Remove widget from Gtk viewport / scrolled window in dynamic GUI

Question

I am building a GUI (Python binding of GTK3) where one Gtk Scrolled Window (from Glade) can contain different treeviews. The program launches with an empty window and the fi

Answer 1

To clear out the scrolled window, do this:

self.scrolled_window.remove(self.scrolled_window.get_child())

Answer 2

After the answer by ptomato I realized that I was adding the TreeViews by using:

  self.scrolled_window.add_with_viewport(some_treeview)

For some reason the scrolled_window.remove() function does not like viewports. Instead one should use:

  self.scrolled_window.add(some_treeview)

It probably makes sense because the documentation states that:

If a widget has native scrolling abilities, such as Gtk.TextView, Gtk.TreeView or Gtk.IconView, it can be added to a Gtk.ScrolledWindow with Gtk.Container.add (). If a widget does not, you must first add the widget to a Gtk.Viewport, then add the viewport to the scrolled window.

(Source: https://lazka.github.io/pgi-docs/Gtk-3.0/classes/Viewport.html)

So because a Gtk.TreeView is already scrollable it should not go into a separate Gtk.Viewport widget.

Working example

I cleaned up the example from above and it is now fully functioning:

Glade file

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.16.1 -->
<interface>
  <requires lib="gtk+" version="3.10"/>
  <object class="GtkWindow" id="window1">
    <property name="can_focus">False</property>
    <property name="default_width">800</property>
    <property name="default_height">600</property>
    <signal name="destroy" handler="on_window1_destroy" swapped="no"/>
    <child>
      <object class="GtkBox" id="box1">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <property name="orientation">vertical</property>
        <child>
          <object class="GtkBox" id="box2">
            <property name="visible">True</property>
            <property name="can_focus">False</property>
            <child>
              <object class="GtkScrolledWindow" id="scrolledwindow1">
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="shadow_type">in</property>
                <child>
                  <placeholder/>
                </child>
              </object>
              <packing>
                <property name="expand">True</property>
                <property name="fill">True</property>
                <property name="position">0</property>
              </packing>
            </child>
            <child>
              <object class="GtkScrolledWindow" id="scrolledwindow2">
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="shadow_type">in</property>
                <child>
                  <placeholder/>
                </child>
              </object>
              <packing>
                <property name="expand">True</property>
                <property name="fill">True</property>
                <property name="position">1</property>
              </packing>
            </child>
          </object>
          <packing>
            <property name="expand">True</property>
            <property name="fill">True</property>
            <property name="position">0</property>
          </packing>
        </child>
        <child>
          <object class="GtkBox" id="box3">
            <property name="visible">True</property>
            <property name="can_focus">False</property>
            <child>
              <object class="GtkButton" id="add_layer">
                <property name="label" translatable="yes">add layer</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">True</property>
                <signal name="clicked" handler="on_add_layer_clicked" swapped="no"/>
              </object>
              <packing>
                <property name="expand">False</property>
                <property name="fill">True</property>
                <property name="position">0</property>
              </packing>
            </child>
            <child>
              <object class="GtkButton" id="add_data">
                <property name="label" translatable="yes">add data</property>
                <property name="name">add_data</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">True</property>
                <signal name="clicked" handler="on_add_data_clicked" swapped="no"/>
              </object>
              <packing>
                <property name="expand">False</property>
                <property name="fill">True</property>
                <property name="position">1</property>
              </packing>
            </child>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">1</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

Python file

#!/usr/bin/python3

from gi.repository import Gtk
import random

class LayerTreeView(Gtk.TreeView):
    def __init__(self, store):
        Gtk.TreeView.__init__(self, store)
        renderer = Gtk.CellRendererText()
        column = Gtk.TreeViewColumn("Name", renderer, text=0)
        self.append_column(column)

class DataTreeView(Gtk.TreeView):
    def __init__(self, store):
        Gtk.TreeView.__init__(self, store)
        self.store = store
        renderer = Gtk.CellRendererText()
        column = Gtk.TreeViewColumn("Dataset", renderer, text=0)
        self.append_column(column)

        for x in range(10):
            self.store.append(None, [str(random.random())])

class MainWindow(object):
    def __init__(self, builder):
        self.main_window = builder.get_object("window1")
        self.sw1 = builder.get_object("scrolledwindow1")
        self.sw2 = builder.get_object("scrolledwindow2")
        self.layernumber = 1

        #Initializing top TreeStore and TreeView
        #First object is the store, second is the view of the bottom data-view
        self.topstore = Gtk.TreeStore(str, object, object)
        self.topview = LayerTreeView(self.topstore)
        self.sw1.add(self.topview)

        #Adding some testdata
        for x in range(3):
            datastore = Gtk.TreeStore(str)
            dataview = DataTreeView(datastore)
            layername = "Layer {0}".format(self.layernumber)
            self.layernumber += 1
            self.topstore.append(None, [layername, datastore, dataview])

        self.select = self.topview.get_selection()
        self.select.connect("changed", self.on_tree_selection_changed)
        self.main_window.show_all()

    def on_add_layer_clicked(self, widget):
        datastore = Gtk.TreeStore(str)
        dataview = DataTreeView(datastore)
        layername = "Layer {0}".format(self.layernumber)
        self.layernumber += 1
        self.topstore.append(None, [layername, datastore, dataview])

    def on_add_data_clicked(self, widget):
        self.selection = self.topview.get_selection()
        model, treeiter = self.selection.get_selected()
        if treeiter != None:
            data_object = model[treeiter][1]
            data_object.append(None, [str(random.random())])

    def on_window1_destroy(self, widget):
        Gtk.main_quit()

    def on_tree_selection_changed(self, selection):
        model, treeiter = selection.get_selected()
        if treeiter != None:
            treeview_object = model[treeiter][2]
            child = self.sw2.get_child()
            if child != None:
                self.sw2.remove(self.sw2.get_child())
            self.sw2.add(treeview_object)
            self.main_window.show_all()

def main():
    builder = Gtk.Builder()
    objects = builder.add_objects_from_file("treeview_switcher.glade",
         ("window1", ""))

    window_instance = MainWindow(builder)
    builder.connect_signals(window_instance)
    Gtk.main()

if __name__ == "__main__":
     main()