ウーフー!! http://help.dottoro.com/ljdchxcl.phpで属性が変更されたときにメッセージを表示する方法を見つけました
<body onload="InitListener ();">
....
<script type="text/javascript">
function InitListener () {
var elemToCheck = document.getElementById ("objectelementid");
if (elemToCheck.addEventListener) {
// all browsers except IE before version 9
elemToCheck.addEventListener ('DOMAttrModified', OnAttrModified, false);
// Firefox, Opera, IE
}
if (elemToCheck.attachEvent) {
// Internet Explorer and Opera
elemToCheck.attachEvent ('onpropertychange', OnAttrModified);
// Internet Explorer
}
console.log("events attached");
// Test the event works
elemToCheck.setAttribute("width","333");
console.log("something happened");
}
function OnAttrModified (event) {
var message = "";
if ('attrChange' in event) {
// Firefox, Opera, Internet Explorer from version 9
message += "Something has happened to an attribute of the " +
event.target.tagName + " element.\n";
message += "The value of the " + event.attrName +
" attribute has been changed from "
+ event.prevValue + " to " + event.newValue + ".";
}
if ('propertyName' in event) { // Internet Explorer
message = "The " + event.propertyName + " property of the "
+ event.srcElement.tagName + " element has been changed.";
}
console.log(message);
}
</script>
残念ながら、このテストでは無駄な結果が得られました。幅や高さが指定されていない場合、IE9 はビデオのサイズを自動的に変更するようです...機能に違いない...深い喜び...