Getting errors while implementing a threadpool on my android studio app - java

I am building an obstacles game and i want to show on screen multiple obstacles. The idea of "moving" the obstacles is to set the shapeable image view on and off until it comes to the bottom of the screen. these are all the relevant methods:
on create:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game_screen);
gm = new GameManager();
findViews();
game_FAB_left.setOnClickListener(v -> moveLeft());
game_FAB_right.setOnClickListener(v -> moveRight());
initCharacterPositions();
startTimer();
playBackgroundMusic();
threadPool = Executors.newFixedThreadPool(2);
startTime = System.currentTimeMillis();
}
the timer with a 1 second delay
private Timer timer;
private void startTimer() {
timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
runOnUiThread(()->{
updateTimerUI();
runObstaclesTasks();
});
}
},DELAY,DELAY);
}
the thread pool execution:
private void runObstaclesTasks() {
threadPool.execute(new Runnable() {
#Override
public void run() {
createObstacle();
}
});
}
creating an obstacle and calling the movement function
private void createObstacle() {
Obstacle o = new Obstacle();
int index = getRandomNum(0,NUMBER_OF_POSITIONS);
LinearLayout chosenLayout = (LinearLayout) game_LL_obstaclesLayout.getChildAt(index);
int numberOfObstaclesPosition = gm.getNumberOfObstaclesPosition();
obstacleMovement(o, index, chosenLayout, numberOfObstaclesPosition);
}
the loop that move the obstacle. there is a delay (Thread.sleep) to make the movement effect (visible-invisible):
public void obstacleMovement(Obstacle o, int index, LinearLayout chosenLayout, int numberOfObstaclesPosition) {
for (int i = 0; i < numberOfObstaclesPosition; i++) {
ShapeableImageView obstacleImg = (ShapeableImageView) chosenLayout.getChildAt(o.getPosition());
showObstacle(obstacleImg);
if(gm.isCollision(index, o.getPosition())){
setLifeImages();
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
String msg = "Ouch! " + String.valueOf(gm.getLifeCount()) + " lives left";
toast(msg);
gm.vibrate(v);
}
delay();
hideObstacle(obstacleImg);
o.setNextPosition();
}
}
game demonstration

Related

handler.postDelayed not working correctly

I have a simple stopwatch code piece. Thread is running in custom class, it connects to the main activity via Interface
public class MainActivity extends AppCompatActivity implements MainActivityInteractionInterface{
public static boolean isRunning = false;
Stopwatch stopWatch;
private TextView textViewMilliSeconds;
private TextView textViewSeconds;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textViewMilliSeconds = findViewById(R.id.textViewStopwatchMilliseconds);
textViewSeconds = findViewById(R.id.textViewStopwatchSeconds);
stopWatch = new Stopwatch(this, getApplicationContext());
stopWatch.runThread();
}
#Override
public void updateUI() {
String time = String.format(Locale.getDefault(), "%03d", stopWatch.getMilliseconds());
textViewMilliSeconds.setText(time);
String timeSeconds = String.format(Locale.getDefault(), "%02d", stopWatch.getSeconds());
textViewSeconds.setText(timeSeconds);
}
public void startTimer(View view) {
isRunning = !isRunning;
}
public class Stopwatch {
private int milliseconds = 0;
private int seconds = 0;
public int getMilliseconds() {
return milliseconds;
}
public int getSeconds() {
return seconds;
}
private MainActivityInteractionInterface interactionInterface;
private Context applicationContext;
public Stopwatch(MainActivityInteractionInterface interactionInterface, Context applicationContext){
this.interactionInterface = interactionInterface;
this.applicationContext = applicationContext;
}
public void runThread(){
final Handler handler = new Handler();
handler.post(new Runnable(){
#Override
public void run(){
if(isRunning) {
milliseconds++;
if (milliseconds == 1000) {
milliseconds = 0;
seconds++;
if(seconds == 60){
seconds = 0;
}
}
}
interactionInterface.updateUI();
handler.postDelayed(this, 1);
}
});
}
handler should update every 1 millisec, when there is 1000 milliseconds, 1 second passes by
If I set handler.postDelayed delay anything below 15 reaching 1000 milliseconds would take exactly 18 seconds, why?
I don't know why it would take up to 18seconds, but I can tell you this: Android refresh the UI every 16msec (to have a rate of 60fps), so setting the handler to updateUI in a lesser time would make no sense and maybe also interfier with it.
In my humble opinion, make it to update in 20msec and change the counter values according, like this:
handler.post(new Runnable(){
#Override
public void run(){
if(isRunning) {
milliseconds++;
if (milliseconds == 50) {
milliseconds = 0;
seconds++;
if(seconds == 60){
seconds = 0;
}
}
}
interactionInterface.updateUI();
handler.postDelayed(this, 20);
}
});
Look at the second argument of handler.postDelayed(this, 1);
Change it according to the way you increment your milliseconds.

