How to use and process GTK enter or leave signals

README

Demonstration of a minimal implementation of a button with enter and leave signals.

Requires:

gtk+-2.0

enter_and_leave_signals_demo.c

/*!
 * \file enter_and_leave_signals_demo.c
 *
 * \brief Demonstration of a minimal implementation of a button with enter and
 * leave signals.
 */


#include <gtk/gtk.h>


static gboolean
enter (GtkWidget *ebox, GdkEventCrossing *event)
{
    g_print ("Gotcha!\n");
    return FALSE;
}


static gboolean
leave (GtkWidget *ebox, GdkEventCrossing *event)
{
    g_print ("Oops!\n");
    return FALSE;
}


int
main (int argc, char *argv[])
{
    GtkWidget *window;
    GtkWidget *button;
    /* Initialise gtk. */
    gtk_init (&argc, &argv);
    /* Create a window. */
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    /* Set event masks for notify of signals. */
    gtk_widget_set_events (GTK_WINDOW (window), GDK_ENTER_NOTIFY_MASK);
    gtk_widget_add_events (GTK_WINDOW (window), GDK_LEAVE_NOTIFY_MASK);
    /* Add a quit signal to the window. */
    g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
    /* Create a button with a label. */
    button = gtk_button_new_with_label ("Don't Click Me");
    /* Add the button to the window. */
    gtk_container_add (GTK_CONTAINER (window), button);
    /* Connect signal handlers to the button. */
    g_signal_connect (button, "enter-notify-event", G_CALLBACK (enter), NULL);
    g_signal_connect (button, "leave-notify-event", G_CALLBACK (leave), NULL);
    /* Show all widgets. */
    gtk_widget_show_all (window);
    /* Return to the main loop. */
    gtk_main ();
    /* We are done. */
    return 0;
}

Makefile

CFLAGS = -Wall -g `pkg-config --cflags gtk+-2.0`
LDFLAGS = `pkg-config --libs gtk+-2.0`

enter_and_leave_signals_demo: enter_and_leave_signals_demo.c
	$(CC) -o enter_and_leave_signals_demo enter_and_leave_signals_demo.c $(CFLAGS) $(LDFLAGS)
clean:
	rm -f *~
	rm -f *.o
	rm -f enter_and_leave_signals_demo