I have some component on the frame and I need it to respond just on right button click. I have to use my own event. Should I extend MouseEvent? How can I separate right button click from others in my event?
No, you wouldn't extend MouseEvent, rather you would use MouseEvent.
If this is a Swing GUI you could add a MouseListener to the component and then in the MouseListener's mousePressed method, get the MouseEvent object that is passed in to the method, get its modifiersEx and then check if right click has been pressed:
public void mousePressed(MouseEvent mEvt) {
if ((mEvt.getModifiersEx() & MouseEvent.BUTTON3_DOWN_MASK) != 0) {
// right button has been pressed
}
}
The MouseEvent class has a method that allows you to check which mouse button was used. It's called getButton and it returns an int value that you can compare to one of predefined values
On top of that, there's a convenient class called SwingUtilities, which provides a nice layer of abstraction over the use of these fields. Here's a method you'll find particularly interesting: isRightMouseButton
In other words, you don't need to create your own MouseEvent, a MouseListener implementation will suffice. Here's an example of inline implementation, irrelevant details excluded.
new MouseListener(){
#Override
public void mouseClicked(MouseEvent e) {
if(SwingUtilities.isRightMouseButton(e)){
//do what you want on right click
}
}
// other methods required by the interface
};
Related
I'm making something like an auto clicker.
I would like to make it so that when the left mouse button is pressed, the auto clicker should turn on. When the button is released, the auto clicker should turn off.
Is there a way to check if the left mouse click (in real life) is pressed after calling the robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK) method?
You should implement MouseListener interface in your class then override these two methods : mousePressed and mouseReleased .
public void mousePressed(MouseEvent e) {
//do the auto click code here
}
public void mouseReleased(MouseEvent e) {
//turn off the auto click here
}
read this article
I added a JPanel to a JRadioButton - so that I may display whatever I want in the radio button.
This all worked as expected. But to allow for text wrapping, I used a JTextArea and added it to the JPanel contained within the radio button.
Now I have an issue where, if the user clicks on the JTextArea, then the JTextArea consumes the mouseEvent and as a result there is no response from the radio button (it doesn't 'select').
Is there a way get the JTextArea to ignore the mouse click, so that the parent may handle it instead?
I tried add the JTextArea's listeners to the radioButton instead.
I also tried to remove its listeners completely, but both these attempts failed.
Anyone have any suggestions?
Strong beware
Most JSomething are not meant to be used as containers even though it's possible - the outcome of doing it anyway is more or less visually and behaviourally undetermined!
That said, did it recently, to implement something similar to a Windows task dialog. If the requirement includes keeping the button clickable (and why else would you mis-use it as a container :-) the main problem (layout apart) is to make all added components completely mouse-transparent. Which is more difficult than can be expected. The minimum is to not allow adding of mouseListeners and disable the acceptance of mouseEvents:
final JTextArea area = new JTextArea("replacement ..") {
#Override
public synchronized void addMouseListener(MouseListener l) {
LOG.info("adding here ...?");
}
#Override
public synchronized void addMouseMotionListener(
MouseMotionListener l) {
}
#Override
public synchronized void addMouseWheelListener(
MouseWheelListener l) {
}
#Override
public void addNotify() {
disableEvents(AWTEvent.MOUSE_EVENT_MASK |
AWTEvent.MOUSE_MOTION_EVENT_MASK |
AWTEvent.MOUSE_WHEEL_EVENT_MASK);
super.addNotify();
}
};
Plus make sure it's not focusable
area.setEditable(false);
area.setFocusable(false);
area.setRequestFocusEnabled(false);
Plus unregister dragging and tooltips
ToolTipManager.sharedInstance().unregisterComponent(area);
area.setDragEnabled(false);
Nevertheless, there might still be surprises ahead, f.i. call the following twice (that is disable and enable again), which will internally re-enable mouseEvent:
area.setAutoscrolls(!area.getAutoscrolls());
So at the end of the day, we might get away with it - but never be entirely certain that we succeeded.
What about this? Create and add your own MouseListener to TextArea
JPanel p = new JPanel();
JTextArea t = new JTextArea("line \n line");
t.addMouseListener(new MyMouseListener());
p.add(t);
jRadioButton1.add(p);
jRadioButton1.addMouseListener(new MyRadioButtonMouseListener());
And in the MyMouseListener Dispatch event
private class MyMouseListener implements MouseListener {
#Override
public void mouseClicked(MouseEvent e) {
Component source = (Component) e.getSource();
source.getParent().getParent().dispatchEvent(e); // 2x getParent() because JTextArea->JPanel->JRadio
}
.
