrete positions in the x-dimension; must be uneven
String heroName;
int screenW;
int screenH;
int[] x; // x-coordinates for falling objects
int[] y; // y-coordinates for falling objects
int[] hero_positions; // x-coordinates for hero
Random random = new Random();
int ballW; // width of each falling object
int ballH; // height of ditto
float dY; //vertical speed
Bitmap falling, hero, jamie2, jamieleft, jamieright, falling2, falling3;
int heroXCoord;
int heroYCoord;
int xsteps;
int score;
int offset;
boolean gameOver; // default value is false
boolean toastDisplayed;
boolean paused = false;
OnScoreListener onScoreListener;
// constructor, load images and get sizes
public CatchGame(Context context, int difficulty, String name, OnScoreListener onScoreListener) {
super(context);
NBRSTEPS = difficulty;
heroName = name;
this.onScoreListener = onScoreListener;
x = new int[NBRSTEPS];
y = new int[NBRSTEPS];
hero_positions = new int[NBRSTEPS];
int resourceIdFalling = 0;
int resourceIdFalling2 = 0;
int resourceIdFalling3 = 0;
int resourceIdHero = 0;
if (heroName.equals("Purple")) {
resourceIdFalling = R.drawable.object2_hdpi;
resourceIdFalling2 = R.drawable.object1_hdpi;
resourceIdHero = R.drawable.right_side_hdpi;
setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
} else if (heroName.equals("Orange")) {
resourceIdFalling = R.drawable.object2_hdpi;
resourceIdFalling2 = R.drawable.object1_hdpi;
resourceIdHero = R.drawable.spaceship3_hdpi;
setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
} else if (heroName.equals("Yellow")) {
resourceIdFalling = R.drawable.object2_hdpi;
resourceIdFalling2 = R.drawable.object1_hdpi;
resourceIdHero = R.drawable.spaceship2_hdpi;
setBackground(getResources().getDrawable(R.drawable.bg_land_hdpi));
}
resourceIdFalling3 = R.drawable.object3_hdpi;
falling = BitmapFactory.decodeResource(getResources(), resourceIdFalling); //load a falling image
falling2 = BitmapFactory.decodeResource(getResources(), resourceIdFalling2); //load a falling image
falling3 = BitmapFactory.decodeResource(getResources(), resourceIdFalling3); //load a falling image
hero = BitmapFactory.decodeResource(getResources(), resourceIdHero); //load a hero image
jamieleft = BitmapFactory.decodeResource(getResources(), R.drawable.right_side_hdpi); //load a hero image
jamieright = BitmapFactory.decodeResource(getResources(), R.drawable.right_side_hdpi); //load a hero image
ballW = falling.getWidth();
ballH = falling.getHeight();
}
// set coordinates, etc.
