MouseEvent consumes KeyEvent?!

[k0m0r0w5k1]

Hi. I got stucked on the following:
This is a panel that allows line drawing.
I want the line to be green if Ctrl is pressed down.

public MyPanel extends JPanel implements MouseListener, KeyListener {

boolean ctrl = false;
Point fromPoint, toPoint;

(...)

public void paint(Graphics g) {
if (ctrl) {
g.setColor(Color.green);
} else {
g.setColor(Color.red);
}
g.drawLine(fromPoint.x, fromPoint.y, toPoint.x, toPoint.y);
}

public void mouseMoved(MouseEvent e) {
toPoint = e.getPoint();
repaint();
}

public void keyPressed(KeyEvent e) {
ctrl = true;
repaint();
}

public void keyReleased(KeyEvent e) {
ctrl = false;
repaint();
}
}

And... it doesn't work
It looks like MouseEvent consumes KeyEvent, beacuse keyPressed() is NOT
called here
The listeners are set up correctly.
Changing this to:

public void mouseMoved(MouseEvent e) {
if (e.isControlDown) {
(...)
}
(...)
}

is not a solution, because it will only change the color after mouse
was moved.
And I want it to happen instantly on every key press/release.
What's wrong here?
How to make it work?

Thx a lot in advance,

k0m0r

 

[Vova Reznik]

try to add KeyListener to a JFrame
that contains your MyPanel
or setFocusable true for your MyPanel

 

[Bart Rider]

Hi. I got stucked on the following:
This is a panel that allows line drawing.
I want the line to be green if Ctrl is pressed down.

public MyPanel extends JPanel implements MouseListener, KeyListener {

boolean ctrl = false;
Point fromPoint, toPoint;

(...)

public void paint(Graphics g) {
if (ctrl) {
g.setColor(Color.green);
} else {
g.setColor(Color.red);
}
g.drawLine(fromPoint.x, fromPoint.y, toPoint.x, toPoint.y);
}

public void mouseMoved(MouseEvent e) {
toPoint = e.getPoint();
repaint();
}

public void keyPressed(KeyEvent e) {
ctrl = true;
repaint();
}

public void keyReleased(KeyEvent e) {
ctrl = false;
repaint();
}
}

And... it doesn't work
It looks like MouseEvent consumes KeyEvent, beacuse keyPressed() is NOT
called here
The listeners are set up correctly.
Changing this to:

public void mouseMoved(MouseEvent e) {
if (e.isControlDown) {
(...)
}
(...)
}

is not a solution, because it will only change the color after mouse
was moved.
And I want it to happen instantly on every key press/release.
What's wrong here?
How to make it work?

Thx a lot in advance,

k0m0r

For modifier keys like shift, ctrl, alt the keypressed,
keyreleases events will not be called.
If your mouseMoved method is called, the MouseEvent object
has the info on modifiers pressed, just call
e.getModifiersEx();

Have a look for the masks on the return value:
http://java.sun.com/j2se/1.5.0/docs/api/java/awt/event/InputEvent.html#getModifiersEx()

Best regards
Bart

 

[k0m0r]

For modifier keys like shift, ctrl, alt the keypressed,

keyreleases events will not be called.
If your mouseMoved method is called, the MouseEvent object
has the info on modifiers pressed, just call
e.getModifiersEx();

Yes, I understand that, but it's not solving my problem
I need to cause the reaction when the Shift is pressed, wether or not
the mouse was moved. Any ideas?

Thx,

k0m0r