Closed Bug 1517067 Opened 5 years ago Closed 5 years ago
Remove "table-caption" special case from dynamic reflow root
747 bytes, text/html
47 bytes, text/x-phabricator-request
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Right now, InitDynamicReflowRoot has a special case with the broad explanation: > // We have a display type where 'width' and 'height' don't actually > // set the width or height (i.e., the size depends on content). ...which includes a check for table-caption frames: > [...] || display == StyleDisplay::TableCaption || https://searchfox.org/mozilla-central/rev/bcc0fe1081dc4f84fc5fdfebe0d2de8c075a4e2c/layout/generic/ReflowInput.cpp#825,828-829 However, from some quick testing, it appears to me that table-caption frames *do* respect their width and height properties (when they are set to fixed values). If you have a caption with e.g. height: 5px; width: 5px; background: red; ...then its orange box is 5px by 5px, even if its content happens to be larger, and even if it happens to be in a table that happens to be larger in one dimension or the other. So I don't think we need this table-caption exemption after all. Or, if we do, I need help figuring out how to trigger the sort of failure that causes us to need this exemption, for the benefit of the automated test that I'm writing in bug 1508420.
dbaron, it looks like the "table-caption" check here dates back to your first patches in bug 1159042 comment 7. (search for "caption" in https://hg.mozilla.org/users/dbaron_mozilla.com/patches/raw-file/22ba869b38a4/set-dynamic-reflow-root ) Do you agree that we can remove this exemption, or is there something I'm not thinking of here?
Note: table-caption does have one kinda-special sizing behavior -- its width (whether specified or content-based) does establish a minimum width for the table itself. However, that's not really that special; the same is true for *any* element that has an intrinsically-sized ancestor; and that doesn't prevent us from making the inner element a dynamic reflow root (if it satisfies all the conditions, e.g. its own size is fixed). Assuming the table caption has a specified pixel-valued size which remains fixed (and that it satisfies all the other dynamic reflow root requirements RE being a fixed-position CB etc.), I believe it's valid for us to label it as a dynamic reflow root and to initiate reflows at the caption itself if the only dirty frames are inside of it.  (s/width/height/ depending on the caption side, of course)
(meant to set ni=dbaron (post-vacation) for comment 1)
Assignee: nobody → dholbert
Status: NEW → ASSIGNED
Pushed by firstname.lastname@example.org: https://hg.mozilla.org/integration/autoland/rev/9969ea8e9a58 Allow table-caption boxes to be dynamic reflow roots. r=dbaron
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