I'm having a problem with my Java code.
I need to execute my doSomething() method, which includes code that manage also global variables. The problem is that the method is invoked twice (both mouseEvent and focusEvent of my JTable are fired at the same time).
How can I execute the doSomething() method only once at a time, in a sort of mutual exclusion ?
Thanks.
addMouseListener (new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
doSomething();
}
});
addFocusListener(new FocusAdapter() {
#Override
public void focusLost(FocusEvent e){
doSomething();
}
});
JTable cells contains String with length 1 or 2.
I need to apply a setValue method (or delete the String), in the exact moment the user stops the cell editing or he writes a 2 character String.
With those listeners I know the exact time to do the setValue or to inform the user that the first character he wrote doesn't exist. So in that way I wanted to block the user's action.
In other words, I need to control the user input in order to do a setValue or delete it. FocusLost tells me when the user clicks outside the JTable Component.
MouseClicked tells me when the user clicks in the JTable Component.
When mouseClicked is invoked and the JOptionPane appears, the cell automatically lose the focus, and so also the focusLost is invoked.
public void doSomething () {
// inEdit and tableCellEdited are the global variables
if ( inEdit && tableCellEdited != null ) {
String temp = "" + tableCellEdited.getDay();
String s = tableCellEdited.getValRenderer().trim();
if (s.length() > 2) s = s.substring(4);
if ( !s.trim().isEmpty() ) {
JOptionPane.showMessageDialog(getParent(),
"Code doesn't exist" , "Error: Code doesn't exist",JOptionPane.WARNING_MESSAGE);
tableCellEdited.setRendererValue(getUltimaGG(), false);
}
else {
tableCellEdited.setRendererValue(s, false);
setValueAt(tableCellEdited, getRowFromMat(tableCellEdited.getMat()), Integer.parseInt(temp.substring(6, 8)) );
}
clearProgrammazioneDueCaratteri();
}
}
repaint();
}
It seems that the Spinner control does not update a manually typed-in value until the user explicitly presses enter. So, they could type in a value (not press enter) exit the control, and submit the form, and the value displayed in the spinner is NOT the value of the Spinner, it is the old value.
My idea was to add a listener to the lost focus event, but I can't see a way to gain access to the typed-in value?
spinner.focusedProperty().addListener((observable, oldValue, newValue) ->
{
//if focus lost
if(!newValue)
{
//somehow get the text the user typed in?
}
});
This is odd behavior, it seems to go against the convention of a GUI spinner control.
Unfortunately, Spinner doesn't behave as expected: in most OS, it should commit the edited value on focus lost. Even more unfortunate, it doesn't provide any configuration option to easily make it behave as expected.
So we have to manually commit the value in a listener to the focusedProperty. On the bright side, Spinner already has code doing so - it's private, though, we have to c&p it
/**
* c&p from Spinner
*/
private <T> void commitEditorText(Spinner<T> spinner) {
if (!spinner.isEditable()) return;
String text = spinner.getEditor().getText();
SpinnerValueFactory<T> valueFactory = spinner.getValueFactory();
if (valueFactory != null) {
StringConverter<T> converter = valueFactory.getConverter();
if (converter != null) {
T value = converter.fromString(text);
valueFactory.setValue(value);
}
}
}
// useage in client code
spinner.focusedProperty().addListener((s, ov, nv) -> {
if (nv) return;
//intuitive method on textField, has no effect, though
//spinner.getEditor().commitValue();
commitEditorText(spinner);
});
Note that there's a method
textField.commitValue()
which I would have expected to ... well ... commit the value, which has no effect. It's (final!) implemented to update the value of the textFormatter if available. Doesn't work in the Spinner, even if you use a textFormatter for validation. Might be some internal listener missing or the spinner not yet updated to the relatively new api - didn't dig, though.
Update
While playing around a bit more with TextFormatter I noticed that a formatter guarantees to commit on focusLost:
The value is updated when the control loses its focus or it is commited (TextField only)
Which indeed works as documented such that we could add a listener to the formatter's valueProperty to get notified whenever the value is committed:
TextField field = new TextField();
TextFormatter fieldFormatter = new TextFormatter(
TextFormatter.IDENTITY_STRING_CONVERTER, "initial");
field.setTextFormatter(fieldFormatter);
fieldFormatter.valueProperty().addListener((s, ov, nv) -> {
// do stuff that needs to be done on commit
} );
Triggers for a commit:
user hits ENTER
control looses focus
field.setText is called programmatically (this is undocumented behaviour!)
Coming back to the spinner: we can use this commit-on-focusLost behaviour of a formatter's value to force a commit on the spinnerFactory's value. Something like
// normal setup of spinner
SpinnerValueFactory factory = new IntegerSpinnerValueFactory(0, 10000, 0);
spinner.setValueFactory(factory);
spinner.setEditable(true);
// hook in a formatter with the same properties as the factory
TextFormatter formatter = new TextFormatter(factory.getConverter(), factory.getValue());
spinner.getEditor().setTextFormatter(formatter);
// bidi-bind the values
factory.valueProperty().bindBidirectional(formatter.valueProperty());
Note that editing (either typing or programmatically replacing/appending/pasting text) does not trigger a commit - so this cannot be used if commit-on-text-change is needed.
