(This is the documentation for SDL3, which is under heavy development and the API is changing! SDL2 is the current stable version!)

SDL_WindowsMessageHook

A callback to be used with SDL_SetWindowsMessageHook.

Header File

Syntax

typedef SDL_bool (SDLCALL *SDL_WindowsMessageHook)(void *userdata, MSG *msg);

Function Parameters

userdata	the app-defined pointer provided to SDL_SetWindowsMessageHook.
msg	a pointer to a Win32 event structure to process.

Return Value

Returns SDL_TRUE to let event continue on, SDL_FALSE to drop it.

Remarks

This callback may modify the message, and should return SDL_TRUE if the message should continue to be processed, or SDL_FALSE to prevent further processing.

As this is processing a message directly from the Windows event loop, this callback should do the minimum required work and return quickly.

Thread Safety

This may only be called (by SDL) from the thread handling the Windows event loop.

Version

This datatype is available since SDL 3.0.0.

Code Examples

#if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_GDK)
SDL_bool MyMessageHook(void *userdata, MSG *msg)
{
    // do things with userdata and msg...

    return SDL_TRUE; // let SDL continue processing the message 
}

// ...
SDL_SetWindowsMessageHook(MyMessageHook, NULL);
#endif