diff --git a/po/wesnoth-lib/POTFILES.in b/po/wesnoth-lib/POTFILES.in
index 3feca3a011a..80487398fd0 100644
--- a/po/wesnoth-lib/POTFILES.in
+++ b/po/wesnoth-lib/POTFILES.in
@@ -6,6 +6,7 @@ src/game_preferences.cpp
 src/game_preferences_display.cpp
 src/gui/auxiliary/canvas.cpp
 src/gui/auxiliary/log.cpp
+src/gui/auxiliary/window_builder/control.cpp
 src/gui/auxiliary/window_builder.cpp
 src/gui/dialogs/addon_connect.cpp
 src/gui/dialogs/addon_list.cpp
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 97f9fcf9a05..e38ebfa4e9b 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -263,6 +263,7 @@ SET(wesnoth-main_SRC
     generic_event.cpp
     gui/auxiliary/canvas.cpp
     gui/auxiliary/log.cpp
+    gui/auxiliary/window_builder/control.cpp
     gui/auxiliary/window_builder.cpp
     gui/dialogs/addon_connect.cpp
     gui/dialogs/addon_list.cpp
diff --git a/src/Makefile.am b/src/Makefile.am
index c0bf4f2250b..69bcbe9d463 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -88,6 +88,7 @@ wesnoth_source = \
 	generic_event.cpp \
 	gui/auxiliary/canvas.cpp \
 	gui/auxiliary/log.cpp \
+	gui/auxiliary/window_builder/control.cpp \
 	gui/auxiliary/window_builder.cpp \
 	gui/dialogs/addon_connect.cpp \
 	gui/dialogs/addon_list.cpp \
diff --git a/src/SConscript b/src/SConscript
index 22891c7bc1d..f51f3d14297 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -244,6 +244,7 @@ wesnoth_sources = Split("""
     widgets/scrollpane.cpp
     gui/auxiliary/canvas.cpp
     gui/auxiliary/log.cpp
+    gui/auxiliary/window_builder/control.cpp
     gui/auxiliary/window_builder.cpp
     gui/dialogs/addon_connect.cpp
     gui/dialogs/addon_list.cpp
diff --git a/src/gui/auxiliary/window_builder.cpp b/src/gui/auxiliary/window_builder.cpp
index 184ebdcf2e2..556c99c74e4 100644
--- a/src/gui/auxiliary/window_builder.cpp
+++ b/src/gui/auxiliary/window_builder.cpp
@@ -543,91 +543,8 @@ tbuilder_grid::tbuilder_grid(const config& cfg) :
 		<< rows << " rows and " << cols << " columns.\n";
 }
 
-tbuilder_control::tbuilder_control(const config& cfg) :
-	tbuilder_widget(cfg),
-	id(cfg["id"]),
-	definition(cfg["definition"]),
-	label(cfg["label"]),
-	tooltip(cfg["tooltip"]),
-	help(cfg["help"]),
-	use_tooltip_on_label_overflow(
-		utils::string_bool("use_tooltip_on_label_overflow", true))
-{
-/*WIKI
- * @page = GUIWidgetInstanceWML
- * @order = 1_widget
- *
- * = Widget =
- *
- * All widgets placed in the cell have some values in common:
- * @start_table = config
- *     id (string = "")                This value is used for the engine to
- *                                     identify 'special' items. This means that
- *                                     for example a text_box can get the proper
- *                                     initial value. This value should be
- *                                     unique or empty. Those special values are
- *                                     documented at the window definition that
- *                                     uses them. NOTE items starting with an
- *                                     underscore are used for composed widgets
- *                                     and these should be unique per composed
- *                                     widget.
- *
- *     definition (string = "default") The id of the widget definition to use.
- *                                     This way it's possible to select a
- *                                     specific version of the widget eg a title
- *                                     label when the label is used as title.
- *
- *     label (tstring = "")            Most widgets have some text associated
- *                                     with them, this field contain the value
- *                                     of that text. Some widgets use this value
- *                                     for other purposes, this is documented
- *                                     at the widget.
- *
- *     tooptip (tstring = "")          If you hover over a widget a while (the
- *                                     time it takes can differ per widget) a
- *                                     short help can show up.This defines the
- *                                     text of that message.
- *
- *
- *     help (tstring = "")             If you hover over a widget and press F1 a
- *                                     help message can show up. This help
- *                                     message might be the same as the tooltip
- *                                     but in general (if used) this message
- *                                     should show more help. This defines the
- *                                     text of that message.
- *
- *    use_tooltip_on_label_overflow (bool = true)
- *                                     If the text on the label is truncated and
- *                                     the tooltip is empty the label can be
- *                                     used for the tooltip. If this variable is
- *                                     set to true this will happen.
- * @end_table
- *
- */
-
-	if(definition.empty()) {
-		definition = "default";
-	}
-
-
-	DBG_GUI_P << "Window builder: found control with id '"
-		<< id << "' and definition '" << definition << "'.\n";
-}
-
-void tbuilder_control::init_control(tcontrol* control) const
-{
-	assert(control);
-
-	control->set_id(id);
-	control->set_definition(definition);
-	control->set_label(label);
-	control->set_tooltip(tooltip);
-	control->set_help_message(help);
-	control->set_use_tooltip_on_label_overflow(use_tooltip_on_label_overflow);
-}
-
 tbuilder_button::tbuilder_button(const config& cfg) :
-	tbuilder_control(cfg),
+	implementation::tbuilder_control(cfg),
 	retval_id_(cfg["return_value_id"]),
 	retval_(lexical_cast_default<int>(cfg["return_value"]))
 {
@@ -707,7 +624,7 @@ tbuilder_gridcell::tbuilder_gridcell(const config& cfg) :
 }
 
