Add preliminary stylesheet editor

10 files changed, 1497 insertions, 44 deletions

diff --git a/data/colloquium.gresource.xml b/data/colloquium.gresource.xml
index 5c8b4b0..369144b 100644
--- a/data/colloquium.gresource.xml
+++ b/data/colloquium.gresource.xml
@@ -3,6 +3,7 @@
   <gresource prefix="/uk/me/bitwiz/Colloquium">
     <file>sky.png</file>
     <file>menus.ui</file>
+    <file>stylesheeteditor.ui</file>
     <file>demo.sc</file>
     <file>canvas.png</file>
     <file>alpha_warning.svg</file>
diff --git a/data/stylesheeteditor.ui b/data/stylesheeteditor.ui
new file mode 100644
index 0000000..514e01c
--- /dev/null
+++ b/data/stylesheeteditor.ui
@@ -0,0 +1,1085 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.20.4 -->
+<interface>
+  <requires lib="gtk+" version="3.20"/>
+  <template class="StylesheetEditor" parent="GtkDialog">
+    <property name="can_focus">False</property>
+    <property name="title" translatable="yes">Stylesheet editor</property>
+    <property name="window_position">center-on-parent</property>
+    <property name="default_width">640</property>
+    <property name="default_height">640</property>
+    <property name="destroy_with_parent">True</property>
+    <property name="type_hint">dialog</property>
+    <child internal-child="vbox">
+      <object class="GtkBox">
+        <property name="can_focus">False</property>
+        <property name="orientation">vertical</property>
+        <property name="spacing">2</property>
+        <child internal-child="action_area">
+          <object class="GtkButtonBox">
+            <property name="can_focus">False</property>
+            <property name="layout_style">end</property>
+            <child>
+              <object class="GtkButton">
+                <property name="label">gtk-revert-to-saved</property>
+                <property name="visible">True</property>
+                <property name="can_focus">True</property>
+                <property name="receives_default">True</property>
+                <property name="use_stock">True</property>
+                <property name="always_show_image">True</property>
+              </object>
+              <packing>
+                <property name="expand">True</property>
+                <property name="fill">True</property>
+                <property name="position">0</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkButton" id="Close">
+                <property name="label">gtk-close</property>
+                <property name="visible">True</property>
+                <property name="can_focus">True</property>
+                <property name="receives_default">True</property>
+                <property name="use_stock">True</property>
+                <property name="always_show_image">True</property>
+              </object>
+              <packing>
+                <property name="expand">True</property>
+                <property name="fill">True</property>
+                <property name="position">2</property>
+              </packing>
+            </child>
+          </object>
+          <packing>
+            <property name="expand">False</property>
+            <property name="fill">False</property>
+            <property name="position">0</property>
+          </packing>
+        </child>
+        <child>
+          <object class="GtkNotebook">
+            <property name="visible">True</property>
+            <property name="can_focus">True</property>
+            <child>
+              <object class="GtkBox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="margin_left">8</property>
+                <property name="margin_right">8</property>
+                <property name="margin_top">8</property>
+                <property name="margin_bottom">8</property>
+                <property name="orientation">vertical</property>
+                <property name="spacing">8</property>
+                <child>
+                  <object class="GtkLabel">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="label" translatable="yes">This style will be used in the narrative editor and for slides unless overridden</property>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">0</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkBox">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="spacing">8</property>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Text:</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">0</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkFontButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                        <property name="font">Sans 12</property>
+                        <property name="preview_text"/>
+                      </object>
+                      <packing>
+                        <property name="expand">True</property>
+                        <property name="fill">True</property>
+                        <property name="position">1</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkColorButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">2</property>
+                      </packing>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">1</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkBox">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="spacing">8</property>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Background:</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">0</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkComboBoxText">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="active">0</property>
+                        <items>
+                          <item translatable="yes">Flat colour</item>
+                          <item translatable="yes">Horizontal gradient</item>
+                          <item translatable="yes">Vertical gradient</item>
+                        </items>
+                      </object>
+                      <packing>
+                        <property name="expand">True</property>
+                        <property name="fill">True</property>
+                        <property name="position">1</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkColorButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">2</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkColorButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">3</property>
+                      </packing>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">2</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkFrame">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="label_xalign">0</property>
+                    <property name="shadow_type">out</property>
+                    <child>
+                      <object class="GtkAlignment">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="left_padding">12</property>
+                        <child>
+                          <object class="GtkBox">
+                            <property name="visible">True</property>
+                            <property name="can_focus">False</property>
+                            <property name="orientation">vertical</property>
+                            <child>
+                              <object class="GtkBox">
+                                <property name="visible">True</property>
+                                <property name="can_focus">False</property>
+                                <child>
+                                  <object class="GtkLabel">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="label" translatable="yes">Top:</property>
+                                    <property name="xalign">1</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">True</property>
+                                    <property name="fill">True</property>
+                                    <property name="padding">4</property>
+                                    <property name="position">0</property>
+                                  </packing>
+                                </child>
+                                <child type="center">
+                                  <object class="GtkSpinButton">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">True</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="position">2</property>
+                                  </packing>
+                                </child>
+                              </object>
+                              <packing>
+                                <property name="expand">False</property>
+                                <property name="fill">True</property>
+                                <property name="padding">5</property>
+                                <property name="position">0</property>
+                              </packing>
+                            </child>
+                            <child>
+                              <object class="GtkBox">
+                                <property name="visible">True</property>
+                                <property name="can_focus">False</property>
+                                <child>
+                                  <object class="GtkLabel">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="label" translatable="yes">Left:</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="padding">4</property>
