BMenu: scroll marked item into view when menu has scrollers attached.

Signed-off-by: Axel Dörfler <[email protected]>

headers/private/interface/MenuWindow.h

@@ -40,6 +40,7 @@ public:
 			bool			HasScrollers() const;
 			bool			CheckForScrolling(const BPoint& cursor);
 			bool			TryScrollBy(const float& step);
+			bool			TryScrollTo(const float& where);
 
 private:
 			bool			_Scroll(const BPoint& cursor);

src/kits/interface/Menu.cpp

@@ -2871,6 +2871,20 @@ BMenu::_UpdateWindowViewSize(const bool &move)
 			}
 
 			window->AttachScrollers();
+
+			BMenuItem* selectedItem = FindMarked();
+			if (selectedItem != NULL && fLayout == B_ITEMS_IN_COLUMN) {
+				// scroll to the selected item
+				if (Supermenu() == NULL) {
+					window->TryScrollTo(selectedItem->Frame().top);
+				} else {
+					BPoint point = selectedItem->Frame().LeftTop();
+					BPoint superpoint = Superitem()->Frame().LeftTop();
+					Supermenu()->ConvertToScreen(&superpoint);
+					ConvertToScreen(&point);
+					window->TryScrollTo(point.y - superpoint.y);
+				}
+			}
 		}
 	} else {
 		_CacheFontInfo();

src/kits/interface/MenuWindow.cpp

@@ -412,6 +412,17 @@ BMenuWindow::TryScrollBy(const float& step)
 }
 
 
+bool
+BMenuWindow::TryScrollTo(const float& where)
+{
+	if (!fMenuFrame || !fUpperScroller || !fLowerScroller)
+		return false;
+
+	_ScrollBy(where - fValue);
+	return true;
+}
+
+
 bool
 BMenuWindow::_Scroll(const BPoint& where)
 {