Setting the displayState property of the Stage to StageDisplayState.FULL_SCREEN_INTERACTIVE puts the window in full-screen mode, and keyboard input is permitted in this mode. (In SWF content running in a browser, keyboard input is not permitted). To exit full-screen mode, the user presses the Escape key.

For example, the following Flex code defines a simple AIR application that sets up a simple full-screen terminal:

<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" 
    layout="vertical" 
    applicationComplete="init()" backgroundColor="0x003030" focusRect="false">
    <mx:Script>
        <![CDATA[
            private function init():void 
            {
                stage.displayState = StageDisplayState.FULL_SCREEN_INTERACTIVE;
                focusManager.setFocus(terminal);
                terminal.text = "Welcome to the dumb terminal app. Press the ESC key to exit..\n";
                terminal.selectionBeginIndex = terminal.text.length;
                terminal.selectionEndIndex = terminal.text.length;
            }
        ]]>
    </mx:Script>
    <mx:TextArea 
        id="terminal" 
        height="100%" width="100%" 
        scroll="false"
        backgroundColor="0x003030" 
        color="0xCCFF00" 
        fontFamily="Lucida Console" 
        fontSize="44"/>
</mx:WindowedApplication>