public ConsoleMenu(IAtomicConsole console, Rectangle availableArea, IEnumerable <ConsoleMenuItem> menuItems, MenuStyles styling)
{
this._console = console ?? throw new ArgumentNullException(nameof(console));
this._availableArea = availableArea;
this._styling = styling ?? throw new ArgumentNullException(nameof(styling));
if (menuItems != null)
{
this._menuItems = menuItems.ToList();
this._selectedItem = this._menuItems.FirstOrDefault();
}
else
{
this._menuItems = new List <ConsoleMenuItem>();
}
}
private void RenderSingleItem(ConsoleMenuItem item, int yIndex)
{
// TODO: reuse printlabel from demos? move these from demo shared to operations / root?
// TODO: use Span<char> to optimize. Hopefully System.Console will receive such overload as well
string caption = "###";
if (item.Caption.Length <= this._availableArea.Width)
{
switch (this._styling.Alignment)
{
case TextAlign.Left:
{
caption = item.Caption.PadRight(this._availableArea.Width);
break;
}
case TextAlign.Right:
{
caption = item.Caption.PadLeft(this._availableArea.Width);
break;
};
case TextAlign.Center:
{
int padLeft = (this._availableArea.Width - item.Caption.Length) / 2;
caption = item.Caption.PadLeft(padLeft + item.Caption.Length).PadRight(this._availableArea.Width);
break;
}
}
}
else
{
caption = (this._styling.AddEllipsisOnOverflow)
? item.Caption.Substring(0, this._availableArea.Width - 1) + ELLIPSIS_CHARACTER
: item.Caption.Substring(0, this._availableArea.Width);
}
this._console.RunAtomicOperations((c) =>
{
c.SetCursorPosition(this._availableArea.X, this._availableArea.Y + yIndex);
c.WriteText(this.ChooseItemStyle(item), caption);
});
}
private ConsoleFontColor ChooseItemStyle(ConsoleMenuItem item)
{
if (item.Enabled)
{
if (this._selectedItem == item)
{
return(this._styling.SelectedItem);
}
else if (this._activeItem == item)
{
return(this._styling.ActiveItem);
}
else
{
return(this._styling.NormalItem);
}
}
else
{
return(this._styling.DisabledItem);
}
}
/// <summary>
/// Activates menu.
/// </summary>
/// <param name="resetActiveItem">When TRUE, currently active element highlight will be removed.</param>
/// <returns>Finally activated menu item.</returns>
/// <remarks>Note - it auto-hides cursor for better interaction, but does not restore it back on exit</remarks>
public ConsoleMenuItem Focus(bool resetActiveItem = false) // TODO: async?
{
this._console.HideCursor();
this._selectedItem = this._activeItem ?? this._menuItems.FirstOrDefault();
if (this._selectedItem != null)
{
this.RenderSingleItem(this._selectedItem, this._menuItems.IndexOf(this._selectedItem));
}
if (resetActiveItem)
{
var tempItem = this._activeItem;
if (tempItem != null)
{
this._activeItem = null;
this.RenderSingleItem(tempItem, this._menuItems.IndexOf(tempItem));
}
}
ConsoleKey key = ConsoleKey.Escape;
while (key != this._styling.SelectionKey)
{
key = this._console.ReadKey().Key;
int?elementIndex = null;
if (key == this._styling.MoveUpKey)
{
elementIndex = this.FindItemAbove();
}
else if (key == this._styling.MoveDownKey)
{
elementIndex = this.FindItemBelow();
}
else if (key == this._styling.MoveTopKey)
{
elementIndex = this.FindFirstItem();
}
else if (key == this._styling.MoveBottomKey)
{
elementIndex = this.FindLastItem();
}
if (elementIndex.HasValue)
{
var currentItemIndex = this.FindSelectedItem();
if (currentItemIndex != elementIndex)
{
var tempItem = this._selectedItem;
this._selectedItem = this._menuItems[elementIndex.Value];
this.RenderSingleItem(this._selectedItem, elementIndex.Value);
if (currentItemIndex.HasValue)
{
this.RenderSingleItem(tempItem, currentItemIndex.Value);
}
this.OnItemChanged(new MenuItemChangedHandlerArgs(this._selectedItem, tempItem));
}
}
}
this._activeItem = this._selectedItem;
this.RenderSingleItem(this._activeItem, this._menuItems.IndexOf(this._activeItem));
this._selectedItem = null;
this.RenderAll();
return(this._activeItem);
}