Java - Doing something when button clicked, then revert it - java

Ok, so I'm doing a Java window (a JFrame, doesn't really matter what it is for) and I have a button on it. What I want to approach is when the button is clicked, it changes its text, then the app does something, and when it's finished the button gets its initial text back.
Something like this...
JButton myButton = new JButton("Initial");
myButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
((JButton) e.getSource()).setText("New");
//Do other things
//Do more other things
((JButton) e.getSource()).setText("Initial");
}
});
That's what I've tried so far, but I know it doesn't work as expected (all the code executes. I'm not really an expert and I'm doing this things to learn, so I have no clue if there's a way to do it or not.
I've already looked for a solution to this in the web but I've not found anything (maybe I didn't search properly), so I hope there's someone who can help me with this!
PS: Sorry if my English is not perfect, I know about it. Ask me if something isn't clear about the question. Thanks to all!
Kevin.
EDIT: The app is a sudoku solver, so it takes a while //doing other things. Thats why I'm trying to change the solve button text (so it sais it is solving and when it finished it says solved).

Your logic is not wrong! Take a look at my example below:
public class MainFrame extends JFrame {
public MainFrame() {
setMinimumSize(new Dimension(200, 100));
JButton myButton = new JButton("Initial");
add(myButton);
myButton.addActionListener(new ActionListener() {
public void actionPerformed(final ActionEvent e) {
final JButton triggerBtn = (JButton) e.getSource();
final String originalValue = triggerBtn.getText();
triggerBtn.setText("New");
JOptionPane.showMessageDialog(null, "Speak softly and carry a big stick and you will go far.");
triggerBtn.setText(originalValue);
}
});
}
public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
MainFrame mainFrame = new MainFrame();
mainFrame.setVisible(true);
}
});
}
}
If you run this you will see that the button is changed. If you were to change the showMessageDialog line to Thread.sleep(10*1000), you would not see a change! This is because you're running the event on the dispatcher thread and the text, even though it is changed, will not allow the change event to be triggered until your method finishes.
Consider the following alternative if the work you're doing is on the same thread:
myButton.addActionListener(new ActionListener() {
public void actionPerformed(final ActionEvent e) {
final JButton triggerBtn = (JButton) e.getSource();
final String originalValue = triggerBtn.getText();
triggerBtn.setText("New");
SwingWorker<Void, Void> sw = new SwingWorker<Void, Void>() {
protected Void doInBackground() throws Exception {
Thread.sleep(10*1000);
return null;
}
#Override
protected void done() {
triggerBtn.setText(originalValue);
}
};
sw.execute();
}
});
This sets the text, and launches a SwingWorker to run the job asynchronously. Once finished, the dispatcher thread will update the text without requiring the dispatcher thread to be tied up waiting for it to finish (and so events are therefore handled properly).
Let me know if that works for you!

Have you tried with:
JButton myButton = new JButton("Initial");
myButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
myButton.setText("New");
//Do other things
//Do more other things
myButton.setText("Initial");
}
});
In your example you're missing actionPerformed and you're not accessing button directly (I can't say what's e in your example)

Just save your current text in a local variable and set it back after you've performed your other actions.
You should also make sure it's really the button that you clicked or at least check instanceof JButton before casting.
final JButton myButton = new JButton("Initial");
myButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == myButton) {
String initialText = myButton.getText();
myButton.setText("New");
// Do other things
// Do more other things
myButton.setText(initialText);
}
}
});
You were also missing out on your actionPerformed method, the code in the question won't compile - I guess you just wrote it in the editor.

