Line height calculation based on the font size is not right for wxGTK3
because native buttons (used as in-line editor buttons) don't scale down
well and they are not displayed properly within the line.
Minimal button size when the label is displayed properly is 35 so this
has to be minimal line height under wxGTK3.
Closes#18715.
For the sake of consistency with editor buttons created with
wxPropertyGrid::GenerateEditorButton(), the borders around the buttons
should be taken into account while positioning the buttons
in wxPGMultiButton.
Check that creating a wxTextCtrl doesn't generate any events to verify
that this problem doesn't exist in other ports, after fixing it in
wxGTK in 3e7e7dd24c (Avoid generating wxEVT_TEXT when wxTextCtrl initial
value is not empty, 2020-04-01).
Because the size of the text (usually) shown in the grid changes, the
size of its columns/rows should change as well when DPI changes. Scale
them by the DPI ratio if necessary, i.e. if any of them were set to
non-default values to achieve this.
Note that this is not ideal because it can result in rounding errors and
hence in slight change of row/column size when moving the grid window to
another display with a different DPI and then back, but to prevent this
from happening we'd need to store the column/rows sizes in DIPs inside
wxGrid and convert them to actual physical pixels everywhere, which
would require much more changes. Still, if the round trip problems turn
out to be a real problem in practice, we probably will need to do this.
Also note that this doesn't take care of the grid with a native header,
but this will be addressed by upcoming commits.
This handler redoes wxGrid layout and refreshes it to at least avoid
ugly display artifacts when moving wxGrid window between displays with
different DPI.
Since the changes in a40acbb28e (Add CanOverflow function to
wxGridCellAttr, 2020-02-06), cells with non-default vertical alignment
didn't overflow any more, even if their horizontal alignment was
unchanged and still defaulted to left-aligned.
This was due to assuming that if the alignment of wxGridCellAttr itself
was different from wxALIGN_LEFT, it meant that it wasn't left-aligned,
which seems logical but is in fact false, as the alignment can also be
wxALIGN_INVALID, in which case the real alignment is taken from the
default grid attribute.
Fix this by using GetNonDefaultAlignment() to get the alignment value
effectively used and add a unit test, as well as an example in the
sample, showing that this now works correctly.
In particular, this makes default column width better suited for high
DPI displays, as it was too narrow before.
Also mark a couple of obsolete constants as such with a comment.
This makes it possible to use wxObjectDataPtr inside functions returning
raw pointers owned by the caller, such as custom GetAttr() in the grid
sample.
