Why does the code enters twice in the change event of the JSpinner?
private javax.swing.JSpinner spinner = new javax.swing.JSpinner()
spinner.setModel(new javax.swing.SpinnerDateModel());
spinner.addChangeListener(new javax.swing.event.ChangeListener() {
#Override
public void stateChanged(javax.swing.event.ChangeEvent evt) {
System.out.println("Just a test");
}
});
The code above shows the message twice when u click only one time.
2 events are generated: one for the value being deselected and another for the new value being selected in the component. As #camickr notes in his comment this behavior occurs in SpinnerDateModel but not in the default SpinnerNumberModel
As a workaround you could use
spinner.addChangeListener(new ChangeListener() {
Object lastValue;
#Override
public void stateChanged(ChangeEvent evt) {
if (lastValue != null && !spinner.getValue().equals(lastValue)) {
// expensive code calls here!
}
lastValue = spinner.getValue();
}
});
This wont prevent the listener being called twice but will prevent any expensive code being invoked unnecessarily
Just bumped into the same problem and found a different workaround, as the one in https://stackoverflow.com/a/19166589/5326620 caused it to miss the event when first editing the date directly on the text field.
In my case, I'm using a SpinnerDateModel for Calendar.DAY_OF_MONTH (same as Calendar.DATE).
If the SpinnerDateModel is initialized with a value precisely at midnight, the event is no longer fired twice.
Calendar now = Calendar.getInstance();
now.set(Calendar.HOUR_OF_DAY, 0);
now.set(Calendar.MINUTE, 0);
now.set(Calendar.SECOND, 0);
now.set(Calendar.MILLISECOND, 0);
Date value = now.getTime();
JSpinner dateSpn = new JSpinner(new SpinnerDateModel(value, null, null, Calendar.DAY_OF_MONTH));
This is probably because the commitEdit of the JFormattedTextField tests the old and new value by equality, and Date equality is on the millisecond.
Related
When I receive a ChangeEvent from my JSpinner, I'd like to detect if user used the arrows to increase/decrease the number value, or directly typed a new number.
What would be the best approach to do this ?
EDIT: for now my non-reliable solution is just to save the last JSpinner changed value, and if new change value is +/- equals to the step value, then I assume user clicked on an arrow. It works except if user typed a value which is equals to (oldValue +/- step).
EDIT: why ?
I want to reproduce the behavior found in Midi editors of several famous DAWs. The JSpinner represents the velocity (0-127) of selected notes. It shows the velocity of the first selected note. Usually notes velocity differ. When you increase with arrow, you want to increase all selected notes by the same amount. When you type in a new value, you want all velocities to be reset to this value.
Distinguishing the trigger of a value change is not supported - the only value-related event fired by JSpinner is a ChangeEvent which carries no state except the source. We need another type of listener or a combination of listeners.
First thought: listen to changes of the editor's textField, f.i. an actionListener or a propertyChangeListener on the value property. This doesn't work, mainly because
both change- and propertyChangeListener are fired always (change before property)
actionListener is not fired on focusLost
Second thought: go dirty and dig into implementation details to hook into the action fired by the arrow buttons.
The idea:
look up the action for increment/decrement from the spinner's actionMap: this is the same as the arrows' actions and also used by up/down keys (which I assume not counting a "editing")
for each, create a wrapper that sets a flag before delegating to super
put that wrapper into the spinner's actionMap
look up the arrow buttons in the spinner's children and replace their respective actionListener with the wrapper
Client code would change the tweak's changeListener to acts according to the flag as appropriate.
