+static bool ScrollVertically(HWND hwnd, int kind, int count)
+{
+ int posStart = GetScrollPosition(hwnd, SB_VERT);
+
+ int pos = posStart;
+ for ( int n = 0; n < count; n++ )
+ {
+ ::SendMessage(hwnd, WM_VSCROLL, kind, 0);
+
+ int posNew = GetScrollPosition(hwnd, SB_VERT);
+ if ( posNew == pos )
+ {
+ // don't bother to continue, we're already at top/bottom
+ break;
+ }
+
+ pos = posNew;
+ }
+
+ return pos != posStart;
+}
+
+bool wxWindowMSW::ScrollLines(int lines)
+{
+ bool down = lines > 0;
+
+ return ScrollVertically(GetHwnd(),
+ down ? SB_LINEDOWN : SB_LINEUP,
+ down ? lines : -lines);
+}
+
+bool wxWindowMSW::ScrollPages(int pages)
+{
+ bool down = pages > 0;
+
+ return ScrollVertically(GetHwnd(),
+ down ? SB_PAGEDOWN : SB_PAGEUP,
+ down ? pages : -pages);
+}
+