gitkrenderer.c

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#define GITK_LIB_C
#define GITK_RENDERER_C

#include "gitkincludes.h"


gboolean gitkrnull_init(guint *argc, gchar ***argv);
void gitkrnull_done(void);
void gitkrnull_dialog_show(GitkDialogPtr dialog);
void gitkrnull_dialog_hide(GitkDialogPtr dialog);
void gitkrnull_event_loop_start(void);
void gitkrnull_event_loop_end(void);


gboolean gitk_renderer_init(guint * const argc, gchar *** const argv, gboolean info_only) {
  gchar *envvar;

  if(!gitk_renderer_activate(argc,argv)) { if(!info_only) { free(gitk_renderer_name);gitk_renderer_name=NULL; } }
  //-- if no (valid) renderer has been choosen yet, check for env-variable
  if(!gitk_renderer_name && (envvar=getenv("GITK_RENDERER"))!=NULL) { //-- use that renderer
    gitk_renderer_name=strdup(envvar);
    gitk_log1("selected renderer (env) : \"%s\"",gitk_renderer_name);
    if(!gitk_renderer_activate(argc,argv)) { if(!info_only) { free(gitk_renderer_name);gitk_renderer_name=NULL; } }
  }
  //-- if no (valid) renderer has been choosen yet, check if there is a link to 'libgitk-renderer-default.so'
  if(!gitk_renderer_name) {
    gitk_renderer_name=strdup("default");
    gitk_log1("selected renderer (def) : \"%s\"",gitk_renderer_name);
    if(!gitk_renderer_activate(argc,argv)) { if(!info_only) { free(gitk_renderer_name);gitk_renderer_name=NULL; } }
    else {
      char link_target[FILENAME_MAX],plugin_name[FILENAME_MAX];
      char *sptr;
      int res;
  
      gitk_log("checking for symlink");
      (void)snprintf(plugin_name,FILENAME_MAX,LIBDIR""G_DIR_SEPARATOR_S"libgitk-renderer-%s.so",gitk_renderer_name);
      if((res=readlink((const char *)plugin_name,link_target,FILENAME_MAX-1))!=-1) {
        link_target[res]='\0';
        free(gitk_renderer_name);
        gitk_log1("... is symlink to : \"%s\"",link_target);
        sptr=&link_target[17];
        while((*sptr!='.') && (*sptr!='\0')) sptr++;
        *sptr='\0';
        gitk_renderer_name=strdup(&link_target[17]);
        gitk_log1("real renderer name is : \"%s\"",gitk_renderer_name);
      }
      else {
        gitk_log1("... is not symlink : res=%d",res);
      }
    }
  }
  //-- if no (valid) renderer has been choosen yet, check which renderers are installed and
  //-- open one of them, this is for console launchers (the gitkLauncher will pass the correct renderer)
  if(!gitk_renderer_name) {
    gint numplugins=0;
    gchar *envvar,*fn;
    DIR *dirp=opendir(LIBDIR);
    struct dirent *dire;
    guint sl;

    gitk_log("scanning available renderers");
    
    //-- check number of installed plugins
    while((dire=readdir(dirp))!=NULL) {
      fn=dire->d_name;
      sl=strlen(fn);
      //-- if it starts and ends with defined strings
      if((sl>20) && !strncmp(fn,"libgitk-renderer-",17) && !strncmp(&fn[sl-3],".so",3)) {
        //-- renderer_name=fn[18...sl-3];
        gitk_log1("renderer : \"%s\"",fn);
        numplugins++;
      }
    }
    closedir(dirp);
    gitk_log1("%d renderers found",numplugins);
    //-- decide which one (if more then one is available) based on the contents
    //-- of the DISPLAY env-var (unset ? (text or audio) : (graphical))
    if((envvar=getenv("DISPLAY"))) {
      gitk_log1("envvar DISPLAY is : \"%s\"",envvar);
      //-- use a graphical renderer
      // contains(GITKR_INFO_MEDIA_DOMAIN,"image");
    }
    else {
      gitk_log("envvar DISPLAY is not set");
      //-- use a text or speech based renderer
      // contains(GITKR_INFO_MEDIA_DOMAIN,"text");
    }
    if(!gitk_renderer_activate(argc,argv)) { if(!info_only) { free((void *)gitk_renderer_name);gitk_renderer_name=NULL; } }
  }
  return(gitk_renderer_name!=NULL);
}

gboolean gitk_renderer_activate(guint * const argc, gchar *** const argv) {
  gboolean res=FALSE;
  
  g_assert(gitk_renderer==NULL);
  
