From dd58b4a93fd202371faaca62c05e740bb1c088a9 Mon Sep 17 00:00:00 2001
From: Eric Kohl <eric.kohl@reactos.org>
Date: Mon, 7 Dec 2015 16:10:09 +0000
Subject: [PATCH] [USETUP] Center the current list item before drawing the
 list. #CORE-10659 #resolve

svn path=/trunk/; revision=70287
---
 reactos/base/setup/usetup/genlist.c | 47 +++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/reactos/base/setup/usetup/genlist.c b/reactos/base/setup/usetup/genlist.c
index 240df1cbebb..709b6f0f0e7 100644
--- a/reactos/base/setup/usetup/genlist.c
+++ b/reactos/base/setup/usetup/genlist.c
@@ -341,6 +341,51 @@ DrawScrollBarGenericList(
 }
 
 
+static
+VOID
+CenterCurrentListItem(
+    PGENERIC_LIST List)
+{
+    PLIST_ENTRY Entry;
+    ULONG MaxVisibleItems, ItemCount, i;
+
+    if ((List->Top == 0 && List->Bottom == 0) ||
+        IsListEmpty(&List->ListHead) ||
+        List->CurrentEntry == NULL)
+        return;
+
+    MaxVisibleItems = (ULONG)(List->Bottom - List->Top - 1);
+
+    ItemCount = 0;
+    Entry = List->ListHead.Flink;
+    while (Entry != &List->ListHead)
+    {
+        ItemCount++;
+        Entry = Entry->Flink;
+    }
+
+    if (ItemCount > MaxVisibleItems)
+    {
+        Entry = &List->CurrentEntry->Entry;
+        for (i = 0; i < MaxVisibleItems / 2; i++)
+        {
+            if (Entry->Blink != &List->ListHead)
+                Entry = Entry->Blink;
+        }
+
+        List->FirstShown = Entry;
+
+        for (i = 0; i < MaxVisibleItems; i++)
+        {
+            if (Entry->Flink != &List->ListHead)
+                Entry = Entry->Flink;
+        }
+
+        List->LastShown = Entry;
+    }
+}
+
+
 VOID
 DrawGenericList(
     PGENERIC_LIST List,
@@ -360,6 +405,8 @@ DrawGenericList(
     if (IsListEmpty(&List->ListHead))
         return;
 
+    CenterCurrentListItem(List);
+
     DrawListEntries(List);
     DrawScrollBarGenericList(List);
 }