[Lazarus] Obtaining screen geometry

[Alexander Grau]

Brad Campbell schrieb:
> G'day all,
>
> My application remembers where it was previously by doing a simple 
> save of the current geometry. Top/Left/Width/Height. This appears to 
> have worked well for a while now, but one of the users has just 
> reported he ordinarily uses a dual head setup with my little app on 
> the right hand screen.
>
> Recently after he had unplugged the right hand screen, the app 
> proceeded to put itself there anyway (off the edge of the accessible 
> desktop). Is there an easy way to detect the current screen width, so 
> if I sense my geometry is going to be off the edge I can provide a 
> sane default instead?
>
> This app runs on Win32, GTK2 & Carbon, so I assume the problem will 
> manifest itself on all three, but in this instance it's running on a Mac.
>
> Regards,
> Brad
Hello Brad,

Below is how we center our main form when it is created (FormCreate) - 
you can see from it, how we can ask for the screen width/height - 
hopefully this will work with dual screen setups too!

Regards,
Alexander

  // always keep space around the window for dock panels (OSX/Win7 etc.)
  // this is the desired size (considering the space around the window)
  w:=round(screen.width - 150);
  h:=round(screen.height - 150);

  // this calculates the best size keeping aspect
  CalcResizeKeepAspect(1024, 768, w, h);
  height:=max(600, h);
  width:=max(800, w);