+                                    <property name="position">0</property>
+                                  </packing>
+                                </child>
+                                <child>
+                                  <object class="GtkSpinButton">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">True</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="position">1</property>
+                                  </packing>
+                                </child>
+                                <child>
+                                  <object class="GtkSpinButton">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">True</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="padding">5</property>
+                                    <property name="pack_type">end</property>
+                                    <property name="position">2</property>
+                                  </packing>
+                                </child>
+                                <child>
+                                  <object class="GtkLabel">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="label" translatable="yes">Right:</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="padding">4</property>
+                                    <property name="pack_type">end</property>
+                                    <property name="position">3</property>
+                                  </packing>
+                                </child>
+                              </object>
+                              <packing>
+                                <property name="expand">False</property>
+                                <property name="fill">True</property>
+                                <property name="padding">5</property>
+                                <property name="position">1</property>
+                              </packing>
+                            </child>
+                            <child>
+                              <object class="GtkBox">
+                                <property name="visible">True</property>
+                                <property name="can_focus">False</property>
+                                <child>
+                                  <object class="GtkLabel">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="label" translatable="yes">Bottom:</property>
+                                    <property name="xalign">1</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">True</property>
+                                    <property name="fill">True</property>
+                                    <property name="padding">4</property>
+                                    <property name="position">0</property>
+                                  </packing>
+                                </child>
+                                <child type="center">
+                                  <object class="GtkSpinButton">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">True</property>
+                                  </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="padding">5</property>
+                                <property name="position">2</property>
+                              </packing>
+                            </child>
+                          </object>
+                        </child>
+                      </object>
+                    </child>
+                    <child type="label">
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Paragraph spacing</property>
+                      </object>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">3</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkFrame">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="label_xalign">0</property>
+                    <property name="shadow_type">in</property>
+                    <child>
+                      <object class="GtkAlignment">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <child>
+                          <object class="GtkTextView" id="default_style_ss">
+                            <property name="visible">True</property>
+                            <property name="can_focus">True</property>
+                            <property name="margin_top">8</property>
+                            <property name="margin_bottom">8</property>
+                            <property name="wrap_mode">char</property>
+                            <property name="left_margin">12</property>
+                            <property name="right_margin">12</property>
+                          </object>
+                        </child>
+                      </object>
+                    </child>
+                    <child type="label">
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Storycode</property>
+                      </object>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">True</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">4</property>
+                  </packing>
+                </child>
+              </object>
+            </child>
+            <child type="tab">
+              <object class="GtkLabel">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Default style</property>
+              </object>
+              <packing>
+                <property name="tab_fill">False</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkBox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="margin_left">8</property>
+                <property name="margin_right">8</property>
+                <property name="margin_top">8</property>
+                <property name="margin_bottom">8</property>
+                <property name="orientation">vertical</property>
+                <property name="spacing">8</property>
+                <child>
+                  <object class="GtkLabel">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="label" translatable="yes">This style will be used in the narrative editor</property>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">0</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkCheckButton">
+                    <property name="label" translatable="yes">Use default style</property>
+                    <property name="visible">True</property>
+                    <property name="can_focus">True</property>
+                    <property name="receives_default">False</property>
+                    <property name="draw_indicator">True</property>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="position">1</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkBox">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="spacing">8</property>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Text:</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">0</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkFontButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                        <property name="font">Sans 12</property>
+                        <property name="preview_text"/>
+                      </object>
+                      <packing>
+                        <property name="expand">True</property>
+                        <property name="fill">True</property>
+                        <property name="position">1</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkColorButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">2</property>
+                      </packing>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">2</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkBox">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="spacing">8</property>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Background:</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">0</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkComboBoxText">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <items>
+                          <item translatable="yes">Flat colour</item>
+                          <item translatable="yes">Horizontal gradient</item>
+                          <item translatable="yes">Vertical gradient</item>
+                        </items>
+                      </object>
+                      <packing>
+                        <property name="expand">True</property>
+                        <property name="fill">True</property>
+                        <property name="position">1</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkColorButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">2</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkColorButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="receives_default">True</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">3</property>
+                      </packing>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">3</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkFrame">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="label_xalign">0</property>
+                    <property name="shadow_type">out</property>
+                    <child>
+                      <object class="GtkAlignment">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="left_padding">12</property>
+                        <child>
