I am using a JSlider in my program, and have implemented a ChangeListener for the same.
public void stateChanged(ChangeEvent e)
{
JSlider source=(JSlider) e.getSource();
frame_value.setText(Integer.toString(source.getValue()));
//Condition to change the frame_no only when user has stopped moving the slider
if (!source.getValueIsAdjusting())
{
frame_no=(int) source.getValue()-1;
if(frame_no<0)
frame_no=0;
}
....
}
What is happening is, that whenever the ChangeListener is called, the program just skips the if block, and goes to the code after that. I don't understand why is this happening. I am not able to get the correct value from the JSlider. Please help!!
PS: I don't know if this is the reason, but recently I have set the UI of the JSlider to place the tick where I click it. I don't know if that is responsible for it or not. Here is the code:
slider.setUI(new MetalSliderUI() {
protected void scrollDueToClickInTrack(int direction) {
int value = HEVC_Analyzer.slider.getValue();
value = this.valueForXPosition(HEVC_Analyzer.slider.getMousePosition().x);
HEVC_Analyzer.slider.setValue(value);
}
});
Must be something wrong in your code, since it's working fine in this example :
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class SliderChangeEffect extends JFrame
{
private JSlider slider;
private int count = 0;
private ChangeListener changeListener = new ChangeListener()
{
public void stateChanged(ChangeEvent ce)
{
JSlider slider = (JSlider) ce.getSource();
if (!slider.getValueIsAdjusting())
System.out.println(slider.getValue());
}
};
private void createAndDisplayGUI()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationByPlatform(true);
JPanel contentPane = new JPanel();
contentPane.setOpaque(true);
slider = new JSlider(0, 10, 5);
slider.setMajorTickSpacing(2);
slider.setMinorTickSpacing(1);
slider.addChangeListener(changeListener);
contentPane.add(slider);
getContentPane().add(contentPane);
pack();
setVisible(true);
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new SliderChangeEffect().createAndDisplayGUI();
}
});
}
}
Just use the String.valueOf() and the event.MouseReleased().
private void jSlider1MouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
try {
String valueOf = String.valueOf(jSlider1.getValue());
jLabel1.setText(valueOf);
} catch (Exception ex) {
ex.printStackTrace();
}
}
Related
I am slightly confused, I have a jFrame of which I have made in Netbeans. This jFrame has a jLabel, of which is set to setVisible(false); from the beginning. Whenever a specific method is called, I then set the jLabel to setVisible(true); and then use a timer to set it to false again after 2 seconds. Apparently it won't work and I am unable to figure out why. I am aware of the repaint(); method, but can figure out how to make that work either.
I know the actual method for setting the visibility is called, as I have set it to print a line with the current state, which it does.
My actual code is the one below.
public JFram() {
initComponents();
setResizable(false);
jLabel2.setVisible(false);
}
static void tesMethod() {
try {
//function that does something
} finally {
new JFram().showHide(); //call function which is supposed to change the vissibility of jLabel
}
}
void showHide() {
jLabel2.setVisible(true);
System.out.println("reached show");
new java.util.Timer().schedule(
new java.util.TimerTask() {
#Override
public void run() {
jLabel2.setVisible(false);
System.out.println("reached timer");
}
},
2000
);
}
The code below here is how I tried to use the repaint(); method.
void showHide() {
jLabel2.setVisible(true);
jLabel2.repaint();
System.out.println("reached show");
new java.util.Timer().schedule(
new java.util.TimerTask() {
#Override
public void run() {
jLabel2.setVisible(false);
jLabel2.repaint();
System.out.println("reached timer");
}
},
2000
);
}
I think your problem lies mainly in you using a java.util.Timer instead of a javax.swing.Timer and probably you're blocking the Event Dispatch Thread (EDT).
You could try this code and compare it with yours, I also don't see where you're adding your JLabel to your frame.
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class ShyLabel {
private JFrame frame;
private JLabel label;
private Timer timer;
private boolean isVisible;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new ShyLabel().createAndShowGui();
}
});
}
public void createAndShowGui() {
String labelText = "I'm a shy label that hides every 2 seconds";
isVisible = true;
frame = new JFrame(getClass().getSimpleName());
label = new JLabel(labelText);
timer = new Timer(2000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
label.setText(isVisible ? "" : labelText);
isVisible = !isVisible;
}
});
timer.setInitialDelay(2000);
timer.start();
frame.add(label);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
The below image is produced by the above code, however because of the time I recorded the GIF it looks really fast instead of taking 2 seconds as it should be...
May be it is a problem of layout.
As you set resizable to false before any layout calculation occurred, the label was ignored (as invisible) by the time of the first layout.
You could try revalidate().
I'm quite new on JAVA, and i have a question (i hope my english is not too bad).
