Lattice/Lattice.Core.Docking/Models/DockLeaf.cs

using Lattice.Core.Docking.Abstractions;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;

namespace Lattice.Core.Docking.Models;

public class DockLeaf : IDockContainer, INotifyPropertyChanged
{
    private readonly ObservableCollection<IDockContent> _items = new();
    private IDockContent? _activeContent;
    private IDockElement? _parent;
    private double _width;
    private double _height;
    private TabPlacement _tabPlacement = TabPlacement.Top;

    public event PropertyChangedEventHandler? PropertyChanged;

    public DockLeaf()
    {
        _items.CollectionChanged += (s, e) => OnPropertyChanged(nameof(Children));
    }

    public string Id { get; } = Guid.NewGuid().ToString();

    public IDockElement? Parent
    {
        get => _parent;
        set
        {
            if (_parent != value)
            {
                _parent = value;
                OnPropertyChanged();
            }
        }
    }

    public IList<IDockContent> Children => _items;

    public IDockContent? ActiveContent
    {
        get => _activeContent;
        set
        {
            if (_activeContent != value)
            {
                _activeContent = value;
                OnPropertyChanged();
            }
        }
    }

    public double Width
    {
        get => _width;
        set
        {
            if (Math.Abs(_width - value) > 0.001)
            {
                _width = value;
                OnPropertyChanged();
            }
        }
    }

    public double Height
    {
        get => _height;
        set
        {
            if (Math.Abs(_height - value) > 0.001)
            {
                _height = value;
                OnPropertyChanged();
            }
        }
    }

    public double MinWidth { get; set; } = 100;
    public double MinHeight { get; set; } = 100;

    public TabPlacement TabPlacement
    {
        get => _tabPlacement;
        set
        {
            if (_tabPlacement != value)
            {
                _tabPlacement = value;
                OnPropertyChanged();
            }
        }
    }

    public void AddContent(IDockContent content)
    {
        if (content == null)
            throw new ArgumentNullException(nameof(content));

        if (!_items.Contains(content))
        {
            _items.Add(content);
        }
        ActiveContent = content;
    }

    public void RemoveContent(IDockContent content)
    {
        if (content == null)
            throw new ArgumentNullException(nameof(content));

        int index = _items.IndexOf(content);
        if (index == -1) return;

        _items.RemoveAt(index);

        if (ActiveContent == content)
        {
            if (_items.Count > 0)
                ActiveContent = _items[Math.Min(index, _items.Count - 1)];
            else
                ActiveContent = null;
        }
    }

    protected virtual void OnPropertyChanged([CallerMemberName] string? propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}