Some code doing the tweaking (beware: not formally tested!):
public static class SpinnerTweaker {
private JSpinner spinner;
private boolean wasButtonAction;
private Object oldValue;
public SpinnerTweaker(JSpinner spinner) {
this.spinner = spinner;
AbstractAction incrementDelegate = createDelegate("increment");
spinner.getActionMap().put("increment", incrementDelegate);
AbstractAction decrementDelegate = createDelegate("decrement");
spinner.getActionMap().put("decrement", decrementDelegate);
// replacing arrow button's action
Component[] components = spinner.getComponents();
for (Component component : components) {
if (component instanceof JButton) {
if (component.getName() == "Spinner.nextButton") {
ActionListener[] actions = ((JButton) component).getActionListeners();
ActionListener uiAction = actions[0];
((JButton) component).removeActionListener(uiAction);
((JButton) component).addActionListener(incrementDelegate);
}
if (component.getName() == "Spinner.previousButton") {
ActionListener[] actions = ((JButton) component).getActionListeners();
ActionListener uiAction = actions[0];
((JButton) component).removeActionListener(uiAction);
((JButton) component).addActionListener(decrementDelegate);
}
}
}
spinner.addChangeListener(e -> {
if (wasButtonAction) {
System.out.println("value changed by button: " + spinner.getValue());
} else {
System.out.println("value changed by editing: " + spinner.getValue());
}
wasButtonAction = false;
});
}
protected AbstractAction createDelegate(String actionCommand) {
// hooking into original button action to set button flag
AbstractAction action = (AbstractAction) spinner.getActionMap().get(actionCommand);
AbstractAction delegate = new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
oldValue = spinner.getValue();
wasButtonAction = true;
action.actionPerformed(e);
// hit min/max - TBD: needs testing!
if (oldValue.equals(spinner.getValue())) {
wasButtonAction = false;
}
}
};
return delegate;
}
}
#kleopatra solution works but I found a simpler solution.
The trick is that commitEdit() is only called internally by JSpinner when change results from the increment or decrement action.
public class Spinner2 extends JSpinner
{
// To be checked by ChangeListener after receiving the ChangeEvent
public boolean wasManualEdit=true;
#Override
public void commitEdit() throws ParseException
{
wasManualEdit = false;
super.commitEdit();
}
#Override
protected void fireStateChanged()
{
super.fireStateChanged();
wasManualEdit = true;
}
}
where I made mistake? I tried to show current time in window every sec.
But it show
ActionListener AL = new ActionListener()
{
public void actionPerformed(ActionEvent actionEvent)
{
Date currentTime=gregorianCalendarCurrrentTime.getTime();
JLabelCurrentTime.setText(String.valueOf(currentTime));
}
};
Timer timer = new Timer(1000, AL);
timer.start();
Assuming, that gregorianCalendarCurrrentTime is of type java.util.GregorianCalendar, the method getTime() returns a Date object which is representing the time of the calendar-objekt which was 'current' at creation time or after last use of set-methods of the calendar-objekt. The method does not determine the current time. To set the current time as labeltext, you simply could use new Date().
LabelCurrentTime.setText(String.valueOf(new Date()));
I am using toedter JDateChooser, and I am having problems retrieving the date picked from it.
jDateChooser2.setDateFormatString("dd-MMMM-yy");
jDateChooser2.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jDateChooser2MouseClicked(evt);
}
});
private void jDateChooser2MouseClicked(java.awt.event.MouseEvent evt) {
Date dateFromDateChooser = jDateChooser2.getDate();
System.out.println(dateFromDateChooser);
}
How can I retrieve the date? Is there a better way to do it? I think the listener is not being fired or triggered. i tried replacing the listener with:
System.out.println("triggered");
Still there are no output.
Basically, you don't want to listener for MouseEvents, as these could be changing the state of the component in a number of ways, most of which you don't want to know about.
You should be monitoring the date property change event, for example...
JDateChooser dateChooser = new JDateChooser();
dateChooser.addPropertyChangeListener("date", new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
Date date = (Date)evt.getNewValue();
System.out.println("Date changed " + date);
}
});
Just beware, this could be triggered in response to calling setDate or by the user selecting a date from the picker, generally, you won't be able to tell
How i would add an action listener to the jcalendar? I want to get the date whenever you click in a day, so i will show the entire date on a jtextfield.
I have tried something like this, but It does nothing when i click a day.
cal = new JCalendar();
cal.setWeekOfYearVisible(false);
cal.getDayChooser().getDayPanel().addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent e) {
System.out.println(e.getPropertyName()
+ ": " + (Date) e.getNewValue());
}
});
I tried the code of the answer to this question too, that is similar, but nothing.
Adding actionListener to jCalendar
I think you are adding the property change listener to the wrong bean. I inspected the JCalendar code and the getDayPanel() method returns just a regular JPanel that I don't think knows about the "day" property you are interested in.
