<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="statusbar.py" xml:lang="ca">

  <info>

    <title type="text">Statusbar (Python)</title>

    <link type="guide" xref="beginner.py#display-widgets"/>

    <link type="seealso" xref="signals-callbacks.py"/>

    <link type="next" xref="spinner.py"/>    

    <revision version="0.2" date="2012-06-12" status="draft"/>

    <credit type="author copyright">

      <name>Marta Maria Casetti</name>

      <email its:translate="no">mmcasetti@gmail.com</email>

      <years>2012</years>

    </credit>

    <desc>Report messages of minor importance to the user</desc>

  </info>

  <title>Statusbar</title>

  <media type="image" mime="image/png" src="media/statusbar.png"/>

  
This statusbar tells you if you click the button or if you press any key (and which key).

  <links type="section"/>

  <section id="code">

  <title>Code used to generate this example</title>

  from gi.repository import Gtk

from gi.repository import Gdk

import sys

class MyWindow(Gtk.ApplicationWindow):

    # a window

    def __init__(self, app):

        Gtk.Window.__init__(self, title="StatusBar Example", application=app)

        self.set_default_size(200, 100)

        # a label

        label = Gtk.Label(label="Press any key or ")

        # a button

        button = Gtk.Button(label="click me.")

        # connected to a callback

        button.connect("clicked", self.button_clicked_cb)

        # the statusbar

        self.statusbar = Gtk.Statusbar()

        # its context_id - not shown in the UI but needed to uniquely identify

        # the source of a message

        self.context_id = self.statusbar.get_context_id("example")

        # we push a message onto the statusbar's stack

        self.statusbar.push(

            self.context_id, "Waiting for you to do something...")

        # a grid to attach the widgets

        grid = Gtk.Grid()

        grid.set_column_spacing(5)

        grid.set_column_homogeneous(True)

        grid.set_row_homogeneous(True)

        grid.attach(label, 0, 0, 1, 1)

        grid.attach_next_to(button, label, Gtk.PositionType.RIGHT, 1, 1)

        grid.attach(self.statusbar, 0, 1, 2, 1)

        # add the grid to the window

        self.add(grid)

    # callback function for the button clicked

    # if the button is clicked the event is signaled to the statusbar

    # onto which we push a new status

    def button_clicked_cb(self, button):

        self.statusbar.push(self.context_id, "You clicked the button.")

    # event handler

    def do_key_press_event(self, event):

    # any signal from the keyboard is signaled to the statusbar

    # onto which we push a new status with the symbolic name

    # of the key pressed

        self.statusbar.push(self.context_id, Gdk.keyval_name(event.keyval) +

                            " key was pressed.")

        # stop the signal emission

        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)

  <note>

    Gdk.keyval_name(event.keyval) converts the key value event.keyval into a symbolic name. The names and corresponding key values can be found <link href="http://git.gnome.org/browse/gtk+/tree/gdk/gdkkeysyms.h">here</link>, but for instance GDK_KEY_BackSpace becomes the string "BackSpace".

  
</note>

  </section>

  <section id="methods">

  <title>Useful methods for a Statusbar widget</title>

    
In line 17 the signal "clicked" is connected to the callback function button_clicked_cb() using widget.connect(signal, callback function). See <link xref="signals-callbacks.py"/> for a more detailed explanation.

  <list>

    <item>
pop(context_id) removes the first message in the statusbar stack with the given context_id.
</item>

    <item>
remove_all(context_id) removes all the messages in the statusbar stack with the given context_id.
</item>

    <item>
remove(context_id, message_id) removes the message with the given message_id in the statusbar stack with the given context_id. The message_id is returned by push(context_id, "the message") when pushing the message on the statusbar.
</item>

  </list>

  </section>

  <section id="references">

  <title>API References</title>

  
In this sample we used the following:

  <list>

    <item>
<link href="http://developer.gnome.org/gtk3/unstable/GtkStatusbar.html">GtkStatusbar</link>
</item>

    <item>
<link href="http://developer.gnome.org/gdk/stable/gdk-Keyboard-Handling.html">Gdk - Key Values</link>
</item>

  </list>

  </section>

</page>