[wx-dev] [wxMac] Transparency for individual wxWindows added

[Alex Bligh]

--On 10 August 2006 23:26 -0700 Stefan Csomor <csomor at advancedconcepts.ch> 
wrote:

> I've read your replies, what I have implemented is the exactely same
> concept that we have introduced for tlw. You pass in an alpha value with
> which the entire control is painted (ie not just the background). So I
> don't see the difference in the concept. 

I think one distinction here (which is a bit more subtle) is what happens
if you set the transparency of a TLW that contains controls. Imagine
we moved the interface up. On gtk, transparency can only be set for
TLWs. Each of the contained controls would report themselves (presumably)
as opaque. The overall transparency of the TLW (including window furniture
I think) is then done as at compositor stage.

Now, I don't know what happens on the Mac here. If I set a TLW to be 50%
transparent, but the controls within it (as above) to be opaque, do they
appear opaque? Or is their transparency value a composite of the their own
value and their parents? If the former, then we should make GetTransparency
(which we, um, don't have yet) return the transparency of their TLW on GTK
in order to simulate the same behaviour. If the latter, we should make it
return "opaque" on GTK non-TLWs.

Also Does a transparency setting affect window furniture, etc.?

I don't have a problem with moving the functions up to wxWindow (heh
it's only VFT space) given we already have "CanSetTransparency". But
my concern is that they should do the same thing on all platforms
as far as possible.

Alex