--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -1633,6 +1633,38 @@
 }
 
 /**
+ * Compute the row of a scrolled widget that a user clicked in.
+ * @param clickpos    Vertical position of the mouse click (without taking scrolling into account).
+ * @param widget      Widget number of the widget clicked in.
+ * @param padding     Amount of empty space between the widget edge and the top of the first row. Default value is \c 0.
+ * @param line_height Height of a single row. A negative value means using the vertical resize step of the widget.
+ * @return Row number clicked at. If clicked at a wrong position, #INT_MAX is returned.
+ */
+int Scrollbar::GetScrolledRowFromWidget(int clickpos, const Window * const w, int widget, int padding, int line_height) const
+{
+	uint pos = w->GetRowFromWidget(clickpos, widget, padding, line_height);
+	if (pos != INT_MAX) pos += this->GetPosition();
+	return (pos >= this->GetCount()) ? INT_MAX : pos;
+}
+
+/**
+ * Set capacity of visible elements from the size and resize properties of a widget.
+ * @param w       Window.
+ * @param widget  Widget with size and resize properties.
+ * @param padding Padding to subtract from the size.
+ * @note Updates the position if needed.
+ */
+void Scrollbar::SetCapacityFromWidget(Window *w, int widget, int padding)
+{
+	NWidgetBase *nwid = w->GetWidget<NWidgetBase>(widget);
+	if (this->is_vertical) {
+		this->SetCapacity(((int)nwid->current_y - padding) / (int)nwid->resize_y);
+	} else {
+		this->SetCapacity(((int)nwid->current_x - padding) / (int)nwid->resize_x);
+	}
+}
+
+/**
  * Scrollbar widget.
  * @param tp     Scrollbar type. (horizontal/vertical)
  * @param colour Colour of the scrollbar.

--- a/src/widget_type.h
+++ b/src/widget_type.h
@@ -502,6 +502,132 @@
 };
 
