Label#

Labels are the main method of placing non-editable text in windows, for instance to place a title next to a Gtk.Entry widget. You can specify the text in the constructor, or later with the Gtk.Label.props.label property.

The width of the label will be adjusted automatically. You can produce multi-line labels by putting line breaks (\n) in the label string.

Labels can be made selectable with Gtk.Label.props.selectable. Selectable labels allow the user to copy the label contents to the clipboard. Only labels that contain useful-to-copy information — such as error messages — should be made selectable.

The label text can be justified using the Gtk.Label.props.justify prop. The widget is also capable of word-wrapping, which can be activated with Gtk.Label.props.wrap. You can configure this wrapping by changing Gtk.Label.props.wrap_mode, in can be Pango.WrapMode.WORD, Pango.WrapMode.CHAR or Pango.WrapMode.WORD_CHAR.

Gtk.Label support some simple formatting, for instance allowing you to make some text bold, colored, or larger. You can do this by enabling markup setting Gtk.Label.props.use_markup to True, then you can use markup with Gtk.Label.props.label using the Pango Markup syntax [1]. For instance, <b>bold text</b> and <s>strikethrough text</s>. In addition, Gtk.Label supports clickable hyperlinks. The markup for links is borrowed from HTML, using the a with href and title attributes. GTK renders links similar to the way they appear in web browsers, with colored, underlined text. The title attribute is displayed as a tooltip on the link. Gtk.Label.set_markup() method can be used to set the text and enable markup at the same time.

label.set_markup("Go to <a href=\"https://www.gtk.org\" "
                 "title=\"Our website\">GTK+ website</a> for more")

Labels may contain mnemonics. Mnemonics are underlined characters in the label, used for keyboard navigation. Mnemonics are created by providing a string with an underscore before the mnemonic character, such as “_File”, to the functions Gtk.Label.new_with_mnemonic() or Gtk.Label.set_text_with_mnemonic(). Mnemonics automatically activate any activatable widget the label is inside, such as a Gtk.Button; if the label is not inside the mnemonic’s target widget, you have to tell the label about the target using Gtk.Label.props.mnemonic_widget.

You can also change the alignment of the label text inside its size allocation. For example if you use Gtk.Widget.props.hexpand in a label, the label may take more space than its inner text. You can change this alignment using Gtk.Label.props.xalign for horizontal alignment and Gtk.Label.props.yalign for vertical.

Example#

import gi

gi.require_version('Gtk', '4.0')
from gi.repository import Gtk


class LabelWindow(Gtk.ApplicationWindow):
    def __init__(self, **kargs):
        super().__init__(**kargs, title='Label Demo')

        box = Gtk.Box(spacing=10)
        self.set_child(box)

        box_left = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, spacing=10)
        box_left.props.hexpand = True
        box_left.props.homogeneous = True
        box_right = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, spacing=10)

        box.append(box_left)
        box.append(box_right)

        label = Gtk.Label(label='This is a normal label')
        box_left.append(label)

        label = Gtk.Label(label='This is a normal label with xalign set to 0')
        label.props.xalign = 0
        box_left.append(label)

        label = Gtk.Label()
        label.props.label = (
            'This is a left-justified label.\nWith multiple lines.'
        )
        label.props.justify = Gtk.Justification.LEFT
        box_left.append(label)

        label = Gtk.Label(
            label='This is a right-justified label.\nWith multiple lines.'
        )
        label.props.justify = Gtk.Justification.RIGHT
        box_left.append(label)

        label = Gtk.Label(
            label='This is an example of a line-wrapped label.  It '
            'should not be taking up the entire             '
            'width allocated to it, but automatically '
            'wraps the words to fit.\n'
            '     It supports multiple paragraphs correctly, '
            'and  correctly   adds '
            'many          extra  spaces. '
        )
        label.props.wrap = True
        label.props.max_width_chars = 32
        box_right.append(label)

        label = Gtk.Label(
            label='This is an example of a line-wrapped, filled label. '
            'It should be taking '
            'up the entire              width allocated to it.  '
            'Here is a sentence to prove '
            'my point.  Here is another sentence. '
            'Here comes the sun, do de do de do.\n'
            '    This is a new paragraph.\n'
            '    This is another newer, longer, better '
            'paragraph.  It is coming to an end, '
            'unfortunately.'
        )
        label.props.wrap = True
        label.props.justify = Gtk.Justification.FILL
        label.props.max_width_chars = 32
        box_right.append(label)

        label = Gtk.Label()
        label.set_markup(
            'Text can be <small>small</small>, <big>big</big>, '
            '<b>bold</b>, <i>italic</i> and even point to '
            'somewhere in the <a href="https://www.gtk.org" '
            'title="Click to find out more">internets</a>.'
        )
        label.props.wrap = True
        label.props.max_width_chars = 48
        box_left.append(label)

        label = Gtk.Label.new_with_mnemonic(
            '_Press Alt + P to select button to the right'
        )
        box_left.append(label)
        label.props.selectable = True

        button = Gtk.Button(label='Click at your own risk')
        label.props.mnemonic_widget = button
        box_right.append(button)


def on_activate(app):
    win = LabelWindow(application=app)
    win.present()


app = Gtk.Application(application_id='com.example.App')
app.connect('activate', on_activate)

app.run(None)