I have a very simple sketch that opens multiple windows, like so:
void setup(){
size(100,100);
noLoop();
}
void keyPressed(){
String[] args={"Secondary window!"};
SecondWindow window=new SecondWindow();
PApplet.runSketch(args, window);
}
class SecondWindow extends PApplet{
void setup(){
size(100,100);
background(~0);
noLoop();
}
void keyPressed(){
exit();
}
}
However, there is an issue: How can I close just child window? Pressing the [X] on the child window closes both the parent and child sketch, and the function exit() does the same.
Is there a method to close only the child applet? The PApplet documentation does not list any methods that seem to do this!
Thank you!
The surface variable gives you access to the underlying window. You can call surface.setVisble(false) to hide the window.
void setup(){
size(100,100);
noLoop();
}
void keyPressed(){
String[] args={"Secondary window!"};
SecondWindow window=new SecondWindow();
PApplet.runSketch(args, window);
}
class SecondWindow extends PApplet{
void setup(){
size(100,100);
background(~0);
noLoop();
}
void keyPressed(){
surface.setVisible(false);
}
}
Related
QUESTION
I'm trying to create a simple object "car" animation in Processing.
My code is:
Car car;
void setup(){
size(800, 600);
background(#818B95);
frameRate(30);
car = new Car(10,10);
}
void draw(){
//refresh background
background(#818B95);
print("-");
car.drawCar();
}
void mouseClicked() {
car.run();
}
public class Car implements Runnable{
private int pos_x, pos_y;
public Car(int pos_x, int pos_y){
this.pos_x = pos_x;
this.pos_y = pos_y;
}
public void drawCar(){
rect(pos_x,pos_y,10,10);
}
public void run(){
while(true){
pos_x += 10;
print("*");
delay(200);
}
}
}
I'm expecting to see the car/rectangle move right when I click the mouse button, but nothing happens.
I've added the two print in order to see if the draw method and my car.run are executed in parallel showing some * and - printed alternately.
What I see is a sequence of - until I click and then only * are printed.
Is it possible that starting a new object thread will stop the main draw cycle?
SOLUTION
This is just a variant of the suggested solution (by Mady Daby) without using threads.
Car car;
void setup(){
size(800, 600);
background(#818B95);
frameRate(30);
car = new Car(10,10);
}
void draw(){
//refresh background
background(#818B95);
print("-");
car.drawCar();
}
void mouseClicked() {
car.moving = true;
}
public class Car{
private int pos_x, pos_y;
boolean moving = false;
public Car(int pos_x, int pos_y){
this.pos_x = pos_x;
this.pos_y = pos_y;
}
public void drawCar(){
rect(pos_x,pos_y,10,10);
//animation
if(moving){
pos_x += 10;
print("*");
}
}
}
You could make the car move right by just introducing a boolean variable to track whether the car is supposed to be moving right moving and then increment pos_x if moving is true. You can also use the clicks to toggle between moving and not moving.
Car car;
void setup() {
size(800, 600);
background(#818B95);
frameRate(30);
car = new Car(10, 10);
}
void draw() {
//refresh background
background(#818B95);
print("-");
car.drawCar();
}
void mouseClicked() {
car.toggleMoving();
}
public class Car implements Runnable {
private int pos_x, pos_y;
private boolean moving = false;
public Car(int pos_x, int pos_y) {
this.pos_x = pos_x;
this.pos_y = pos_y;
}
public void toggleMoving() {
moving = !moving;
}
public void drawCar() {
if (moving) {
this.run();
}
rect(pos_x, pos_y, 10, 10);
}
public void run() {
pos_x += 10;
print("*");
delay(200);
}
}
I have a platformer class that creates a window and spawns platforms and a "character". It uses another class platform to make platforms. The character is supposed to jump up and land on the platforms. I use the getBounds and getTopY functions for collision detection but they only work for the first platform. How can i get them to work for multiple platforms?
public class Platformer extends JPanel {
Platform platform = new Platform(this);
Character character = new Character(this);
public Platformer() {
addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {
character.keyTyped(e);
}
#Override
public void keyReleased(KeyEvent e) {
character.keyReleased(e);
}
#Override
public void keyPressed(KeyEvent e) {
character.keyPressed(e);
}
});
setFocusable(true);
}
#Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
platform.Location(150,200);
platform.paint(g2d);
platform.Location(200,120);
platform.paint(g2d);
character.paint(g2d);
}
private void move(){
character.move();
}
public static void main(String args[]){
JFrame frame = new JFrame("Mini Tennis");
//create new game
Platformer platformer = new Platformer();
//add game
frame.add(platformer);
//size
frame.setSize(400, 400);
frame.setVisible(true);
//set close condition
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
while (true) {
platformer.move();
platformer.repaint();
try {
Thread.sleep(10);//sleep for 10 sec
} catch (InterruptedException ex) {
Thread.currentThread().interrupt();
}
}
}
}
public class Platform {
private static final int Height = 10;
private static final int Width = 60;
int x;
int Y;
private Platformer platformer;
public Platform(Platformer platformer) {
this.platformer = platformer;
}
public void Location(int xin, int yin) {
x = xin;
Y = yin;
}
public void paint(Graphics2D g) {
g.fillRect(x, Y, Width, Height);
}
public Rectangle getBounds() {
return new Rectangle(x, Y, Width, Height);
}
public int getTopPlat() {
return Y;
}
}
Actually you have only one platform. And you draw this platform twice in different places (paint function in Platformer):
platform.Location(150,200);
platform.paint(g2d);
platform.Location(200,120);
platform.paint(g2d);
Therefore I suppose you handle only one platform (with coordinates 200 and 120). You must keep all of your platforms and handle each of them separately.
