26775 2014-09-10 18:21:08 +0000 CSSOM-View extensions to Element and Window break backwards-compatibility 2014-09-12 12:09:27 +0000 1 1 1 Unclassified CSS CSSOM View unspecified All All RESOLVED FIXED P2 normal --- 1 kgilbert zcorpan bzbarsky public-css-bugzilla oldest_to_newest 111358 0 kgilbert 2014-09-10 18:21:08 +0000 Existing web content may fail as it expects the coordinates passed to CSSOM-View functions to treat non-finite numbers (NaN, Infininity, and -Infinity) as 0. WebIDL for these functions defines the x and y coordinates using the "double" data type: http://www.w3.org/TR/cssom-view/#extensions-to-the-window-interface http://www.w3.org/TR/cssom-view/#extensions-to-the-element-interface This affects all functions that accept a double value for coordinates, including: window.scroll window.scrollTo window.scrollBy element.scrollTop; element.scrollLeft I propose that this could be solved by defining the coordinates as "unrestricted double" so that these functions can accept the non-finite values. The function implementations should then coerce any non-finite values to 0. For example, window.scrollTo would be defined as: void scrollTo(unrestricted double x, unrestricted double y, optional ScrollOptions options); 111359 1 bzbarsky 2014-09-10 18:27:12 +0000 Note that this not a theoretical concern. See https://bugzilla.mozilla.org/show_bug.cgi?id=1062406 and https://bugzilla.mozilla.org/show_bug.cgi?id=1064385 for two sites we've already found that are broken by this API change. 111393 2 zcorpan 2014-09-11 17:33:15 +0000 Should I do this across the board? window.moveTo window.moveBy window.resizeTo window.resizeBy window.moveTo document.elementFromPoint document.elementsFromPoint document.caretPositionFromPoint ScrollOptionsHorizontal#x ScrollOptionsVertical#y What about initMouseEvent()? MouseEventInit? (similar for touch events?) 111396 3 bzbarsky 2014-09-11 18:03:08 +0000 > Should I do this across the board? Only for the things that used to take integers, I'd say. Things that have been taking doubles/floats all along are likely web-compatible, since browsers are already shipping those. > What about initMouseEvent()? MouseEventInit? Those take integers in https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#interface-MouseEvent and https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#idl-def-MouseEventInit as far as I can tell. No idea on touch events. 111421 4 zcorpan 2014-09-12 07:45:18 +0000 OK, that makes sense. https://dvcs.w3.org/hg/csswg/rev/0bd322b87db6 CSSOM View defines MouseEvent as double. But I've left that alone for now. 111434 5 bzbarsky 2014-09-12 12:09:27 +0000 > CSSOM View defines MouseEvent as double. Then it likely needs the same change. Also, why are we defining the same thing in multiple specs? :(