Related

Higlight text in JTextField but only when tabbing

I want to create a JDialog where the text in the textfields is selected but only if the focus is gained from keyboard (TAB, CTRL+TAB). I have found several topics on this matter but had problems with implementing it.
Here is one which I was trying.
And my code:
public class Dialogg extends JDialog implements FocusListener, MouseListener {
private boolean focusFromMouse = false;
public Dialogg() {
JTextField tf1 = new JTextField("text1");
JTextField tf2 = new JTextField("text2");
tf1.addMouseListener(this);
tf2.addMouseListener(this);
tf1.addFocusListener(this);
tf2.addFocusListener(this);
}
#Override
public void focusGained(FocusEvent e) {
if (!focusFromMouse) {
JTextField tf = (JTextField) e.getComponent();
tf.selectAll();
focusFromMouse = true;
}
}
#Override
public void focusLost(FocusEvent e) {
focusFromMouse = false;
}
#Override
public void mouseClicked(MouseEvent e) {
focusFromMouse = true;
}
}
It does not work as intended, it does not matter what is focus source the text always highlights. When I run the code and follow it step by step it turns out that focusGained code happens before mouseClicked code so the flag is not reset when it should. Any hints?
EDIT:
As suggested by M. Prokhorov I have deleted less relevant (for the question) lines from the code.Thank you.
EDIT 2:
I am trying to wrap focus listener as suggested by camickr. It looks like this now:
tf1.addFocusListener(new FocusAdapter() {
public void focusGained(FocusEvent evt){
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
if (!focusFromMouse){
tf1.selectAll();
focusFromMouse=true;
}
}
});
}
public void focusLost(FocusEvent evt){
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
focusFromMouse=false;
}
});
}
});
public void mouseClicked(MouseEvent e) {
focusFromMouse=true;
I am printing line after each event to see the action order and still mouseClicked happens last. What am I doing wrong?
EDIT 3:
OK, I have found a solution which fulfils requirements of my simple Dialog.
I could not find a way of doing this with use of invokeLater or EventQueue. Vladislav's method works but as I understand it restricts the user to only use the keyboard.
I have used the initial approach but I have added an auxiliary variable and few conditions which allow to pass the flag "unharmed" trough Events that should not change the flag at given moment. It may not be subtle or universal but works for my app. Here is the code:
public void focusGained(FocusEvent e) {
if(!focusFromMouse){
if (higlight){
JTextField tf = (JTextField) e.getComponent();
tf.selectAll();
focusFromMouse=false;
}
}
}
public void focusLost(FocusEvent e) {
if (focusFromMouse){
higlight=false;
focusFromMouse=false;
}else{
higlight=true;
}
}
public void mousePressed(MouseEvent e) {
focusFromMouse=true;
}
At the first, by default, focus on JTextField is requested by mouse-press event, not by mouse-click.
So, this method:
public void mouseClicked(MouseEvent e) {
focusFromMouse = true;
}
is useless because the mouse-click event is triggered after the mouse-press event.
One way to solve your problem is to remove all native MouseListeners from JTextField:
...
for( MouseListener ml : tf1.getMouseListeners() ){
tf1.removeMouseListener(ml);
}
for( MouseMotionListener mml : tf1.getMouseMotionListeners() ){
tf1.removeMouseMotionListener(mml);
}
...
Another way is to handle all mouse events and consume those of them, which are triggered by JTextField:
Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener() {
#Override
public void eventDispatched(AWTEvent event) {
if( event.getSource() == tf1 ){
((MouseEvent)event).consume();
}
}
}, AWTEvent.MOUSE_EVENT_MASK);
When I run the code and follow it step by step it turns out that focusGained code happens before mouseClicked
Wrap the code in the FocusListener in a SwingUtilities.invokeLater(). The will place the code on the end of the Event Dispatch Thread (EDT), so the code will run after the variable in the MouseListener has been set.
See Concurrency in Swing for more information about the EDT.
Edit:
Just noticed the other answer. You might be able to do something simpler. Istead of listener for mouseClicked, listen for mousePressed. A mouseClicked event is only generated AFTER the mouseReleased event, so by that time the FocusListener logic has already been executed, even when added to the end of the EDT.
Edit 2:
If the above doesn't work then you might be able to use the EventQueue.peek() method to see if a MouseEvent is on the queue. This might even be easier than worrying about using the invokeLater.

