private MenuItem MenuItemFromCursorKey(VirtualKey virtualKey)
{
const int NextMenuItem = 0;
const int PrevMenuItem = 1;
const int Nothing = 2;
int action = Nothing;
if (DropDownMenu)
{
if (virtualKey == VirtualKey.VK_UP)
{
action = PrevMenuItem;
}
else if (virtualKey == VirtualKey.VK_DOWN)
{
action = NextMenuItem;
}
}
else
{
if (virtualKey == VirtualKey.VK_LEFT)
{
action = PrevMenuItem;
}
else if (virtualKey == VirtualKey.VK_RIGHT)
{
action = NextMenuItem;
}
}
if (action == Nothing || !VisibleMenuItems.Any())
{
return(null);
}
var currentMenuItem = ActiveMenuItem ?? VisibleMenuItems.First();
var index = _menuItems.IndexOf(currentMenuItem);
var count = VisibleMenuItems.Count();
do
{
if (action == NextMenuItem)
{
index = (index + 1) % count;
}
else if (action == PrevMenuItem)
{
index = (index - 1 + count) % count;
}
}while (_menuItems[index].Separator);
return(_menuItems[index]);
}
public override void OnKeyUp(object sender, KeyEvent e)
{
if (!this._active)
{
this._active = true;
if (VisibleMenuItems.Any() && !this.AllowNoSelection)
{
ActivateMenuItem((Screen)sender, VisibleMenuItems.First());
}
}
else
{
if (e.VirtualKey == VirtualKey.VK_MENU)
{
Deactivate((Screen)sender);
}
}
}
public void Update( )
{
if (this != CurrentMenu)
{
return;
}
if (SelectedItem == null)
{
SelectedItem = VisibleMenuItems.FirstOrDefault( );
}
int lineNumber = 0;
bool ScrollNeeded = Display.MaxLines < CountVisibleMenuItems;
if (ScrollNeeded)
{
throw new NotImplementedException("Too many visible menu items");
}
Display.WriteLine(int.MaxValue, MenuHeading, Color.Aqua);
foreach (var item in VisibleMenuItems)
{
Display.WriteLine(
lineNumber++,
item.DisplayString,
SelectedItem == item ? SelectedColour : ItemColour);
}
while (lineNumber < Display.MaxLines)
{
// blank the unused lines.
Display.WriteLine(lineNumber++, "", Color.White);
}
}
