I'm trying to get the mouse position while pressing the mouse button but it doesn't work.
I'm extending the MouseAdapter and as stated at the Javadoc the mouseMove() is invoked when the mouse cursor has been moved onto a component but no buttons have been pushed.
This is an example class I have created to show you my problem:
public class TestMouse extends MouseAdapter{
int x,y;
boolean pressed;
public void mousePressed(MouseEvent e){
pressed = true;
}
public void mouseReleased(MouseEvent e){
pressed = false;
}
/*
Invoked when the mouse is not pressed only.
*/
public void mouseMoved(MouseEvent e){
x = e.getX();
y = e.getY();
}
/*
I want something like that.
*/
public void mousePressedAndMoved(MouseEvent e){
....
}
}
That's the problem with MouseAdapter, since it's a abstract class and not an interface (MouseMotionListener is the one you need), it gives empty implementations for all the possible events just to avoid you from being forced to override them all, this also implies that you could miss some of these events if you don't read docs.
If you look carefully at documentation though, you will see that you have
public void mouseDragged(MouseEvent e)
that you can override to listen exactly to what you need.
Related
Seen this somewhere in StackOverflow. Just want to know how it works...
public void mouseClicked(MouseEvent e){
int x = e.getX();
int y = e.getY();
}
x and y are coordinates and can be shown to screen using JLabel, but the method name is mouseClicked. How does java know the mouse has been clicked?
(Hope this makes sense)...
The method mouseClicked is likely from java.awt.event.MouseListener interface (https://docs.oracle.com/javase/7/docs/api/java/awt/event/MouseListener.html)
A listener is a type of callback that follows the observer pattern, something happens, you get notified.
You can attach listener to items that support it. For example:
MouseListener listener = new MouseListener() { /* see example code below */ };
JLabel label = new JLabel("This is a clickable lable");
label.addMouseListener(listener);
See the following answer to get more info and reference to reading articles.
https://stackoverflow.com/a/17415300/132121
#transformer here is an empty implementation of the MouseListener you would create in Java code.
MouseListener listener = new MouseListener() {
#Override
public void mouseClicked(MouseEvent e) {
// This is the method where you would get your callback
// whenever somebody clicked on the view that has this listener
}
#Override
public void mousePressed(MouseEvent e) {
}
#Override
public void mouseReleased(MouseEvent e) {
}
#Override
public void mouseEntered(MouseEvent e) {
}
#Override
public void mouseExited(MouseEvent e) {
}
};
This is an event handler. In order for it to work, it has to be "attached" to something in the front end (most likely a button, but it could be another UI element too).
Exactly how this works depends on which UI framework is being used, but since this is Java I assume it's most likely AWT. You can find more details in tutorials, e.g. here.
Incidentally, how significant the name is depends on which UI framework this is from. In Android, WPF, and ASP.NET, for example, the name of event handlers could theoretically be anything, it's mostly just a matter of convention (not actual requirement) what you call it. (Obviously, you have to be consistent with the name, though). As pointed out in the comments, though, in AWT this name is actually likely significant due to the class that contains it implementing an interface.
I currently am using this code here for my mouse listener:
public void mousePressed(MouseEvent e) {
JLabel labelReference=(JLabel)e.getSource();
if(labelReference.getBackground()==HighLight) {
turn^=true;
if(turn==true){
labelReference.setBackground(Color.blue);
};
if(turn==false){
labelReference.setBackground(Color.red);
};
}
}
This works but i am trying to change /remove that for when adding my Mouse listener to all JLabels:
Pjaser[i][j].addMouseListener(e ->{
});
But seems to give me an error, this seems to work fine when its a addActionListener( e->{
Could someone give me any tips on fixing this
Thanks
So, let's take a look at ActionListener and MouseListener...
public interface ActionListener extends EventListener {
/**
* Invoked when an action occurs.
*/
public void actionPerformed(ActionEvent e);
}
public interface MouseListener extends EventListener {
/**
* Invoked when the mouse button has been clicked (pressed
* and released) on a component.
*/
public void mouseClicked(MouseEvent e);
/**
* Invoked when a mouse button has been pressed on a component.
*/
public void mousePressed(MouseEvent e);
/**
* Invoked when a mouse button has been released on a component.
*/
public void mouseReleased(MouseEvent e);
/**
* Invoked when the mouse enters a component.