pause program between adding and removing a TextView

I'm working on a tank-game and I have a TextView which represents the shot. Now I want to display the TextView at the specific point and remove it after a second that it looks like the shot goes further step by step. But when I add a countdown or a Thread.sleep the program stops for a second but the TextView doesn't disappear. i want to move the TextView over the screen and after every iteration of my for loop i want to wait a second and then rearrange it again?
Here is the code :
public void shot(float power, float winkel, Button button) {
if(winkel>90) {
winkel = winkel - 10;
}else if(winkel<90){
winkel = winkel +10;
}
for (double i = 0; i<100;i = i+ 1) {
final TextView textView = new TextView(context);
textView.setText(".");
double x = tanks.get(currentTank).getxPos()+(i*power*Math.cos(winkel *(Math.PI/180)));
double y = tanks.get(currentTank).getyPos()+(-1*(i*power*Math.sin(winkel *(Math.PI/180))));
double gravity = (-1*((9.81/2)*Math.pow(i,2)));
y = (y-gravity);
textView.setX((float) x);
textView.setY((float) y);
layout.addView(textView);
for (int j = 0;j<tanks.size();j++){
if(textView.getX()>tanks.get(j).getxPos()&&textView.getX()<tanks.get(j).getxPos()+100){
if(textView.getY()>tanks.get(j).getyPos()&&textView.getY()<tanks.get(j).getyPos()+100){
float k = tanks.get(j).getxPos()-textView.getX();
if(k<0){
k = k*-1;
}
makeDamage(k,tanks.get(j));
}
}
}
new CountDownTimer(2000,1000){
#Override
public void onTick(long millisUntilFinished) {
}
#Override
public void onFinish() {
layout.removeView(textView);
}
}.start();
}
newTurn();
}
I want to pause the program after adding the TextView for one second and the remove it. The program stops but the TextView doesn't disappear till the for-loop finished. Then all TextViews disappear.
Problem solved:
i've added all positions in a array and then this
public void drawShot(final Button firework, final ArrayList<TextView> toDraw){
final int[] i = {0};
final Handler mHandler = new Handler();
firework.setOnClickListener(new View.OnClickListener() {
#RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
#Override
public void onClick(View v) {
firework(firework,toDraw.get(i[0]).getX(),toDraw.get(i[0]).getY());
}
});
Runnable runnable = new Runnable() {
#Override
public void run() {
layout.addView(toDraw.get(i[0]));
if(!check(toDraw.get(i[0]))) {
mHandler.postDelayed(this, (long) 1);
}
i[0]++;
}
};
// start it with:
mHandler.post(runnable);
}
probably need to run the remove command on main thread
Handler mainHandler = new Handler(context.getMainLooper());
Runnable myRunnable = new Runnable() {
#Override
public void run() {
layout.removeView(textView);
}
};
mainHandler.post(myRunnable);

