From 4898c615d6c4f72deb9433c784b9e6d84419efb0 Mon Sep 17 00:00:00 2001
From: Jessica Hamilton <jessica.l.hamilton@gmail.com>
Date: Sat, 4 May 2013 00:13:41 +1200
Subject: [PATCH] BMenu: scroll marked item into view when menu has scrollers
 attached.
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Signed-off-by: Axel Dörfler <axeld@pinc-software.de>
---
 headers/private/interface/MenuWindow.h |  1 +
 src/kits/interface/Menu.cpp            | 14 ++++++++++++++
 src/kits/interface/MenuWindow.cpp      | 11 +++++++++++
 3 files changed, 26 insertions(+)

diff --git a/headers/private/interface/MenuWindow.h b/headers/private/interface/MenuWindow.h
index 80c03716d7..eb1b943c9d 100644
--- a/headers/private/interface/MenuWindow.h
+++ b/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);
diff --git a/src/kits/interface/Menu.cpp b/src/kits/interface/Menu.cpp
index e8b7283e72..97373d6a9a 100644
--- a/src/kits/interface/Menu.cpp
+++ b/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();
diff --git a/src/kits/interface/MenuWindow.cpp b/src/kits/interface/MenuWindow.cpp
index b568f75c48..9523f67178 100644
--- a/src/kits/interface/MenuWindow.cpp
+++ b/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)
 {