Sapere via codice se il tasto 'Blocco Maiuscole' è attivo

E' possibile sapere mediante il codice, se il tasto Blocco maiuscole è attivo, utilizzando alcune risorse della libreria SDL.

Per poter utilizzare tali risorse sarà necessario installare nel sistema ed utilizzare nell'applicazione Gambas la libreria dinamica condivisa: "libSDL-1.2.so.0.11.4"

Mostriamo un semplice codice:

Library "libSDL-1.2:0.11.4"

Private Const KMOD_CAPS As Integer = 8192

' int SDL_Init(Uint32 flags)
' Initialize the SDL library.
Private Extern SDL_Init(flags As Integer) As Integer

' SDL_Surface *SDL_SetVideoMode(int width, int height, int bpp, Uint32 flags)
' Set up a video mode with the specified width, height and bits-per-pixel.
Private Extern SDL_SetVideoMode(width As Integer, height As Integer, bitsperpixel As Integer, flags As Integer) As Pointer

' SDL_Keymod SDLCALL SDL_GetModState(void)
' Get the current key modifier state for the keyboard.
Private Extern SDL_GetModState() As Integer

' void SDL_FreeSurface(SDL_Surface* surface)
' Free an RGB surface.
Private Extern SDL_FreeSurface(surface As Pointer)

' void SDL_Quit(void)
' Clean up all initialized subsystems.
Private Extern SDL_Quit()


Public Sub Main()

 Dim i, modifiers As Integer
 Dim sf As Pointer
 
  i = SDL_Init(0)
  If i <> 0 Then Error.Raise("Imposible inicializar la libreria SDL !")
  
  sf = SDL_SetVideoMode(1, 1, 0, 0)
  If IsNull(sf) Then Error.Raise("Imposible configurar una modalidad video !")
  
  modifiers = SDL_GetModState()
 
  If modifiers And KMOD_CAPS Then Print "Tecla Bloq Mayúsculas: activada !"
  
' Va in chiusura:
  SDL_FreeSurface(sf)
  SDL_Quit()
  
End

Riferimenti

• http://www.libsdl.org/docs/html/index.html