I'm really lost with this:
In this Case the Button should diasable (btnStart.setEnable(false)) when it got clicked.
after this it should call a function, located in an other class.
Everything works, except that the btnStart doesn't disable on click but after the function ist called.
So this:
#Override
public void actionPerformed(ActionEvent buttonKLick) {
if(buttonKLick.getSource() == this.btnStart){
btnStart.setEnabled(false);
try {
Funktionen.fileFinder(Pfad); //The Function
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
Will call the function FileFinder and then disable the button although the button should be disabled before.
You've likely got a threading issue where your other method is taking time and locking up the Swing event thread, preventing Swing from properly painting the button as disabled. What happens if you use a background thread?
i.e.,
if(buttonKLick.getSource() == this.btnStart){
btnStart.setEnabled(false);
new Thread(new Runnable() {
public void run() {
try {
Funktionen.fileFinder(Pfad); //The Function
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
}).start();
}
Edit:
Please be sure to read: Lesson: Concurrency in Swing.
No, it will disable the button right when you call setEnabled( false ). Just try calling isEnabled() before you call that function.
What you observe is that the button is only painted in disabled state after the function is executed. That is because your function occupies the one and only thread used to update the UI (the Event Dispatch Thread).
Solution: execute your function on a worker thread, for example using a SwingWorker. Also, read the Swing concurrency guide. This explains in more detail what I mentioned here
Related
this is how I'm trying to accomplish this:
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Hello there");
Thread.sleep(1000);
panel.updateUI();
}
});
I set Enter button as the default button so when I keep pressing it the button press maybe 100 times or more but because I'm using Thread.sleep(1000) it takes some time so I have time to type in my JtextField or even close the window but can't do anything.
also, I tried to put btnNewButton.addActionListener() in the run method of a thread but no difference.
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Hello there");
Thread.sleep(1000);
panel.updateUI();
}
});
}
});
thread.start();
// I used try catch block in real code
can anyone help me to solve the issue?
**I'm creating this application in eclipse using windowsBuilder.
This is because of something that is called EDT - the Event Dispatch Thread.
This special purpose thread is responsible for all the events in your GUI - including drawing (refreshing) and interactions (button click). This means, that exactly the same thread is used to draw your application as the one that is used to execute actionPerformed code. Since you are literally halting that thread for some amount of time, your application will be non responsive for that exact period of time.
Whatever is being executed on user interactions should be short and execute fast for the reason of not blocking the application. If you need to do some heavy stuff, there is a facility for that purpose called SwingWorker that allows you to easily do some processing in the background thread (pool) and schedule UI updates during execution (like update of progress bar)
In your second "thread" snippet, your thread is not doing anything beside adding actionListener to the button, and then it terminates (probably after less than 1ms ;)) - action callback is still executed by the EDT. If you would start that custom thread from inside of run method - then it would be indeed in parallel and GUI would not be frozen - but again, SwingWorker is the way to go here.
Not entirely sure what your code is supposed to do, but if you want to press the button and then 1000ms later it will check your field you should do something like this:
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
System.out.println("before 1000ms");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("after 1000ms");
System.out.println("Reading the text field ...");
}
});
thread.start();
System.out.println("after the thread");
Output:
after the thread
before 1000ms
after 1000ms
Reading the text field ...
I have a GUI with a TextArea and a Save Button. When I press the latter the text is saved. This takes around 2 seconds. During the process of saving the buttons should get another caption than before and after saving.
Here is my code:
saveButton.setText("Saving...");
Util.print("Saving...");
Thread saveIt = new Thread(new Runnable() {
#Override public void run() {
Platform.runLater(() -> {
try {
Thread.sleep(2000);
} catch (Exception ex) {
Util.print(ex);
}
saveButton.setText("Saved!");
Util.print("Saved!");
});
}
});
saveIt.setDaemon(true);
saveIt.start();
What happens:
The following output is produced on the command line after pressing the button:
Saving...
Saved!
The command line prints "Saving..." directly after I click on saveButton. 2 seconds after pressing saveButton the command line prints "Saved!" and the button caption changes to "Saved!".
What I would expect:
The command line output and the button caption show "Saving..." directly after I click on the save button. After 2 seconds the caption changes to "Saved!".