How to change buttons colors with delay in sequnce

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
take = getIntent();
levelone = take.getIntArrayExtra("level1");
take = getIntent();
leveltwo = take.getIntArrayExtra("level2");
take = getIntent();
levelthree = take.getIntArrayExtra("level3");
colors[0] = (R.drawable.blue1);//Suppose to give integer value for the colors
colors[1] = (R.drawable.purple1);
colors[2] = (R.drawable.yellow1);
colors[3] = (R.drawable.green1);
colors1[0] = (R.drawable.blue);//Suppose to set the colors back to origin
colors1[1] = (R.drawable.purple);
colors1[2] = (R.drawable.yellow);
colors1[3] = (R.drawable.green);
purple = findViewById(R.id.purplee); //1
green = findViewById(R.id.greenn);//2
yellow = findViewById(R.id.yelloww);//3
blue = findViewById(R.id.bluee);//4
for (int i = 0; i < btn.length; i++) {
buttons[i] = findViewById(btn[i]);
buttons[i].setOnClickListener(this);
}
/*new CountDownTimer(5000,1000)//5000=5sec to wait and 1000=1sec for interval
{
// loop for timer
#Override
public void onTick(long l) {
Toast.makeText(Main.this, ""+l/1000, Toast.LENGTH_SHORT).show();
}
//what happend after finish 5 sec
#Override
public void onFinish() {
Intent go=new Intent(Main.this,Start.class);
startActivity(go);
}
}.start();*/
new CountDownTimer(2000,500)//5000=5sec to wait and 1000=1sec for interval
{
// loop for timer
#Override
public void onTick(long l) {
buttons[1].setBackgroundResource(colors1[1]);//purple Butttons[1]
buttons[2].setBackgroundResource(colors1[2]);//Yellow Buttons[2]
buttons[3].setBackgroundResource(colors1[3]);//Green Buttons[3]
buttons[0].setBackgroundResource(colors1[0]);//Blue Buttons[0]
}
//what happend after finish 5 sec
#Override
public void onFinish() {
}
}.start();
I want to change the buttons color by delay so I ran a couple of options to do so and none of them worked, I mean I didn't see the delay and the color of the buttons didn't change as it supposed to so how should I do that? In the code, I have tried something but it didn't work so if you have any ideas I will be happy to hear.
You can use a handler
Handler handler = new Handler();
for(int i=0; i<btn.size; i++){
handler.postDelayed(new Runnable() {
#Override
public void run() {
buttons[i].setBackgroundResource(colors1[i]);
}
},1000); // Delay every "1" second
}
//Write This Code Inside onCreate Methode
Timer timer = new Timer();
MyTimer myTimer = new MyTimer();
timer.schedule(myTimer, 1000, 1000);
//Make this Class Outside onCreate Methode
class MyTimer extends TimerTask {
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
Random random = new Random();
for (int i = 0; i < btn.size; i++) {
buttons[i].setBackgroundColor(Color.argb(255, random.nextInt(256), random.nextInt(256), random.nextInt(256)));
}
}
});
}
}

App crashing when using SharedPreferences to carry over final score

My android app is crashing when using SharedPreferences to try and carry the final score over from when the game ends. The app crashes inside the onTouchEvent at the line.
SharedPreferences.Editor editor = mySharedPreferences.edit();
The idea is when the game ends it final score that is within the SVGameView to carry over into the SVGameOver class and display there. If anyone could give some advice that would be great!
SVGameView:
public class SVGameView extends SurfaceView implements Runnable {
private SurfaceHolder holder;
Thread thread = null;
volatile boolean running = false;
static final long FPS = 30;
private Sprite sprite;
private long lastClick;
private Bitmap ball, gameOver;
//private int x = 200, y = 200;
private int scorePosX = 100;
private int scorePosY = 100;
private int countScore = 0;
private int life = 1;
SharedPreferences mySharedPreferences;
public SVGameView(Context context) {
super(context);
thread = new Thread(this);
holder = getHolder();
holder.addCallback(new SurfaceHolder.Callback() {
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
boolean retry = true;
running = false;
while (retry) {
try {
thread.join();
retry = false;
} catch (InterruptedException e) {
}
}
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
running = true;
thread.start();
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
}
});
ball = BitmapFactory.decodeResource(getResources(), R.drawable.ball2);
gameOver = BitmapFactory.decodeResource(getResources(),R.drawable.endscreen);
sprite = new Sprite(this, ball);
context.getSharedPreferences("myPrefsFile",Context.MODE_PRIVATE);
}
#Override
public void run() {
long ticksPS = 1000 / FPS;
long startTime;
long sleepTime;
while (running) {
Canvas c = null;
startTime = System.currentTimeMillis();
try {
c = getHolder().lockCanvas();
synchronized (getHolder()) {
update();
onDraw(c);
}
} finally {
if (c != null) {
getHolder().unlockCanvasAndPost(c);
}
}
sleepTime = ticksPS-(System.currentTimeMillis() - startTime);
try {
if (sleepTime > 0)
thread.sleep(sleepTime);
else
thread.sleep(10);
} catch (Exception e) {}
}
}
private void update(){
sprite.update();
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
Paint paint = new Paint();
canvas.drawPaint(paint);
paint.setColor(Color.WHITE);
paint.setTextSize(48);
canvas.drawText("Score: " + countScore, scorePosX, scorePosY, paint);
canvas.drawText("Lives: " + life, 500, 100, paint);
sprite.onDraw(canvas);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if(System.currentTimeMillis()-lastClick > 300){
lastClick = System.currentTimeMillis();
}
synchronized (getHolder()){
if(sprite.isHit(event.getX(), event.getY())){
countScore += 1;
sprite.increase();
}else{
life --;
}
}
if(life == 0) {
getContext().startActivity(new Intent(getContext(), SVGameOver.class));
//Intent intent;
//intent = new Intent(getContext(), SVGameView.class);
//intent.putExtra("scoreOutput", countScore);
//Crashes Here
SharedPreferences.Editor editor = mySharedPreferences.edit();
editor.putString("cScore", String.valueOf(countScore));
}
return super.onTouchEvent(event);
}
}
SVGameOver Class:
public class SVGameOver extends Activity implements View.OnClickListener{
Button btnBack;
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game);
btnBack = (Button)findViewById(R.id.btnBack);
btnBack.setOnClickListener(this);
SharedPreferences mySharedPreferences = getSharedPreferences("myPrefsFile", 0);
String theScore = mySharedPreferences.getString("cScore","");
TextView textView = (TextView)findViewById(R.id.scoreOutput);
textView.setText(theScore);
//intent = getIntent();
//String uir = intent.getStringExtra("scoreOutput");
}
#Override
public void onClick(View v) {
}
}
XML Layout:
https://gyazo.com/8e49d02c66dde7ff0e7f09a4fa9eacd2
You're missing:
mySharedPreferences = context.getSharedPreferences("myPrefsFile", Context.MODE_PRIVATE);
in your SVGameView, so mySharedPreferences always null.
You missed assigning SharedPreferencesobject to your reference mySharedPreferences in SVGameView(Context context) -
context.getSharedPreferences("myPrefsFile",Context.MODE_PRIVATE);
Change it to
mySharedPreferences = context.getSharedPreferences("myPrefsFile",Context.MODE_PRIVATE);
You are not initializing the SharedPreference object right.
Use this library, which simplifies the use of SharedPreferences and will make life simpler for you.
Android-SharedPreferences-Helper simplifies usage of the default Android SharedPreferences Class. The developer can do in a few lines
of code which otherwise would have required several. Simple to
understand as compared to the default class and easy to use.

