Bug introduced in 7.0 or earlier and persisting through 11.0 or later. Fixed in 13.0.0 or earlier
I have run into another problem with Grid today.
An explicitly specified ItemSize is being ignored:
dot = Graphics[{Pink, Disk[]}, ImageSize -> 40];
tab = {{"Type", "Name", [SpanFromLeft], [SpanFromLeft],
Item[dot, ItemSize -> 2.7],
Item["Esculap",
Alignment ->
Left], [SpanFromLeft], [SpanFromLeft]}, {[SpanFromAbove],
"Dia.", "Spec", [SpanFromLeft], [SpanFromAbove],
Item[8.3 "mm", ItemSize -> {3.5, 2.7}, Alignment -> Right],
Item[11, Alignment -> Right], "6.3"}, {Item[dot, ItemSize -> 2.7],
Item["Flycatcher",
Alignment -> Left], [SpanFromLeft], [SpanFromLeft],
Item[dot, ItemSize -> 2.7],
Item["Apus",
Alignment ->
Left], [SpanFromLeft], [SpanFromLeft]}, {[SpanFromAbove],
Item[6.9 "mm", ItemSize -> {3.5, 2.7}, Alignment -> Right],
Item[17, Alignment -> Right], "9.8", [SpanFromAbove],
Item[7.8 "mm", ItemSize -> {3.5, 2.7}, Alignment -> Right],
Item[8, Alignment -> Right], "6.7"}};
Grid[tab,
Spacings -> {Automatic, {{0, -1.1}}},
Alignment -> {Center, Center},
Dividers -> All
]

Please note Item[8.3 "mm", ItemSize -> {3.5, 2.7}, Alignment -> Right] where a vertical ItemSize is explicitly specified, yet it is ignored in the layout.
If the "Spec" cell is not spanned this does not happen:
tab[[2, 4]] = "X";
Grid[tab,
Spacings -> {Automatic, {{0, -1.1}}},
Alignment -> {Center, Center},
Dividers -> All
]

Is this another bug in
Grid?Is it still present in version 8?
How can I best work around it?






Gridwith spanned cells and I must say I'm finding it an aggravating experience. – Mr.Wizard Oct 21 '12 at 15:24ItemSizeis causing the problem? Would something like "Grid -- nested spanning causing problem" be better? – m_goldberg Oct 21 '12 at 15:58ItemSizeis being ignored. If you leave outItemSizethen the bottom (twin) row looks like the top one. I was trying to keep the title distinct from this one. – Mr.Wizard Oct 21 '12 at 16:04Spacingssetting? I find thatSpacings -> {Automatic, {{0}, -1.3}}gets me a much better layout. You have to cut away a bit of vertical spacing in the last row only, not in all other rows. – Sjoerd C. de Vries Oct 21 '12 at 19:37Spacingscertainly is part of the picture, but my settings are intentional (at least the way I believe them to work) to get a layout that is not too unlike the target here. Yours do not do that. – Mr.Wizard Oct 21 '12 at 20:23