How to register a xul window as listener of another?

I have a keylistener that receives a function and calls it when a key is pressed:

function addKeyListener(functionToCall) {
    addKeyEvent("keypress", function() { functionToCall(arguments[0]) }, false);
}

Wha开发者_StackOverflowt can I pass to that function to let my window be a keylistener?

I'm not quite sure what your code snippet is trying to achieve, but if you have a reference to another window, and you want to listen to key events on that window, simply use otherWindow.addEventListener("keypress", eventHandler, false);.

OK, so given your clarification, it looks as if you need to do the following:

1. Locate the focused document in the other window: otherWindow.document.commandDispatcher.focusedWindow.document
2. Create a key event: otherDocument.createEvent('KeyEvents')
3. Initialise the event (type, code, modifiers etc.) from your key event
4. Locate the focused element, if any, in the other window: otherWindow.document.commandDispatcher.focusedElement
5. Dispatch the event to the focused element, or document if no element has focus.