Mouse entered, mouse exited changing the text on the button on each event

I am trying to connect a button to say "Hi" when the mouse enters it and "Bye" when the mouse leaves. I have been using mouse events with a MouseListener but to no avail.
I'm new to Java and this question has been plaguing me for the last 2 days and I just have not been able to figure it out. Any help would be greatly appreciated.
private abstract class HandlerClass implements MouseListener {
}
private abstract class Handlerclass implements MouseListener {
#Override
public void mouseEntered(java.awt.event.MouseEvent e) {
mousebutton.setText("Hi");
}
#Override
public void mouseExited(java.awt.event.MouseEvent e) {
mousebutton.setText("Bye");
}
}
Try like this. It is working for me.
public class ChangeTextMouseEvent extends Frame
{
static JButton btn;
public ChangeTextMouseEvent()
{
setTitle("ChangeText");
btn = new JButton("SSS");
add(btn);
setVisible(true);
setBounds(0, 0, 100, 100);
}
public static void main(String[] args)
{
ChangeTextMouseEvent frame = new ChangeTextMouseEvent();
btn.addMouseListener(new MouseAdapter(){
#Override
public void mouseExited(MouseEvent e)
{
btn.setText("Bye");
}
#Override
public void mouseEntered(MouseEvent e)
{
btn.setText("Hi");
}
});
}
}
Updating the UI component alone is often not enough; you also have to trigger a repaint action.
In other words: there are two "layers" here. One is the "data model" (where some button knows about its text); the other is the actual "graphical content". The later one comes into existence by somehow displaying the first parts. Therefore both layers need to be addressed in order to make your chances visible to the user.
See here for some examples around that.

Disable buttons on GUI in Swing

I have buttons on a GUI that execute tests when clicked on in Selenium. They can only be run serially and are currently added to EventQueue. I would like it so that if a button is clicked on and a test is executed, then it will disable the other buttons so that other tests cannot be added to a queue.
Currently a button looks like:
Test1 = new JButton("Test1 ");
Test1.setLocation(290, 30);
Test1.setSize(120, 30);
Test1.addActionListener(this);
Test1.addMouseListener(new MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent e) {
if (Test1.isEnabled()) {
Test1.setEnabled(false);
errorLabel.setText("");
service.submit(()->{
Result result = JUnitCore.runClasses(Test1.class);
EventQueue.invokeLater(()->{
errorMessageDisplay(result);
Test1.setEnabled(true);
});
});
}
}
});
buttonPanel.add(Test1);
I have used the EventQueue as it allows me to reset update Pass/Fail error messages on the GUI.
How can I best achieve this?
You should add ActionListener to your button. What's even more important, you should use naming conventions what also means that your objects' names should start with a small letter. Capital letters are reserved for Classes and static fields (all upper case). The following code adds an ActionListener to your JButton and disables it after clicked. If it's not what you're looking for, I'll add another version in a moment.
test1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
test1.setEnabled(false);
}
});
In case, you want to keep the state of your button, but don't disable it, the following code might be a solution:
private final static String ENABLED = "ENABLED";
private final static String DISABLED = "DISABLED";
public static void main(String[] args) {
Map<JButton, String> map = new HashMap<>();
JButton test1 = new JButton();
map.put(test1, ENABLED);
test1.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (map.get(test1).equals(ENABLED)) {
//do something
} else {
//do something else. I'll enable.
map.remove(test1);
map.put(test1, ENABLED);
}
}
});
}