#kleopatra headed to a right direction, but the copy-paste solution feels awkward and the TextFormatter-based one did not work for me at all. So here's a shorter one, which forces Spinner to call it's private commitEditorText() as desired:
spinner.focusedProperty().addListener((observable, oldValue, newValue) -> {
if (!newValue) {
spinner.increment(0); // won't change value, but will commit editor
}
});
This is standard behavior for the control according to the documentation:
The editable property is used to specify whether user input is able to
be typed into the Spinner editor. If editable is true, user input will
be received once the user types and presses the Enter key. At this
point the input is passed to the SpinnerValueFactory converter
StringConverter.fromString(String) method. The returned value from
this call (of type T) is then sent to the
SpinnerValueFactory.setValue(Object) method. If the value is valid, it
will remain as the value. If it is invalid, the value factory will
need to react accordingly and back out this change.
Perhaps you could use a keyboard event to listen to and call the edit commit on the control as you go.
Here is an improved variant of Sergio's solution.
The initialize method will attach Sergio's code to all Spinners in the controller.
public void initialize(URL location, ResourceBundle resources) {
for (Field field : getClass().getDeclaredFields()) {
try {
Object obj = field.get(this);
if (obj != null && obj instanceof Spinner)
((Spinner) obj).focusedProperty().addListener((observable, oldValue, newValue) -> {
if (!newValue) {
((Spinner) obj).increment(0);
}
});
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}
Using a listener should work. You can get access to the typed in value through the spinner's editor:
spinner.getEditor().getText();
I use an alternate approach - update it live while typing. This is my current implementation:
getEditor().textProperty().addListener { _, _, nv ->
// let the user clear the field without complaining
if(nv.isNotEmpty()) {
Double newValue = getValue()
try {
newValue = getValueFactory().getConverter().fromString(nv)
} catch (Exception e) { /* user typed an illegal character */ }
getValueFactory().setValue(newValue)
}
I used this approach
public class SpinnerFocusListener<T> implements ChangeListener<Boolean> {
private Spinner<T> spinner;
public SpinnerFocusListener(Spinner<T> spinner) {
super();
this.spinner = spinner;
this.spinner.getEditor().focusedProperty().addListener(this);
}
#Override
public void changed(ObservableValue<? extends Boolean> observable,
Boolean oldValue, Boolean newValue) {
StringConverter<T>converter=spinner.getValueFactory().getConverter();
TextField editor=spinner.getEditor();
String text=editor.getText();
try {
T value=converter.fromString(text);
spinner.getValueFactory().setValue(value);
}catch(Throwable ex) {
editor.setText(converter.toString(spinner.getValue()));
}
}
}
My Question:
In the code below I try to ask user a value. SC.askforValue() is called with all possible variables, a Dialog is given as parameter to adjust the dialog.
My problem is what happens, when user presses cancel? On my current smartGwt version (2.1), is it possible to see the cancel alone? Now empty value and cancel get both handled in the same way.
My Code:
Dialog dialog = new Dialog();
dialog.setWidth(200);
SC.askforValue("myTitle", "myQuestion", "defaultValue", new ValueCallback() {
#Override
public void execute(String value) {
if (value != null) {
// do sth.
} else {
/* cancel pressed / empty value. */
}
}
}, dialog);
As per the documentation,
if you want to differantiate blank input and cancel event, you can check the value, you receive in the callback. When user has entered nothing and clicks OK, blank string will be there as value. And when user clicks Cancel, the value will be null.
I have this combo box that I would like to enable or disable depending on a selection of "SDO/OD", (coded as 10 in database) in a previous combo box. When I use the following code it gives me the drop down listing, but for every choice. I want the drop down for only when "SDO/OD" is chosen. Otherwise, disable the combo box but allow the data to pass the null for the record. I don't think it is reading the Listener. My question is why is this happening? How to I handle the Listerner to accommodate such a task?
fcbRole.addSelectionChangedListener(new SelectionChangedListener<ModelData>()
{
#Override
public void selectionChanged(SelectionChangedEvent<ModelData> se)
{
fcbOfficeRegion.clearSelections();
fcbOfficeRegion.getStore().clearFilters();
if(fcbRole.getValue().equals("SDO/OD") && se.getSelectedItem() != null)
{
fcbOfficeRegion.enable();
fcbOfficeRegion.setValueField(se.getSelectedItem().get("strValue").toString());
StoreFilter<ModelData> sfRole = new StoreFilter<ModelData>()
{
#Override
public boolean select(Store<ModelData> store,
ModelData parent, ModelData item,
String property) {
String name = item.get("filterDepts");
name = getScc().cleanString(name.toLowerCase());
if (name.contains("(" + fcbRole.getValue().get("strValue") + ")"))
{
return true;
}
return false;
}
};
fcbOfficeRegion.getStore().addFilter(sfRole);
fcbOfficeRegion.getStore().applyFilters("fcbOfficeRegion");
}
else
Best of Listeners for JComboBox is ItemListener, this Listener fired events SELECTED/DESELECTED, always twice
Is there any way to tell during the execution of the valueChanged method of a ListSelectionListener whether the user clicked the JList or whether setSelectedIndex was called by some other code?
AFAIK, no. But if the goal is to only execute something if the selection comes from the user, you may set a flag before selecting an index in the code to signal that the selection doesn't come from the user, or remove the listener and add it afterwards:
private void selectIndexInList(int index) {
this.selectionComesFromTheCode = true;
try {
list.setSelectedIndex(index);
}
finally {
this.selectionComesFromTheCode = false;
}
}
#Override
public void valueChanged(ListSelectionEvent e) {
if (!this.selectionComesFromTheCode) {
...
}
}