  //-- try only to activate a renderer, if the renderer_name is not empty
  if(gitk_renderer_name && *gitk_renderer_name) {
    gitk_renderer=g_new0(GitkRenderer,1);
    //-- try only to activate a renderer, if we are not in check mode (renderer-name="dummy")
    if(!strncmp(gitk_renderer_name,"dummy",5)) {
      gitk_log("check mode activated");
      check_mode=TRUE;
      gitk_renderer->gitkr_init=(GitkrInitPtr)gitkrnull_init;
      gitk_renderer->gitkr_done=(GitkrDonePtr)gitkrnull_done;
      gitk_renderer->gitkr_event_loop_start=(GitkrEventLoopStartPtr)gitkrnull_dialog_show;
      gitk_renderer->gitkr_event_loop_end=(GitkrEventLoopEndPtr)gitkrnull_dialog_hide;
      gitk_renderer->gitkr_dialog_show=(GitkrElementsShowPtr)gitkrnull_event_loop_start;
      gitk_renderer->gitkr_dialog_hide=(GitkrElementsHidePtr)gitkrnull_event_loop_end;
      gitk_log("dummy renderer init okay");
      res=TRUE;
    }
    else {
      gchar plugin_name[FILENAME_MAX],*plugin_path;
      // load renderer
      //-- don't need to specify absolute location, dlopen finds everything in LD_LIBRAY_PATH/ld.so.conf
      snprintf(plugin_name,FILENAME_MAX,"libgitk-renderer-%s",gitk_renderer_name);
      //plugin_path=g_module_build_path(LIBDIR,plugin_name);
      //gitk_log1("load renderer from \"%s\"",plugin_path);
      gitk_log1("load renderer from \"%s\"",plugin_name);
      if((gitk_renderer->plugin=g_module_open(plugin_name,G_MODULE_BIND_LAZY))!=NULL) {
        gitk_log("renderer loaded");
        if(g_module_symbol(gitk_renderer->plugin,"gitkr_info"               ,(gpointer *)&gitk_renderer->gitkr_info) &&
           g_module_symbol(gitk_renderer->plugin,"gitkr_init"               ,(gpointer *)&gitk_renderer->gitkr_init) &&
           g_module_symbol(gitk_renderer->plugin,"gitkr_done"               ,(gpointer *)&gitk_renderer->gitkr_done) &&
           g_module_symbol(gitk_renderer->plugin,"gitkr_event_loop_start"   ,(gpointer *)&gitk_renderer->gitkr_event_loop_start) &&
           g_module_symbol(gitk_renderer->plugin,"gitkr_event_loop_end"     ,(gpointer *)&gitk_renderer->gitkr_event_loop_end) &&
           g_module_symbol(gitk_renderer->plugin,"gitkr_event_loop_restart" ,(gpointer *)&gitk_renderer->gitkr_event_loop_restart) &&
           g_module_symbol(gitk_renderer->plugin,"gitkr_dialog_show"        ,(gpointer *)&gitk_renderer->gitkr_dialog_show) &&
           g_module_symbol(gitk_renderer->plugin,"gitkr_dialog_hide"        ,(gpointer *)&gitk_renderer->gitkr_dialog_hide)
          ) {
          gitk_log("functions connected");
#ifdef ENABLE_NLS
          {
            gchar *renderer_package_name;
            //-- definitely do this before gitk_renderer->gitkr_init() !
            renderer_package_name=gitk_renderer->gitkr_info(GITKR_INFO_PACKAGE);
            gitk_log1("renderer package is \"%s\"",renderer_package_name);
            (void)bindtextdomain(renderer_package_name, gitk_renderer->gitkr_info(GITKR_INFO_LOCALEDIR));
            (void)bind_textdomain_codeset(renderer_package_name,"UTF-8");
          }
#endif
          if(gitk_renderer->gitkr_init(argc,argv)) {
            gitk_log("renderer init okay");
            res=TRUE;
          }
        }
        else gitk_err2("can't connect functions in renderer \"%s\": %s",gitk_renderer_name,g_module_error());
      }
      else gitk_log2("can't open renderer \"%s\": %s",gitk_renderer_name,g_module_error());
      g_free(plugin_path);
    }
  }
  else gitk_log("empty renderer name supplied");
  if(!res) gitk_renderer_done();
  return(res);
}

void gitk_renderer_done(void) {
  if(gitk_renderer) {
    if(gitk_renderer->plugin) {
      if(gitk_renderer->gitkr_done) gitk_renderer->gitkr_done();
      // This make the gtk+ renderer crash on programm exit
      // It not seems to be due to gtk+/gtk/gtkmain.c:
      //   gdk_event_handler_set ((GdkEventFunc)gtk_main_do_event, NULL, NULL);
      // but because of gtk+/gtk/gtkmain.c:
      //   g_atexit (gtk_exit_func);
      // which is triggered, when exiting the program. If already tried to reset
      // those handlers in gitk_renderer->gitkr_done();
      //
      g_module_close(gitk_renderer->plugin);
    }
    g_free(gitk_renderer);
    gitk_renderer=NULL;
  } 
}


/* dummy renderer (for make check) */

gboolean gitkrnull_init(guint *argc, gchar ***argv) {
  return(TRUE);
}

void gitkrnull_done(void) {
}

void gitkrnull_dialog_show(GitkDialogPtr dialog) {
}

void gitkrnull_dialog_hide(GitkDialogPtr dialog) {
}

void gitkrnull_event_loop_start(void) {
}

void gitkrnull_event_loop_end(void) {
}

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