Java Swing: Focus issue

I'm making a level editor for my game. I have a property panel where I can modify the selected object its properties. I also have a Save button to write the level xml.
A field-edit is submitted(*) when the editor component lost the focus or Enter is pressed. This is working great, but the only problem is that when I have this sequence of actions:
Edit a field
Press the save button
Because, what happens is this:
I edit the field
I press the save button
The level is saved
The field lost the focus
The edit is submitted
As you can see, this is the wrong order. Of course I want the field to lose its focus, which causes the submit and then save the level.
Is there a trick, hack or workaround to make the field first lose the focus and then perform the action listener of the save button?
Thanks in advance.
(* submit = the edit to the field is also made in the object property)
EDIT: For the field I'm using a FocusAdapter with focusLost:
FocusAdapter focusAdapter = new FocusAdapter()
{
#Override
public void focusLost(FocusEvent e)
{
compProperties.setProperty(i, getColor());
record(); // For undo-redo mechanism
}
};
And for the button a simple ActionListener with actionPerformed`.
btnSave.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
// Save the level
}
});
Hmm ... can't reproduce: in the snippet below the lost is always notified before the actionPerfomed, independent on whether I click the button or use the mnemonic:
final JTextField field = new JTextField("some text to change");
FocusAdapter focus = new FocusAdapter() {
#Override
public void focusLost(FocusEvent e) {
LOG.info("lost: " + field.getText());
}
};
field.addFocusListener(focus);
Action save = new AbstractAction("save") {
#Override
public void actionPerformed(ActionEvent e) {
LOG.info("save: " + field.getText());
}
};
save.putValue(Action.MNEMONIC_KEY, KeyEvent.VK_S);
JButton button = new JButton(save);
JComponent box = Box.createHorizontalBox();
box.add(field);
box.add(button);
On the other hand, focus is a tricky property to rely on, the ordering might be system-dependent (mine is win vista). Check how the snippet behave on yours.
If you see the same sequence as I do, the problem is somewhere else
if you get the save before the lost, try to wrap the the save action into invokeLater (which puts it at the end of the EventQueue, so it's executed after all pending events)
Action save = new AbstractAction("save") {
#Override
public void actionPerformed(ActionEvent e) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
LOG.info("save: " + field.getText());
}
});
}
};
Normally, wrapping your save code into an SwingUtilities.invokeLater() should do the trick. As you already mentioned, this doesn't work? Try this:
private boolean editFocus = false;
FocusAdapter focusAdapter = new FocusAdapter()
{
#Override
public void focusGained(FocusEvent e){
editFocus = true;
}
#Override
public void focusLost(FocusEvent e){
compProperties.setProperty(i, getColor());
record(); // For undo-redo mechanism
editFocus = false;
if (saveRequested){
save();
}
}
};
and for your button:
private boolean saveRequested = false;
btnSave.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
if (editFocus){
saveRequested = true;
return;
} else {
save();
}
}
});
and then your save method:
private void save(){
// do your saving work
saveRequested = false;
}
This only works when your focusLost gets called after your button's action. If suddenly the order is correct, this code will get save() called twice.
But again, wrapping your save() code in your original approach should work, because the save code will execute after processing all events. That is after processing your button click and your focusLost events. Because your focusLost code executes immediately (it's not wrapped in an invokeLater()), the focusLost code should be executed always before your save code. This does not mean that the event order will be correct! But the code associated to the events will executed in the right order.

Why wont my JFrame hide?

