view docs/html/guideeventexamples.html @ 3261:72b542f34739

The new, cleaner, version of the atomic operations. The dummy code is what you should start working with to port atomic ops. The linux code appears to be complete and *should* be the base of all Unix and GCC based versions. The macosx and win32 versions are currently just copies of the dummy code. I will begin working on the windows version as soon as this check in is done. I need someone to work on the Mac OS X version. I'm afraid that this check in will break QNX (Sorry!)
author Bob Pendleton <bob@pendleton.com>
date Thu, 17 Sep 2009 20:35:12 +0000
parents 355632dca928
children
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>Event Examples</H1
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>Filtering and Handling Events</H2
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CLASS="PROGRAMLISTING"
>#include &#60;stdio.h&#62;
#include &#60;stdlib.h&#62;

#include "SDL.h"

/* This function may run in a separate event thread */
int FilterEvents(const SDL_Event *event) {
    static int boycott = 1;

    /* This quit event signals the closing of the window */
    if ( (event-&#62;type == SDL_QUIT) &#38;&#38; boycott ) {
        printf("Quit event filtered out -- try again.\n");
        boycott = 0;
        return(0);
    }
    if ( event-&#62;type == SDL_MOUSEMOTION ) {
        printf("Mouse moved to (%d,%d)\n",
                event-&#62;motion.x, event-&#62;motion.y);
        return(0);    /* Drop it, we've handled it */
    }
    return(1);
}

int main(int argc, char *argv[])
{
    SDL_Event event;

    /* Initialize the SDL library (starts the event loop) */
    if ( SDL_Init(SDL_INIT_VIDEO) &#60; 0 ) {
        fprintf(stderr,
                "Couldn't initialize SDL: %s\n", SDL_GetError());
        exit(1);
    }

    /* Clean up on exit, exit on window close and interrupt */
    atexit(SDL_Quit);

    /* Ignore key events */
    SDL_EventState(SDL_KEYDOWN, SDL_IGNORE);
    SDL_EventState(SDL_KEYUP, SDL_IGNORE);

    /* Filter quit and mouse motion events */
    SDL_SetEventFilter(FilterEvents);

    /* The mouse isn't much use unless we have a display for reference */
    if ( SDL_SetVideoMode(640, 480, 8, 0) == NULL ) {
        fprintf(stderr, "Couldn't set 640x480x8 video mode: %s\n",
                        SDL_GetError());
        exit(1);
    }

    /* Loop waiting for ESC+Mouse_Button */
    while ( SDL_WaitEvent(&#38;event) &#62;= 0 ) {
        switch (event.type) {
            case SDL_ACTIVEEVENT: {
                if ( event.active.state &#38; SDL_APPACTIVE ) {
                    if ( event.active.gain ) {
                        printf("App activated\n");
                    } else {
                        printf("App iconified\n");
                    }
                }
            }
            break;
                    
            case SDL_MOUSEBUTTONDOWN: {
                Uint8 *keys;

                keys = SDL_GetKeyState(NULL);
                if ( keys[SDLK_ESCAPE] == SDL_PRESSED ) {
                    printf("Bye bye...\n");
                    exit(0);
                }
                printf("Mouse button pressed\n");
            }
            break;

            case SDL_QUIT: {
                printf("Quit requested, quitting.\n");
                exit(0);
            }
            break;
        }
    }
    /* This should never happen */
    printf("SDL_WaitEvent error: %s\n", SDL_GetError());
    exit(1);
}</PRE
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