 tbuilder_label::tbuilder_label(const config& cfg)
-	: tbuilder_control(cfg)
+	: implementation::tbuilder_control(cfg)
 	, wrap(utils::string_bool("wrap"))
 {
 /*WIKI
@@ -740,7 +657,7 @@ twidget* tbuilder_label::build() const
 }
 
 tbuilder_listbox::tbuilder_listbox(const config& cfg) :
-	tbuilder_control(cfg),
+	implementation::tbuilder_control(cfg),
 	vertical_scrollbar_mode(
 			get_scrollbar_mode(cfg["vertical_scrollbar_mode"])),
 	horizontal_scrollbar_mode(
@@ -862,7 +779,7 @@ twidget* tbuilder_listbox::build() const
 }
 
 tbuilder_menubar::tbuilder_menubar(const config& cfg) :
-	tbuilder_control(cfg),
+	implementation::tbuilder_control(cfg),
 	must_have_one_item_selected_(utils::string_bool(cfg["must_have_one_item_selected"])),
 	direction_(read_direction(cfg["direction"])),
 	selected_item_(lexical_cast_default<int>(
@@ -945,7 +862,7 @@ twidget* tbuilder_minimap::build() const
 }
 
 tbuilder_multi_page::tbuilder_multi_page(const config& cfg) :
-	tbuilder_control(cfg),
+	implementation::tbuilder_control(cfg),
 	builder(0),
 	data()
 {
@@ -1025,7 +942,7 @@ twidget* tbuilder_multi_page::build() const
 }
 
 tbuilder_panel::tbuilder_panel(const config& cfg) :
-	tbuilder_control(cfg),
+	implementation::tbuilder_control(cfg),
 	grid(0)
 {
 /*WIKI
@@ -1106,7 +1023,7 @@ twidget* tbuilder_scroll_label::build() const
 }
 
 tbuilder_slider::tbuilder_slider(const config& cfg) :
-	tbuilder_control(cfg),
+	implementation::tbuilder_control(cfg),
 	best_slider_length_(lexical_cast_default<unsigned>(cfg["best_slider_length"])),
 	minimum_value_(lexical_cast_default<int>(cfg["minimum_value"])),
 	maximum_value_(lexical_cast_default<int>(cfg["maximum_value"])),
@@ -1162,7 +1079,7 @@ tbuilder_slider::tbuilder_slider(const config& cfg) :
 }
 
 tbuilder_scrollbar_panel::tbuilder_scrollbar_panel(const config& cfg)
-	: tbuilder_control(cfg)
+	: implementation::tbuilder_control(cfg)
 	, vertical_scrollbar_mode(
 			get_scrollbar_mode(cfg["vertical_scrollbar_mode"]))
 	, horizontal_scrollbar_mode(
@@ -1325,7 +1242,7 @@ twidget* tbuilder_toggle_button::build() const
 }
 