I'm in the process of creating a GUI in Netbeans 6.1 for my senior design project but i've run into an annoying snag. Temporary Windows like my login PopUp and others wont disappear when i tell it. I've been researching how to solve this for about 2 months on an off. I've even mad a separate thread for my Pop Up but it still wont work....the only way it will disappear if i literally dont mess with any of the other GUI components....my sample code should help describe my anger...dont mind the shadow code, it was for testing purposes, which obviously didnt help.
//This method is called once a user presses the "first" login button on the main GUI
public synchronized void loginPopUpThread() {
doHelloWorld = new Thread(){
#Override
public synchronized void run()
{
try
{
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(true);
System.out.println("waitin");
doHelloWorld.wait();
System.out.println("Not Sleepin..");
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(false);
}
catch (InterruptedException e)
{
}
}
};
doHelloWorld.start();
//This is called when the "second" loginB is pressed and the password is correct...
public synchronized void notifyPopUp() {
synchronized(doHelloWorld) {
doHelloWorld.notifyAll();
System.out.println("Notified");
}
}
I've also tried Swing Utilities but maybe i implemented it wrong as it's my first time using them. It essentially does the same thing as the code above except the window freezes when it gets to wait, which the above code doesnt do:
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public synchronized void run() {
try
{
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(true);
System.out.println("waitin");
wait();
System.out.println("Not Sleepin.");
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(false);
}
catch (InterruptedException e)
{
}
}
});
PLEASE HELP ME!!!
Rules of thumb:
Don't manipulate GUI components in arbitrary threads; always arrange to manipulate them in the event thread
Never wait or sleep inside the event thread (so, never inside code sent to invokeLater())
So the answer to how you solve this problem is "some other way"...
Standing back from the problem a bit, what is it you're actually trying to do? If you just want a login dialog to wait for the user to enter user name and password, is there a reason not to just use a modal JDialog (after all, that's what it's there for...).
If you really do want some arbitrary thread to wait for a signal to close the window/manipulate the GUI, then you need to do the waiting in the other thread, and then make that thread call SwingUtilities.invokeLater() with the actual GUI manipulation code.
P.S. There are actually some GUI manipulation methods that it is safe to call from other threads, e.g. calls that are "just setting a label" are often safe. But which calls are safe isn't terribly well-defined, so it's best just to avoid the issue in practice.
The Swing components should only be manipulated by the swing event dispatch thread.
class SwingUtilites has methods to submit tasks to the dispatch thread.
It is difficult to diagnose your problem. I'm not sure what you're trying to do with the wait methods, but I recommend leaving wait/notify alone.
This code has two frames - when you create a second frame, the first is hidden until you close it.
public class SwapFrames {
private JFrame frame;
private JFrame createMainFrame() {
JButton openOtherFrameButton = new JButton(
"Show other frame");
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container contentPane = frame.getContentPane();
contentPane.setLayout(new FlowLayout());
contentPane.add(openOtherFrameButton);
frame.pack();
openOtherFrameButton
.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
onClickOpenOtherFrame();
}
});
return frame;
}
private void onClickOpenOtherFrame() {
frame.setVisible(false);
JFrame otherFrame = new JFrame();
otherFrame
.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
otherFrame.setContentPane(new JLabel(
"Close this to make other frame reappear."));
otherFrame.pack();
otherFrame.setVisible(true);
otherFrame.addWindowListener(new WindowAdapter() {
#Override
public void windowClosed(WindowEvent e) {
frame.setVisible(true);
}
});
}
public static void main(String[] args) {
JFrame frame = new SwapFrames().createMainFrame();
frame.setVisible(true);
}
}
Because I don't see any evidence of them in your code, I'm going to suggest you read up on using event listeners rather than trying to "wait" for code to finish.
It isn't entirely clear what you're trying to achieve, but you might be better off with a modal dialog:
public class DialogDemo {
public JFrame createApplicationFrame() {
JButton openDialogButton = new JButton("Open Dialog");
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container container = frame.getContentPane();
container.setLayout(new FlowLayout());
container.add(openDialogButton);
frame.pack();
openDialogButton
.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
onOpenDialog(frame);
}
});
return frame;
}
private void onOpenDialog(JFrame frame) {
JDialog dialog = createDialog(frame);
dialog.setVisible(true);
}
private JDialog createDialog(JFrame parent) {
JButton closeDialogButton = new JButton("Close");
boolean modal = true;
final JDialog dialog = new JDialog(parent, modal);
dialog
.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
Container container = dialog.getContentPane();
container.add(closeDialogButton);
dialog.pack();
dialog.setLocationRelativeTo(parent);
closeDialogButton
.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
dialog.setVisible(false);
}
});
return dialog;
}
public static void main(String[] args) {
new DialogDemo().createApplicationFrame().setVisible(
true);
}
}
How about doing simply:
//This method is called once a user presses the "first" login button on the main GUI
public void loginPopUpThread() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(true);
}
};
}
//This is called when the "second" loginB is pressed and the password is correct...
public void notifyPopUp() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
loginPopUpFrame.setVisible(false);
}
};
}
What you really want to be using is a modal JDialog.
Note, bits of this are left out. It's your homework/project.
public void actionPerformed(ActionEvent e)
{
// User clicked the login button
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
LoginDialog ld = new LoginDialog();
// Will block
ld.setVisible(true);
}
});
}
public class LoginDialog extends JDialog
{
public LoginDialog()
{
super((Frame)null, "Login Dialog", true);
// create buttons/labels/components, add listeners, etc
}
public void actionPerformed(ActionEvent e)
{
// user probably clicked login
// valid their info
if(validUser)
{
// This will release the modality of the JDialog and free up the rest of the app
setVisible(false);
dispose();
}
else
{
// bad user ! scold them angrily, a frowny face will do
}
}
}

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