Don't take the value of "mask" parameter of wxImageList constructor too
prescriptively, it predates support for alpha in wxWidgets by many years
and was never meant to actually suppress using it.
Instead, do the best thing we can in all cases, i.e. use alpha if it's
specified and supported and use mask otherwise. But only create the mask
from light grey colour if we have nothing else if "mask" is true in
wxImageList constructor, as this is a potentially destructive action
that must not be performed if the user has explicitly decided to set
this parameter to false.
Incidentally fix handling of alpha with comctl32.dll v5 (which is used
in the absence of any manifest) by converting it to a mask in this case:
this is not ideal, but better than just using black background as it
happened before, and restores pre-3.1.5 behaviour.
Also simplify the generic version which just has to create the default
mask if necessary and doesn't have to do anything at all in all the
other cases.
Note that these changes required relaxing some of the existing unit
tests as wxMSW implementation now can add alpha channel to the bitmaps
that didn't have it -- but this is a more useful behaviour, and so it
makes more sense to adapt the tests to it rather than doing a less
useful thing just to conform to the tests.
This commit is best viewed with git --color-moved
--color-moved-ws=ignore-all-spac options.
Closes#22349.
This reverts commit b6d305e4f2 because
silently discarding images using a different scale factor is simply too
user-unfriendly: this can silently break the existing code, i.e. it can
still compile perfectly and not give any errors during run-time but not
show any images neither.
Also revert most of dc43d15cf7 (Add tests of storing HiDPI images in
generic wxImageList (wxOSX, wxGTK3), 2021-04-05) as these tests don't
pass any longer because the behaviour was intentionally changed.
See #22189.
Replace old functions with the new ones in the library code itself.
Note that wxSTC and wxRichText still use GetScaledXXX(), but they're
different functions that might need to be renamed/dealt with separately.
Sizing the images stored in the list should stick to the convention
adopted in the native wxImageList implemented in wxMSW.
Images stored in the list should have the sizes as it is declared for
the list even if provided bitmaps have different sizes.
In case of discrepancies their dimensions should be adjusted accordingly
(cropped or extended).
If image using bitmap and mask colour is added to nonmasked wxImageList we
need to convert effective mask to alpha channel values prior to adding the
image to the native list to preserve transparency.
Bitmaps stored in the list as a result of replacing existing ones should
conform to the same constraints as bitmaps directly added to the list.
These constraints are applied in the shared GetImageListBitmap() function
called both on adding and replacing the images.
