Created attachment 820589 [details] treeTooltipLocal.xul User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Firefox/24.0 (Beta/Release) Build ID: 20130917102605 Steps to reproduce: Attached are 2 XULs: - treeTooltipGlobal has <treechildren tooltip="id-of-tooltip-here">. Tooltip works for it. This is just for reference. - treeTooltipLocal has <treechildren tooltip="_child"> and that element has a child element <tooltip label="text-here">. That doesn't work. Actual results: When I put a mouse over cells in treeTooltipLocal, I get no tooltip. Expected results: According to https://developer.mozilla.org/en-US/docs/XUL/Attribute/tooltip, when I use tooltip="_child" (as in treeTooltipLocal.xul), it should use the first tooltip child element. It's not doing it.
treechildren doesn't layout or draw its child elements so this is correct. You'll need to point to an element elsewhere.
The behaviour may be correct. However, the documentation is not: https://developer.mozilla.org/en-US/docs/XUL/treechildren#Attributes clearly lists 'tooltip' attribute (even though inherited from XUL). That page doesn't mention anything about treechildren not laying out/drawing its child elements. That page links to https://developer.mozilla.org/en-US/docs/XUL/Attribute/tooltip, which doesn't mention this special treechildren-specific behaviour, either. The documentation doesn't clearly describe the behaviour. There may be docs on this somewhere else, but that doesn't matter; the above docs are misleading (for treechildren). I'm requesting the docs to be changed. Putting this back to UNCONFIRMED.
Also, tooltip="_child" doesn't work for <treeitem> or <treecell>. You need to fix their documentation, too. See attached treeItemOrRowTooltip.xul.
Implementation of <tree>, <treeitem>, <treecell> etc. seems to be a can of worms. According to https://developer.mozilla.org/en-US/docs/XUL/treecell and similar respective pages, they're supposed to have 'className' property, inherited from XUL, which operates on 'class' attribute. However, setting 'className' property has no visual effect.
No, everything inside a treechildren element is not drawn directly. The children inside it only serve as a shorthand placeholders for the data to be placed in the tree for those simple cases where you don't want to implement a tree view. This is all documented at https://developer.mozilla.org/en/XUL_Tutorial/Trees