Develop Reference

java: make program wait until transition is finished

I've been writing a method to switch two images. This method is called in a mouse drag-and-drop event and is followed by another method that lets images drop down a few positions (I'm talking about a sort of candy crush mechanism).
In my case, the transition in the second method starts before the switch is done, which is why you can barely see the switch.
What I'm looking for is a way to make the program wait until the first transition is finished before it steps into the next method. Thread.sleep() isn't working for me since it stops the switch animation as well, and I don't know how to use the transition.setOnFinished() properly within my switch method without causing an infinite loop.
This is part of my switch method:
public void animateSwitch(int xFirst, int yFirst, int xLast, int yLast) {
/.../
ParallelTransition allMovements = new ParallelTransition();
TranslateTransition tt = new TranslateTransition(Duration.millis(FALL_TIME_PER_ROW), getNodeFromGridPane(grdPane, xFirst, yFirst));
TranslateTransition tt2 = new TranslateTransition(Duration.millis(FALL_TIME_PER_ROW), getNodeFromGridPane(grdPane, xLast, yLast));
Image old = iv1.getImage();
iv1.setImage(iv2.getImage());
iv1.setTranslateX(iv2.getX());
iv1.setTranslateY(iv2.getY());
iv2.setImage(old);
iv2.setTranslateX(iv1.getX());
iv2.setTranslateY(iv1.getY());
if (xFirst == xLast) {
tt.toYProperty().set(0);
tt.toXProperty().set(tt.getFromX());
if (yFirst < yLast) {
tt.fromYProperty().set(rowHeight);
tt2.fromYProperty().set(-rowHeight);
}
else {
tt.fromYProperty().set(-rowHeight);
tt2.fromYProperty().set(rowHeight);
}
tt2.toYProperty().set(0);
tt2.toXProperty().set(tt2.getFromX());
}
else if (yFirst == yLast) {
tt.toXProperty().set(0);
tt.toYProperty().set(tt.getFromY());
if (xFirst < xLast) {
tt.fromXProperty().set(rowWidth);
tt2.fromXProperty().set(-rowWidth);
}
else {
tt.fromXProperty().set(-rowWidth);
tt2.fromXProperty().set(rowWidth);
}
tt2.toXProperty().set(0);
tt2.toYProperty().set(tt2.getFromY());
}
allMovements.getChildren().add(tt);
allMovements.getChildren().add(tt2);
allMovements.play();
}
Thanks in advance!

You will have to set the onFinished event handler using allMovements.setOnFinished(eventHandler); Here eventHandler is an object that implements the EventHandler interface.
EDIT:
I skipped past the part where you don't know how to prevent an infinite loop using this solution. You can use two different eventHandlers to do the different parts. The first calls the second when it finishes. The second doesn't need to call the first, so you will not get into a loop.

Why is it adding more than 1 to my speed control?

import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
public class Turtle extends Actor
{
/**
* Act - do whatever the Turtle wants to do. This method is called whenever
* the 'Act' or 'Run' button gets pressed in the environment.
*/
int laufmenge;
public void act()
{
if(Greenfoot.isKeyDown("left")){
move(-speed);
}
if(Greenfoot.isKeyDown("right")){
move(speed);
}
if(Greenfoot.isKeyDown("up")){
setLocation(getX() ,getY() -speed);
}
if(Greenfoot.isKeyDown("down")){
setLocation(getX() ,getY() +speed);
}
if(Greenfoot.isKeyDown("x")){
if(speed<10) speed++;
}
if(Greenfoot.isKeyDown("y")){
if(speed>0) speed--;
}
System.out.println(speed);
}
private int speed=1;
}
This is code from Greenfoot because i am currently trying to learn coding. I cant understand why when i execute the programm and control the speed he is changing the value by more than one. I guess it will be an easy question.
And is it possible to put the increase and decrease of the speed on one button with two letters like the >< key? i didnt work in my case.

