Re: WinRT keep display on

I think that'll work.  If not, I went ahead and made SDL manage its own
DisplayRequest, via calls to SDL_EnableScreenSaver() and
SDL_DisableScreenSaver() (via https://hg.libsdl.org/SDL/rev/db77073d402d
).  To note, SDL2 will, by default, call SDL_EnableScreenSaver().

-- David L.


On Sat, Aug 27, 2016 at 12:11 PM, hardcoredaniel <[email protected]>
wrote:

> Hi David,
>
> unfortunately that was the only message of the exception, "a function
> being called at an unexpected time".
>
> I have googled a bit and found a suggestion to keep the DisplayRequest
> object that the requestActive() was called on for the corresponding
> requestRelease() call. This code does at least not crash immediately:
>
>
> DisplayRequest ^ request = nullptr;
>
> void SetKeepDisplayOn(int keepOn)
> {
>
>     if (request == nullptr)
>     {
>         request = ref new DisplayRequest();
>         if (keepOn != 0)
>         {
>             request->RequestActive();
>         }
>         else
>         {
>             SDL_Log("Error: Trying to release display although not
> acquired!\n");
>         }
>     }
>     else
>     {
>         if (keepOn == 0)
>         {
>             request->RequestRelease();
>             request = nullptr;
>         }
>         else
>         {
>             SDL_Log("Error: Trying to acquire display although already
> acquired!\n");
>         }
>     }
> }
>
> but I can't say whether this is really correct and without side effects,
> esp. w.r.t. the lifetime of DisplayRequest objects. Can you please take a
> look at this code for obvious defects?
>
> Regards,
>
> Daniel
>
>
>
> ---------- Původní zpráva ----------
> Od: David Ludwig <[email protected]>
> Komu: SDL Development List <[email protected]>
> Datum: 27. 8. 2016 15:29:14
> Předmět: Re: [SDL] WinRT keep display on
>
> I'm not sure why this call isn't working.  SDL's main thread on WinRT is,
> at present, typically the main thread.
>
> Did the exception contain any more info?
>
> I can plan on looking into this when I get a chance, hopefully in within
> the next few weeks, but make no guarantees.
>
> -- David L.
>
>
> On Sat, Aug 27, 2016 at 7:54 AM, hardcoredaniel <[email protected]>
> wrote:
>
> Hi David,
>
> I'm trying to keep the screen programmatically on for some time, but I'm
> not doing it right. This is my simple code:
>
> --------------------------
>
>     using namespace Windows::System::Display;
>
>     DisplayRequest ^ request = ref new DisplayRequest();
>
>     if (keepOn != 0)
>     {
>         request->RequestActive();
>     }
>     else
>     {
>         request->RequestRelease();
>     }
>
> ---------------------------
>
> but there must be sth. fundamentally wrong with it, because when I call
> RequestRelease() I get an exception from WinRT about calling something at
> an unexpected time. I'm calling it from SDL's main thread, which is
> probably not the UI thread.
>
> I saw in your code for the game bar that you are using something called a
> "dispatcher", I suppose this is to run sth. on the UI thread. Do I need to
> do the same for DisplayRequest()? Anything else I have missed?
>
>
> Regards,
>
> Daniel
>
>
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