gui-cs.Terminal.Gui/Terminal.Gui/Views/Tile.cs

#nullable enable
using System.ComponentModel;

namespace Terminal.Gui;

/// <summary>
///     A single <see cref="ContentView"/> presented in a <see cref="TileView"/>. To create new instances use
///     <see cref="TileView.RebuildForTileCount(int)"/> or <see cref="TileView.InsertTile(int)"/>.
/// </summary>
public class Tile
{
    private string _title = string.Empty;

    /// <summary>Creates a new instance of the <see cref="Tile"/> class.</summary>
    public Tile ()
    {
        ContentView = new View
        {
            Width = Dim.Fill (),
            Height = Dim.Fill (),
            CanFocus = true
        };
#if DEBUG_IDISPOSABLE
        ContentView.Data = "Tile.ContentView";
#endif
        Title = string.Empty;
        MinSize = 0;
    }

    /// <summary>
    ///     The <see cref="ContentView"/> that is contained in this <see cref="TileView"/>. Add new child views to this
    ///     member for multiple <see cref="ContentView"/>s within the <see cref="Tile"/>.
    /// </summary>
    public View? ContentView { get; internal set; }

    /// <summary>
    ///     Gets or Sets the minimum size you to allow when splitter resizing along parent
    ///     <see cref="TileView.Orientation"/> direction.
    /// </summary>
    public int MinSize { get; set; }

    /// <summary>
    ///     The text that should be displayed above the <see cref="ContentView"/>. This will appear over the splitter line
    ///     or border (above the view client area).
    /// </summary>
    /// <remarks>Title are not rendered for root level tiles <see cref="Gui.LineStyle"/> is <see cref="LineStyle.None"/>.</remarks>
    public string Title
    {
        get => _title;
        set
        {
            if (!OnTitleChanging (_title, value))
            {
                string old = _title;
                _title = value;
                OnTitleChanged (old, _title);

                return;
            }

            _title = value;
        }
    }

    /// <summary>Called when the <see cref="Title"/> has been changed. Invokes the <see cref="TitleChanged"/> event.</summary>
    /// <param name="oldTitle">The <see cref="Title"/> that is/has been replaced.</param>
    /// <param name="newTitle">The new <see cref="Title"/> to be replaced.</param>
    public virtual void OnTitleChanged (string oldTitle, string newTitle)
    {
        var args = new EventArgs<string> (in newTitle);
        TitleChanged?.Invoke (this, args);
    }

    /// <summary>
    ///     Called before the <see cref="Title"/> changes. Invokes the <see cref="TitleChanging"/> event, which can be
    ///     cancelled.
    /// </summary>
    /// <param name="oldTitle">The <see cref="Title"/> that is/has been replaced.</param>
    /// <param name="newTitle">The new <see cref="Title"/> to be replaced.</param>
    /// <returns><c>true</c> if an event handler cancelled the Title change.</returns>
    public virtual bool OnTitleChanging (string oldTitle, string newTitle)
    {
        var args = new CancelEventArgs<string> (ref oldTitle, ref newTitle);
        TitleChanging?.Invoke (this, args);

        return args.Cancel;
    }

    /// <summary>Event fired after the <see cref="Title"/> has been changed.</summary>
    public event EventHandler? TitleChanged;

    /// <summary>
    ///     Event fired when the <see cref="Title"/> is changing.
    ///     <see cref="CancelEventArgs.Cancel"/> can be set to <c>true</c> to cancel the change.
    /// </summary>
    public event EventHandler<CancelEventArgs<string>>? TitleChanging;
}