Re: How to use thread???

[Chris Vine <chris cvine freeserve co uk>]

On Sunday 09 April 2006 09:46, sahlot arvind wrote:
> Hello All,
> I tried to create a thread in a simple gtk program but I am getting an
> error....
> Actually wat I wanted to do is that , I want some rectangles to be drawn
> side by side in a plot area but wid a time  gap of 1 second each, so that
> we can see actual simulation of drawing.. first i simply put a sleep()
> function in my code but that didnt wrk rather program run for few seconds
> without drawing anything and then drew all rectangles alltogether.... now i
> am trying to create a thread so that this thread can run in background and
> can print rectangles after 1 sec. each but i am getting an error..... my
> code is below, someone please help me in this regard as soon as possible
> ,its very urgent for my academic project...
>
>
> /**************************CODE*************************************/
>
> #include <gtk/gtk.h>
> #include <glib.h>
>
>
> #define NO_PADDING 0
> #define NO_SPACING 0
> #define width 40
> #define height 40
>
>
>
> char val[20];
>
>
>
>
> char *inttostr(int num)
> {
> int i;
> int j;
> char ch;
> int dig;
> i = 0;
> if(num == 0)
> {
> val[0] = '0';
> val[1] = '\0';
> return val;
> }
> while(num != 0)
> {
> dig = num%10;
> val[i] = dig + '0';
> num = (num - dig)/10;
> i++;
> }
> val[i] = '\0';
> for(j = i - 1, i = 0; i < j; j--, i++)
> {
> ch = val[i];
> val[i] = val[j];
> val[j] = ch;
> }
> return val;
> }
>
>
>
> /* Callbacks */
>
> /**************************************************************************
>/
>
>
> int draw_array( GtkWidget *where_to_draw )
> {
>  gint count_size;
>  gint x = 40,y = 120;
>  GdkGC *array_gc;
>  array_gc = where_to_draw->style->black_gc;
>  gchar *size,*dstype;
>
>  gdk_draw_string(where_to_draw->window,where_to_draw->style->font,
> array_gc,10,20,"ARRAY");
>  gdk_draw_string(where_to_draw->window,where_to_draw->style->font,
> array_gc,10,35,"INTEGER");
>
>  for(count_size=0;count_size<6;count_size++) {
>  gdk_draw_rectangle(where_to_draw->window,array_gc,FALSE,x,y,width,height);
>   //sleep(1);
>  gdk_draw_string(where_to_draw->window,where_to_draw->style->font,
> array_gc,x+width/2,y+60,inttostr(count_size));
>  x+=width;
>  }
>  return ( TRUE );
>  }
>
>
>
> void print_screen(GtkWidget *widget,GtkWidget *where_to_draw )
> {
>   //draw_array(where_to_draw);
>   g_thread_create(draw_array, where_to_draw,FALSE, NULL);
>
> }
>
> /*------------------------------------------------------------------------*
>/ void print_and_quit( GtkButton *was_clicked, gpointer user_data )
> {
>  /* Use glibs printf equivalent to print a message */
>   g_print( "Thank you for using this program.\n");
>   gtk_main_quit();
> }
>
> gboolean delete_event_handler( GtkWidget *widget, GdkEvent *event,
>                               gpointer user_data )
> {
>    /* Received closure from the window manager */
>    g_print("The window manager is asking to close this application\n");
>    return( FALSE );  /* FALSE - do not prevent closure */
> }
>
>
>
>
>
> /******************************************************/
>
>
>
> int main( int argc, char *argv[] )
> {
>  GtkWidget *top_widget;
>  GtkWidget *vbox, *menu_bar, *file_item, *file_menu, *exit_item;
>  GtkWidget *plot_area;
>  GtkWidget *plot_item;
>  GtkWidget *help_item,*array1D;
>
>
>   /* 1. Initialize the environment */
>    gtk_init( &argc, &argv );
>
>  /* 2a. Create widgets */
>    top_widget = gtk_window_new( GTK_WINDOW_TOPLEVEL );
>    vbox = gtk_vbox_new( FALSE, NO_SPACING );
>    menu_bar = gtk_menu_bar_new( );
>
>    /* Create the File item and its menu */
>    file_item = gtk_menu_item_new_with_label( "File" );
>    file_menu = gtk_menu_new();
>    array1D   = gtk_menu_item_new_with_label("Array");
>    exit_item = gtk_menu_item_new_with_label( "Exit" );
>
>   /* Create the Plot item */
>    plot_item = gtk_menu_item_new_with_label( "Plot" );
>
>   /* Create the Help item */
>    help_item = gtk_menu_item_new_with_label( "Help" );
>
>   /* Create the Work Area */
>    plot_area = gtk_drawing_area_new();
>
>  /* 2b. Set Attributes */
>    gtk_window_set_title( GTK_WINDOW( top_widget ), "DSDe" );
>    gtk_drawing_area_size( GTK_DRAWING_AREA(plot_area), 800, 400 );
>
>  /* 3. Registering Callback routines */
>    gtk_signal_connect( GTK_OBJECT( top_widget ), "delete_event",
>                        GTK_SIGNAL_FUNC(delete_event_handler), NULL );
>    gtk_signal_connect( GTK_OBJECT( top_widget ), "destroy",
>                        GTK_SIGNAL_FUNC(print_and_quit), NULL );
>    gtk_signal_connect( GTK_OBJECT( exit_item ), "activate",
>                        print_and_quit, NULL );
>
>    gtk_signal_connect( GTK_OBJECT( array1D ), "activate",
>                        print_screen, plot_area );
>
>  /* 4. Defining the Instance Hierarchy */
>    gtk_container_add( GTK_CONTAINER( top_widget ), vbox );
>    gtk_box_pack_start( GTK_BOX(vbox), menu_bar, FALSE, FALSE, NO_PADDING);
>    gtk_box_pack_start( GTK_BOX(vbox), plot_area, FALSE, FALSE, NO_PADDING
> );
>
>    /* Pack the Menu Bar and move Help to Far Right */
>    gtk_menu_bar_append( GTK_MENU_BAR( menu_bar ), file_item );
>    gtk_menu_bar_append( GTK_MENU_BAR( menu_bar ), plot_item );
>    gtk_menu_bar_append( GTK_MENU_BAR( menu_bar ), help_item );
>    gtk_menu_bar_append( GTK_MENU_BAR( menu_bar ), array1D );
>    gtk_menu_item_right_justify( GTK_MENU_ITEM( help_item ) );
>
>    /* Attach and pack the menus */
>    gtk_menu_item_set_submenu( GTK_MENU_ITEM( file_item ), file_menu );
>    gtk_menu_append( GTK_MENU(file_menu), exit_item );
>
>  /* 5. Showing the Widgets */
>    gtk_widget_show_all( top_widget );
>
>  /* 6. Processing Loop */
>    gtk_main();
>    g_print( "Bye!\n");
>    return 0;
> }
>
> /*******************************************END OF
> CODE*******************************/
>
> command used and error which I am getting while compilation is ..
> [root arvind Desktop]# gcc thread.c -o run `gtk-config --libs --cflags`

pkg-config --libs --cflags gtk+-2.0 gthread-2.0

> /tmp/ccoiba3m.o(.text+0x1f4): In function `print_screen':
> : undefined reference to `g_thread_create'
>
> collect2: ld returned 1 exit status