# ComboBox (Vala)

Tiffany Antopolski
tiffany.antopolski@gmail.com 2013
Ένα γραφικό συστατικό χρησιμοποιείται για επιλογή από μια λίστα στοιχείων
Δημήτρης Σπίγγος
dmtrs32@gmail.com 2012, 2013

# ComboBox (δύο στήλες)

Αυτό το ComboBox τυπώνει στον τερματικό την επιλογή σας όταν την αλλάζετε.

# Ο χρησιμοποιούμενος κώδικας για παραγωγή αυτού παραδείγματος

class MyWindow : Gtk.ApplicationWindow {

string[] file = {"Select", "New", "Open", "Save"}· string[] stock_item = {"","gtk-new", "gtk-open", "gtk-save"}·

enum Column { FILE, STOCK_ITEM }

/* 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 (2, typeof (string), typeof (string))·

for (int i = 0· i < file.length· i++){ Gtk.TreeIter iter· liststore.append (out iter)· liststore.set (iter, Column.FILE, file[i])· liststore.set (iter, Column.STOCK_ITEM, stock_item[i])· }

Gtk.ComboBox combobox = new Gtk.ComboBox.with_model (liststore)·

/* CellRenderers render the data. */ Gtk.CellRendererText cell = new Gtk.CellRendererText ()· Gtk.CellRendererPixbuf cell_pb = new Gtk.CellRendererPixbuf ()·

/* we pack the cell into the beginning of the combobox, allocating * no more space than needed· * first the image, then the text· * note that it does not matter in which order they are in the model, * the visualization is decided by the order of the cellrenderers */ combobox.pack_start (cell_pb, false)· combobox.pack_start (cell, false)·

/* associate a property of the cellrenderer to a column in the model * used by the combobox */ combobox.set_attributes (cell_pb, "stock_id", Column.STOCK_ITEM)· combobox.set_attributes (cell, "text", Column.FILE)·

/* 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 ()· }

void item_changed (Gtk.ComboBox combo) { if (combo.get_active () !=0) { print ("You chose " + file [combo.get_active ()] +"\n")· } } }

class MyApplication : Gtk.Application { protected override void activate () { new MyWindow (this).show ()· } }

int main (string[] args) { return new MyApplication ().run (args)· }

# Αναφορές API

Σε αυτό το παράδειγμα χρησιμοποιήσαμε τα παρακάτω:

GtkComboBox

GtkListStore

GtkCellRendererText

GtkCellRendererPixbuf

Stock Items