How can I achieve the expected behaviour?
Thank you very much in advance for your help.
P.S.: I know so many people have had problems with changing GUI elements from Threads. I already read some articles on StackOverflow & the web about it, but this one's a too hard nut for me. Just for reference, here is some of the things I tried so far, among others Tasks:
Constantly Update UI in Java FX worker thread
Why am I getting java.lang.IllegalStateException "Not on FX application thread" on JavaFX?
javafx, update ui from another thread
http://blog.axxg.de/javafx-ui-thread-update/
I had to put the Thread.sleep() part out of the Platform.runLater() process. Seemingly runLater() must as few workload as possible.
Platform.runLater(() -> {
saveButton.setText("Saving...");
Util.print("Saving...");
});
Thread saveIt = new Thread(new Runnable() {
#Override public void run() {
try {
sleep(2000);
} catch (Exception ex) {
Util.print(ex);
}
Platform.runLater(() -> {
saveButton.setText("Saved!");
Util.print("Saved!");
});
}
});
saveIt.setDaemon(true);
saveIt.start();
try wrapping your first setText into a Platform.runLater like this:
Platform.runLater(() -> {
saveButton.setText("Saving...");
});
Every change made to a JavaFX UI component has to been called from the JavaFX thread using the Platform.runLater
The problem that I have in my code is that when it runs the button.setVisible(true); it won't set the button to visible until all the other if statements are passed through which really confuses me.
I'm trying to make simon says, and what this try-catch does is that it makes the button in the sequence order blink so that the user can know which button it is that follows.
I'm new to programming so any tips and advises are welcome.
Thank you for taking a look!
try {
inputOrder.clear();
// System.out.println("THIS IS INPUT" + inputOrder);
Sequence.add(randomNumber());
int f = 0;
for (; f < Sequence.size(); f++) {
//Thread.sleep(2000);
if (Sequence.get(f) == 1) {
try {`
btnNewButton.setVisible(false);
Thread.sleep(1000);
} catch (InterruptedException e1) {
}
Thread.sleep(1000);
System.out.println("it ran here");
btnNewButton.setVisible(true);
}
if (Sequence.get(f) == 2) {
try {
btnBlue.setVisible(false);
Thread.sleep(1000);
} catch (InterruptedException e1) {
}Thread.sleep(1000);
System.out.println("it ran here");
btnBlue.setVisible(true);
}
if (Sequence.get(f) == 3) {
try {
btnYellow.setVisible(false);
Thread.sleep(1000);
} catch (InterruptedException e1) {
}Thread.sleep(1000);
System.out.println("it ran here");
btnYellow.setVisible(true);
}
if (Sequence.get(f) == 4) {
try {
btnGreen.setVisible(false);
Thread.sleep(1000);
} catch (InterruptedException e1) {
}
Thread.sleep(1000);
System.out.println("it ran here");
btnGreen.setVisible(true);
}
System.out.println(Sequence);
// Order.add(getColor(Sequence.get(f)));
System.out.println(Order);
text.setText(String.valueOf(Order.size()));
}
btnNextRound.setVisible(false);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
Looks like this happens because you are doing this operation in the UI thread, and it does not have time to execute EventQueue since you force to sleep the UI thread, due to this thread gets chance to actually do the paint once it finish all the sleep calls.
In order to get desired output, I think you should move the sleep logic into a separate thread or to a SwingWorker. If you moved the logic to a separate thread you need to use the EventQueue.InvokeLater to enable buttons.
The way that the Java Swing GUI works is that everything happens one after another. Only when the entire method you posted is finished will the next GUI events (such as the repainting events that need to occur to show that the button's not visible anymore). Doing a Thread.sleep just makes your method take longer to finish. The result is that your UI is frozen because no other events (such as mouse, keyboard, or repainting events) are able to run until after all of your sleep calls.
To perform animation in Java, you should use the javax.swing.Timer class rather than using Thread.sleep. Below I've posted a quick example of a timer that, when started, will cause a button to flash. This doesn't completely solve your problem (you're also looping, but you really need another timer to actually schedule when the buttons will flash so that they don't all happen at once).
import javax.swing.Timer
/**
* Timer that causes a button to flash (become invisible for 1 second, and then become visible again).
