[Lazarus] "Defeating" a screen saver
list2010 at BrenemanLabs.com
Fri Sep 28 14:55:38 CEST 2012
Mark Morgan Lloyd wrote:
> Mark Morgan Lloyd wrote:
>> Mark Morgan Lloyd wrote:
>>> Graeme Geldenhuys wrote:
>>>> On 2012-09-25 17:57, Mark Morgan Lloyd wrote:
>>>>> suggestion of looking at the VLC sources I see they use it which
>>>>> has to
>>>>> be a recommendation.
>>>> Interesting... I was wondering what they did. :)
>>>>> I'll see what I can work in, but particularly allowing that
>>>>> xdg-screensaver can take several seconds to run it's more suited to
>>>>> being run at the start and end of a program session than "on the fly"
>> Needs a window ID. I think I can get that from a shell variable if
>> there's a shell, but not if started directly from the desktop: anybody
>> got any thoughts?
> Health warning:
> suggests following a handle in TForm to arrive at a window ID, but that
> appears to depend on the combination of widget set and window manager:
> as a particular example, it's unreliable with gtk2 on top of KDE.
> Without delving into the raw X API, the only reliable way of doing this
> appears to be to run xwininfo and parse the output. The window ID from
> that is compatible with xdg-screensaver.
Just a little warning that seems related to this topic...
In my Delphi communication programs I used PostMessage *very* much. I
used to pass the main form's handle down into my threads so they could
post to that handle. But a form's handle is not guaranteed to remain
the same. Therefore I now pass a TForm reference down so the handle can
be obtained when needed.
A month ago some of my code that still passed just the handle failed
under Win7. Seems that Win7 was doing something to an *invisible* form
and changing the form's handle so my messages went nowhere. Passing the
TForm reference fixed the bug.
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