# HG changeset patch
# User frosch <frosch@openttd.org>
# Date 1281595228 0
# Node ID b7e37b045c8631afe7c858b5f7ef51873b666327
# Parent  dcbb01a539ea9fac293f87de9ebea579836459ab
(svn r20451) -Codechange: Add helper function Window::GetScrollbar() to get the Scrollbar belonging to a scrollbar widget.

diff --git a/src/window.cpp b/src/window.cpp
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -131,6 +131,39 @@
 }
 
 /**
+ * Return the Scrollbar to a widget index.
+ * @param widnum Scrollbar widget index
+ * @return Scrollbar to the widget
+ */
+const Scrollbar *Window::GetScrollbar(uint widnum) const
+{
+	const NWidgetLeaf *wid = this->GetWidget<NWidgetLeaf>(widnum);
+	switch (wid->type) {
+		case WWT_HSCROLLBAR: return &this->hscroll;
+		case WWT_SCROLLBAR:  return &this->vscroll;
+		case WWT_SCROLL2BAR: return &this->vscroll2;
+		default: NOT_REACHED();
+	}
+}
+
+/**
+ * Return the Scrollbar to a widget index.
+ * @param widnum Scrollbar widget index
+ * @return Scrollbar to the widget
+ */
+Scrollbar *Window::GetScrollbar(uint widnum)
+{
+	NWidgetLeaf *wid = this->GetWidget<NWidgetLeaf>(widnum);
+	switch (wid->type) {
+		case WWT_HSCROLLBAR: return &this->hscroll;
+		case WWT_SCROLLBAR:  return &this->vscroll;
+		case WWT_SCROLL2BAR: return &this->vscroll2;
+		default: NOT_REACHED();
+	}
+}
+
+
+/**
  * Set the window that has the focus
  * @param w The window to set the focus on
  */
diff --git a/src/window_gui.h b/src/window_gui.h
--- a/src/window_gui.h
+++ b/src/window_gui.h
@@ -407,6 +407,8 @@
 	template <class NWID>
 	inline NWID *GetWidget(uint widnum);
 
+	const Scrollbar *GetScrollbar(uint widnum) const;
+	Scrollbar *GetScrollbar(uint widnum);
 
 	void InitNested(const WindowDesc *desc, WindowNumber number = 0);
 	void CreateNestedTree(const WindowDesc *desc, bool fill_nested = true);