Here is my process :
Open a first JFrame in the Main, with a JButton (to open the second
JFrame).
On click, with ActionLister, i call the process to open my second
window, with a black background (this works very well).
BUT, if i add a long process (in my code, just a sleep(5000)) just after setVisible() my second JFrame, this one will appear in white, and waits for the sleep(5000) to end before being black.
Questions :
Can someone tell me why the second JFrames appears white until the
end of process ? Maybe i make something wrong when i build my JFrame
?
Can someone tell me how to show my second JFrame black BEFORE the process ends ?
I searched for a long time, and saw that if my second window is built direct in the main thread it's ok even with the sleep before end of process.
But when i am in another thread (like when i click on the button), that doesn't work good !
SECOND PART :
On click on the button from the first window :
The second window shows up (empty with black background). then, the result's calcul is launched.
Calculate the result cant take 20sec, and will find 1 element each 5 seconds.
Each times an element is found, i want it to be shown in the second window.
For that, i added an observer on this result from the JFrame, which will add an element each time one element is found. I hope you understand.
Here picture of what i want to make :
Process
Here my project .JAR : http://dl.free.fr/b5IUSStBJ
Here my result's calcul :
public void launchCalculateResult(){
String[] tabelements = {"test1","test2", "test3", "test4", "test5"};
for (int i=0; i < 5; i++){
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
_elementslist.add(tabelements[i]);
notifyObservers();
}
}
you can see that it adds an element in a list each 2 seconds, and then notify the observers (my second window), then the observer adds an element :
public void refresh(Observable o) {
_otherwindow.addResultElement(_result.getLastElement());
}
The behaviour I got :
The Result calculates good, and in the end the second window looks good, with its 5 elements. But during the result's search, my second windows remains empty and white . . .
I repeat the aim :
Each time an element is added in the Result, i want to show it in my second window.
You're calling the long process on the Swing event thread, and this will tie up the thread preventing it from doing its important jobs, including painting your new JFrame.
The canonical solution is to use a background thread for your long processes, and for Swing GUI's, you'd want to use a SwingWorker -- if the background process needs to communicate with the GUI (which is usually the case).
For the details on this problem and solution, please check out: Concurrency in Swing
Side issue: you'll usually not want to show multiple JFrames in your application. For why this is important and for how you can improve this design, please check out Multiple JFrames
For example
import java.awt.Color;
import java.awt.Dialog.ModalityType;
import java.awt.Dimension;
import java.awt.Window;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class SwingExample extends JPanel {
private JButton openDialogBtn = new JButton(new OpenDialogAction("Open Dialog"));
private JDialog dialog;
private DialogPanel dialogPanel = new DialogPanel();
public SwingExample() {
setPreferredSize(new Dimension(400, 400));
add(openDialogBtn);
}
private class OpenDialogAction extends AbstractAction {
public OpenDialogAction(String name) {
super(name);
}
#Override
public void actionPerformed(ActionEvent e) {
dialogPanel.setText("");
if (dialog == null) {
Window win = SwingUtilities.getWindowAncestor(SwingExample.this);
dialog = new JDialog(win, "Dialog", ModalityType.MODELESS);
dialog.add(dialogPanel);
dialog.pack();
dialog.setLocationRelativeTo(win);
}
new SwingWorker<Void, Integer> () {
private final int maxI = 5;
#Override
protected Void doInBackground() throws Exception {
for (int i = 0; i < maxI; i++) {
publish(i);
Thread.sleep(1000);
}
return null;
}
protected void process(java.util.List<Integer> chunks) {
for (Integer chunk : chunks) {
dialogPanel.setText("Time: " + chunk);
}
};
protected void done() {
dialogPanel.setText("Done!");
};
}.execute();
dialog.setVisible(true);
}
}
private class DialogPanel extends JPanel {
private JTextField textField = new JTextField(10);
public DialogPanel() {
setBackground(Color.BLACK);
setPreferredSize(new Dimension(200, 200));
add(textField);
}
public void setText(String text) {
textField.setText(text);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
private static void createAndShowGui() {
SwingExample mainPanel = new SwingExample();
JFrame frame = new JFrame("SwingExample");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
}
Example 2: handles Strings being passed into a JList<String> using a SwingWorker<Void, String>
import java.awt.Color;
import java.awt.Dialog.ModalityType;
import java.awt.Dimension;
import java.awt.Window;
import java.awt.event.ActionEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class SwingExample extends JPanel {
private JButton openDialogBtn = new JButton(new OpenDialogAction("Open Dialog"));
private JDialog dialog;
private DialogPanel dialogPanel = new DialogPanel();
public SwingExample() {
setPreferredSize(new Dimension(400, 400));
add(openDialogBtn);
}
