Introduction
A dialog box is used to create a pop-up window of some kind. Usually, they are used for simple tasks such as displaying a message to the user or prompting for a simple input. In this example, we have a GtkButton widget in the main window that, when pressed, creates a dialog box. This dialog box displays a simple message and has a button that closes the dialog box when pressed.
Source Code
/*
*File name: dialog.c
*/
#include <gtk/gtk.h>
#include <glib.h>
/*-- This function allows the program to exit properly when the window is closed --*/
gint destroyapp (GtkWidget *widget, gpointer gdata)
{
g_print ("Quitting...\n");
gtk_main_quit();
return (FALSE);
}
/*-- This function responds to the mouse click on the button --*/
void button_clicked(GtkWidget *widget, gpointer gdata)
{
GtkWidget *dialog, *label, *okay_button;
/* Create the widgets */
dialog = gtk_dialog_new();
label = gtk_label_new ("This is a dialog box");
okay_button = gtk_button_new_with_label("Okay");
/* Ensure that the dialog box is destroyed when the user clicks ok. */
gtk_signal_connect_object(GTK_OBJECT (okay_button), "clicked", gtk_widget_destroy, GTK_OBJECT(dialog));
gtk_container_add (GTK_CONTAINER (GTK_DIALOG(dialog)->action_area), okay_button);
/* Add the label, and show everything we've added to the dialog. */
gtk_container_add (GTK_CONTAINER (GTK_DIALOG(dialog)->vbox), label);
gtk_widget_show_all (dialog);
g_print("Button was clicked.\n");
}
int main (int argc, char *argv[])
{
/*-- Declare the GTK Widgets used in the program --*/
GtkWidget *window;
GtkWidget *button;
/*-- Initialize GTK --*/
gtk_init (&argc, &argv);
/*-- Create the new window --*/
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
/*-- Create a button --*/
button = gtk_button_new_with_label("Click Me");
/*-- Connect the window to the destroyapp function --*/
gtk_signal_connect(GTK_OBJECT(window), "delete_event", GTK_SIGNAL_FUNC(destroyapp), NULL);
/*-- Connect the button to the button_was_clicked function --*/
gtk_signal_connect(GTK_OBJECT(button), "clicked", GTK_SIGNAL_FUNC(button_clicked), NULL);
/*-- Add the button to the window --*/
gtk_container_add(GTK_CONTAINER (window), button);
/*-- Add a border to the window to give the button a little room --*/
gtk_container_border_width (GTK_CONTAINER (window), 15);
/*-- Display the widgets --*/
gtk_widget_show(button);
gtk_widget_show(window);
/*-- Start the GTK event loop --*/
gtk_main();
/*-- Return 0 if exit is successful --*/
return 0;
}
Compile the Source Code
gcc -Wall -g dialog.c -o dialog `gtk-config –cflags` `gtk-config –libs`
Execute the Program
./dialog
