<?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="buttonbox.py" xml:lang="pt-BR">
<info>
<title type="text">ButtonBox (Python)</title>
<link type="guide" xref="beginner.py#layout"/>
<link type="seealso" xref="button.py"/>
<link type="next" xref="statusbar.py"/>
<revision version="0.2" date="2012-08-01" status="stub"/>
<credit type="author copyright">
<name>Marta Maria Casetti</name>
<email its:translate="no">mmcasetti@gmail.com</email>
<years>2012</years>
</credit>
<desc>A container for arranging buttons</desc>
<mal:credit xmlns:mal="http://projectmallard.org/1.0/" type="translator copyright">
<mal:name>Rafael Ferreira</mal:name>
<mal:email>rafael.f.f1@gmail.com</mal:email>
<mal:years>2013</mal:years>
</mal:credit>
</info>
<title>ButtonBox</title>
<media type="image" mime="image/png" src="media/buttonbox_calculator.png"/>
<p>A calculator - the buttons are enclosed in horizontal ButtonBoxes.</p>
<links type="section"/>
<section id="code">
<title>Code used to generate this example</title>
<code mime="text/python" style="numbered">from gi.repository import Gtk
import sys
class MyWindow(Gtk.ApplicationWindow):
def __init__(self, app):
Gtk.Window.__init__(self, title="Calculator", application=app)
self.set_default_size(350, 200)
self.set_border_width(10)
# an entry
self.entry = Gtk.Entry()
# with an initial text
self.entry.set_text('0')
# text aligned on the right
self.entry.set_alignment(1)
# the text in the entry cannot be modified writing in it
self.entry.set_can_focus(False)
# a grid
grid = Gtk.Grid()
grid.set_row_spacing(5)
# to attach the entry
grid.attach(self.entry, 0, 0, 1, 1)
# the labels for the buttons
buttons = [7, 8, 9, '/',
4, 5, 6, '*',
1, 2, 3, '-',
'C', 0, '=', '+']
# each row is a ButtonBox, attached to the grid
for i in range(4):
hbox = Gtk.ButtonBox.new(Gtk.Orientation.HORIZONTAL)
hbox.set_spacing(5)
grid.attach(hbox, 0, i + 1, 1, 1)
# each ButtonBox has 4 buttons, connected to the callback function
for j in range(4):
button = Gtk.Button(label=buttons[i * 4 + j])
button.set_can_focus(False)
button.connect("clicked", self.button_clicked)
hbox.add(button)
# some variables for the calculations
self.first_number = 0
self.second_number = 0
self.counter = 0
self.operation = ""
# add the grid to the window
self.add(grid)
# callback function for all the buttons
def button_clicked(self, button):
# for the operations
if button.get_label() == '+':
self.counter += 1
if self.counter > 1:
self.do_operation()
self.entry.set_text('0')
self.operation = "plus"
elif button.get_label() == '-':
self.counter += 1
if self.counter > 1:
self.do_operation()
self.entry.set_text('0')
self.operation = "minus"
elif button.get_label() == '*':
self.counter += 1
if self.counter > 1:
self.do_operation()
self.entry.set_text('0')
self.operation = "multiplication"
elif button.get_label() == '/':
self.counter += 1
if self.counter > 1:
self.do_operation()
self.entry.set_text('0')
self.operation = "division"
# for =
elif button.get_label() == '=':
self.do_operation()
self.entry.set_text(str(self.first_number))
self.counter = 1
# for Cancel
elif button.get_label() == 'C':
self.first_number = 0
self.second_number = 0
self.counter = 0
self.entry.set_text('')
self.operation = ""
# for a digit button
else:
new_digit = int(button.get_label())
if self.entry.get_text() == 'error':
number = 0
else:
number = int(self.entry.get_text())
number = number * 10 + new_digit
if self.counter == 0:
self.first_number = number
else:
self.second_number = number
self.entry.set_text(str(number))
def do_operation(self):
if self.operation == "plus":
self.first_number += self.second_number
elif self.operation == "minus":
self.first_number -= self.second_number
elif self.operation == "multiplication":
self.first_number *= self.second_number
elif self.operation == "division":
try:
self.first_number /= self.second_number
except ZeroDivisionError:
self.first_number = 0
self.second_number = 0
self.counter = 0
self.entry.set_text('error')
self.operation = ""
return
else:
self.first_number = 0
self.second_number = 0
self.counter = 0
self.entry.set_text('error')
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 ButtonBox widget</title>
<list>
<item><p>The layout of the ButtonBox are set with <code>set_layout(layout)</code>, where <code>layout</code> can be <code>Gtk.ButtonBoxStyle.SPREAD</code> (buttons are evenly spread across the box), <code>Gtk.ButtonBoxStyle.EDGE</code> (buttons are placed at the edges of the box), <code>Gtk.ButtonBoxStyle.START</code> (buttons are grouped towards the start of the box), <code>Gtk.ButtonBoxStyle.END</code> (buttons are grouped towards the end of the box), <code>Gtk.ButtonBoxStyle.CENTER</code> (buttons are centered in the box).</p></item>
<item><p><code>set_child_secondary(button, is_secondary)</code> sets whether <code>button</code> should appear in a secondary group of children. A typical use of a secondary child is the help button in a dialog. This group appears after the other children if the style is <code>START</code>, <code>SPREAD</code> or <code>EDGE</code>, and before the other children if the style is <code>END</code>. If the style is <code>START</code> or <code>END</code>, then the secondary children are aligned at the other end of the button box from the main children. For the other styles, they appear immediately next to the main children.</p></item>
<item><p><code>set_child_non_homogeneous(button, is_non_homogeneous)</code> sets whether the child is exempted from homogeneous sizing. Default value is <code>False</code>.</p></item>
<item><p><code>set_spacing(spacing)</code> sets the spacing, in pixels, between the buttons of the box.</p></item>
</list>
</section>
<section id="references">
<title>API References</title>
<p>In this sample we used the following:</p>
<list>
<item><p><link href="http://developer.gnome.org/gtk3/stable/GtkButtonBox.html">GtkButtonBox</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/stable/GtkBox.html">GtkBox</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/stable/GtkButton.html">GtkButton</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/stable/GtkEntry.html">GtkEntry</link></p></item>
<item><p><link href="http://developer.gnome.org/gtk3/stable/GtkGrid.html">GtkGrid</link></p></item>
</list>
</section>
</page>