Java Threads are not running on separate objects - java

I am working on a school project that involves generating two separate Swing Canvas objects which animate Breadth/Depth-First Search Algorithms on cloned copies of a Matrix/Grid Data Structure I have designed.
I have created a few classes that help translate the Matrix/Grid into graphics, which are combined in a SearchAnimation class that acts a ViewController for managing the animations. In the image below, they appear on the right (not in the yellow background area). Each SearchAnimation object includes a JLabel, Canvas, and White Background.
Below is a screenshot of the layout:
The JFrame contains two instances of the SearchAnimation Class in the Application Controller Class (ICL.java). These animations must run concurrently. I have created separate Threads for each animation, passing it separate SearchAnimation objects:
public void setupDepthFirstPanel() {
// Create a new GridGraphic Panel
//canvasDepthFirst = new GridPanel(null, DEPTH_FIRST_LABEL);
mDepthAnimation = new SearchAnimation(null, SearchAnimationType.DEPTH_FIRST_ANIMATION);
mDepthThread = new Thread(mDepthAnimation, "Depth Thread");
}
public void setupBreadthFirstPanel() {
// Create a new GridGraphic Panel
//canvasBreadthFirst = new GridPanel(null, BREADTH_FIRST_LABEL);
mBreadthAnimation = new SearchAnimation(null, SearchAnimationType.BREADTH_FIRST_ANIMATION);
mBreadthThread = new Thread(mBreadthAnimation, "Breadth Thread");
}
I start the Threads in the ActionListener class that responds to the Click Event of the button that labeled "Label Components":
if ( source == labelComponents ) {
if (DEBUG && DEBUG_CLICK_LISTENER) System.out.println("\"Label Components\" Button Clicked!");
/*This is where the call for the labelBreadth and labelDepth of the
ICLLogic class is going to occur*/
// Run Animation
// Set Up Threads
System.out.println("ICL.ActionPerformed - Current Thread: " + Thread.currentThread());
//mBreadthThread = new Thread(mBreadthAnimation, "Breadth Animation");
//mDepthThread = new Thread(mDepthAnimation, "Depth Animation");
// Start Threads
mBreadthThread.start();
mDepthThread.start();
}
When the program runs and the "Label Components" button is clicked, only one of the graphics starts animating, but it seems as though both SearchAnimation Threads are running within a single JPanel/Canvas since the animation does not follow the logic of either algorithm.
Here is the implementation of the Runnable Interface within SearchAnimation:
// THREAD METHODS
/** Implementation of the Runnable interface for Multithreading of the
* SearchAnimation Class, which allows multiple SearchAnimations to run Concurrently.
* In this case, the Breadth & Depth-First SearchAnimations
*
*/
public void run() {
System.out.println("Thread Started - " + mAnimationType.toString());
// Run the Animation
step();
}
Which eventually calls determineSearchType() that switches on an Enum to pick the appropriate Algorithm:
public void determineSearchType(Pixel p) {
// Animate a single pixel movement, step depends on AnimationType
if (DEBUG && DEBUG_STEP_NEXT_PIXEL) { System.out.println("Determining Animation Type..."); }
switch (mAnimationType) {
case BREADTH_FIRST_ANIMATION:
if (DEBUG && DEBUG_STEP_NEXT_PIXEL) { System.out.println("Animation Type: Breadth-First"); }
// Begin Breadth-First Search
stepBreadthSearch(p);
break;
case DEPTH_FIRST_ANIMATION:
if (DEBUG && DEBUG_STEP_NEXT_PIXEL) { System.out.println("Animation Type: Depth-First"); }
// Begin Depth-First Search
stepDepthSearch(p);
//simpleDepthSearch(mCurrentPixel);
break;
}
}
When I alternate commenting them out, each Thread/Animation executes in its own JPanel/Canvas graphic and produces the expected results. I am pretty new to threading and I'm sure someone has an easy solution. Any ideas at how I can fix the issue that the animations won't animate simultaneously?

option1 :
to give another Thread chance to be executed. at the end of thread code, try yield() and see if you have some luck
Thread.currentThread().yield();
option2 :
add flag in your thread, to pause and continue the thread. the idea is
after thread 1 finish the step
- pause thread 1 - then start thread 2 - after thread 2 finish the step
- pause thread 2 - and continue thread 1 again.

Related

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.

