Getting mouse position in a transparent window

Question

so I have a transparent window that draws a few lines and hud elements. I'm wondering if there's a way to get the position of the mouse within said window when I hit a hotkey set-up such as, say, ctrl-s or something and save the mouse x and y so I can repaint the frame with the updated variables.

My frame code is this:

JFrame frame = new JFrame();
frame.setUndecorated(true);
frame.add(new AimDriver());
frame.setBackground(new Color(0,0,0,0));
frame.setSize(resolutionX, resolutionY);
frame.setAlwaysOnTop(true);
frame.setVisible(true);

Where aimDriver has all the painting methods. Thanks for any help!

Answer 1

A KeyBinding provides several advantages over an KeyListener. Perhaps the most important advantages is that a KeyBinding does not suffer from issues of focus that can plague a KeyListener (See this question for a detailed explanation.)

The below approach follows the KeyBinding Java Tutorial. First, create an AbstractAction that captures the location of the mouse within the window:

AbstractAction action = new AbstractAction() {

    @Override
    public void actionPerformed(ActionEvent e) {
        Point mLoc = MouseInfo.getPointerInfo().getLocation();
        Rectangle bounds = frame.getBounds();

        // Test to make sure the mouse is inside the window
        if(bounds.contains(mLoc)){
            Point winLoc = bounds.getLocation();
            mouseLoc = new Point(mLoc.x - winLoc.x, mLoc.y - winLoc.y);
        }

    }
};

Note: It's important to test that the window contains the mouse location; if you don't, the mouse location could easily contain a meaningless coordinate (e.g. (-20,199930), what does that even mean?).

Now that you have the desired action, create the appropriate KeyBinding.

// We add binding to the RootPane 
JRootPane rootPane = frame.getRootPane();

//Specify the KeyStroke and give the action a name
KeyStroke KEY = KeyStroke.getKeyStroke("control S");
String actionName = "captureMouseLoc";

//map the keystroke to the actionName
rootPane.getInputMap().put(KEY, actionName);

//map the actionName to the action itself
rootPane.getActionMap().put(actionName, action);