.
.
}
And finally RadioButtonMouseListener
private class MyRadioButtonMouseListener implements MouseListener {
#Override
public void mouseClicked(MouseEvent e) {
System.out.println("CLICK ON RADIOBUTTON !!");
}
.
.
.
}
I have a JButton titled "select"
In the class that creates that JButton and other classes, I want to use an if condition with ActionPerformed method.
Something like(pseudo-code)
if(_selectListener.actionPerformed(ActionEvent)) { //i.e., if select Button is clicked,
//do something
}
Is this possible?
I want to call this method because I have to handle a situation in which a player should be able to choose something by clicking "select" button, or another "scroll" button, and I want to control it using something similar to a bunch of if statements like the one above.
If it is possible, what is the syntax for it? What is the argument ActionEvent?
Thank you!
The easiest and cleanest way is to add a dedicated, specific action listener to each button. That way, when the actionPerformed() method is called, you're sure that the associated button has been clicked, and don't need to test which button has been clicked:
selectButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// handle click on select button
}
});
scrollButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// handle click on scroll button
}
});
Another way is to use a common ActionListener, and use the getSource() method of ActionEvent to know which component triggered the event. Compare the result with each potential button to determine which is the one that has been clicked:
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == selectButton) {
// handle click on select button
}
else if (e.getSource() == scrollButton) {
// handle click on scroll button
}
}
What is the argument ActionEvent?
The answer is in the documentation. Read it.
no you cant call, if needs boolean expression/value, but this method returns void.
I have a JComboBox component in the panel and ItemListener attached to it. But it gets fired after every up/down keypress (when scrolling though opened popup list). I want to change the selected value after the user accepts selection by pressing for example Enter key.
This is not a case when using mouse. When I move mouse over the combobox's list the highlight follows mouse pointer, but selected item is not changed until I press the mouse button. I would like to have the same behavior for keyboard, i.e. moving highlight via up/down arrow does not change selected item, but pressing Enter does.
I believe you should be able to do:
comboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
after you have created your comboBox instance to get this functionality
In Java 8 they have fixed this behaviour, but only trigger if u set one UI property
UIManager.getLookAndFeelDefaults().put("ComboBox.noActionOnKeyNavigation", true);
the JComboBox.isTableCellEditor method works for arrow movement through the list, but does not work for type-ahead supported by the KeySelectionManager. i.e. you still get ActionEvents for every non-navigation key the user types, as the JComboBox interprets those characters for searching though the model to move to (or move close to) the user's intended selection.
this solution has a drawback in that it changes the action command for mouse clicks, which was a OK compromise for me because the the flow of the GUI forces the user to change the focus away from the combo box
I ended up making a special KeyListener, that relys on changing the combo box's default action command from comboBoxChanged to comboBoxMovement. Here's the line of code I need after my combo box is all initialized:
setExplicitSelectionManager(myComboBox);
... and here is the method and its contained class that do all the work:
private void setExplicitSelectionManager(JComboBox comboBox) {
class ExplicitSelectionManager implements KeyListener, FocusListener {
private JComboBox src;
private KeyListener superKeyListener;
ExplicitSelectionManager(JComboBox src) {
this.src = src;
// we like what the default key listener does, but not the action command
// it uses for ActionEvents it fires for plain text type-ahead characters
this.superKeyListener = src.getKeyListeners()[0]; // we only have one
src.removeKeyListener(superKeyListener); // will be replace right away, below
}
#Override
public void keyTyped(KeyEvent e) {
// basic combo box has no code in keyTyped
}
#Override
public void keyPressed(KeyEvent e) {
// in the default JComboBox implementation, the KeySelectionManager is
// called from keyPressed. I'm fine with the implementation of
// the default, but I don't want it firing ActionEvents that will cause
// model updates
src.setActionCommand("comboBoxMovement");
this.superKeyListener.keyPressed(e);
src.setActionCommand("comboBoxChanged");
if (e.getKeyCode() == 10) {
src.setSelectedIndex(src.getSelectedIndex());
}
}
#Override
public void keyReleased(KeyEvent e) {
// basic combo box has no code in keyReleased
}
#Override
public void focusGained(FocusEvent e) {
}
#Override
// this will also give us the event we want, if the user decides to Tab out of
// the combo box, instead of hitting Enter
public void focusLost(FocusEvent e) {
src.setSelectedIndex(src.getSelectedIndex());
}
}
ExplicitSelectionManager newSelectionManager = new ExplicitSelectionManager(comboBox);
comboBox.addKeyListener(newSelectionManager);
comboBox.addFocusListener(newSelectionManager);
}
... and here's the action performed method
private void comboBoxActionPerformed(java.awt.event.ActionEvent evt) {
JComboBox source = (JComboBox) evt.getSource();
// "comboBoxChanged" is the default,
// so any normal JComboBox can also use this action listener
if (evt.getActionCommand().equals("comboBoxChanged")) {
updateModel(source.getName(), (String) source.getSelectedItem());
}
}
Its the expected behavior with the ItemListener. whenever the displayed value changes the event is fired. For your requirement use an ActionListener.