This happens because act() is called in rapid succession. Even if you just press and release x, act() will have run several times while the key is down, and therefore updated the speed several times.
To avoid that, you can track whether or not you've adjusted the speed since the first time you noticed that the button was pressed.
For example, you can have a private bool adjustedSpeed = false; in your class, and then do:
if(Greenfoot.isKeyDown("x")){
if(speed<10 && !adjustedSpeed) speed++;
adjustedSpeed = true;
} else if(Greenfoot.isKeyDown("y")){
if(speed>0 && !adjustedSpeed) speed--;
adjustedSpeed = true;
} else {
adjustedSpeed = false
}

How to make a delay in processing project?

I'm using Java within a Processing project. I'm trying to make a delay that doesn't stop the program, but stops only a given block of code. That "processing" block of code could for example add 1 to a variable, then wait one second and then add 1 again. The problem is that delay() (see reference) stops the whole program and Thread.sleep() doesn't work in a Processing project.

You should not use delay() or Thread.sleep() in Processing unless you're already using your own threads. Don't use it on the default Processing thread (so don't use it in any of the Processing functions).
Instead, use the frameCount variable or the millis() function to get the time that your event starts, and then check that against the current time to determine when to stop the event.
Here's an example that shows a circle for 5 seconds whenever the user clicks:
int clickTime = 0;
boolean showCircle = false;
void draw(){
background(64);
if(showCircle){
ellipse(width/2, height/2, width, height);
if(clickTime + 5*1000 < millis()){
showCircle = false;
}
}
}
void mousePressed(){
clickTime = millis();
showCircle = true;
}
Side note: please try to use proper punctuation when you type. Right now your question is just one long run-on sentence, which makes it very hard to read.

How to handle event in a program running in a cycle (loop)?

I´ve been dealing with this for some days now I´ve serach over the internet and tried everything that came up to my mind but nothing works. My problem is that I am making a pexeso game, we have some additionaly library directly from school or something like that which allows us to draw some pictures instead of comad line only... (We didn´t have graphics yet) So my problem is that my game is running in cycle and waiting for my click som I am checking the condition if click was made. And if I want to click I have to have just a method public void vyberSuradnice(int, int) declared in my code.
So the problem is that my game is runinng in cycle and checking if click was made. But when the click was made the method vyberSuradnice is executed and there I am setting the value off atrrbiute - cakatNaKlik on false, so click was made and one step of game can be made.. But since the function is running in cycle, then even If I clicked and in the method vyberSuradnice the value of attribute is changed, my function which is running in cycle isn´t respond to that change, so the game isn´t going on.
this is the method for clicking
public void vyberSuradnice(int paSuradnicaX, int paSuradnicaY) {
this.riadokOdkry = (paSuradnicaY ) / 25;
this.stlpecOdkry = (paSuradnicaX - 10) / 25;
if (this.riadokOdkry > this.aPocetRiadkov || this.stlpecOdkry > this.aPocetStlpcov) {
System.out.println("Klikli ste mimo hracieho pola ");
} else {
this.cakatNaKlik = false;
}
}
This the part of code where I am waiting for cakatNaklik - false value
while (uhadol) {
if (!this.cakatNaKlik) {
if (this.pocetUhadnutych >= (this.aPocetRiadkov * this.aPocetStlpcov) / 2) {
uhadol = false;
}
this.hraciaPlocha[this.riadokOdkry][this.stlpecOdkry].setUhadnute(true);
But even if the value is changed in method vyberSuradnice this condition is not triggered. But when I make something like this :
while (uhadol) {
System.out.print(this.cakatNaKlik);
if (!this.cakatNaKlik) {
if (this.pocetUhadnutych >= (this.aPocetRiadkov * this.aPocetStlpcov) / 2) {
uhadol = false;
}
this.hraciaPlocha[this.riadokOdkry][this.stlpecOdkry].setUhadnute(true);
the game is working like by writing the variable refresh it or something... but I am getting neverending print of true true or false on command line and this is something I can´t afford to have...
I know this may can be dan by threads but it´s something I can´t allowed to make and I am basically trying to do two things at once.
Is there any other to do this that the variable will be refreshed even without that println and the code will work ?
Thanks very much for every help

Thanks everybody for help, I finally solved it. I just tried tu put a sleep before the if condition. It only need to sleep for even a one miliseconds and it´s seems that the condition is refreshed so it works.

