# ComboBox (Vala)

Tiffany Antopolski
tiffany.antopolski@gmail.com 2012
A widget used to choose from a list of items
Fran Dieguez
frandieguez@gnome.org 2012-2013.

# ComboBox

This ComboBox prints to the terminal when you change your selection.

/* A window in the application */ class MyWindow : Gtk.ApplicationWindow {

/* An instance array of linux distributions belonging to this window. */ string[] distros = {"Select distribution", "Fedora", "Mint", "Suse"};

/* This enum makes the code more readable when we refer to * the column as Column.DISTRO, instead of just 0. */ enum Column { DISTRO }

/* Constructor */ internal MyWindow (MyApplication app) { Object (application: app, title: "Welcome to GNOME");

this.set_default_size (200, -1); this.border_width = 10;

Gtk.ListStore liststore = new Gtk.ListStore (1, typeof (string));

for (int i = 0; i < distros.length; i++){ Gtk.TreeIter iter; liststore.append (out iter); liststore.set (iter, Column.DISTRO, distros[i]); }

Gtk.ComboBox combobox = new Gtk.ComboBox.with_model (liststore); Gtk.CellRendererText cell = new Gtk.CellRendererText (); combobox.pack_start (cell, false);

combobox.set_attributes (cell, "text", Column.DISTRO);

/* Set the first item in the list to be selected (active). */ combobox.set_active (0);

/* Connect the 'changed' signal of the combobox * to the signal handler (aka. callback function). */ combobox.changed.connect (this.item_changed);

/* Add the combobox to this window */ this.add (combobox); combobox.show (); }

/* Signal handler for the 'changed' signal of the combobox. */ void item_changed (Gtk.ComboBox combo) { if (combo.get_active () !=0) { print ("You chose " + distros [combo.get_active ()] +"\n"); } } }

/* This is the application */ class MyApplication : Gtk.Application {

/* Constructor */ internal MyApplication () { Object (application_id: "org.example.MyApplication"); }

/* Override the activate signal of GLib.Application, * which is inherited by Gtk.Application. */ protected override void activate () {

/* Create the window of this application * and show it. */ new MyWindow (this).show (); } }

/* main creates and runs the application */ int main (string[] args) { return new MyApplication ().run (args); }

Neste exemplo empregaremos o seguinte:

Gtk.ListStore

Gtk.ComboBox

Gtk.CellRendererText

set_attributes