Class Threading Consistency

As part of a project I am currently working on we (a few fellow coding enthusiasts friends) we are trying to make a relatively simple game. The game was to consist of several smaller games that we would program separately and my job was to combine them together into a sorta frankensteined super game.
One of these mini games consists of a "transportation Simulator". Very similar to something like frogger; just a lane swerving minigame. My friend who programmed this has it running 14 swing workers to complete tasks like spawning oncoming cars, road animations and your car. The problem I am having is when I call this class all of the threads don't launch. Some don't activate till after others finish, and others will run behind others. I moved the swingworkers into an Execution Service, but still get similar results. Is there a cap on number of threads running simultaneously? Are swingworkers the wrong thing for the job? It is very confusing for me because I cannot see any consistency in the failed threads. There seems to be no reason why sometimes they launch and other times don't. Any suggestions?
This is the Constructor
travelGUI(Player playerIn) throws InterruptedException {
...
//player is a object that contains a variable for each GUI
//it is also a Parameter
player = playerIn;
player.mapGUI.setVisible(false);
player.mapGUI.dispose();
methodNewThread();//road display
carThread();//Used to update the car in the game
copShootThread();
copShootThread();//Used to set up the bullet shoot thread that shoots at the car
healthThread();
bulletThread();
copThread("1", 1, "1" + "p");
copThread("2", 2, "2" + "p");
copThread("3", 3, "3" + "p");
copThread("4", 4, "4" + "p");
//Creates the background animation for the road and the end conditions for the level
intComponents();
}
an example of one of the threads is
public static void healthThread() {//This thread is used to update the players health
SwingWorker<Void, String> he;
he = new SwingWorker<Void, String>() {
#Override
protected Void doInBackground() throws Exception {
//code to be run in the new thread
...
}
return null;
}
};
// he.execute();
executorService.submit(he);
}

Java - JProgress bar not showing (threaded)

I am adding a feature to a program to save some content to file. The progress is shown by a progress bar (in its own JFrame), but the progress bar is only being displayed on the last value it reads. I have a global being updated by the main thread, that represents the % of work completed, and the other thread reads this global and updates the progress bar accordingly.
Right now when it runs, the JFrame is empty, then activity completes, then the progress bar shows itself with complete amount. How do i make it update the progress as it goes along (and show the JProgressbar from the start)? Here is my code:
public class GenomeAnnotator{
private JProgressBar csvProgressBar;
private JFrame csvSaveLoadFrame; //for the progress bar
private Container csvCon;
private double csvPercentSaved; //% of work completed
public JFrame m_frame; //main program frame
....
public static void main(String[] args){
...
showGUI();
...
}
public void showGUI(){
...
JMenu file = new JMenu("File");
JMenu exptann = new JMenu("Export annotation..);
JMenuItem exptcsv = newJMenuItem("CSV format");
exptcsv.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
..determine output file + checks...
System.out.println("Writing to .csv file......");
csvSaveLoadFrame = new JFrame("Saving to csv file..");
csvProgressBar =new JProgressBar(0,100);
csvSaveLoadFrame.setSize(300,100);
csvCon = csvSaveLoadFrame.getContentPane();
csvCon.setLayout(null);
csvProgressBar.setBounds(10,10,280,20);
csvCon.add(csvProgressBar);
csvSaveLoadFrame.setResizable(false);
csvSaveLoadFrame.setVisible(true);
ORF [] ora= orfPanel.getAcceptedOrfs();
int val;
double toload = blastData.size() + ora.length; //how much work
double loaded=0.0; //how much work completed
/*Thread that will read % value from global and update prog. bar*/
Thread progressBarMover = new Thread() {
#Override
public void run() {
int previous=0;
while(csvPercentSaved<100){
csvProgressBar.setValue((int)csvPercentSaved);
//tried putting a sleep() in here when testing
//values from global is read successfully
}
}
System.out.println("Thread done!");
csvPercentSaved = 0; //reset value when done
csvSaveLoadFrame.setVisible(false);
}
};
progressBarMover.start();
for (int k=0; k<blastData.size(); k++) {
..do output work...
loaded+=1; //update % values
csvPercentSaved = (loaded/toload)*100;
val = (int)csvPercentSaved;
System.out.println("main complete "+val+"%");
}
for (int k=0; k<ora.length; k++) {
...do more ouput work...
loaded+=1;
csvPercentSaved = (loaded/toload)*100; //update % value
val = (int)csvPercentSaved;
System.out.println("main complete "+val+"%");
}
System.out.println("Output file finished!");
csvPercentSaved = 100;
}
});
exptann.add(exptcsv);
file.add(exptann);
}
EDIT
found solution here:
https://weblogs.java.net/blog/mkarg/archive/2010/01/03/did-you-know-swingworker-can-send-progress-status
Several issues there:
Most most important (and I missed this initially!), you're not doing your long running code within the background thread but rather within the Swing event thread, the EDT. I am meaning these two for loops: A) for (int k=0; k<blastData.size(); k++) {...} and B) for (int k=0; k<ora.length; k++) {...} which looks to be the code where you're loading or saving information. This will freeze your GUI right up.
Also important, you're doing Swing calls from within a background thread, including setting the progress bar's value and setting a JFrame's visiblity, something that you never want to do, and that mostly negates the benefits of using the background thread in the first place.
In other words, you're doing all your Swing threading work exactly backwards -- making Swing calls from the background thread and running the long process in the event thread.
Instead, do the opposite -- do all the long-running work in a background thread and make all of the non-thread-safe Swing calls on the EDT.
One way to do this is to use a SwingWorker, do your loading and saving from within its doInBackground(...) method
and set its progress field as progress is being made..
You would then monitor the worker's progress field in a PropertyChangeListener, this being done on the EDT, and then use this to set your progress bar's value.
Or if you have to use your own background thread, then
Have the inner class implement Runnable, not extend Thread
If you make Swing calls from within your background thread, then wrap these calls in a Runnable and queue them onto the Swing event thread via SwingUtilities.invokeLater(yourRunnable)
More minor issues:
You should not be using null layouts and absolute positioning but rather use layout managers. While null layouts and setBounds() might seem to Swing newbies like the easiest and best way to create complex GUI's, the more Swing GUI'S you create the more serious difficulties you will run into when using them. They won't resize your components when the GUI resizes, they are a royal witch to enhance or maintain, they fail completely when placed in scrollpanes, they look gawd-awful when viewed on all platforms or screen resolutions that are different from the original one.
Your secondary dialog window should be a JDialog, and probably a modal JDialog, not another JFrame. You're not creating and showing a new stand-alone program, but rather are displaying a dialog window off of the main GUI window. If you want the main GUI window non-functioning while the dialog is displayed, then the modal JDialog is the way to go, as it works just like a JOptionPane (which is a form of a modal JDialog), and makes the calling window non-functional while its visible.
For some of my code examples:
How do I make my SwingWorker example work properly?
For a lot more of my examples