+                          <object class="GtkBox">
+                            <property name="visible">True</property>
+                            <property name="can_focus">False</property>
+                            <property name="orientation">vertical</property>
+                            <child>
+                              <object class="GtkBox">
+                                <property name="visible">True</property>
+                                <property name="can_focus">False</property>
+                                <child>
+                                  <object class="GtkLabel">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="margin_right">5</property>
+                                    <property name="label" translatable="yes">Top:</property>
+                                    <property name="xalign">1</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">True</property>
+                                    <property name="fill">True</property>
+                                    <property name="position">0</property>
+                                  </packing>
+                                </child>
+                                <child type="center">
+                                  <object class="GtkSpinButton">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">True</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="position">2</property>
+                                  </packing>
+                                </child>
+                              </object>
+                              <packing>
+                                <property name="expand">False</property>
+                                <property name="fill">True</property>
+                                <property name="padding">5</property>
+                                <property name="position">0</property>
+                              </packing>
+                            </child>
+                            <child>
+                              <object class="GtkBox">
+                                <property name="visible">True</property>
+                                <property name="can_focus">False</property>
+                                <child>
+                                  <object class="GtkLabel">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="margin_right">5</property>
+                                    <property name="label" translatable="yes">Left:</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="padding">5</property>
+                                    <property name="position">0</property>
+                                  </packing>
+                                </child>
+                                <child>
+                                  <object class="GtkSpinButton">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">True</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="position">1</property>
+                                  </packing>
+                                </child>
+                                <child>
+                                  <object class="GtkSpinButton">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">True</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="padding">5</property>
+                                    <property name="pack_type">end</property>
+                                    <property name="position">2</property>
+                                  </packing>
+                                </child>
+                                <child>
+                                  <object class="GtkLabel">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="margin_right">5</property>
+                                    <property name="label" translatable="yes">Right:</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">False</property>
+                                    <property name="fill">True</property>
+                                    <property name="pack_type">end</property>
+                                    <property name="position">3</property>
+                                  </packing>
+                                </child>
+                              </object>
+                              <packing>
+                                <property name="expand">False</property>
+                                <property name="fill">True</property>
+                                <property name="padding">5</property>
+                                <property name="position">1</property>
+                              </packing>
+                            </child>
+                            <child>
+                              <object class="GtkBox">
+                                <property name="visible">True</property>
+                                <property name="can_focus">False</property>
+                                <child>
+                                  <object class="GtkLabel">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">False</property>
+                                    <property name="margin_right">5</property>
+                                    <property name="label" translatable="yes">Bottom:</property>
+                                    <property name="xalign">1</property>
+                                  </object>
+                                  <packing>
+                                    <property name="expand">True</property>
+                                    <property name="fill">True</property>
+                                    <property name="position">0</property>
+                                  </packing>
+                                </child>
+                                <child type="center">
+                                  <object class="GtkSpinButton">
+                                    <property name="visible">True</property>
+                                    <property name="can_focus">True</property>
+                                  </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="padding">5</property>
+                                <property name="position">2</property>
+                              </packing>
+                            </child>
+                          </object>
+                        </child>
+                      </object>
+                    </child>
+                    <child type="label">
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Paragraph spacing</property>
+                      </object>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">4</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkFrame">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="label_xalign">0</property>
+                    <property name="shadow_type">in</property>
+                    <child>
+                      <object class="GtkAlignment">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <child>
+                          <object class="GtkTextView">
+                            <property name="visible">True</property>
+                            <property name="can_focus">True</property>
+                            <property name="margin_top">8</property>
+                            <property name="margin_bottom">8</property>
+                            <property name="wrap_mode">char</property>
+                            <property name="left_margin">12</property>
+                            <property name="right_margin">12</property>
+                          </object>
+                        </child>
+                      </object>
+                    </child>
+                    <child type="label">
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Storycode</property>
+                      </object>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">True</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">5</property>
+                  </packing>
+                </child>
+              </object>
+              <packing>
+                <property name="position">1</property>
+              </packing>
+            </child>
+            <child type="tab">
+              <object class="GtkLabel">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Narrative style</property>
+              </object>
+              <packing>
+                <property name="position">1</property>
+                <property name="tab_fill">False</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkBox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="margin_left">8</property>
+                <property name="margin_right">8</property>
+                <property name="margin_top">8</property>
+                <property name="margin_bottom">8</property>
+                <property name="orientation">vertical</property>
+                <property name="spacing">8</property>
+                <child>
+                  <object class="GtkComboBoxText">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="active">0</property>
+                    <items>
+                      <item translatable="yes">Presentation title</item>
+                      <item translatable="yes">Slide title</item>
