paint.c

linux开发环境下

#include <gtk/gtk.h>

static void destroy( GtkWidget *widget, gpointer data )
{
    gtk_main_quit ();
}

static gboolean
my_expose( GtkWidget      *da,
                  GdkEventExpose *event,
                  gpointer              data )
{
    GdkGC *gc1, *gc2, *gc;
    GdkColor color;

    gc1 = gdk_gc_new( da->window );
    color.red = 30000;
    color.green = 0;
    color.blue = 30000;
    gdk_gc_set_rgb_fg_color(gc1, &color );

    gc2 = gdk_gc_new( da->window );
    color.red = 65535;
    color.green = 0;
    color.blue = 65535;
    gdk_gc_set_rgb_fg_color( gc2, &color );

    gc = gc1;
    gdk_draw_rectangle( da->window,
                                    gc,
                                    TRUE,//fill or not
                                    5, 5, 100, 100 );

    gc = gc2;
    gdk_draw_arc( da->window,
                              gc,
                              FALSE, //don't fill
                              105, 5, 100, 100, 0, 60 * 64 );

    PangoLayout *layout =
        gtk_widget_create_pango_layout( da, "I'm a demon\nfrom hell.\nhahaha." );
    PangoFontDescription *fontdesc =
        pango_font_description_from_string( "Luxi Mono 12" );
    pango_layout_set_font_description( layout, fontdesc );
    gdk_draw_layout( da->window,
                    gc1,
                    5, 105, layout );
    pango_font_description_free( fontdesc );
    g_object_unref( layout );
 
    g_object_unref( G_OBJECT(gc1) );
    g_object_unref( G_OBJECT(gc2) );
 
    return TRUE;
}

int main( int  argc, char *argv[] )
{
    GtkWidget *window;
    GtkWidget *da; //drawing area

    gtk_init (&argc, &argv);
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    g_signal_connect( G_OBJECT (window), "destroy",
                              G_CALLBACK (destroy), NULL );
   
    da = gtk_drawing_area_new ();
    /* set a minimum size */
    gtk_widget_set_size_request( da, 300, 300 );

    gtk_container_add( GTK_CONTAINER(window), da );

    g_signal_connect( da, "expose_event",
                                  G_CALLBACK(my_expose), NULL );

    gtk_widget_show_all( window ); //simply show all widgets
    gtk_main();
   
    return 0;
}