Added some more hooks to the page editing pipeline. It should now be possible to add controls to the page editor, send the data from them out to the server, and process them on the server side.
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>{#advanced_dlg.code_title}</title>
<script type="text/javascript" src="../../tiny_mce_popup.js"></script>
<script type="text/javascript" src="js/source_editor.js"></script>
</head>
<body onresize="resizeInputs();" style="display:none; overflow:hidden;">
<form name="source" onsubmit="saveContent();return false;" action="#">
<div style="float: left" class="title">{#advanced_dlg.code_title}</div>
<div id="wrapline" style="float: right">
<input type="checkbox" name="wraped" id="wraped" onclick="toggleWordWrap(this);" class="wordWrapCode" /><label for="wraped">{#advanced_dlg.code_wordwrap}</label>
</div>
<br style="clear: both" />
<textarea name="htmlSource" id="htmlSource" rows="15" cols="100" style="width: 100%; height: 100%; font-family: 'Courier New',Courier,monospace; font-size: 12px;" dir="ltr" wrap="off" class="mceFocus"></textarea>
<div class="mceActionPanel">
<div style="float: left">
<input type="submit" name="insert" value="{#update}" id="insert" />
</div>
<div style="float: right">
<input type="button" name="cancel" value="{#cancel}" onclick="tinyMCEPopup.close();" id="cancel" />
</div>
</div>
</form>
</body>
</html>