Full-screen mode security

Flash Player 9.0.27.0 and later support full-screen mode, in which content running in Flash Player can fill the entire screen. To enter full-screen mode, the displayState property of the Stage is set to the StageDisplayState.FULL_SCREEN constant. For more information, see Working with full-screen mode.

For SWF files running in a remote sandbox, there are some security considerations.

To enable full-screen mode, in the <object> and <embed> tags in the HTML page that contains a reference to the SWF file, add the allowFullScreen parameter, with its value set to "true" (the default value is "false"), as shown in the following example:

<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000"
    codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,18,0"
    width="600" height="400" id="test" align="middle">
    <param name="allowFullScreen" value="true" />
    <param name="movie" value="test.swf" />
    <param name="bgcolor" value="#333333" />
    <embed src="test.swf" allowFullScreen="true" bgcolor="#333333"
        width="600" height="400"
        name="test" align="middle" type="application/x-shockwave-flash"
        pluginspage="http://www.macromedia.com/go/getflashplayer" />
</object>

An HTML page may also use a script to generate SWF-embedding tags. You must alter the script so that it inserts the proper allowFullScreen settings. HTML pages generated by Flash Professional and Flash Builder use the AC_FL_RunContent() function to embed references to SWF files, and you need to add the allowFullScreen parameter settings, as in the following:

AC_FL_RunContent( ... "allowFullScreen", "true", ...)

The ActionScript that initiates full-screen mode can be called only in response to a mouse event or keyboard event. If it is called in other situations, Flash Player throws an exception.

A message appears when the content enters full-screen mode, instructing the user how to exit and return to normal mode. The message appears for a few seconds and then fades out.

For content that is running in a browser, keyboard usage is restricted in full-screen mode. In Flash Player 9, only keyboard shortcuts that return the application to normal mode, such as pressing the Escape key, are supported. Users can't enter text in text fields or navigate around the screen. In Flash Player 10 and later, certain non-printing keys (specifically the arrow keys, space, and Tab key) are supported. However, text input is still prohibited.

Full-screen mode is always permitted in the stand-alone player or in a projector file. Also, keyboard usage (including text input) is fully supported in those environments.

Calling the displayState property of a Stage object throws an exception for any caller that is not in the same security sandbox as the Stage owner (the main SWF file). For more information, see Stage security.

Administrators can disable full-screen mode for SWF files running in browsers by setting FullScreenDisable = 1 in the mms.cfg file. For details, see Administrator controls.

In a browser, a SWF file must be contained in an HTML page to allow full-screen mode.