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#include <gtk/gtk.h>
#include <math.h>
GtkAdjustment *adjustment;
int cursor_x, cursor_y;
static void
on_motion_notify (GtkWidget *window,
GdkEventMotion *event)
{
if (event->window == gtk_widget_get_window (window))
{
float processing_ms = gtk_adjustment_get_value (adjustment);
g_usleep (processing_ms * 1000);
cursor_x = event->x;
cursor_y = event->y;
gtk_widget_queue_draw (window);
}
}
static void
on_draw (GtkWidget *window,
cairo_t *cr)
{
cairo_set_source_rgb (cr, 1, 1, 1);
cairo_paint (cr);
cairo_set_source_rgb (cr, 0, 0.5, 0.5);
cairo_arc (cr, cursor_x, cursor_y, 10, 0, 2 * M_PI);
cairo_stroke (cr);
}
int
main (int argc, char **argv)
{
GtkWidget *window;
GtkWidget *vbox;
GtkWidget *label;
GtkWidget *scale;
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_default_size (GTK_WINDOW (window), 300, 300);
gtk_widget_set_app_paintable (window, TRUE);
gtk_widget_add_events (window, GDK_POINTER_MOTION_MASK);
gtk_widget_set_app_paintable (window, TRUE);
vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
gtk_container_add (GTK_CONTAINER (window), vbox);
adjustment = gtk_adjustment_new (20, 0, 200, 1, 10, 0);
scale = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, adjustment);
gtk_box_pack_end (GTK_BOX (vbox), scale, FALSE, FALSE, 0);
label = gtk_label_new ("Event processing time (ms):");
gtk_widget_set_halign (label, GTK_ALIGN_CENTER);
gtk_box_pack_end (GTK_BOX (vbox), label, FALSE, FALSE, 0);
g_signal_connect (window, "motion-notify-event",
G_CALLBACK (on_motion_notify), NULL);
g_signal_connect (window, "draw",
G_CALLBACK (on_draw), NULL);
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_main_quit), NULL);
gtk_widget_show_all (window);
gtk_main ();
return 0;
}
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