Java System-Wide Keyboard Shortcut

I am the author of JIntellitype and I can tell you for a fact this must be done natively in DLL and called from Java JNI just like JIntellitype does it. This is an OS level hook that is not implemented in the JDK so libraries like JIntellitype and jxGrabKey must be used. As far as I know no one has written one for OSX yet.

JIntellitype is open source on Github, so if you want an idea of how it works just check out the source code

There is not, but in windows you can use this:

jintellitype

Unfortunately there is nothing I'm aware of for Linux and OSX, probably that's why it doesn't come with java out of the box.

If you find for the other platforms post it here please :)

Just for couriosity, what are you doing with that?

I just found https://github.com/kwhat/jnativehook

Seems to be cross platform.

Here's their sample code for listening for key presses:

import org.jnativehook.GlobalScreen;
import org.jnativehook.NativeHookException;
import org.jnativehook.keyboard.NativeKeyEvent;
import org.jnativehook.keyboard.NativeKeyListener;

public class GlobalKeyListenerExample implements NativeKeyListener {
    public void nativeKeyPressed(NativeKeyEvent e) {
        System.out.println("Key Pressed: " + NativeKeyEvent.getKeyText(e.getKeyCode()));

        if (e.getKeyCode() == NativeKeyEvent.VC_ESCAPE) {
            GlobalScreen.unregisterNativeHook();
        }
    }

    public void nativeKeyReleased(NativeKeyEvent e) {
        System.out.println("Key Released: " + NativeKeyEvent.getKeyText(e.getKeyCode()));
    }

    public void nativeKeyTyped(NativeKeyEvent e) {
        System.out.println("Key Typed: " + e.getKeyText(e.getKeyCode()));
    }

    public static void main(String[] args) {
        try {
            GlobalScreen.registerNativeHook();
        }
        catch (NativeHookException ex) {
            System.err.println("There was a problem registering the native hook.");
            System.err.println(ex.getMessage());

            System.exit(1);
        }

        GlobalScreen.addNativeKeyListener(new GlobalKeyListenerExample());
    }
}

Checking for modifiers is based on bit masks (stuff we all should know but always forget :-P):

    boolean isAltPressed = (e.getModifiers() & NativeKeyEvent.ALT_MASK) != 0;
    boolean isShiftPressed = (e.getModifiers() & NativeKeyEvent.SHIFT_MASK) != 0;

This you could combine with KeyCode:

if (e.getKeyCode() == NativeKeyEvent.VK_2 && isShiftPressed && isAltPressed){...}

This is modified example from here

You should also modify the default logging behavior otherwise it will spam the console:

// Get the logger for "org.jnativehook" and set the level to warning.
Logger logger = Logger.getLogger(GlobalScreen.class.getPackage().getName());
logger.setLevel(Level.WARNING);

// Don't forget to disable the parent handlers.
logger.setUseParentHandlers(false);

Code example is from here

UPDATE: I don't know if you can hook events from OUTSIDE the JVM. I think a Swing/AWT component must have focus for this to work.

You'll want to hook in the Java AWT Event Queue to be absolutely sure you can get a global (jvm wide) keypress.

Use

EventQueue ev = Toolkit.getSystemEventQueue();
// MyCustomEventQueue extends EventQueue and processes keyboard events in the dispatch
ev.push(new MyCustomEventQueue());

class MyEventQueue extends EventQueue
{
    protected void dispatchEvent(AWTEvent event)
    {
       // all AWTEvents can be indentified by type, KeyEvent, MouseEvent, etc
       // look for KeyEvents and match against you hotkeys / callbacks
    }
}

I think there may be other ways to accomplish global key presses with action maps. I've actually used the above mether

Java System-Wide Keyboard Shortcut

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