Table page-break improvements #11291
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Bump tables to the next page if we cannot fit the caption, thead and first cell on the current page. Ideally this should be checking the height of all cells in the first row in the same manner as is done in the table section render but as this is more of a nice to have I've done the minimal amount of work for now. We now only layout section rows once each section has been positioned within the table, and only supply head and foot reservation heights to the appropriate sections. When re-drawing the thead and tfoot only do so if the rect we are painting is explicitly before/after the "original" thead/tfoot rather than simply outside of its boundaries. This prevents issues with re-drawing a redundant head when bumping tables to the next page. Re-work the table section row layout code so that it's a bit more streamlined. Additionally, to cater for cells spanning multiple rows we avoid page breaks in the middle of their content. Note that rows are always bumped to the next page even if their content doesn't fit on a full page so as to avoid daft situtations like having the first 1px on the preceeding page.
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Any issue associated with this one? If not, please create it first. |
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Just to chime in here this looks to have been taken from my branch of qt at https://gitorious.org/~trvrnrth/qt/trvrnrths-qt which I put together to port across repeating table headers and footers to wkhtmltopdf. There is some discussion at https://code.google.com/p/wkhtmltopdf/issues/detail?id=168. This particular commit resolved a few issues I discovered along the way, more or less as described in the commit message. I'm afraid I don't really have any further details to hand, though what I will say is that there are also a few later commits in my repo that would want pulling in too. |
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Has this been pushed to upstream QtWebKit? That'll be the preferred solution. |
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@vovan22 see my question above? |
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@vovan22 Can you clarify your question? |
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@vovan22 There's no known problem yet. It's just a lot of work. |
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@vovan22, we haven't set a date. We'll switch to Qt5 as soon as we're ready. |
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It's better than anything not directly related to this issue is discussed in the mailing-list or in that Qt 5 update issue. |
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In the mean time, I'll put this on |
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As I mentioned earlier, the patch provided here was taken from my branch of qt on gitorious. That's absolutely fine, and it's great to see it being included. It would however be best to base it on the latest head revision as even when this pull request was opened the patch provided was out of date and the later commits resolve some further edge cases (including an issue trying to measure a non-existent cell which causes a segfault). I could open a new pull request with an updated patch if you'd prefer? |
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I've opened #11490 |
Includes the following fixes taken from trvrnrths-qt: - Ensure we have a first cell to measure when checking required table height - Handle page break edge case with exactly fitting last table row In the case where the last table row on a page fitted exactly no extra offset was afforded to the next row. This resulted in no space being left for the painting of the table header on the next page. - Fix segfault when checking heights for pagination if table body does not have a cell at 0,0 See #11291 and #11490.
Bump tables to the next page if we cannot fit the caption, thead
and first cell on the current page. Ideally this should be checking
the height of all cells in the first row in the same manner as is
done in the table section render but as this is more of a nice to
have I've done the minimal amount of work for now.
We now only layout section rows once each section has been positioned
within the table, and only supply head and foot reservation heights
to the appropriate sections.
When re-drawing the thead and tfoot only do so if the rect we are
painting is explicitly before/after the "original" thead/tfoot
rather than simply outside of its boundaries. This prevents issues
with re-drawing a redundant head when bumping tables to the next page.
Re-work the table section row layout code so that it's a bit more
streamlined. Additionally, to cater for cells spanning multiple rows
we avoid page breaks in the middle of their content. Note that rows
are always bumped to the next page even if their content doesn't
fit on a full page so as to avoid daft situtations like having the
first 1px on the preceeding page.