private void TrackDropDown(int index)
{
while (index >= 0)
{
this.trackNextItem = -1;
this.BeginUpdate();
CommandBarMenu menu = this.items[index] as CommandBarMenu;
if (menu != null)
{
menu.PerformDropDown(EventArgs.Empty);
this.contextMenu.Items.Clear();
this.contextMenu.Items.AddRange(menu.Items); // = menu.Items;
this.contextMenu.Mnemonics = true;
}
else
{
this.contextMenu.Items.Clear(); // .Items = new CommandBarItemCollection();
this.contextMenu.Mnemonics = true;
}
// Item state
NativeMethods.SendMessage(this.Handle, NativeMethods.TB_PRESSBUTTON, index, -1);
// Trick to get the first menu item selected
NativeMethods.PostMessage(this.Handle, NativeMethods.WM_KEYDOWN, (int)Keys.Down, 1);
NativeMethods.PostMessage(this.Handle, NativeMethods.WM_KEYUP, (int)Keys.Down, 1);
this.SetState(State.HotTracking, index);
// Hook
NativeMethods.HookProc hookProc = new NativeMethods.HookProc(DropDownHook);
GCHandle hookProcHandle = GCHandle.Alloc(hookProc);
this.hookHandle = NativeMethods.SetWindowsHookEx(NativeMethods.WH_MSGFILTER, hookProc, IntPtr.Zero, NativeMethods.GetCurrentThreadId());
if (this.hookHandle == IntPtr.Zero)
{
throw new SecurityException();
}
// Ask for position
NativeMethods.RECT rect = new NativeMethods.RECT();
NativeMethods.SendMessage(Handle, NativeMethods.TB_GETRECT, index, ref rect);
Point position = new Point(rect.left, rect.bottom);
this.EndUpdate();
this.Update();
this.contextMenu.Show(this, position);
// Unhook
NativeMethods.UnhookWindowsHookEx(hookHandle);
hookProcHandle.Free();
this.hookHandle = IntPtr.Zero;
// Item state
NativeMethods.SendMessage(Handle, NativeMethods.TB_PRESSBUTTON, index, 0);
this.SetState(trackEscapePressed ? State.Hot : State.None, index);
index = trackNextItem;
}
}