Hi folks, I’m planning to remove nsStackFrame in bug 1576946 [0]. This is part of a larger effort to make the browser stop using XUL layouts and align on more standard CSS layouts such as CSS grid or flexbox instead. The removal is targeted for Firefox 72.
The removal includes these two non web-exposed features: - `display: -moz-stack` and the `-moz-stack-sizing` property - support for XUL absolute positioning attributes (left/top/bottom/right/start/end XUL attributes), that only worked in display: -moz-stack contexts Note that the <stack> element is not going away. It will instead be implemented using a single-area CSS grid, so those usages won’t need to be rewritten. However, if you were planning to use XUL absolute positioning attributes, you’ll need to look into alternatives: - `align-self: start` or `align-self: end` can be used to position the element on the vertical axis if you were using `top="0"` or `bottom="0"` - `justify-self: start` or `justify-self: end` can be used to position the element on the horizontal axis if you were using `start="0"` or `end="0"` - If you were using non-zero values in the attributes and the element is using `display: block;` or a non-XUL block-level display value, you can use CSS absolute positioning instead. - If you were using non-zero values in the attributes with a XUL display value, you can use a combination of `margin` and `justify-self`/`align-self`, see this code change [1] as a reference. Regarding `-moz-stack-sizing`, this property was used to determine whether a certain element would influence the size of its parent. The current usages in mozilla-central were only used for children of <stack> [2] and those usages didn’t seem to change visually with the new CSS grid-based implementation of <stack> which ignores the `-moz-stack-sizing` property, so it made sense to remove it. [0]: https://bugzilla.mozilla.org/show_bug.cgi?id=1576946 [1]: https://i.imgur.com/8hUDUDS.png [2]: https://searchfox.org/mozilla-central/search?q=-moz-stack-sizing&case=false®exp=false&path= Cheers, Tim _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