Pressing a JButton by hand yields different results to doClick()?

I have a problem when a JButton on my interface, when pressed the button triggers this event listener:
if (event.getSource() == goButton)
{
MainLauncher.doProgram(assetsField.getText(), FileFinder.completePath(String.format("%s\\%s", modDirectoryPath, modList.getSelectedValue())), databaseField.getText());
}
which runs the following code:
public static void doProgram(final String baseGamePath, final String modPath, final String databasePath)
{
new Thread()
{
public void run()
{
System.out.println("Running: " + modPath + "\n");
reader = new MetaDataReader(databasePath);
reader.formConnection();
long start = System.currentTimeMillis();
long temp;
File cache = new File("RegisterCache.SC");
if (!cache.exists())
{
temp = System.currentTimeMillis();
start += System.currentTimeMillis() - temp;
System.out.println("Calculating number of files");
FileFinder baseGame = new FileFinder();
baseGame.calculateNumFiles(baseGamePath);
System.out.println(String.format("Loading %s base game files", baseGame.getNumFiles()));
gui.doProgressBar();
baseGame.findFiles(baseGamePath, true);
gui.killProgressBar();
System.out.println();
//load the base game assets, we want to move this to metadata later
System.out.println("Checking for base game reference errors");
new ReferenceDetector(Table.getRegister()).findReferences(true);
Table.serializeTable(cache); //write the database to cache, we can use it next time
}
else
{
System.out.println("Loading cache");
Table.unserializeTable(cache);
}
gui.doCommands(); //calls reset()!!! be careful with the temporary excludes!
System.out.println("Eliminating base game requires errors");
RequiresWhere.executeRequires(true);
temp = System.currentTimeMillis();
start += System.currentTimeMillis() - temp;
System.out.println("Calculating number of files");
FileFinder mod = new FileFinder();
mod.calculateNumFiles(modPath);
System.out.println(String.format("Loading %s mod files", mod.getNumFiles()));
gui.doProgressBar();
mod.findFiles(modPath, false);
gui.killProgressBar();
System.out.println();
System.out.println("Finding reference errors");
new ReferenceDetector(Table.getRegister()).findReferences(false);
System.out.println("Finding requires errors");
RequiresWhere.executeRequires(false);
System.out.println("Checks complete");
reader.killConnection();
System.out.println(String.format("Execution Time: %dms", System.currentTimeMillis() - start));
Table.reset();
}
}.run();
}
The odd thing is this:
When testing I didn't have my button added to the interface, and so on main() I was calling goButton.doClick(); which triggered the doProgram(), and gives me the results I expected which is this:
a couple of things are printed out (to a JTextArea on the interface that receives from System.out.println()), a progress bar pops up above the console, and goes from 0% to 100% in around 10 seconds, disappears, a few more things are printed etc etc.
However when I added the button to the interface I clicked it and the behavior was not the same at all:
Nothing is printed. The progress Bar comes up, and stays at 0% for 10 seconds, then disappears, a few seconds later the doProgram finishes executing and all the information that should have been printed during runtime is suddenly printed all at once.
Can anybody tell me what is causing this strange behavior and how it can be fixed?
I would post a SSCCE, but it is a little difficult to do for this program as there are so many tasks and subprocesses. Note that, the progress bar I use it run on the GUI thread, the main code is done in it's own thread (as you can see)
EDIT: I added setEnabled(false); and true inside the listener surrounding the call to doProgram, and when the button is programatically pressed, the button is greyed out and this renabled as I expect, however if I click the button by hand it does not disable, and I can press it again
The code looks a bit confusing.
However, first of all: You are calling the run() method of the new Thread that you are creating there. This will cause the code from the run() method to be executed by the thread that calls doProgram, and not by the new Thread that you are creating there. In order to execute the code really in this new Thread, you have to call start() instead of run().
This explains probably most of the differences that you described. However, keep in mind that modifications to Swing components always have to be done on the Event Dispatch Thread. So whatever you are doing, for example, with gui.doCommands(), make sure that you don't violate this Single Thread Rule.