+                    </items>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="position">0</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkFrame">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="label_xalign">0</property>
+                    <property name="shadow_type">in</property>
+                    <child>
+                      <object class="GtkAlignment">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <child>
+                          <object class="GtkTextView">
+                            <property name="visible">True</property>
+                            <property name="can_focus">True</property>
+                            <property name="margin_top">8</property>
+                            <property name="margin_bottom">8</property>
+                            <property name="wrap_mode">char</property>
+                            <property name="left_margin">12</property>
+                            <property name="right_margin">12</property>
+                          </object>
+                        </child>
+                      </object>
+                    </child>
+                    <child type="label">
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Storycode</property>
+                      </object>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">True</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">1</property>
+                  </packing>
+                </child>
+              </object>
+              <packing>
+                <property name="position">2</property>
+              </packing>
+            </child>
+            <child type="tab">
+              <object class="GtkLabel">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Style definitions</property>
+              </object>
+              <packing>
+                <property name="position">2</property>
+                <property name="tab_fill">False</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkBox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="margin_left">8</property>
+                <property name="margin_right">8</property>
+                <property name="margin_top">8</property>
+                <property name="margin_bottom">8</property>
+                <property name="orientation">vertical</property>
+                <property name="spacing">8</property>
+                <child>
+                  <object class="GtkComboBoxText">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="active">0</property>
+                    <items>
+                      <item translatable="yes">Presentation title</item>
+                      <item translatable="yes">Slide title</item>
+                    </items>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="position">0</property>
+                  </packing>
+                </child>
+                <child>
+                  <object class="GtkFrame">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="label_xalign">0</property>
+                    <property name="shadow_type">in</property>
+                    <child>
+                      <object class="GtkAlignment">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <child>
+                          <object class="GtkTextView">
+                            <property name="visible">True</property>
+                            <property name="can_focus">True</property>
+                            <property name="margin_top">8</property>
+                            <property name="margin_bottom">8</property>
+                            <property name="wrap_mode">char</property>
+                            <property name="left_margin">12</property>
+                            <property name="right_margin">12</property>
+                          </object>
+                        </child>
+                      </object>
+                    </child>
+                    <child type="label">
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Storycode</property>
+                      </object>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">True</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">1</property>
+                  </packing>
+                </child>
+              </object>
+              <packing>
+                <property name="position">3</property>
+              </packing>
+            </child>
+            <child type="tab">
+              <object class="GtkLabel">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Templates</property>
+              </object>
+              <packing>
+                <property name="position">3</property>
+                <property name="tab_fill">False</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkBox">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="margin_top">8</property>
+                <property name="margin_bottom">8</property>
+                <property name="orientation">vertical</property>
+                <property name="spacing">8</property>
+                <child>
+                  <object class="GtkBox">
+                    <property name="visible">True</property>
+                    <property name="can_focus">False</property>
+                    <property name="margin_left">8</property>
+                    <property name="margin_right">8</property>
+                    <property name="spacing">8</property>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Slide width:</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">0</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkSpinButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="width_chars">6</property>
+                        <property name="numeric">True</property>
+                        <property name="value">1024</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">1</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">Slide height:</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">2</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkSpinButton">
+                        <property name="visible">True</property>
+                        <property name="can_focus">True</property>
+                        <property name="width_chars">6</property>
+                        <property name="numeric">True</property>
+                        <property name="value">768</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">3</property>
+                      </packing>
+                    </child>
+                    <child>
+                      <object class="GtkLabel">
+                        <property name="visible">True</property>
+                        <property name="can_focus">False</property>
+                        <property name="label" translatable="yes">(arbitrary units)</property>
+                      </object>
+                      <packing>
+                        <property name="expand">False</property>
+                        <property name="fill">True</property>
+                        <property name="position">4</property>
+                      </packing>
+                    </child>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="padding">4</property>
+                    <property name="position">0</property>
+                  </packing>
+                </child>
+                <child>
+                  <placeholder/>
+                </child>
+              </object>
+              <packing>
+                <property name="position">4</property>
+              </packing>
+            </child>
+            <child type="tab">
+              <object class="GtkLabel">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="label" translatable="yes">Properties</property>
+              </object>
+              <packing>
+                <property name="position">4</property>
+                <property name="tab_fill">False</property>
+              </packing>
+            </child>
+          </object>
+          <packing>
+            <property name="expand">True</property>
+            <property name="fill">True</property>
+            <property name="position">1</property>
+          </packing>
+        </child>
+      </object>
+    </child>
+    <child>
+      <placeholder/>
+    </child>
+  </template>
+  <object class="GtkListStore" id="liststore1"/>
+</interface>
diff --git a/meson.build b/meson.build
index 24f54ed..a2e3fb2 100644
--- a/meson.build
+++ b/meson.build
@@ -44,6 +44,7 @@ executable('colloquium',
             'src/print.c',
             'src/sc_parse.c',
             'src/utils.c',
+            'src/stylesheet_editor.c',
            ],
            gresources,
            dependencies : [gtkdep, mdep],
diff --git a/po/POTFILES b/po/POTFILES
index 0d736d9..ff4049c 100644
--- a/po/POTFILES
+++ b/po/POTFILES
@@ -15,3 +15,4 @@ src/slide_window.c
 src/testcard.c
 src/utils.c
 data/menus.ui
+data/stylesheeteditor.ui
diff --git a/po/colloquium.pot b/po/colloquium.pot
index 67114d4..ac51e51 100644
--- a/po/colloquium.pot
+++ b/po/colloquium.pot
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: colloquium\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-04-22 12:15+0200\n"
+"POT-Creation-Date: 2018-04-22 23:21+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -40,12 +40,12 @@ msgstr ""
 msgid "Open Presentation"
 msgstr ""
 
