The Button Widget

GTK+ 2.0 Tutorial
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# The Button Widget

# Normal Buttons

We've almost seen all there is to see of the button widget. It's pretty simple. There is however more than one way to create a button. You can use the gtk_button_new_with_label() or gtk_button_new_with_mnemonic() to create a button with a label, use gtk_button_new_from_stock() to create a button containing the image and text from a stock item or use gtk_button_new() to create a blank button. It's then up to you to pack a label or pixmap into this new button. To do this, create a new box, and then pack your objects into this box using the usual gtk_box_pack_start(), and then use gtk_container_add() to pack the box into the button.

Here's an example of using gtk_button_new() to create a button with a image and a label in it. I've broken up the code to create a box from the rest so you can use it in your programs. There are further examples of using images later in the tutorial.

    #include <stdlib.h>
    #include <gtk/gtk.h>

    /* Create a new hbox with an image and a label packed into it
     * and return the box. */

    static GtkWidget *xpm_label_box( gchar     *xpm_filename,
                                     gchar     *label_text )
    {
        GtkWidget *box;
        GtkWidget *label;
        GtkWidget *image;

        /* Create box for image and label */
        box = gtk_hbox_new (FALSE, 0);
        gtk_container_set_border_width (GTK_CONTAINER (box), 2);

        /* Now on to the image stuff */
        image = gtk_image_new_from_file (xpm_filename);

        /* Create a label for the button */
        label = gtk_label_new (label_text);

        /* Pack the image and label into the box */
        gtk_box_pack_start (GTK_BOX (box), image, FALSE, FALSE, 3);
        gtk_box_pack_start (GTK_BOX (box), label, FALSE, FALSE, 3);

        gtk_widget_show (image);
        gtk_widget_show (label);

        return box;
    }

    /* Our usual callback function */
    static void callback( GtkWidget *widget,
                          gpointer   data )
    {
        g_print ("Hello again - %s was pressed\n", (char *) data);
    }

    int main( int   argc,
              char *argv[] )
    {
        /* GtkWidget is the storage type for widgets */
        GtkWidget *window;
        GtkWidget *button;
        GtkWidget *box;

        gtk_init (&argc, &argv);

        /* Create a new window */
        window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

        gtk_window_set_title (GTK_WINDOW (window), "Pixmap'd Buttons!");

        /* It's a good idea to do this for all windows. */
        g_signal_connect (window, "destroy",
    	              G_CALLBACK (gtk_main_quit), NULL);

        g_signal_connect (window, "delete-event",
    	 	      G_CALLBACK (gtk_main_quit), NULL);

        /* Sets the border width of the window. */
        gtk_container_set_border_width (GTK_CONTAINER (window), 10);

        /* Create a new button */
        button = gtk_button_new ();

        /* Connect the "clicked" signal of the button to our callback */
        g_signal_connect (button, "clicked",
    		      G_CALLBACK (callback), (gpointer) "cool button");

        /* This calls our box creating function */
        box = xpm_label_box ("info.xpm", "cool button");

        /* Pack and show all our widgets */
        gtk_widget_show (box);

        gtk_container_add (GTK_CONTAINER (button), box);

        gtk_widget_show (button);

        gtk_container_add (GTK_CONTAINER (window), button);

        gtk_widget_show (window);

        /* Rest in gtk_main and wait for the fun to begin! */
        gtk_main ();

        return 0;
    }

The xpm_label_box() function could be used to pack images and labels into any widget that can be a container.

The Button widget has the following signals:

- `pressed` - emitted when pointer button is pressed within Button widget

- `released` - emitted when pointer button is released within Button widget

- `clicked` - emitted when pointer button is pressed and then released within Button widget

- `enter` - emitted when pointer enters Button widget

- `leave` - emitted when pointer leaves Button widget

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Widgets Without Windows |  | Toggle Buttons