*/
public class ButtonFlashTimer extends Timer {
private final JButton buttonToFlash;
public ButtonFlashTimer(JButton button) {
super(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// This method is called every 1000 ms (until we tell
// it to stop). This allows us to perform the next "step"
// in the animation.
boolean isVisible = buttonToFlash.isVisible();
if (isVisible) {
buttonToFlash.setVisible(false);
} else {
buttonToFlash.setVisible(true);
// Once we've flashed, stop the timer (don't keep flashing).
stop();
}
}
});
buttonToFlash = button;
// Become invisible immediately; the 1000 ms will be the time between the first
// call to the actionPerformed (which will set it as invisible) and the second
// call (which makes it visible again).
setInitialDelay(0);
setRepeats(true);
}
}
In the code below I am running my method which adds text to a JTextArea, then i wait 4 seconds and add more text. However it simply waits four seconds then puts all the text down at once. How can I make it so it adds the first text, waits then adds the second block of text?
public static void configuresettings() {
GUI.add("To Begin, Go to www.opionsxo.com");
try {
Thread.sleep(4000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
GUI.add("Welcome to Configure Settings!");
}
I figured it out, if anyone is interested in how. Then view the code below...
public static void configuresettings() {
GUI.add("To Begin, Go to www.opionsxo.com");
ActionListener actionListener = new ActionListener() {
public void actionPerformed(ActionEvent actionEvent) {
GUI.add("Welcome to Configure Settings!");
}
};
Timer timer = new Timer( 4000, actionListener );
timer.setRepeats(false);
timer.start();
}
You shouldn't use Thread.sleep with swing, or it will block your application. For instance, if you resize your window or move a window in front of your application, it won't repaint as needed, because you stopped it. Instead, you should be using Swing Timers.
Your problem is probably because you should revalidate() your JTextArea before sleep or something, but as said, you should change the implementation of it.
Read more here: http://docs.oracle.com/javase/tutorial/uiswing/misc/timer.html
Don't do anything within the context of the Event Dispatching Thread that might cause it to stop, like calling Thread.sleep.
Instead, trying using a javax.swing.Timer or SwingWorker
Take a look at:
Concurrency in Swing
Worker Threads and SwingWorker
How to Use Swing Timers
For more details
For example:
java for-loop in GUI TextArea
Displaying contents of String array in Swing component as iterations using Time delay. JAVA
I cant run JTextArea multiple times?
I am making a game having squares in it (a grid of panels) and when the game ends there is an algorithm that changes the color of the panels one by one in a "live" fashion where the user watches the squares change color slowly. I try something like:
Thread.sleep(1000);
grid.getComponent(boxNumber).setBackground(Color.YELLOW);
Thread.sleep(1000);
grid.getComponent(boxNumber).setBackground(Color.ORANGE);
Although the color of a box changes to Yellow, it does not change to Orange afterwards. Anyone have any ideas? Hope I was able to be clear.
Read the section from the Swing tutorial on Concurrency to understand why you should not be using the sleep() method.
One solution is to use a SwingWorker, then you can 'publish' the color of the component so it can be updated properly on the EDT and you can invoke the sleep() method in the worker as well.
These need to happen on the Swing event thread. call set background via:
SwingUtilities.invokeLater(new Runnable() {
public void run() {
grid.getComponent(boxNumber).setBackground(Color.ORANGE);
}
});
Note, your Thread.sleep() should not be in the event thread (or directly from within a Swing event listener (ActionListener, WindowListener, etc).
It would also be prudent to look the Swing Timing Framework which is specifically for things like this.
-Generally its not a good idea to do Thread.sleep(1000); in the EDT. You should try using Timers.
-You also need to call revalidate()/validate() and repaint() afterward.
So maybe something like this:
Timer yellowTimer = new Timer(1000,new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
jtp.setBackground(Color.YELLOW);
//call revalidate()/validate() and repaint() afterward
jtp.revalidate();
jtp.repaint();
}
});
yellowTimer.setRepeats(false);
Timer orangeTimer = new Timer(2000,new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
jtp.setBackground(Color.ORANGE);
//call revalidate()/validate() and repaint() afterward
jtp.revalidate();
jtp.repaint();
}
});
orangeTimer.setRepeats(false);
yellowTimer.start();
orangeTimer.start();