-#: src/colloquium.c:198 src/narrative_window.c:129 src/narrative_window.c:341
-#: src/narrative_window.c:508
+#: src/colloquium.c:198 src/narrative_window.c:130 src/narrative_window.c:340
+#: src/narrative_window.c:507
 msgid "_Cancel"
 msgstr ""
 
-#: src/colloquium.c:199 src/narrative_window.c:342
+#: src/colloquium.c:199 src/narrative_window.c:341
 msgid "_Open"
 msgstr ""
 
@@ -391,76 +391,76 @@ msgstr ""
 msgid "%s :\n"
 msgstr ""
 
-#: src/narrative_window.c:108
+#: src/narrative_window.c:109
 msgid "Failed to save presentation"
 msgstr ""
 
-#: src/narrative_window.c:126
+#: src/narrative_window.c:127
 msgid "Save Presentation"
 msgstr ""
 
-#: src/narrative_window.c:130 data/menus.ui:24
+#: src/narrative_window.c:131 data/menus.ui:24
 msgid "_Save"
 msgstr ""
 
-#: src/narrative_window.c:173
+#: src/narrative_window.c:174
 #, c-format
 msgid "Not a slide!\n"
 msgstr ""
 
-#: src/narrative_window.c:300
+#: src/narrative_window.c:301
 #, c-format
 msgid "Not a style sheet\n"
 msgstr ""
 
-#: src/narrative_window.c:303
+#: src/narrative_window.c:304
 #, c-format
 msgid "Failed to load\n"
 msgstr ""
 
-#: src/narrative_window.c:338
+#: src/narrative_window.c:337
 msgid "Load stylesheet"
 msgstr ""
 
-#: src/narrative_window.c:372
+#: src/narrative_window.c:371
 #, c-format
 msgid "Failed to split paragraph\n"
 msgstr ""
 
-#: src/narrative_window.c:505
+#: src/narrative_window.c:504
 msgid "Export PDF"
 msgstr ""
 
-#: src/narrative_window.c:509
+#: src/narrative_window.c:508
 msgid "_Export"
 msgstr ""
 
-#: src/narrative_window.c:803
+#: src/narrative_window.c:802
 #, c-format
 msgid "Narrative window is already open!\n"
 msgstr ""
 
-#: src/narrative_window.c:853 data/menus.ui:134
+#: src/narrative_window.c:852 data/menus.ui:134
 msgid "Start slideshow"
 msgstr ""
 
-#: src/narrative_window.c:864
+#: src/narrative_window.c:863
 msgid "Add slide"
 msgstr ""
 
-#: src/narrative_window.c:874
+#: src/narrative_window.c:873
 msgid "First slide"
 msgstr ""
 
-#: src/narrative_window.c:881
+#: src/narrative_window.c:880
 msgid "Previous slide"
 msgstr ""
 
-#: src/narrative_window.c:888
+#: src/narrative_window.c:887
 msgid "Next slide"
 msgstr ""
 
-#: src/narrative_window.c:895
+#: src/narrative_window.c:894
 msgid "Last slide"
 msgstr ""
 
@@ -969,7 +969,7 @@ msgstr ""
 msgid "Slide"
 msgstr ""
 
-#: data/menus.ui:124
+#: data/menus.ui:124 data/stylesheeteditor.ui:822 data/stylesheeteditor.ui:902
 msgid "Slide title"
 msgstr ""
 