Android: Pause/Resume Timer OR Thread

I have checked all SO answers about how to pause/resume timer, but can't find a solution.
I have created a Timer task which counts the effort time for an employee and puts it inside a TextView to show.
Code below:
Timer T = new Timer();
T.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
String workingTime = "Your effort is "
+ format.format(Double.valueOf(hr)) + ":"
+ format.format(Double.valueOf(min)) + ":"
+ format.format(Double.valueOf(sec))
+ " till now for the day";
storeEffort.setText(workingTime);
sec++;
if (sec > 59) {
sec = 0;
min = min + 1;
}
if (min > 59) {
min = 0;
hr = hr + 1;
}
}
});
}
}, 1000, 1000);
where storeEffort is my TextView which shows the effort time which is stuck inside the running thread(main problem). I want to pause the effort timer with a button click and resume it when the same button clicked again.Is there any other way to do this kind of task?
You solution might have a slight problem - you are using timer to count time intervals whereas there is no need to. You could use i.e. StopWatch to count elapsed time. So instead of adding seconds in a timer job you could just get elapsed time from this timer. To pause the timer you could call stopWatch.stop() and to start it, you could call stopWatch.start().
It could look like this:
Stopwatch stopwatch = Stopwatch.createStarted();
void startThreadUpdateTimer(){}
Timer T = new Timer();
T.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
String workingTime = "Your effort is " + sw.toString() +
" till now for the day";
}
});
}
}, 1000, 1000);
}
public void pause(){
if(stopwatch.isRunning()){
stopwatch.stop();
}
}
public void resume(){
if(!stopwatch.isRunning()){
stopwatch.start();
}
}
UPDATE Solution if the timer needs to start from beginning every second time:
public class YourOuterClass extends Activity {
private YourTimerTask mTimerTask;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Button button;
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if (mTimerTask != null && mTimerTask.isTaskActive()) {
mTimerTask.deactivateTimer();
mTimerTask = null;
} else {
startTask();
}
}
});
...
}
private class YourTimerTask extends TimerTask {
private boolean mIsTimerActive;
public YourTimer() {
mIsTimerActive = true;
}
public void deactivateTimer() {
mIsTimerActive = false;
}
public boolean isTaskActive() {
return mIsTimerActive;
}
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
String workingTime = "Your effort is "
+ format.format(Double.valueOf(hr)) + ":"
+ format.format(Double.valueOf(min)) + ":"
+ format.format(Double.valueOf(sec))
+ " till now for the day";
if (!mIsTimerActive) {
cancel(); // will cancel this timer instance
}
sec++;
if (sec > 59) {
sec = 0;
min = min + 1;
}
if (min > 59) {
min = 0;
hr = hr + 1;
}
}
});
}
}
...
private void startTask() {
Timer T = new Timer();
mTimerTask = new YourTimertask();
T.scheduleAtFixedRate(mTimerTask, 1000, 1000);
}
}

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