How to get Gtk.DrawingArea to fill Gtk.Grid?

Question

I am trying to draw an array of circles in a Gtk Window. I can draw one in a Gtk.DrawingArea and when the DrawingArea is the only object, it expands to fit the window. However, when I put multiple in a Gtk.Grid, they fail to expand to fill the Grid.

How do I get them to fill the grid?

I reviewed this post which referred to this page, but they did not solve the problem (or I failed to grasp the concept).

I have tried to set the properties expand, hexpand, vexpand, hexpand_set, and vexpand_set to True, and set_halign, and set_valign to Gtk.Align.FILL to no avail

My circles are created via CircleArea.py

from gi.repository import Gtk
import cairo
import math


class CircleArea(Gtk.DrawingArea):
    """Establishes the space for the circle and paints the circle in it"""

    def __init__(self):
        super(CircleArea, self).__init__()
        self.hexpand = True
        self.vexpand = True
        self.set_halign = Gtk.Align.FILL
        self.set_valign = Gtk.Align.FILL
        self.connect('draw', self.on_draw)

    def on_draw(self, widget, cr):
        height = widget.get_allocated_height()
        width = widget.get_allocated_width()
        smaller = width if width < height else height
        cr.set_source_rgb(self.red, self.green, self.blue)
        cr.arc(height / 2, width / 2, smaller * 0.45, 0, 2 * math.pi)
        cr.fill()

And the window itself is in Grid.py

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk
from CircleArea import CircleArea

class CircleWindow(Gtk.Window):

    def __init__(self):
        Gtk.Window.__init__(self, title="Circle Grid")
        self.set_border_width(10)

        self.grid = Gtk.Grid()
        self.circle_area1 = CircleArea()
        self.circle_area2 = CircleArea()
        self.grid.attach(self.circle_area1, 0, 0, 1, 1)
        self.grid.attach(self.circle_area2, 1, 0, 1, 1)
        self.add(self.grid)


win = CircleWindow()
win.connect("destroy", Gtk.main_quit)
win.show_all()
Gtk.main()

I expect the circles to fill the available grid space, but instead they are both of size 1x1.

score 1 · Answer 1 · answered Apr 17 '19 at 20:05

My problem was that set_halign, set_valign, set_hexpand, and set_vexpand are methods and not properties. So in CirleArea.init(), I changed the code to:

def __init__(self):
        super(CircleArea, self).__init__()
        self.set_hexpand(True)
        self.set_vexpand(True)
        self.set_halign(Gtk.Align.FILL)
        self.set_valign(Gtk.Align.FILL)
        self.connect('draw', self.on_draw)

How to get Gtk.DrawingArea to fill Gtk.Grid?

1 Answers1