 tbuilder_toggle_panel::tbuilder_toggle_panel(const config& cfg) :
-	tbuilder_control(cfg),
+	implementation::tbuilder_control(cfg),
 	grid(0),
 	retval_id_(cfg["return_value_id"]),
 	retval_(lexical_cast_default<int>(cfg["return_value"]))
diff --git a/src/gui/auxiliary/window_builder/control.cpp b/src/gui/auxiliary/window_builder/control.cpp
new file mode 100644
index 00000000000..de82303bf29
--- /dev/null
+++ b/src/gui/auxiliary/window_builder/control.cpp
@@ -0,0 +1,113 @@
+/* $Id$ */
+/*
+   Copyright (C) 2008 - 2009 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License version 2
+   or at your option any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#define GETTEXT_DOMAIN "wesnoth-lib"
+
+#include "gui/auxiliary/window_builder/control.hpp"
+
+#include "config.hpp"
+#include "gui/auxiliary/log.hpp"
+#include "gui/widgets/control.hpp"
+
+namespace gui2 {
+
+namespace implementation {
+
+tbuilder_control::tbuilder_control(const config& cfg) :
+	tbuilder_widget(cfg),
+	id(cfg["id"]),
+	definition(cfg["definition"]),
+	label(cfg["label"]),
+	tooltip(cfg["tooltip"]),
+	help(cfg["help"]),
+	use_tooltip_on_label_overflow(
+		utils::string_bool("use_tooltip_on_label_overflow", true))
+{
+	if(definition.empty()) {
+		definition = "default";
+	}
+
+
+	DBG_GUI_P << "Window builder: found control with id '"
+		<< id << "' and definition '" << definition << "'.\n";
+}
+
+void tbuilder_control::init_control(tcontrol* control) const
+{
+	assert(control);
+
+	control->set_id(id);
+	control->set_definition(definition);
+	control->set_label(label);
+	control->set_tooltip(tooltip);
+	control->set_help_message(help);
+	control->set_use_tooltip_on_label_overflow(use_tooltip_on_label_overflow);
+}
+
+} // namespace implementation
+
+} // namespace gui2
+
+/*WIKI
+ * @page = GUIWidgetInstanceWML
+ * @order = 1_widget
+ *
+ * = Widget =
+ *
+ * All widgets placed in the cell have some values in common:
+ * @start_table = config
+ *     id (string = "")                This value is used for the engine to
+ *                                     identify 'special' items. This means that
+ *                                     for example a text_box can get the proper
+ *                                     initial value. This value should be
+ *                                     unique or empty. Those special values are
+ *                                     documented at the window definition that
+ *                                     uses them. NOTE items starting with an
+ *                                     underscore are used for composed widgets
+ *                                     and these should be unique per composed
+ *                                     widget.
+ *
+ *     definition (string = "default") The id of the widget definition to use.
+ *                                     This way it's possible to select a
+ *                                     specific version of the widget eg a title
+ *                                     label when the label is used as title.
+ *
+ *     label (tstring = "")            Most widgets have some text associated
+ *                                     with them, this field contain the value
+ *                                     of that text. Some widgets use this value
+ *                                     for other purposes, this is documented
+ *                                     at the widget.
+ *
+ *     tooptip (tstring = "")          If you hover over a widget a while (the
+ *                                     time it takes can differ per widget) a
+ *                                     short help can show up.This defines the
+ *                                     text of that message.
+ *
+ *
+ *     help (tstring = "")             If you hover over a widget and press F1 a
+ *                                     help message can show up. This help
+ *                                     message might be the same as the tooltip
+ *                                     but in general (if used) this message
+ *                                     should show more help. This defines the
+ *                                     text of that message.
+ *
+ *    use_tooltip_on_label_overflow (bool = true)
+ *                                     If the text on the label is truncated and
+ *                                     the tooltip is empty the label can be
+ *                                     used for the tooltip. If this variable is
+ *                                     set to true this will happen.
+ * @end_table
+ *
+ */
+
diff --git a/src/gui/auxiliary/window_builder/control.hpp b/src/gui/auxiliary/window_builder/control.hpp
new file mode 100644
index 00000000000..487a6c7264b
--- /dev/null
+++ b/src/gui/auxiliary/window_builder/control.hpp
@@ -0,0 +1,50 @@
+/* $Id$ */
+/*
+   Copyright (C) 2008 - 2009 by Mark de Wever <koraq@xs4all.nl>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License version 2
+   or at your option any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#ifndef GUI_AUXILIARY_WINDOW_BUILDER_CONTROL_HPP_INCLUDED
+#define GUI_AUXILIARY_WINDOW_BUILDER_CONTROL_HPP_INCLUDED
+
+#include "gui/auxiliary/window_builder.hpp"
+
+namespace gui2 {
+
+class tcontrol;
+
+namespace implementation {
+
+struct tbuilder_control : public tbuilder_widget
+{
+private:
+	tbuilder_control();
+public:
+
+	tbuilder_control(const config& cfg);
+
+	void init_control(tcontrol* control) const;
+
+	/** Parameters for the control. */
+	std::string id;
+	std::string definition;
+	t_string label;
+	t_string tooltip;
+	t_string help;
+	bool use_tooltip_on_label_overflow;
+};
+
+} // namespace implementation
+
+} // namespace gui2
+
+#endif
+
diff --git a/src/gui/auxiliary/window_builder_private.hpp b/src/gui/auxiliary/window_builder_private.hpp
index 97f59e635dd..d0497231549 100644
--- a/src/gui/auxiliary/window_builder_private.hpp
+++ b/src/gui/auxiliary/window_builder_private.hpp
@@ -24,31 +24,13 @@
 #include "gui/auxiliary/window_builder.hpp"
 