 /**
+ * Scrollbar data structure
+ */
+class Scrollbar {
+private:
+	const bool is_vertical; ///< Scrollbar has vertical orientation.
+	uint16 count;           ///< Number of elements in the list.
+	uint16 cap;             ///< Number of visible elements of the scroll bar.
+	uint16 pos;             ///< Index of first visible item of the list.
+
+public:
+	Scrollbar(bool is_vertical) : is_vertical(is_vertical)
+	{
+	}
+
+	/**
+	 * Gets the number of elements in the list
+	 * @return the number of elements
+	 */
+	FORCEINLINE uint16 GetCount() const
+	{
+		return this->count;
+	}
+
+	/**
+	 * Gets the number of visible elements of the scrollbar
+	 * @return the number of visible elements
+	 */
+	FORCEINLINE uint16 GetCapacity() const
+	{
+		return this->cap;
+	}
+
+	/**
+	 * Gets the position of the first visible element in the list
+	 * @return the position of the element
+	 */
+	FORCEINLINE uint16 GetPosition() const
+	{
+		return this->pos;
+	}
+
+	/**
+	 * Checks whether given current item is visible in the list
+	 * @param item to check
+	 * @return true iff the item is visible
+	 */
+	FORCEINLINE bool IsVisible(uint16 item) const
+	{
+		return IsInsideBS(item, this->GetPosition(), this->GetCapacity());
+	}
+
+	/**
+	 * Sets the number of elements in the list
+	 * @param num the number of elements in the list
+	 * @note updates the position if needed
+	 */
+	void SetCount(int num)
+	{
+		assert(num >= 0);
+		assert(num <= MAX_UVALUE(uint16));
+
+		this->count = num;
+		num -= this->cap;
+		if (num < 0) num = 0;
+		if (num < this->pos) this->pos = num;
+	}
+
+	/**
+	 * Set the capacity of visible elements.
+	 * @param capacity the new capacity
+	 * @note updates the position if needed
+	 */
+	void SetCapacity(int capacity)
+	{
+		assert(capacity > 0);
+		assert(capacity <= MAX_UVALUE(uint16));
+
+		this->cap = capacity;
+		if (this->cap + this->pos > this->count) this->pos = max(0, this->count - this->cap);
+	}
+
+	void SetCapacityFromWidget(Window *w, int widget, int padding = 0);
+
+	/**
+	 * Sets the position of the first visible element
+	 * @param position the position of the element
+	 */
+	void SetPosition(int position)
+	{
+		assert(position >= 0);
+		assert(this->count <= this->cap ? (position == 0) : (position + this->cap <= this->count));
+		this->pos = position;
+	}
+
+	/**
+	 * Updates the position of the first visible element by the given amount.
+	 * If the position would be too low or high it will be clamped appropriately
+	 * @param difference the amount of change requested
+	 */
+	void UpdatePosition(int difference)
+	{
+		if (difference == 0) return;
+		this->SetPosition(Clamp(this->pos + difference, 0, max(this->count - this->cap, 0)));
+	}
+
+	/**
+	 * Scroll towards the given position; if the item is visible nothing
+	 * happens, otherwise it will be shown either at the bottom or top of
+	 * the window depending on where in the list it was.
+	 * @param position the position to scroll towards.
+	 */
+	void ScrollTowards(int position)
+	{
+		if (position < this->GetPosition()) {
+			/* scroll up to the item */
+			this->SetPosition(position);
+		} else if (position >= this->GetPosition() + this->GetCapacity()) {
+			/* scroll down so that the item is at the bottom */
+			this->SetPosition(position - this->GetCapacity() + 1);
+		}
+	}
+
+	int GetScrolledRowFromWidget(int clickpos, const Window * const w, int widget, int padding = 0, int line_height = -1) const;
+};
+
+/**
  * Nested widget to display and control a scrollbar in a window.
  * Also assign the scrollbar to other widgets using #SetScrollbar() to make the mousewheel work.
  * @ingroup NestedWidgets

--- a/src/window.cpp
+++ b/src/window.cpp
@@ -98,38 +98,6 @@
 }
 
 /**
- * Compute the row of a scrolled widget that a user clicked in.
- * @param clickpos    Vertical position of the mouse click (without taking scrolling into account).
- * @param widget      Widget number of the widget clicked in.
- * @param padding     Amount of empty space between the widget edge and the top of the first row. Default value is \c 0.
- * @param line_height Height of a single row. A negative value means using the vertical resize step of the widget.
- * @return Row number clicked at. If clicked at a wrong position, #INT_MAX is returned.
- */
-int Scrollbar::GetScrolledRowFromWidget(int clickpos, const Window * const w, int widget, int padding, int line_height) const
-{
-	uint pos = w->GetRowFromWidget(clickpos, widget, padding, line_height);
-	if (pos != INT_MAX) pos += this->GetPosition();
-	return (pos >= this->GetCount()) ? INT_MAX : pos;
-}
-
-/**
- * Set capacity of visible elements from the size and resize properties of a widget.
- * @param w       Window.
- * @param widget  Widget with size and resize properties.
- * @param padding Padding to subtract from the size.
- * @note Updates the position if needed.
- */
-void Scrollbar::SetCapacityFromWidget(Window *w, int widget, int padding)
-{
-	NWidgetBase *nwid = w->GetWidget<NWidgetBase>(widget);
-	if (this->is_vertical) {
-		this->SetCapacity(((int)nwid->current_y - padding) / (int)nwid->resize_y);
-	} else {
-		this->SetCapacity(((int)nwid->current_x - padding) / (int)nwid->resize_x);
-	}
-}
-
-/**
  * Return the Scrollbar to a widget index.
  * @param widnum Scrollbar widget index
  * @return Scrollbar to the widget

--- a/src/window_gui.h
+++ b/src/window_gui.h
@@ -184,132 +184,6 @@
 };
 