/**
* Returns the day panel.
*
* #return the day panel
*/
public JPanel getDayPanel() {
return dayPanel;
}
I think you should add your property change listener to the daychooser itself, which is the class that knows about the "day" property. Also, you might want to register for the "day" property of the day chooser:
cal = new JCalendar();
cal.setWeekOfYearVisible(false);
cal.getDayChooser().addPropertyChangeListener("day", new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent e) {
System.out.println(e.getPropertyName()
+ ": " + e.getNewValue());
}
});
Still, that will only give you the day that the user picked, not the entire date.
I am showing some results in a JTable that consists of 2 columns.
File - Result
I implemented a JPopupMenu which displays a copy entry, and I try to copy the value of the cell, where I right-clicked.
filelistTable.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
if(SwingUtilities.isRightMouseButton(e))
{
TablePopupMenu popup = new TablePopupMenu(filelistTable, e.getPoint());
filelistTable.setComponentPopupMenu(popup);
}
}
});
--
public TablePopupMenu(JTable table, Point p) {
this.table = table;
this.p = p;
JMenuItem mntmKopieren = new JMenuItem("Kopieren");
mntmKopieren.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
copyCellToClipboard();
}
});
add(mntmKopieren);
}
public void copyCellToClipboard()
{
int r = table.rowAtPoint(p);
int c = table.columnAtPoint(p);
System.out.println(table.getValueAt(table.convertRowIndexToView(r),
table.convertRowIndexToView(c)));
StringSelection entry = new StringSelection(table.getValueAt(table.convertRowIndexToView(r),
table.convertRowIndexToView(c)).toString());
Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
clipboard.setContents( entry, this );
}
Anyhow, this only works for a small number of tests.
Did I do something wrong or something missing? It looks to me, as if the cell will not even get choosen correctly.
Two thingies are slightly off:
setting the componentPopup in the clicked is too late in the sequence of mouseEvents (popups are typically triggered on pressed or released which happen before the click)
the value is taken from the incorrect cell: all coordinates in a JTable are in view coordinate system, converting them to view coordinates will be completely off
That said: getting cell-coordinate related context is poorly supported. Often, the best bet is to (code snippet below)
override getPopupLocation(MouseEvent) and store the location somewhere
implement a popup/action to access the location
Fails if (as should be done in a well-behaved application), the popup could be triggered by keyboard: if that's the case, you'll need to provide some other marker (f.i. the focused cell) to act on.
final String popupLocation = "table.popupLocation";
final JTable table = new JXTable(new AncientSwingTeam()) {
#Override
public Point getPopupLocation(MouseEvent event) {
// event may be null if triggered by keyboard, f.i.
// thanks to #Mad for the heads up!
((JComponent) event.getComponent()).putClientProperty(
popupLocation, event != null ? event.getPoint() : null);
return super.getPopupLocation(event);
}
};
JPopupMenu popup = new JPopupMenu();
Action printLocation = new AbstractAction("print cell") {
#Override
public void actionPerformed(ActionEvent e) {
Point p = (Point) table.getClientProperty(popupLocation);
if (p != null) { // popup triggered by mouse
int row = table.rowAtPoint(p);
int column = table.columnAtPoint(p);
LOG.info("" + table.getValueAt(row, column));
} else { // popup triggered otherwise
// could choose f.i. by leadRow/ColumnSelection
...
}
}
};
popup.add(printLocation);
table.setComponentPopupMenu(popup);
Edit (triggered by Mad's comment):
You should be checking MouseEvent.isPopupTrigger as the trigger point is platform dependent. This does mean you need to monitor mousePressed, mouseReleased and mouseClicked
No, that's not needed (just checked :-): the mechanism that shows the componentPopup in response to a mouseEvent - happens in BasicLookAndFeel.AWTEventHelper - only does so if it is a popupTrigger.
By reading the api doc (should have done yesterday ;-) again, it turns out that the method is called always before showing the componentPopup, that is also if triggered by other means, f.i. keyboard. In that case the event param is null - and the original code would blow. On the bright side, with that guarantee, all the logic of finding the target cell/s could be moved into that method. Didn't try though, so it might not be feasable (f.i. if then the location should be based on the leadRow/ColumnSelection that might not yet be fully handled at that time)