 #include "config.hpp"
+#include "gui/auxiliary/window_builder/control.hpp"
 #include "gui/widgets/menubar.hpp"
 #include "gui/widgets/scrollbar_container.hpp"
 
 namespace gui2 {
 
-struct tbuilder_control : public tbuilder_widget
-{
-private:
-	tbuilder_control();
-public:
-
-	tbuilder_control(const config& cfg);
-
-	void init_control(tcontrol* control) const;
-
-	/** Parameters for the control. */
-	std::string id;
-	std::string definition;
-	t_string label;
-	t_string tooltip;
-	t_string help;
-	bool use_tooltip_on_label_overflow;
-};
-
-struct tbuilder_button : public tbuilder_control
+struct tbuilder_button : public implementation::tbuilder_control
 {
 
 private:
@@ -63,7 +45,7 @@ private:
 	int retval_;
 };
 
-struct tbuilder_image : public tbuilder_control
+struct tbuilder_image : public implementation::tbuilder_control
 {
 /*WIKI
  * @page = GUIWidgetInstanceWML
@@ -75,7 +57,7 @@ struct tbuilder_image : public tbuilder_control
  */
 
 	tbuilder_image(const config& cfg)
-		: tbuilder_control(cfg)
+		: implementation::tbuilder_control(cfg)
 	{
 	}
 
@@ -104,7 +86,7 @@ struct tbuilder_gridcell : public tbuilder_widget
 	twidget* build () const { return NULL; }
 };
 
-struct tbuilder_horizontal_scrollbar : public tbuilder_control
+struct tbuilder_horizontal_scrollbar : public implementation::tbuilder_control
 {
 private:
 	tbuilder_horizontal_scrollbar();
@@ -120,13 +102,13 @@ public:
  *
  */
 	tbuilder_horizontal_scrollbar(const config& cfg) :
-		tbuilder_control(cfg)
+		implementation::tbuilder_control(cfg)
 	{}
 
 	twidget* build () const;
 };
 
-struct tbuilder_label : public tbuilder_control
+struct tbuilder_label : public implementation::tbuilder_control
 {
 
 private:
@@ -139,7 +121,7 @@ public:
 	bool wrap;
 };
 
-struct tbuilder_listbox : public tbuilder_control
+struct tbuilder_listbox : public implementation::tbuilder_control
 {
 
 private:
@@ -168,7 +150,7 @@ public:
 };
 
 
-struct tbuilder_menubar : public tbuilder_control
+struct tbuilder_menubar : public implementation::tbuilder_control
 {
 	tbuilder_menubar(const config& cfg);
 
@@ -185,7 +167,7 @@ private:
 
 };
 
-struct tbuilder_minimap : public tbuilder_control
+struct tbuilder_minimap : public implementation::tbuilder_control
 {
 /*WIKI
  * @page = GUIWidgetInstanceWML
@@ -196,7 +178,7 @@ struct tbuilder_minimap : public tbuilder_control
  * A minimap has no extra fields.
  */
 	tbuilder_minimap(const config& cfg) :
-		tbuilder_control(cfg)
+		implementation::tbuilder_control(cfg)
 	{
 	}
 