Try this:
Implement an ActionListener interface or extend a class that implements an ActionListener interface. For example:
public class MyClass implements ActionListener {
}
Register an instance of the event handler class as a listener on one or more components. For example:
someComponent.addActionListener(instanceOfMyClass);
instanceOfClass = this; //(if it is handled in the same Class)
Include code that implements the methods in listener interface. For example:
public void actionPerformed(ActionEvent e) {
...//code that reacts to the action...
}
Reference:
https://docs.oracle.com/javase/tutorial/uiswing/events/actionlistener.html

Counting headset button clicks in BroadcastReceiver

Inside of the onReceive(Content context, Intent intent) method of my public class MediaButtonIntentReceiver extends BroadcastReceiver I need to count the number of headset button clicks (single, double, triple), which is denoted by KeyEvent.ACTION_DOWN of the ACTION_MEDIA_BUTTON.
What I have almost works, but my current algorithm sucks and is unreliable after a few times. Basically every successive ACTION_DOWN (hit within a certain number of milliseconds to the previous ACTION_DOWN) I do numClicks++. But also I need to see when the user is done pressing, so after each event I start a CountDownTimer, and if by the time it runs out there are no new clicks, then I'm done and now know the number of clicks.
The problems I'm running into are as follows: for one, the button itself seems noisy - if I press it too fast I usually miss a click. Two, after a few trials when the app it loaded, it starts getting random and I'm assuming that there are multiple CountDownTimer threads (is that the right word?) still running which screws my stuff up.
Anyways here's the main code snippet:
//note: thisClickTime uses System.currentTimeMillis()
if (action == KeyEvent.ACTION_UP) {
if (isDown == true) {
if (numClicks == 0 && lastClickTime == 0) {
//we have a new click
numClicks++;
lastClickTime = thisClickTime; //update the click time
isDown = false;
elapsedTime = thisClickTime - lastClickTime;
} else if (thisClickTime - lastClickTime < clickDelay) { //&& thisClickTime - lastClickTime > 10
numClicks++;
lastClickTime = thisClickTime;
isDown = false;
}
final int oldNumClicks = numClicks;
final CountDownTimer checkIfDone = new CountDownTimer(clickDelay, 10) {
public void onTick(long millisUntilFinished) {
if (oldNumClicks != numClicks) {
cancel();
}
}
public void onFinish() { //code that executes when counter is done
if (oldNumClicks == numClicks) {
//if user doesn't click anymore in time clickDelay + X milliseconds, then it's done
Toast.makeText(context, "Number of clicks: " + Integer.toString(numClicks), Toast.LENGTH_SHORT).show();
//reset state variables
numClicks = 0;
lastClickTime = 0;
}
}
}.start();
} else {
//?
}
}
For reference, I've been looking around at stuff like:
http://musicqueueproject.googlecode.com/svn-history/r83/trunk/src/com/yannickstucki/android/musicqueue/old/PlayerService.java
To see if there's a good way to register number of clicks. I don't really understand their code too well though, and from what I can see they only deal with single/double clicks (I may need triple and quadruple).
EDIT - uploaded the current code I'm working with. It works pretty decently most of the time. Here's what I've noticed though: if I do my button testing too close together in time, the results start screwing up and under counting the clicks. I think this is because other CountDownTimers from previous attempts are still open, and when they finish, they reset certain state variables (numClicks = 0, for one). So am I misusing the timer? I can't think of another solution though as I need some concept of elapsed time after the last click to determine when the clicking is done.
Thanks for any help.

If your BroadcastReceiver is registered in the manifest, the BroadcastReceiver will only exist for a single call to onReceive() -- subsequent broadcasts may result in another BroadcastReceiver instance. And a manifest-registered BroadcastReceiver cannot fork threads, as the whole process may get shut down once onReceive() is over.
I am skeptical that there a clean way to get your code to be reliable, as the media button simply was not designed for your intended use pattern.