995795 - initMouseEvent() and number of parameters (D2E vs D3E spec)

Status: RESOLVED INVALID

(Core :: DOM: Events, defect)

Description

[Arkadiusz Michalski (Spirit)]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0 (Beta/Release)
Build ID: 20140314220517

Steps to reproduce:

In D2E this method define 15 parameters (http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-Event-initMouseEvent) 

D3E introduces one new buttons property (https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#widl-MouseEvent-buttons). Firefox support buttons but not in initMouseEvent method (https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#h4_idl-interface-MouseEvent-initializers). Passing 16 arguments to initMouseEvent() throws error. I don't know if changing this behavior would not be too invasive for the already created code. Maybe detect how many arguments were passed, if 15 use old way, if 16 new way.

Chrome take 16 arguments but in general does not support buttons property (we have undefined). IE support buttons property but not in initMouseEvent(), we can pass more than 15 argumetns and do not get any error.

So, at now only Firefox throw error. Even if this method is mark as deprecated should be implemented correctly.

Comment 1

[Olli Pettay [:smaug][[e-mail]]]

I guess we could add another initMouseEvent method which takes 16 arguments.
But as of now, D3E isn't backwards compatible with D2E.

In which case does Gecko throw if you pass 16 arguments? There can be type error, which is correct.

Comment 2

[Arkadiusz Michalski (Spirit)]

Of course TypeError. Fast test:

<script>

	var mouseEvent1 = document.createEvent("MouseEvent");
	
	mouseEvent1.initMouseEvent("hello", true, true, window,
				   69, 50, 100, 150,
				   200, true, true, true,
				   true, 1, 7, document.documentElement); // remove 7 for Firefox

	document.write(mouseEvent1); // [object MouseEvent]
	document.write("<br>");
	document.write(mouseEvent1.type); // hello
	document.write("<br>");
	document.write(mouseEvent1.bubbles); // true 
	document.write("<br>"); 
	document.write(mouseEvent1.cancelable); // true 
	document.write("<br>"); 
	document.write(mouseEvent1.view); // window 
	document.write("<br>"); 
	document.write(mouseEvent1.detail); // 69 
	document.write("<br>"); 
	document.write(mouseEvent1.screenX); // 50 
	document.write("<br>"); 
	document.write(mouseEvent1.screenY); // 100 
	document.write("<br>"); 
	document.write(mouseEvent1.clientX); // 150 
	document.write("<br>"); 
	document.write(mouseEvent1.clientY); // 200 
	document.write("<br>"); 
	document.write(mouseEvent1.altKey); // true 
	document.write("<br>");
	document.write(mouseEvent1.ctrlKey); // true
	document.write("<br>");
	document.write(mouseEvent1.metaKey); // true
	document.write("<br>");
	document.write(mouseEvent1.shiftKey); // true
	document.write("<br>");
	document.write(mouseEvent1.button); // 1
	document.write("<br>");
	document.write(mouseEvent1.buttons); // 7 (missing in all browser)
	document.write("<br>");
	document.write(mouseEvent1.relatedTarget); // [object HTMLHtmlElement]
	document.write("<br>");
	document.write(mouseEvent1.defaultPrevented); // false
	document.write("<br>");
	document.write(mouseEvent1.isTrusted); // false
	document.write("<br>");
	document.write(mouseEvent1.eventPhase); // 0
	document.write("<br>");
	document.write(mouseEvent1.timeStamp); // depends on the browser
	document.write("<br>");
	document.write(mouseEvent1.currentTarget); // null
	document.write("<br>");
	document.write(mouseEvent1.target); // null

</script>

Comment 3

[Arkadiusz Michalski (Spirit)]

Maybe it will better if D3E spec add this new parameter at the end of method, sth like this:

void initMouseEvent (DOMString type, boolean bubbles, boolean cancelable,
		     Window? view, long detail, long screenX,
		     long screenY, long clientX, long clientY,
		     boolean ctrlKey, boolean altKey, boolean shiftKey,
		     boolean metaKey, short button, EventTarget? relatedTarget,
		     unsigned short buttons);

Redundant arguments will never cause an error, and if necessary someday the browser could redefine initMouseEvent(). In this method we have so many arguments that remember their order is very hard, moving buttons at the end should not be a big problem, just more compatibile with D2E.

Comment 4

[Olli Pettay [:smaug][[e-mail]]]

it should be [optional].

but I think adding another version of initMouseEvent which has buttons as second to last param
is ok per webidl.

Comment 5

[Arkadiusz Michalski (Spirit)]

Ok, I opened a bug for this case (https://www.w3.org/Bugs/Public/show_bug.cgi?id=25346). If anyone are interested please share your comments/ideas.

Comment 6

[Arkadiusz Michalski (Spirit)]

D3E spec delete buttons parameter in initMouseEvent(), so nothing need change. If there are no objections you can close this bug.