private class OpenDialogAction extends AbstractAction {
public OpenDialogAction(String name) {
super(name);
}
#Override
public void actionPerformed(ActionEvent e) {
dialogPanel.clearList();
if (dialog == null) {
Window win = SwingUtilities.getWindowAncestor(SwingExample.this);
dialog = new JDialog(win, "Dialog", ModalityType.MODELESS);
dialog.add(dialogPanel);
dialog.pack();
dialog.setLocationRelativeTo(win);
}
new SwingWorker<Void, String>() {
#Override
protected Void doInBackground() throws Exception {
String[] tabelements = { "test1", "test2", "test3", "test4", "test5" };
for (int i = 0; i < 5; i++) {
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
publish(tabelements[i]);
}
return null;
}
protected void process(java.util.List<String> chunks) {
for (String chunk : chunks) {
dialogPanel.addText(chunk);
}
};
protected void done() {
dialogPanel.addText("Done!");
};
}.execute();
dialog.setVisible(true);
}
}
private class DialogPanel extends JPanel {
private DefaultListModel<String> listModel = new DefaultListModel<>();
private JList<String> jList = new JList<>(listModel);
public DialogPanel() {
jList.setPrototypeCellValue("ABCDEFG HIJKLMNOP");
jList.setVisibleRowCount(6);
JScrollPane scrollPane = new JScrollPane(jList);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
setBackground(Color.BLACK);
setPreferredSize(new Dimension(200, 200));
add(scrollPane);
}
public void clearList() {
listModel.clear();
}
public void addText(String text) {
listModel.addElement(text);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
private static void createAndShowGui() {
SwingExample mainPanel = new SwingExample();
JFrame frame = new JFrame("SwingExample");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
}
//Make constructor class for both JFrame then
//write this code into your JFrame where your button is accesing another JFrame
//Note:- jb=button var name,
// jf=JFrame vatr name,
// addnew()=JFrame Class to be open.
jb.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
new addnew();
jf.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
});
It might work as well.
I have an application I'm making for a game to automatically update a game client.
Once you press Launch, it will open up my DownloadFrame (extends JDialog), and will look like this:
If you click the icon for the application in the taskbar, (maybe Windows 8 is the problem?) it will minimize the application like usual. However when you go to maximise the application again, the JDialog will be hidden, I'm assuming, behind the parent. It looks like this:
Here's my code for my extension of JDialog. Apologies in advance for it being messy.
public class DownloadFrame extends JDialog implements Runnable {
private static final long serialVersionUID = -8764984599528942303L;
private Background frame;
private ImageIcon[] gifs;
private JLabel spinner;
public DownloadFrame() {
super(Loader.application, false);
setLayout(null);
setUndecorated(true);
setAutoRequestFocus(true);
new Thread(this).start();
generateBackground();
generateButton();
generateGif();
}
private void generateBackground() {
frame = new Background("sub_background.png");
setSize(frame.getWidth(), frame.getHeight());
setBackground(new Color(1.0f, 1.0f, 1.0f, 0.0f));
setLocationRelativeTo(null);
setLocation(this.getX(), this.getY() + 5);
setLayout(null);
setContentPane(frame);
}
private void generateGif() {
gifs = Utils.generateGifImages();
spinner = new JLabel(gifs[0]);
spinner.setBounds(70, 30, gifs[0].getIconWidth(), gifs[0].getIconHeight());
add(spinner);
}
private HoverableButton cancel;
public HoverableButton getCancelButton() {
return cancel;
}
private void generateButton() {
cancel = new HoverableButton(Settings.CANCEL_BUTTON, 75, 145);
cancel.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
/*
* TODO -
* stop the download in progress
*/
for (HoverableButton button : Loader.application.getPrimaryButtons()) {
button.setActive(true);
button.setVisible(true);
}
dispose();
}
});
add(cancel);
}
private int cycleCount;
private void cycleGif() {
if (spinner == null) {
return;
}
cycleCount++;
if (cycleCount > 7) {
cycleCount = 0;
}
spinner.setIcon(gifs[cycleCount]);
}
#Override
public void run() {
while (true) {
cycleGif();
try {
Thread.sleep(100L);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
In case it's needed, here's my usage of it. Most of the stuff can be ignored I'm sure, it's simply there to hide the four buttons while the download is in progress.
((HoverableButton) components[2]).addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
HoverableButton source = (HoverableButton) components[2];
if (source.isActive()) {
try {
Thread.sleep(500L);
} catch (Exception ex) {
ex.printStackTrace();
}
if (panel == null) {
panel = new DownloadFrame();
panel.setVisible(true);
} else {
panel.setVisible(true);
panel.getCancelButton().removeHighlight();
}
for (HoverableButton button : getPrimaryButtons()) {
button.setActive(false);
button.setVisible(false);
button.removeHighlight();
}
/*
* TODO -
* handle checking for updates / downloading updates
*/
}
}
});
However when you go to maximise the application again, the JDialog will be hidden, I'm assuming, behind the parent
Yes. When you create the JDialog, you need to specify the "owner" JFrame of the dialog in the constructor.