void initialize() {
if (!gameOver) { // run only once, when the game is first started
int maxOffset = (NBRSTEPS - 1) / 2;
for (int i = 0; i < x.length; i++) {
int origin = (screenW / 2) + xsteps * (i - maxOffset);
x[i] = origin - (ballW / 2);
hero_positions[i] = origin - hero.getWidth();
}
int heroWidth = hero.getWidth();
int heroHeight = hero.getHeight();
hero = Bitmap.createScaledBitmap(hero, heroWidth * 2, heroHeight * 2, true);
hero = Bitmap.createScaledBitmap(hero, heroWidth * 2, heroHeight * 2, true);
jamieleft = Bitmap.createScaledBitmap(jamieleft, jamieleft.getWidth() * 2, jamieright.getWidth() * 2, true);
jamieright = Bitmap.createScaledBitmap(jamieright, jamieright.getWidth() * 2, jamieright.getWidth() * 2, true);
heroYCoord = screenH - 2 * heroHeight; // bottom of screen
}
for (int i = 0; i < y.length; i++) {
y[i] = -random.nextInt(1000); // place items randomly in vertical direction
}
offset = (NBRSTEPS - 1) / 2; // place hero at centre of the screen
heroXCoord = hero_positions[offset];
// initialize or reset global attributes
dY = 2.0f;
score = 0;
gameOver = false;
toastDisplayed = false;
}
// method called when the screen opens
@Override
public void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
screenW = w;
screenH = h;
xsteps = w / NBRSTEPS;
initialize();
}
// method called when the "game over" toast has finished displaying
void restart(Canvas canvas) {
toastDisplayed = true;
initialize();
draw(canvas);
}
// update the canvas in order to display the game action
@Override
public void onDraw(Canvas canvas) {
if (toastDisplayed) {
restart(canvas);
return;
}
super.onDraw(canvas);
int heroHeight = hero.getHeight();
int heroWidth = hero.getWidth();
int heroCentre = heroXCoord + heroWidth / 2;
Context context = this.getContext();
// compute locations of falling objects
for (int i = 0; i < y.length; i++) {
if (!paused) {
y[i] += (int) dY;
}
// if falling object hits bottom of screen
if (y[i] > (screenH - ballH) && !gameOver) {
dY = 0;
gameOver = true;
paused = true;
int duration = Toast.LENGTH_SHORT;
final Toast toast = Toast.makeText(context, "GAME OVER!\nScore: " + score, duration);
toast.show();
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
toast.cancel();
toastDisplayed = true;
}
}, 3000);
//Vibrator v = (Vibrator) context.getSystemService(context.VIBRATOR_SERVICE);
// Vibrate for 3000 milliseconds
//v.vibrate(3000);
}
// if the hero catches a falling object
if (x[i] < heroCentre && x[i] + ballW > heroCentre &&
y[i] > screenH - ballH - heroHeight) {
y[i] = -random.nextInt(1000); // reset to new vertical position
score += 1;
onScoreListener.onScore(score);
}
}
canvas.save(); //Save the position of the canvas.
Random rand = new Random();
int randomNum = 1 + rand.nextInt((3 - 1) + 1);
for (int i = 0; i < y.length; i++) {
if (i % 3 == 1)
canvas.drawBitmap(falling2, x[i], y[i], null); //Draw the falling on the canvas.
else if (i % 3 == 2)
canvas.drawBitmap(falling, x[i], y[i], null); //Draw the falling on the canvas.
else if (i % 3 == 0)
canvas.drawBitmap(falling3, x[i], y[i], null); //Draw the falling on the canvas.
}
canvas.drawBitmap(hero, heroXCoord, heroYCoord, null); //Draw the hero on the canvas.
canvas.restore();
//Call the next frame.
invalidate();
}
// event listener for when the user touches the screen
@Override
public boolean onTouchEvent(MotionEvent event) {
if (paused) {
paused = false;
}
int action = MotionEventCompat.getActionMasked(event);
if (action != MotionEvent.ACTION_DOWN || gameOver) { // non-touchdown event or gameover
return true; // do nothing
}
int coordX = (int) event.getX();
int xCentre = (screenW / 2) - (hero.getWidth() / 2);
int maxOffset = hero_positions.length - 1; // can't move outside right edge of screen
int minOffset = 0; // ditto left edge of screen
if (coordX < xCentre && offset > minOffset) { // touch event left of the centre of screen
offset--; // move hero to the left
if (coordX < heroXCoord)// + heroWidth / 2)
hero = Bitmap.createScaledBitmap(hero, hero.getWidth(), hero.getHeight(), true);
}
if (coordX > xCentre && offset < maxOffset) { // touch event right of the centre of screen
offset++; // move hero to the right
if (coordX > heroXCoord)
hero = Bitmap.createScaledBitmap(hero, hero.getWidth(), hero.getHeight(), true);
}
heroXCoord = hero_positions[offset];
return true;
}
}
}
This is my first Android project and I'd like to learn how to improve my code.