@@ -1004,3 +1004,102 @@ msgstr ""
 #: data/menus.ui:192
 msgid "_About"
 msgstr ""
+
+#: data/stylesheeteditor.ui:7
+msgid "Stylesheet editor"
+msgstr ""
+
+#: data/stylesheeteditor.ui:77
+msgid ""
+"This style will be used in the narrative editor and for slides unless "
+"overridden"
+msgstr ""
+
+#: data/stylesheeteditor.ui:95 data/stylesheeteditor.ui:471
+msgid "Text:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:146 data/stylesheeteditor.ui:522
+msgid "Background:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:160 data/stylesheeteditor.ui:535
+msgid "Flat colour"
+msgstr ""
+
+#: data/stylesheeteditor.ui:161 data/stylesheeteditor.ui:536
+msgid "Horizontal gradient"
+msgstr ""
+
+#: data/stylesheeteditor.ui:162 data/stylesheeteditor.ui:537
+msgid "Vertical gradient"
+msgstr ""
+
+#: data/stylesheeteditor.ui:227 data/stylesheeteditor.ui:603
+msgid "Top:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:264 data/stylesheeteditor.ui:640
+msgid "Left:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:301 data/stylesheeteditor.ui:678
+msgid "Right:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:327 data/stylesheeteditor.ui:704
+msgid "Bottom:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:364 data/stylesheeteditor.ui:740
+msgid "Paragraph spacing"
+msgstr ""
+
+#: data/stylesheeteditor.ui:402 data/stylesheeteditor.ui:778
+#: data/stylesheeteditor.ui:858 data/stylesheeteditor.ui:938
+msgid "Storycode"
+msgstr ""
+
+#: data/stylesheeteditor.ui:419
+msgid "Default style"
+msgstr ""
+
+#: data/stylesheeteditor.ui:439
+msgid "This style will be used in the narrative editor"
+msgstr ""
+
+#: data/stylesheeteditor.ui:450
+msgid "Use default style"
+msgstr ""
+
+#: data/stylesheeteditor.ui:798
+msgid "Narrative style"
+msgstr ""
+
+#: data/stylesheeteditor.ui:821 data/stylesheeteditor.ui:901
+msgid "Presentation title"
+msgstr ""
+
+#: data/stylesheeteditor.ui:878
+msgid "Style definitions"
+msgstr ""
+
+#: data/stylesheeteditor.ui:958
+msgid "Templates"
+msgstr ""
+
+#: data/stylesheeteditor.ui:984
+msgid "Slide width:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:1010
+msgid "Slide height:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:1036
+msgid "(arbitrary units)"
+msgstr ""
+
+#: data/stylesheeteditor.ui:1064
+msgid "Properties"
+msgstr ""
diff --git a/po/de.po b/po/de.po
index 7e019a0..4ef8954 100644
--- a/po/de.po
+++ b/po/de.po
@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: colloquium\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-04-22 12:15+0200\n"
+"POT-Creation-Date: 2018-04-22 23:21+0200\n"
 "PO-Revision-Date: 2018-04-10 23:10+0200\n"
 "Last-Translator: Automatically generated\n"
 "Language-Team: none\n"
@@ -40,12 +40,12 @@ msgstr ""
 msgid "Open Presentation"
 msgstr ""
 
-#: src/colloquium.c:198 src/narrative_window.c:129 src/narrative_window.c:341
-#: src/narrative_window.c:508
+#: src/colloquium.c:198 src/narrative_window.c:130 src/narrative_window.c:340
+#: src/narrative_window.c:507
 msgid "_Cancel"
 msgstr ""
 
-#: src/colloquium.c:199 src/narrative_window.c:342
+#: src/colloquium.c:199 src/narrative_window.c:341
 msgid "_Open"
 msgstr ""
 
@@ -391,76 +391,76 @@ msgstr ""
 msgid "%s :\n"
 msgstr ""
 
-#: src/narrative_window.c:108
+#: src/narrative_window.c:109
 msgid "Failed to save presentation"
 msgstr ""
 
-#: src/narrative_window.c:126
+#: src/narrative_window.c:127
 msgid "Save Presentation"
 msgstr ""
 
-#: src/narrative_window.c:130 data/menus.ui:24
+#: src/narrative_window.c:131 data/menus.ui:24
 msgid "_Save"
 msgstr ""
 
-#: src/narrative_window.c:173
+#: src/narrative_window.c:174
 #, c-format
 msgid "Not a slide!\n"
 msgstr ""
 
-#: src/narrative_window.c:300
+#: src/narrative_window.c:301
 #, c-format
 msgid "Not a style sheet\n"
 msgstr ""
 
-#: src/narrative_window.c:303
+#: src/narrative_window.c:304
 #, c-format
 msgid "Failed to load\n"
 msgstr ""
 
-#: src/narrative_window.c:338
+#: src/narrative_window.c:337
 msgid "Load stylesheet"
 msgstr ""
 
-#: src/narrative_window.c:372
+#: src/narrative_window.c:371
 #, c-format
 msgid "Failed to split paragraph\n"
 msgstr ""
 
-#: src/narrative_window.c:505
+#: src/narrative_window.c:504
 msgid "Export PDF"
 msgstr ""
 
-#: src/narrative_window.c:509
+#: src/narrative_window.c:508
 msgid "_Export"
 msgstr ""
 
-#: src/narrative_window.c:803
+#: src/narrative_window.c:802
 #, c-format
 msgid "Narrative window is already open!\n"
 msgstr ""
 
-#: src/narrative_window.c:853 data/menus.ui:134
+#: src/narrative_window.c:852 data/menus.ui:134
 msgid "Start slideshow"
 msgstr ""
 
-#: src/narrative_window.c:864
+#: src/narrative_window.c:863
 msgid "Add slide"
 msgstr ""
 
-#: src/narrative_window.c:874
+#: src/narrative_window.c:873
 msgid "First slide"
 msgstr ""
 
-#: src/narrative_window.c:881
+#: src/narrative_window.c:880
 msgid "Previous slide"
 msgstr ""
 
-#: src/narrative_window.c:888
+#: src/narrative_window.c:887
 msgid "Next slide"
 msgstr ""
 
-#: src/narrative_window.c:895
+#: src/narrative_window.c:894
 msgid "Last slide"
 msgstr ""
 
