/* * * Sample Code for Gtk+ Programming in C, 1st Edition, Prentice Hall * * Copyright 2000 - 2002 Syd Logan, All Rights Reserved * * This code is distributed without warranty. You are free to use this * code for any purpose, however, if this code is republished or * redistributed in its original form, as hardcopy or electronically, * then you must include this copyright notice along with the code. * * Questions or comments regarding this code or any bugs it contains can * be directed to the author via e-mail at slogan@cts.com **/#include <gtk/gtk.h> gintHandleExposeEvent (GtkWidget *widget, GdkEventExpose *event){  GtkLayout *layout;   gint i,j;  char buf[128];  gint imin, imax, jmin, jmax;   layout = GTK_LAYOUT (widget);   // compute loop ranges    imin = (layout->xoffset + event->area.x) / 10;  imax = (layout->xoffset + event->area.x + event->area.width + 9) / 10;   jmin = (layout->yoffset + event->area.y) / 10;  jmax = (layout->yoffset + event->area.y + event->area.height + 9) / 10;   // clear the area that was exposed   gdk_window_clear_area (widget->window, event->area.x, event->area.y,    event->area.width, event->area.height);  for (i=imin; i<imax; i++)    for (j=jmin; j<jmax; j++)      if ( (i + j) % 2 == 0 ) // draw every other arc/rectangle on a line        if ( j % 2 == 0 ) // even lines rectangles, others get arcs          gdk_draw_rectangle(layout->bin_window,             widget->style->black_gc, TRUE,             10*i - layout->xoffset,             10*j - layout->yoffset, 10, 10);        else          gdk_draw_arc(layout->bin_window,             widget->style->black_gc, TRUE,             10*i - layout->xoffset,             10*j - layout->yoffset, 10, 10,             0, 360 * 64);  return TRUE;} voidGtkLayoutDialog(){  GtkWidget *dialog_window, *scrolledwindow, *layout;   dialog_window = gtk_window_new(GTK_WINDOW_TOPLEVEL);  gtk_window_position (GTK_WINDOW (dialog_window), GTK_WIN_POS_MOUSE);  gtk_widget_set_usize (dialog_window, 200, 200);   gtk_signal_connect (GTK_OBJECT (dialog_window), "destroy",    GTK_SIGNAL_FUNC(gtk_widget_destroyed), &dialog_window);   gtk_window_set_title (GTK_WINDOW (dialog_window), "GtkLayout Demo");  gtk_container_border_width (GTK_CONTAINER (dialog_window), 0);   scrolledwindow = gtk_scrolled_window_new (NULL, NULL);   gtk_container_add (GTK_CONTAINER (dialog_window), scrolledwindow);   layout = gtk_layout_new (NULL, NULL);  gtk_container_add (GTK_CONTAINER (scrolledwindow), layout);   // set the scrollbar step sizes to 10 pixels    GTK_LAYOUT (layout)->hadjustment->step_increment = 10.0;  GTK_LAYOUT (layout)->vadjustment->step_increment = 10.0;   // solicit expose events on the layout widget   gtk_widget_set_events (layout, GDK_EXPOSURE_MASK);  gtk_signal_connect (GTK_OBJECT (layout), "expose_event",    GTK_SIGNAL_FUNC (HandleExposeEvent), NULL);   gtk_layout_set_size (GTK_LAYOUT (layout), 1600, 128000);   gtk_widget_show_all (dialog_window);} main( argc, argv )int argc;char *argv[];{  gtk_init( &argc, &argv );   GtkLayoutDialog();  gtk_main();}