@@ -204,7 +186,7 @@ struct tbuilder_minimap : public tbuilder_control
 };
 
 struct tbuilder_multi_page
-	: public tbuilder_control
+	: public implementation::tbuilder_control
 {
 
 private:
@@ -225,7 +207,7 @@ public:
 	std::vector<string_map> data;
 };
 
-struct tbuilder_panel : public tbuilder_control
+struct tbuilder_panel : public implementation::tbuilder_control
 {
 
 private:
@@ -238,7 +220,7 @@ public:
 	tbuilder_grid_ptr grid;
 };
 
-struct tbuilder_slider : public tbuilder_control
+struct tbuilder_slider : public implementation::tbuilder_control
 {
 
 private:
@@ -261,7 +243,7 @@ private:
 	std::vector<t_string> value_labels_;
 };
 
-struct tbuilder_scroll_label : public tbuilder_control
+struct tbuilder_scroll_label : public implementation::tbuilder_control
 {
 public:
 /*WIKI
@@ -279,7 +261,7 @@ public:
  * @end_table
  */
 	tbuilder_scroll_label(const config& cfg)
-		: tbuilder_control(cfg)
+		: implementation::tbuilder_control(cfg)
 		, auto_hide_scrollbar_(
 			utils::string_bool(cfg["auto_hide_scrollbar"], true))
 	{
@@ -293,7 +275,7 @@ private:
 };
 
 struct tbuilder_scrollbar_panel
-	: public tbuilder_control
+	: public implementation::tbuilder_control
 {
 
 private:
@@ -310,7 +292,7 @@ public:
 	tbuilder_grid_ptr grid;
 };
 
-struct tbuilder_spacer : public tbuilder_control
+struct tbuilder_spacer : public implementation::tbuilder_control
 {
 
 private:
@@ -336,7 +318,7 @@ public:
  * items.
  */
 	tbuilder_spacer(const config& cfg) :
-		tbuilder_control(cfg),
+		implementation::tbuilder_control(cfg),
 		width_(cfg["width"]),
 		height_(cfg["height"])
 	{}
@@ -348,7 +330,7 @@ private:
 	tformula<unsigned> height_;
 };
 
-struct tbuilder_text_box : public tbuilder_control
+struct tbuilder_text_box : public implementation::tbuilder_control
 {
 private:
 	tbuilder_text_box();
@@ -383,7 +365,7 @@ public:
 
 // copy & paste from tbuilder_text_box...
 // does it make more sense to inherit from it?
-struct tbuilder_password_box : public tbuilder_control
+struct tbuilder_password_box : public implementation::tbuilder_control
 {
 private:
 	tbuilder_password_box();
@@ -409,14 +391,14 @@ public:
  *
  */
 	tbuilder_password_box(const config& cfg) :
-		tbuilder_control(cfg),
+		implementation::tbuilder_control(cfg),
 		history_(cfg["history"])
 	{}
 
 	twidget* build () const;
 };
 
-struct tbuilder_toggle_button : public tbuilder_control
+struct tbuilder_toggle_button : public implementation::tbuilder_control
 {
 private:
 	tbuilder_toggle_button();
@@ -437,7 +419,7 @@ public:
  * @end_table
  */
 	tbuilder_toggle_button(const config& cfg) :
-		tbuilder_control(cfg),
+		implementation::tbuilder_control(cfg),
 		icon_name_(cfg["icon"]),
 		retval_id_(cfg["return_value_id"]),
 		retval_(lexical_cast_default<int>(cfg["return_value"]))
@@ -451,7 +433,7 @@ private:
 	int retval_;
 };
 
-struct tbuilder_toggle_panel : public tbuilder_control
+struct tbuilder_toggle_panel : public implementation::tbuilder_control
 {
 
 private:
@@ -468,7 +450,7 @@ private:
 	int retval_;
 };
 
-struct tbuilder_vertical_scrollbar : public tbuilder_control
+struct tbuilder_vertical_scrollbar : public implementation::tbuilder_control
 {
 private:
 	tbuilder_vertical_scrollbar();
@@ -484,7 +466,7 @@ public:
  *
  */
 	tbuilder_vertical_scrollbar(const config& cfg) :
-		tbuilder_control(cfg)
+		implementation::tbuilder_control(cfg)
 	{}
 
 	twidget* build () const;