 /**
- * Scrollbar data structure
- */
-class Scrollbar {
-private:
-	const bool is_vertical; ///< Scrollbar has vertical orientation.
-	uint16 count;           ///< Number of elements in the list.
-	uint16 cap;             ///< Number of visible elements of the scroll bar.
-	uint16 pos;             ///< Index of first visible item of the list.
-
-public:
-	Scrollbar(bool is_vertical) : is_vertical(is_vertical)
-	{
-	}
-
-	/**
-	 * Gets the number of elements in the list
-	 * @return the number of elements
-	 */
-	FORCEINLINE uint16 GetCount() const
-	{
-		return this->count;
-	}
-
-	/**
-	 * Gets the number of visible elements of the scrollbar
-	 * @return the number of visible elements
-	 */
-	FORCEINLINE uint16 GetCapacity() const
-	{
-		return this->cap;
-	}
-
-	/**
-	 * Gets the position of the first visible element in the list
-	 * @return the position of the element
-	 */
-	FORCEINLINE uint16 GetPosition() const
-	{
-		return this->pos;
-	}
-
-	/**
-	 * Checks whether given current item is visible in the list
-	 * @param item to check
-	 * @return true iff the item is visible
-	 */
-	FORCEINLINE bool IsVisible(uint16 item) const
-	{
-		return IsInsideBS(item, this->GetPosition(), this->GetCapacity());
-	}
-
-	/**
-	 * Sets the number of elements in the list
-	 * @param num the number of elements in the list
-	 * @note updates the position if needed
-	 */
-	void SetCount(int num)
-	{
-		assert(num >= 0);
-		assert(num <= MAX_UVALUE(uint16));
-
-		this->count = num;
-		num -= this->cap;
-		if (num < 0) num = 0;
-		if (num < this->pos) this->pos = num;
-	}
-
-	/**
-	 * Set the capacity of visible elements.
-	 * @param capacity the new capacity
-	 * @note updates the position if needed
-	 */
-	void SetCapacity(int capacity)
-	{
-		assert(capacity > 0);
-		assert(capacity <= MAX_UVALUE(uint16));
-
-		this->cap = capacity;
-		if (this->cap + this->pos > this->count) this->pos = max(0, this->count - this->cap);
-	}
-
-	void SetCapacityFromWidget(Window *w, int widget, int padding = 0);
-
-	/**
-	 * Sets the position of the first visible element
-	 * @param position the position of the element
-	 */
-	void SetPosition(int position)
-	{
-		assert(position >= 0);
-		assert(this->count <= this->cap ? (position == 0) : (position + this->cap <= this->count));
-		this->pos = position;
-	}
-
-	/**
-	 * Updates the position of the first visible element by the given amount.
-	 * If the position would be too low or high it will be clamped appropriately
-	 * @param difference the amount of change requested
-	 */
-	void UpdatePosition(int difference)
-	{
-		if (difference == 0) return;
-		this->SetPosition(Clamp(this->pos + difference, 0, max(this->count - this->cap, 0)));
-	}
-
-	/**
-	 * Scroll towards the given position; if the item is visible nothing
-	 * happens, otherwise it will be shown either at the bottom or top of
-	 * the window depending on where in the list it was.
-	 * @param position the position to scroll towards.
-	 */
-	void ScrollTowards(int position)
-	{
-		if (position < this->GetPosition()) {
-			/* scroll up to the item */
-			this->SetPosition(position);
-		} else if (position >= this->GetPosition() + this->GetCapacity()) {
-			/* scroll down so that the item is at the bottom */
-			this->SetPosition(position - this->GetCapacity() + 1);
-		}
-	}
-
-	int GetScrolledRowFromWidget(int clickpos, const Window * const w, int widget, int padding = 0, int line_height = -1) const;
-};
-
-/**
  * Data structure for resizing a window
  */
 struct ResizeInfo {