Ich erstelle eine GUI (Python-Bindung von GTK3), in der ein Gtk Scrolled Window (von Glade) verschiedene Baumansichten enthalten kann. Das Programm startet mit einem leeren Fenster und beim ersten Mal funktioniert alles mit:

 self.scrolled_window.add_with_viewport(treeview)
 self.main_window.show_all()

Bearbeiten Bild des Testprogramms (siehe Quelle unten):

Das zweite Mal bekomme ich den folgenden Fehler:

(main.py:15905): Gtk-CRITICAL **: gtk_scrolled_window_add_with_viewport: Zusicherung 'gtk_bin_get_child (GTK_BIN (child_widget)) == NULL' fehlgeschlagen

Ich denke, dass ich möglicherweise zuerst das Ansichtsfenster oder das gescrollte Fenster leeren muss, aber ich weiß nicht, wie das gemacht wird, und kann keine Dokumentation dafür finden.

Bearbeiten Beim Benutzen self.scrolled_window.remove (self.scrolled_window.get_child ()) Ich sehe den Datensatz beim Start nicht und es erscheinen Fehlermeldungen beim Layerwechsel.

Bearbeiten: Ich habe den Code noch einmal aktualisiert, damit die Beispieldaten von Anfang an zur Verfügung stehen.

Die Lichtungsdatei (test_project.glade):

<?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">440</property>
    <property name="default_height">250</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="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>
        <child>
          <object class="GtkBox" id="box2">
            <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">2</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

Der Python-Code:

#!/usr/bin/python3

from gi.repository import Gtk
import random

class BottomTreeView(Gtk.TreeView):
    def __init__(self, store):
        Gtk.TreeView.__init__(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 = 0

        self.topstore = Gtk.TreeStore(str, object)
        self.topview = Gtk.TreeView(self.topstore)
        renderer1 = Gtk.CellRendererText()
        column1 = Gtk.TreeViewColumn("Name", renderer1, text=0)
        self.topview.append_column(column1)
        self.sw1.add_with_viewport(self.topview)

        #Adding test data in a dumb way
        self.store1 = Gtk.TreeStore(str)
        for x in range(10):
            self.store1.append(None, [str(random.random())])
        self.view1 = Gtk.TreeView(self.store1)
        self.rend1 = Gtk.CellRendererText()
        self.col1 = Gtk.TreeViewColumn("Dataset", self.rend1, text=0)
        self.view1.append_column(self.col1)
        self.sw2.add_with_viewport(self.view1)
        self.topstore.append(None, ["Layer 1", self.view1])

        self.store2 = Gtk.TreeStore(str)
        for x in range(10):
            self.store2.append(None, [str(random.random())])
        self.view2 = Gtk.TreeView(self.store2)
        self.rend2 = Gtk.CellRendererText()
        self.col2 = Gtk.TreeViewColumn("Dataset", self.rend2, text=0)
        self.view2.append_column(self.col2)
        self.topstore.append(None, ["Layer 2", self.view2])

        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):
        self.layernumber += 1
        store = Gtk.TreeStore(str)
        bottom = BottomTreeView(store)
        self.topstore.append(None, [str(self.layernumber), bottom])

    def on_add_data_clicked(self, widget):
        self.selection = self.topview.get_selection()
        model, treeiter = self.selection.get_selected()
        print("Adding data to {0}".format(model[treeiter][0]))
        datasheet = model[treeiter][1]
        datasheet.store.append(None, [str(random.random())])

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

    def on_tree_selection_changed(self, selection):
        print("\n>>> Selection changed")
        model, treeiter = selection.get_selected()
        print(">>> Model: {0}, Treeiter: {1}".format(model, treeiter))
        if treeiter != None:
             print(">>> You selected Layer {0}.".format(model[treeiter][1]))
             tree_obj = model[treeiter][1]
             #The following lines mess up the program from the startup
             #self.sw2.remove(self.sw2.get_child())
             #self.sw2.add_with_viewport(tree_obj)
             #self.main_window.show_all()

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

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

if __name__ == "__main__":
     main()