i have a Jframe application with the defaultbutton set to btnClose_ (Close Button: this button closes the window).
I have 2 textfields that must also fire an event when user clicks the Enter key on the textfields. What happens is that when I press the Enter key while the cursor is on the textfield, the event on the Close button is fired causing the window to close.
Is it possible to remove the listener of the default button if the Enter key is pressed on the textfield? Here's my code for the textfield listener
/**
* Receives the two textfield instance
*/
private void addFilterListener(JTextField txf) {
txf.addKeyListener(new KeyAdapter() {
/**
* Invoked when a key has been pressed.
*/
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_ENTER) {
ActionListener al = btnClose_.getActionListeners()[0];
btnClose_.removeActionListener(al);
btnFilter_.doClick();
e.consume();
btnClose_.addActionListener(al);
}
}
});
}
private JButton getBtnClose(){
if(btnClose == null){
btnClose.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
getWindow().dispose();
}
});
}
return btnClose;
}
}
Where to start?
The first thing that springs out at me is the bad variable names. txf? What's wrong with proper words? textField or field, say. Or much better, a name descriptive of its purpose, not what it is.
Secondly, the first comment is wrong (not uncommon) and the second comment is redundant (already specified in the KeyListener interface, you don't need to try and half-heartedly specify it again).
Next up, low level key listeners tend not to work so well on Swing components (JComboBox being the most notorious example - it typically is implemented with child components). In general you can use JComponent.registerKeyboardAction (the API docs says this is obsolete but not deprecated, and to use more verbose code). For text components, you often want to play with the document (typically through DocumentFilter). In this particular case, looks like you just want to add an ActionListener.
Now doClick. It's a bit of an evil method. For one thing it blocks the EDT. It is probably the easiest way to make it look as if a button is pressed. From a programming logic point of view, it's best to keep away from modifying Swing components, when you can keep everything in your abstracted code.
Removing and adding listeners from components is generally a bad idea. Your code should determine what to do with an event including whether to ignore it. Do that at an appropriate point when handling the event. Don't duplicate state unnecessarily.
A potential issue is that the code seems to assume that there is precisely one action listener. There could be others. The code is not robust under unexpected behaviour. Set your components up at initialisation time, and you shouldn't need to refer to them again.
As far as I understood your question, you want that buttonClick should not get fired if Enter is pressed .
This won't fire doClick() if enter is pressed
if (e.getKeyCode() != KeyEvent.VK_ENTER) {
btnFilter_.doClick();
}
In the ActionListener of the close button, assuming you can change its code, don't close if one of the text fields have the focus.
public void actionPerformed(ActionEvent e) {
if (field1.hasFocus() || field2.hasFocus())
return; // don't close if text field has focus
frame.dispose();
}
If you can not change the ActionListener of the close button, add a FocusListener to the text fields. If one of them gets the focus, remove the default button. If the text field lost the focus, reset the default button.
FocusAdapter listener = new FocusAdapter() {
#Override
public void focusGained(FocusEvent e) {
frame.getRootPane().setDefaultButton(null);
}
#Override
public void focusLost(FocusEvent e) {
frame.getRootPane().setDefaultButton(close);
}
};
field1.addFocusListener(listener);
field2.addFocusListener(listener);
This should be better than depending on the listeners being called in the correct sequence - it is of no avail to remove the listener if it was already called...