From c5f65c93708df972d68e14c069c0fb18bbfa3099 Mon Sep 17 00:00:00 2001
From: Dave Kerr <dwmkerr@gmail.com>
Date: Thu, 7 Nov 2019 13:10:05 +0800
Subject: [PATCH] fix: context menu positioning (#316)

---
 .../NativeContextMenuWrapper.cs                | 18 ++++++++++--------
 .../SharpContextMenu/SharpContextMenu.cs       |  2 +-
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/SharpShell/SharpShell/SharpContextMenu/NativeContextMenuWrapper.cs b/SharpShell/SharpShell/SharpContextMenu/NativeContextMenuWrapper.cs
index 24cd3c2a..79106ed7 100644
--- a/SharpShell/SharpShell/SharpContextMenu/NativeContextMenuWrapper.cs
+++ b/SharpShell/SharpShell/SharpContextMenu/NativeContextMenuWrapper.cs
@@ -27,14 +27,17 @@ public void ResetNativeContextMenu()
         /// Builds a native context menu, on to the provided HMENU.
         /// </summary>
         /// <param name="hMenu">The handle to the menu.</param>
+        /// <param name="itemIndex">The zero-based position at which to insert the first new menu item.</param>
         /// <param name="firstItemId">The first item id.</param>
         /// <param name="toolStripItems">The tool strip menu items.</param>
         /// <returns>The index of the last item created.</returns>
-        public uint BuildNativeContextMenu(IntPtr hMenu, uint firstItemId, ToolStripItemCollection toolStripItems)
+        public uint BuildNativeContextMenu(IntPtr hMenu, uint itemIndex, uint firstItemId, ToolStripItemCollection toolStripItems)
         {
-            //  Create an ID counter and position counter.
+            //  Create an ID counter and position counter. The position is provided by the caller. If this is a top level menu item (i.e.
+            //  top level in the shell context menu) then 'position' will be provided by the Shell via an earlier call to IContextMenu::QueryContextMenu.
+            //  When we create submenus, we simply start at position '0'.
             var idCounter = firstItemId;
-            uint positionCounter = 0;
+            var positionCounter = itemIndex;
 
             //  Go through every tool strip item.
             foreach (ToolStripItem item in toolStripItems)
@@ -58,17 +61,16 @@ public uint BuildNativeContextMenu(IntPtr hMenu, uint firstItemId, ToolStripItem
                     continue;
                 }
 
-                //  We successfully created the menu item, so increment the counters.
+                //  We successfully created the menu item, so increment the position and ID counters.
                 indexedCommands.Add(item);
                 idCounter++;
                 positionCounter++;
 
                 //  Have we just built a menu item? If so, does it have child items?
-                var toolStripMenuItem = item as ToolStripMenuItem;
-                if (toolStripMenuItem != null && toolStripMenuItem.HasDropDownItems)
+                if (item is ToolStripMenuItem toolStripMenuItem && toolStripMenuItem.HasDropDownItems)
                 {
-                    //  Create each drop down item.
-                    idCounter = BuildNativeContextMenu(menuItemInfo.hSubMenu, idCounter, toolStripMenuItem.DropDownItems);
+                    //  Create the drop down menu. As this is a submenu, we start at position zero and go from there.
+                    idCounter = BuildNativeContextMenu(menuItemInfo.hSubMenu, 0, idCounter, toolStripMenuItem.DropDownItems);
                 }
             }
 
diff --git a/SharpShell/SharpShell/SharpContextMenu/SharpContextMenu.cs b/SharpShell/SharpShell/SharpContextMenu/SharpContextMenu.cs
index 57593490..a96a2333 100644
--- a/SharpShell/SharpShell/SharpContextMenu/SharpContextMenu.cs
+++ b/SharpShell/SharpShell/SharpContextMenu/SharpContextMenu.cs
@@ -73,7 +73,7 @@ int IContextMenu.QueryContextMenu(IntPtr hMenu, uint indexMenu, int idCmdFirst,
             try
             {
                 nativeContextMenuWrapper.ResetNativeContextMenu();
-                lastItemId = nativeContextMenuWrapper.BuildNativeContextMenu(hMenu, firstItemId, contextMenuStrip.Value.Items);
+                lastItemId = nativeContextMenuWrapper.BuildNativeContextMenu(hMenu, indexMenu, firstItemId, contextMenuStrip.Value.Items);
             }
             catch (Exception exception)
             {