Transparency with Qt on Darwin
lazarus / 29-QT

----------------------------------------------------------------------
Ocye · 2012-05-18 09:59

I (strech-)draw an image which transparent color is set to clWhite
along with some other layers on a bitmap. That works for Windows and
Linux (both Gtk2 and Qt) but not with Qt on Darwin. Is it a known bug?
What can I do?

----------------------------------------------------------------------
zeljko · 2012-05-20 16:58

qt version, lazarus version ?

----------------------------------------------------------------------
Ocye · 2012-05-20 18:14

I have no idea how to retrieve the Qt version for Darwin. Perhaps in
this way:
Quote from: otool -L /Library/Frameworks/QtCore.framework/Versions/Cur
rent/QtCore/Library/Frameworks/QtCore.framework/Versions/Current/QtCor
e:
   QtCore.framework/Versions/4/QtCore (compatibility version 4.7.0,
current version 4.7.4)
Quote from: system_profiler SPSoftwareDataTypeSystem Version: Mac OS X
10.6.4 (10F569)
Kernel Version: Darwin 10.3.0
Quote from: Lazarus HelpLazarus 1.1 r37348M FPC 2.6.0 i386-darwin-
carbon

I resolved the problem by using a png instead of bmp. If you want to
test the issue, a simple project is attached to this thread
http://www.lazarus.freepascal.org/index.php/topic,17005.0.html

----------------------------------------------------------------------
zeljko · 2012-05-21 11:40

I've fixed taskbar appereance for dragimagelist in qt and gtk2, but if
it work for png under darwin then fine.

----------------------------------------------------------------------
Ocye · 2012-05-21 15:40

Taskbar entry is okay now but bitmaps don't become transparent. At
least those I load from resource.
To make it clear: If I load a bmp from resource and set a particular
color to be transparent it isn't applied. When the resource contains a
png with transparency it works as expected.
Not a big issue for me. The taskbar thing was much more annoying