How do you repaint a container immediately as components are added in a separate thread in JAVA?

I am using java.
I have a click event that adds "squares" to a container, in a loop. I want each square to show up RIGHT when it is added. I tried running the 'adding of the squares' in a separate thread, but it is not working.
Here is some code I use for 'public class GuiController implements ActionListener, MouseListener':
#Override
public void mouseClicked(MouseEvent e)
{
//createBoardPane();
new Thread
(
new Runnable()
{
public void run()
{
showAnimation();
}
}
).start();
}
public void showAnimation()
{
for(int i = 0; i < model.getAnimationList().size(); i++)
{
String coord = model.getAnimationList().get(i);
int x = Integer.parseInt(coord.substring(0, coord.indexOf(',')));
int y = Integer.parseInt(coord.substring(coord.indexOf(',') + 1, coord.length() - 2));
boolean shouldPlacePiece = (coord.charAt(coord.length() - 1) == 'p');
if(shouldPlacePiece)
{
model.getView().getBoardPane().getComponent(x + (y * model.getBoardSize())).setBackground(Color.BLACK);
}
else
{
model.getView().getBoardPane().getComponent(x + (y * model.getBoardSize())).setBackground(Color.WHITE);
}
model.getView().getBoardPane().repaint();
long time = System.currentTimeMillis();
while((System.currentTimeMillis() - time) < 250)
{
// wait loop
}
}
}
any help is appreciated!
Creating a separate Thread to run for this longish-running task was an excellent idea - unless you want to lock-up interactions with your GUI while doing your animation.
Now, Swing GUI objects are not Thread safe (with few exceptions), so you cannot work with them from a thread other than Swing's Event Dispatch Loop's thread. So take all the GUI update code in your for-loop, and wrap it with a new Runnable (yes, another one).
Then call SwingUtilities.invokeLater(Runnable doRun) with that Runnable on each iteration of the loop.
Your GUI update code will then be scheduled to run ASAP on the Event Dispatch Loop, which will occur while your worker thread goes to sleep (do you have anything against Thread.sleep?).
Alternative: Use SwingWorker instead of Thread
SwingWorker will create and manage a new the Thread for you, and publish data that it (SwingWorker) will cause to be run on the Event Dispatch Loop's thread. You'll override doInBackground with your code. Call publish with parameters to push across into the Event Dispatch Thread. Override process with code to process those parameters and update your GUI.
On gotcha with SwingWorker is that it accumulates published events over a period of about 33 milliseconds. If you're publishing more frequent than that you may get all your events bunched together every 33 milliseconds or so. In you case, 250 milliseconds between updates shouldn't be a problem.

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