@@ -969,7 +969,7 @@ msgstr ""
 msgid "Slide"
 msgstr ""
 
-#: data/menus.ui:124
+#: data/menus.ui:124 data/stylesheeteditor.ui:822 data/stylesheeteditor.ui:902
 msgid "Slide title"
 msgstr ""
 
@@ -1004,3 +1004,102 @@ msgstr ""
 #: data/menus.ui:192
 msgid "_About"
 msgstr ""
+
+#: data/stylesheeteditor.ui:7
+msgid "Stylesheet editor"
+msgstr ""
+
+#: data/stylesheeteditor.ui:77
+msgid ""
+"This style will be used in the narrative editor and for slides unless "
+"overridden"
+msgstr ""
+
+#: data/stylesheeteditor.ui:95 data/stylesheeteditor.ui:471
+msgid "Text:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:146 data/stylesheeteditor.ui:522
+msgid "Background:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:160 data/stylesheeteditor.ui:535
+msgid "Flat colour"
+msgstr ""
+
+#: data/stylesheeteditor.ui:161 data/stylesheeteditor.ui:536
+msgid "Horizontal gradient"
+msgstr ""
+
+#: data/stylesheeteditor.ui:162 data/stylesheeteditor.ui:537
+msgid "Vertical gradient"
+msgstr ""
+
+#: data/stylesheeteditor.ui:227 data/stylesheeteditor.ui:603
+msgid "Top:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:264 data/stylesheeteditor.ui:640
+msgid "Left:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:301 data/stylesheeteditor.ui:678
+msgid "Right:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:327 data/stylesheeteditor.ui:704
+msgid "Bottom:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:364 data/stylesheeteditor.ui:740
+msgid "Paragraph spacing"
+msgstr ""
+
+#: data/stylesheeteditor.ui:402 data/stylesheeteditor.ui:778
+#: data/stylesheeteditor.ui:858 data/stylesheeteditor.ui:938
+msgid "Storycode"
+msgstr ""
+
+#: data/stylesheeteditor.ui:419
+msgid "Default style"
+msgstr ""
+
+#: data/stylesheeteditor.ui:439
+msgid "This style will be used in the narrative editor"
+msgstr ""
+
+#: data/stylesheeteditor.ui:450
+msgid "Use default style"
+msgstr ""
+
+#: data/stylesheeteditor.ui:798
+msgid "Narrative style"
+msgstr ""
+
+#: data/stylesheeteditor.ui:821 data/stylesheeteditor.ui:901
+msgid "Presentation title"
+msgstr ""
+
+#: data/stylesheeteditor.ui:878
+msgid "Style definitions"
+msgstr ""
+
+#: data/stylesheeteditor.ui:958
+msgid "Templates"
+msgstr ""
+
+#: data/stylesheeteditor.ui:984
+msgid "Slide width:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:1010
+msgid "Slide height:"
+msgstr ""
+
+#: data/stylesheeteditor.ui:1036
+msgid "(arbitrary units)"
+msgstr ""
+
+#: data/stylesheeteditor.ui:1064
+msgid "Properties"
+msgstr ""
diff --git a/src/colloquium.c b/src/colloquium.c
index 3b1caa3..66e3dcb 100644
--- a/src/colloquium.c
+++ b/src/colloquium.c
@@ -338,6 +338,7 @@ static void colloquium_startup(GApplication *papp)
 	                                 G_N_ELEMENTS(app_entries), app);
 
 	app->builder = gtk_builder_new_from_resource("/uk/me/bitwiz/Colloquium/menus.ui");
+	gtk_builder_add_from_resource(app->builder, "/uk/me/bitwiz/Colloquium/windows.ui", NULL);
 	gtk_application_set_menubar(GTK_APPLICATION(app),
 	    G_MENU_MODEL(gtk_builder_get_object(app->builder, "menubar")));
 
diff --git a/src/narrative_window.c b/src/narrative_window.c
index 33609eb..1d254b1 100644
--- a/src/narrative_window.c
+++ b/src/narrative_window.c
@@ -40,6 +40,7 @@
 #include "pr_clock.h"
 #include "print.h"
 #include "utils.h"
+#include "stylesheet_editor.h"
 
 
 struct _narrative_window
@@ -313,6 +314,18 @@ static gint load_ss_response_sig(GtkWidget *d, gint response,
 }
 
