I would like to place buttons at different coordinates using GTK4 UI files. For this I use GTKFixed containers. From what I understand, to indicate the position of the buttons, I have to use the keyword “layout”. However, “x” and “y” are not recognized for the coordinates.

<?xml version="1.0" encoding="UTF-8"?>

<interface>
  <requires lib="gtk" version="4.0"/>
  <object class="GtkApplicationWindow" id="main_window">
    <property name="default-width">1050</property>
    <property name="default-height">700</property>
    <property name="resizable">false</property>
    <child>
      <object class="GtkFixed">
        <child>
          <object class="GtkButton">
            <property name="label">button1</property>
            <layout>
              <property name="x">10</property>
              <property name="y">200</property>
            </layout>
          </object>
        </child>
        <child>
          <object class="GtkButton">
            <property name="label">button2</property>
            <layout>
              <property name="x">400</property>
              <property name="y">750</property>
            </layout>
          </object>
        </child>
      </object>
    </child>
  </object>
</interface>

For information, I managed to place a button at the correct coordinates with the following Python code. However, I would like to do everything in the UI XML files.

my_fixed_container.put(button1, 10, 200)

Thank you in advance for your help.