I am trying to use AsyncTask and the activity is working perfectly but I am facing a problem. The problem comes after I have pressed back button, because pressing this button my app crashes. I have seen other posts saying that I must cancel the task in onStop() and onDestroy() but still crashes. Does anyone have any idea how can I solve that?
private class MyAsyncTask extends AsyncTask<Void, Integer, Boolean> {
#Override
protected Boolean doInBackground(Void... args0) {
for(int i=1; i<=10; i++) {
try{
if(isCancelled())
break;
publishProgress(i*10);
Thread.sleep(1000);
}catch (InterruptedException e){}
}
return null;
}
/*
* it will update the publishProgress method and it will
* update the interface (if it's necessary)
*/
#Override
protected void onProgressUpdate(Integer... values) {
int progreso = values[0].intValue();
pbarProgreso.setProgress(progreso); // showing progress
pbarProgreso.setSecondaryProgress(progreso + 5);
}
/*
* Initializing progressBar
*/
#Override
protected void onPreExecute() {
pbarProgreso.setMax(100); // maximum value for process bar
pbarProgreso.setProgress(0); // minimum value to start
}
#Override
protected void onPostExecute(Boolean result) {
if(!this.isCancelled())
Toast.makeText(getApplicationContext(), "Task finished!",
Toast.LENGTH_SHORT).show();
}
#Override
protected void onCancelled() {
Toast.makeText(getApplicationContext(), "Task cancelled!",
Toast.LENGTH_SHORT).show();
}
}
#Override
protected void onStop() {
super.onStop();
if(task != null && task.getStatus() == Status.RUNNING){
task.cancel(true);
}
}
#Override
protected void onDestroy() {
super.onDestroy();
if(task != null && task.getStatus() == Status.RUNNING) {
task.cancel(true);
}
}
It's because when you press back button, AsyncTask continues to work, and when it do context related work, that context no longer exists, and a crash happens, it's better to use a "isResumed" boolean indicator variable inside an activity, and set it to false in onPause and set to true inside onResume, and inside an AsyncTask do context related things, inside an if condition.
Or if this code is inside a fragment, can use isAdded() method, to check if fragment is active or not. Cancel is also important, but there may be a delay, between an Activity pause and AsyncTask cancel, so keeping that variable is important.
I want to rotate my ImageView 2 times
Initially it will rotate 360 degree and after that extra some degree..
I am using following code
protected void rotation(int start, int end, int time) {
Animation a = new RotateAnimation((float)start, (float)end,
Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,0.5f);
a.setDuration((long)time);
a.setInterpolator(new LinearInterpolator());
a.setFillAfter(true);
ImageView.startAnimation(a);
}
My problem is
I am calling this function 2 times so it doesn't waits for first and directly starts second rotation.
I want to wait until first rotation completes and then start second rotation
Set a Listener in first animation
a.setAnimationListener(new Animation.AnimationListener() {
#Override
public void onAnimationStart(Animation animation) {
}
#Override
public void onAnimationEnd(Animation animation) {
callNewAnimation();
}
#Override
public void onAnimationRepeat(Animation animation) {
}
});
I have a customized gridview where i'm checking onScroll method to find the end of the list. If the scroll reaches the end of the list, it will again add few elements in to the list.
gridview.setOnScrollListener(new OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView arg0, int arg1) {
}
#Override
public void onScroll(AbsListView arg0, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
int lastInScreen = firstVisibleItem + visibleItemCount;
//is the bottom item visible & not loading more already ? Load more !
if((lastInScreen == totalItemCount) && (!loadingMore))
{
new LoadDataTask().execute();
}
}
});
And this is my Asynchronous task class..
private class LoadDataTask extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... params) {
if (isCancelled()) {
return null;
}
loadingMore = true;
for (int i = 0; i < mNames.length; i++)
mListItems.add(mNames[i]);
return null;
}
#Override
protected void onPostExecute(Void result) {
mListItems.add("Added after load more");
loadingMore=false;
adapter.notifyDataSetChanged();
super.onPostExecute(result);
}
#Override
protected void onCancelled() {
}
}
Now the issue is that the onScroll method keep on calling. It doesn't stop even when the user not scrolling. Can anyone have a solution ?
Please check the answer for this question: onScroll gets called when I set listView.onScrollListener(this), but without any touch .
The same is true for the GridView, since it has AbsListView as superclass just as ListView does.