 
+static void edit_ss_sig(GSimpleAction *action, GVariant *parameter,
+                        gpointer vp)
+{
+	NarrativeWindow *nw = vp;
+	StylesheetEditor *se;
+
+	se = stylesheet_editor_new(nw->p);
+	gtk_window_set_transient_for(GTK_WINDOW(se), GTK_WINDOW(nw->window));
+	gtk_widget_show_all(GTK_WIDGET(se));
+}
+
+
 static void load_ss_sig(GSimpleAction *action, GVariant *parameter,
                         gpointer vp)
 {
@@ -741,6 +754,7 @@ GActionEntry nw_entries[] = {
 	{ "deleteslide", delete_slide_sig, NULL, NULL, NULL },
 	{ "slide", add_slide_sig, NULL, NULL, NULL },
 	{ "loadstylesheet", load_ss_sig, NULL, NULL, NULL },
+	{ "stylesheet", edit_ss_sig, NULL, NULL, NULL },
 	{ "startslideshow", start_slideshow_sig, NULL, NULL, NULL },
 	{ "startslideshowhere", start_slideshow_here_sig, NULL, NULL, NULL },
 	{ "startslideshownoslides", start_slideshow_noslides_sig, NULL, NULL, NULL },
diff --git a/src/stylesheet_editor.c b/src/stylesheet_editor.c
new file mode 100644
index 0000000..85e053c
--- /dev/null
+++ b/src/stylesheet_editor.c
@@ -0,0 +1,79 @@
+/*
+ * stylesheet_editor.c
+ *
+ * Copyright © 2013-2018 Thomas White <taw@bitwiz.org.uk>
+ *
+ * This file is part of Colloquium.
+ *
+ * Colloquium is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <gtk/gtk.h>
+
+#include "stylesheet_editor.h"
+#include "presentation.h"
+
+G_DEFINE_TYPE_WITH_CODE(StylesheetEditor, stylesheet_editor,
+                        GTK_TYPE_DIALOG, NULL)
+
+struct stylesheet_editor_private
+{
+	GtkDialog *default_style_ss;
+};
+
+
+static void stylesheet_editor_init(StylesheetEditor *se)
+{
+	se->priv = G_TYPE_INSTANCE_GET_PRIVATE(se, COLLOQUIUM_TYPE_STYLESHEET_EDITOR,
+	                                       struct stylesheet_editor_private);
+	gtk_widget_init_template(GTK_WIDGET(se));
+}
+
+
+void stylesheet_editor_class_init(StylesheetEditorClass *klass)
+{
+	GtkWidgetClass *widget_class = GTK_WIDGET_CLASS(klass);
+	GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
+
+	gtk_widget_class_set_template_from_resource(widget_class,
+	                                    "/uk/me/bitwiz/Colloquium/stylesheeteditor.ui");
+
+	gtk_widget_class_bind_template_child(widget_class,
+	                                     struct stylesheet_editor_private,
+	                                     default_style_ss);
+
+	g_type_class_add_private(gobject_class,
+	                         sizeof(struct stylesheet_editor_private));
+}
+
+
+StylesheetEditor *stylesheet_editor_new(struct presentation *p)
+{
+	StylesheetEditor *se;
+
+	se = g_object_new(COLLOQUIUM_TYPE_STYLESHEET_EDITOR, NULL);
+	if ( se == NULL ) return NULL;
+
+	return se;
+}
+
diff --git a/src/stylesheet_editor.h b/src/stylesheet_editor.h
new file mode 100644
index 0000000..ab2d65c
--- /dev/null
+++ b/src/stylesheet_editor.h
@@ -0,0 +1,73 @@
+/*
+ * stylesheet_editor.h
+ *
+ * Copyright © 2013-2018 Thomas White <taw@bitwiz.org.uk>
+ *
+ * This file is part of Colloquium.
+ *
+ * Colloquium is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef STYLESHEET_EDITOR_H
+#define STYLESHEET_EDITOR_H
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <gtk/gtk.h>
+
+#include "presentation.h"
+
+#define COLLOQUIUM_TYPE_STYLESHEET_EDITOR (stylesheet_editor_get_type())
+
+#define COLLOQUIUM_STYLESHEET_EDITOR(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), \
+                                             COLLOQUIUM_TYPE_STYLESHEET_EDITOR, \
+                                             StylesheetEditor))
+
+#define COLLOQUIUM_IS_STYLESHEET_EDITOR(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), \
+                                                COLLOQUIUM_TYPE_STYLESHEET_EDITOR))
+
+#define COLLOQUIUM_STYLESHEET_EDITOR_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((obj), \
+                                                     COLLOQUIUM_TYPE_STYLESHEET_EDITOR, \
+                                                     StylesheetEditorClass))
+
+#define COLLOQUIUM_IS_STYLESHEET_EDITOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((obj), \
+                                                        COLLOQUIUM_TYPE_STYLESHEET_EDITOR))
+
+#define COLLOQUIUM_STYLESHEET_EDITOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj), \
+                                                        COLLOQUIUM_TYPE_STYLESHEET_EDITOR, \
+                                                        StylesheetEditorClass))
+
+struct stylesheet_editor_private;
+
+struct _stylesheeteditor
+{
+	GtkDialog parent_instance;
+	struct stylesheet_editor_private *priv;
+};
+
+
+struct _stylesheeteditorclass
+{
+	GtkDialogClass parent_class;
+};
+
+typedef struct _stylesheeteditor StylesheetEditor;
+typedef struct _stylesheeteditorclass StylesheetEditorClass;
+
+extern StylesheetEditor *stylesheet_editor_new(struct presentation *p);
+
+#endif	/* STYLESHEET_EDITOR_H */