*/
public void mouseEntered(MouseEvent e);
/**
* Invoked when the mouse exits a component.
*/
public void mouseExited(MouseEvent e);
}
Okay, so ActionListener has only one possible method, where as MouseListener has 5, so when you do...
Pjaser[i][j].addMouseListener(e ->{
});
Which method is Java suppose to call?
Lucky for you (and the rest of us), the Java developers also felt the same way, they didn't want to have ti implement ALL the methods of MouseListener (or MouseMotionListener or MouseWheelListener), so they provided a "default" implementation of all of them, which basically just creates empty implementations of the methods, MouseAdapter...
Pjaser[i][j].addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
}
});
Okay, it's not "exactly" the same, but it's a darn sight easier to read and manage
In my animation one of elements is moving oval. There are two ways to control it. The first is setting x,y position by mouse listener and the second is Key Listener. During first using animation both methods work. But after using stop (clear) button mouse listener doesn't work, but Key method is still working.
Code stop method:
void clear() {
waves.clear();
xz_list.clear();
yz_list.clear();
time_list.clear();
f_list.clear();
time=0;
timer.stop();
repaint();
}
MouseListener method:
void SourcePosition(double v, String d) {
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
{
x_o = e.getX();
y_o = e.getY();
repaint();
}
}
});
}
Generally this is application showing Doppler Effect. Start button make setting data from interface, disable interface and start animation and chart. Stop button uses clear() method and enable interface.
I've extended a JList to provide two separate functionalities, toolTipText for items, and right-click options. Both work separately, but when I try to use them together, the MouseMoved events aren't being recognized? Below are the guts of my new listener methods. How should I be negotiating these various events?
public class JListTT extends javax.swing.JList {
public JListTT() {
super();
addMouseListener(new ttListener());
...
class ttListener extends MouseAdapter {
public void mouseMoved(MouseEvent e) {
String nodeID = bldItemNodeID();
theList.setToolTipText(nodeID);
}
public void mousePressed(MouseEvent ev) {check(ev); }
public void mouseReleased(MouseEvent ev) {check(ev); }
public void mouseClicked(MouseEvent ev) {check(ev); }
public void check(MouseEvent ev) {
if (ev.isPopupTrigger()) {
theList.setSelectedIndex(theList.locationToIndex(ev.getPoint()));
menu.show(theList, ev.getX(), ev.getY());
}
}
}
You add the ttListener object as a MouseListener, but I don't see you adding the ttListener object as a MouseMotionListener. For example:
ttListener myMouseadapter = new ttListener();
addMouseListener(myMouseadapter);
addMouseMotionListener(myMouseadapter);
I did not test this myself, but looking at the javadoc of JList the tooltip functionality is available out of the box. The javadoc of JList#getTooltipText clearly states
Overrides JComponent's getToolTipText method in order to allow the
renderer's tips to be used if it has text set.
So if your ListCellRenderer returns a Component in the getListCellRendererComponent method which has a tooltip it will be displayed by the JList without the need of a listener.
there's not necessarily a need for a low-level approach as a custom mouse-/motionListener:
as to a per-cell tooltip, see #Robin's answer
as to a context menu, JComonent has a property componentPopupMenu: using that will cope with opening the menu on keyboard short-cut automatically
"not necessarily" because you seem to rely on the cell being selected on right click. If so, you would still need a MouseListener to trigger the selection (after decade long debates, Swing doesn't - which seems to be unusual in current native apps ;-)
You can achieve it by using mouseDragged
YourClass extends JPanel implements MouseListener{
......
#Override
public void mouseDragged(MouseEvent e) {
//code go here
}
}
Should a mouseReleased() event be called when the mouse is released after a mouse is dragged?
I need mouseReleased() to be called to reset some variables used in mouseDragged(), but it never seems to be called.
Check the Oracle tutorial for a simple method to implement both listeners as Paŭlo asks in his comments
Basically (modified from the link above):
//where initialization occurs:
MyListener myListener = new MyListener();
addMouseListener(myListener);
addMouseMotionListener(myListener);
private class MyListener extends MouseInputAdapter {
public void mousePressed(MouseEvent e) {
int x = e.getX();
int y = e.getY();
// you may not need this method
}
public void mouseDragged(MouseEvent e) {
// do your code
}
public void mouseReleased(MouseEvent e) {
// reset your variables
}