<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" xmlns:its="http://www.w3.org/2005/11/its" xmlns:xi="http://www.w3.org/2001/XInclude" type="guide" style="task" id="combobox_multicolumn.py" xml:lang="de">
<info>
<title type="text">ComboBox (Python)</title>
<link type="guide" xref="beginner.py#menu-combo-toolbar"/>
<link type="next" xref="treeview_advanced_liststore.py"/>
<revision version="0.1" date="2012-06-03" status="draft"/>
<credit type="author copyright">
<name>Marta Maria Casetti</name>
<email its:translate="no">mmcasetti@gmail.com</email>
<years>2012</years>
</credit>
<desc>A widget used to choose from a list of items</desc>
<mal:credit xmlns:mal="http://projectmallard.org/1.0/" type="translator copyright">
<mal:name>Mario Blättermann</mal:name>
<mal:email>mario.blaettermann@gmail.com</mal:email>
<mal:years>2011, 2013</mal:years>
</mal:credit>
</info>
<title>ComboBox (zweispaltig)</title>
<media type="image" mime="image/png" src="media/combobox_multicolumn.png"/>
<p>This ComboBox prints to the terminal your selection when you change it.</p>
<links type="section"/>
<section id="code">
<title>Code used to generate this example</title>
<code mime="text/x-python" style="numbered">from gi.repository import Gtk
import sys
actions = [["Select", None],
["New", Gtk.STOCK_NEW],
["Open", Gtk.STOCK_OPEN],
["Save", Gtk.STOCK_SAVE]]
class MyWindow(Gtk.ApplicationWindow):
def __init__(self, app):
Gtk.Window.__init__(self, title="Welcome to GNOME", application=app)
self.set_default_size(200, -1)
self.set_border_width(10)
# the data in the model, of type string on two columns
listmodel = Gtk.ListStore(str, str)
# append the data
for i in range(len(actions)):
listmodel.append(actions[i])
# a combobox to see the data stored in the model
combobox = Gtk.ComboBox(model=listmodel)
# cellrenderers to render the data
renderer_pixbuf = Gtk.CellRendererPixbuf()
renderer_text = Gtk.CellRendererText()
# 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(renderer_pixbuf, False)
combobox.pack_start(renderer_text, False)
# associate a property of the cellrenderer to a column in the model
# used by the combobox
combobox.add_attribute(renderer_text, "text", 0)
combobox.add_attribute(renderer_pixbuf, "stock_id", 1)
# the first row is the active one at the beginning
combobox.set_active(0)
# connect the signal emitted when a row is selected to the callback
# function
combobox.connect("changed", self.on_changed)
# add the combobox to the window
self.add(combobox)
def on_changed(self, combo):
# if the row selected is not the first one, write on the terminal
# the value of the first column in the model
if combo.get_active() != 0:
print("You chose " + str(actions[combo.get_active()][0]) + "\n")
return True
class MyApplication(Gtk.Application):
def __init__(self):
Gtk.Application.__init__(self)
def do_activate(self):
win = MyWindow(self)
win.show_all()
def do_startup(self):
Gtk.Application.do_startup(self)
app = MyApplication()
exit_status = app.run(sys.argv)
sys.exit(exit_status)
</code>
</section>
<section id="methods">
<title>Useful methods for a ComboBox widget</title>
<p>The ComboBox widget is designed around a <em>Model/View/Controller</em> design: the <em>Model</em> stores the data; the <em>View</em> gets change notifications and displays the content of the model; the <em>Controller</em>, finally, changes the state of the model and notifies the view of these changes. For more information and for a list of useful methods for ComboBox see <link xref="model-view-controller.py"/>.</p>
<p>In line 45 the <code>"changed"</code> signal is connected to the callback function <code>on_changed()</code> using <code><var>widget</var>.connect(<var>signal</var>, <var>callback function</var>)</code>. See <link xref="signals-callbacks.py"/> for a more detailed explanation.</p>
</section>
<section id="references">
<title>API-Referenzen</title>
<p>In this sample we used the following:</p>
<list>
<item><p><link href="http://developer.gnome.org/gtk3/unstable/GtkComboBox.html">GtkComboBox</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/unstable/GtkListStore.html">GtkListStore</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/unstable/GtkCellRendererText.html">GtkCellRendererText</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/unstable/GtkCellRendererPixbuf.html">GtkCellRendererPixbuf</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/unstable/gtk3-Stock-Items.html">Stock Items</link></p></item>
<item><p><link href="http://git.gnome.org/browse/pygobject/tree/gi/overrides/Gtk.py">pygobject - Python bindings for GObject Introspection</link></p></item>
</list>
</section>
</page>