So you must create and make the JFrame and make the frame visible before you create the dialog.
I have a slider inside another class and I want to assign the values that it has to that of a variable every time the value of the slider changes. I have this code
public double setSliderValue() {
double myVariable;
sliders.mySlider.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent event) {
myVariable = Sliders.variableSlider.getValue();
System.out.println(myVariable); //returns 0 each time
}
});
return myVariable;
}
what have I missed / what do I need to add so that the value currently on my slider is assigned to myVariable?? Thanks
This may not be the best way, but you can give the class that contains the JSlider a reference to the outer class.
import java.lang.Object;
import java.lang.String;
import java.lang.System;
import javax.swing.*;
import javax.swing.event.*;
The class that contains the JSlider, as an example:
class Window extends JFrame {
private JSlider slider;
// a reference to the other class needs to be final
private final Test testClass;
public Window(Test incomingReference) {
// set the reference
this.testClass = incomingReference;
// JSlider stuff
slider = new JSlider(JSlider.HORIZONTAL, 0, 100, 1);
slider.addChangeListener(new ChangeListener() {
#Override public void stateChanged(ChangeEvent e) {
JSlider src = (JSlider) e.getSource();
if (src.getValueIsAdjusting()) return;
testClass.setSomeVariable(src.getValue());
System.out.println(testClass.getSomeVariable());
}
});
// window stuff
JFrame window = new JFrame("JSlider Test");
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setSize(800, 600);
window.add(slider);
window.setVisible(true);
}
}
The "outer class":
public class Test extends Object {
public int someVariable = 0;
public void setSomeVariable(int value) { someVariable = value; }
public int getSomeVariable() { return someVariable; }
public static void main(String ... args) {
// give the window a reference to this object
Test foo = new Test();
Window window = new Window(foo);
}
}
Also notice the line in the ChangeListener: if (!src.getValueIsAdjusting()) return; which is not in your snippet. That prevents the ChangeListener from setting the value when the slider is motion.
I have a function graphics() that creates my JFrame and two JRadioButtons and adds ActionListeners to them. This graphics is called from main() and graphics itself calls game().
public void game() throws Exception
{
jTextArea1.setLineWrap(true);
jTextArea1.setWrapStyleWord(true);
jTextArea1.setText("This is private information.");
jRadioButton1.setVisible(true);
jRadioButton2.setVisible(true);
try {
t.sleep(40000);
repaint();
} catch (InterruptedException e) {
// We've been interrupted: no more messages.
return;
}
After displaying "This is private information." in the text Area, I want the program execution to pause for 40 seconds, or until the user presses the JRadioButton, whichever is earlier. So I added an ActionListener and called t.interrupt() inside it.
private void jRadioButton1ActionPerformed(java.awt.event.ActionEvent evt) {
t.interrupt();
jRadioButton1.setVisible(false);
jRadioButton2.setVisible(false);
//System.out.println(t.interrupted());
jTextArea1.setText("Please wait...");
}
However, even after choosing the JRadioButton which should trigger the interrupt, that does not happen and t.interrupted returns false.
Any help would be appreciated.
Never, ever call Thread.sleep(...) on the Swing event thread as you will freeze the thread and effectively freeze your program. The solution is to consider use of a Swing Timer for the time-dependent portion of your requirement and using a SelectionListener for the JCheckBox or JRadioButton requirement.
For example:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.*;
public class PausingExecution extends JPanel {
private static final String SELECTED_TEXT = "Snafus are Better!!!";
private static final String UNSELECTED_TEXT = "Fubars Rule!!";
private static final String TIMES_UP = "Time's Up!!!!";
private static final int TIMER_DELAY = 10 * 1000;
private JTextField messageField = new JTextField(UNSELECTED_TEXT, 10);
private JCheckBox checkBox = new JCheckBox("Click Me");
public PausingExecution() {
add(messageField);
add(checkBox);
checkBox.addItemListener(new ItemListener() {
#Override
public void itemStateChanged(ItemEvent iEvt) {
if (iEvt.getStateChange() == ItemEvent.SELECTED) {
messageField.setText(SELECTED_TEXT);
} else {
messageField.setText(UNSELECTED_TEXT);
}
}
});
Timer mySwingTimer = new Timer(TIMER_DELAY, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
messageField.setText(TIMES_UP);
checkBox.setEnabled(false);
}
});
mySwingTimer.setRepeats(false);
mySwingTimer.start();
}
private static void createAndShowGui() {
PausingExecution mainPanel = new PausingExecution();
JFrame frame = new JFrame("PausingExecution");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}