Ursa.Avalonia/src/Ursa/Controls/Dialog/DialogControlBase.cs

using Avalonia;
using Avalonia.Controls;
using Avalonia.Controls.Metadata;
using Avalonia.Controls.Primitives;
using Avalonia.Input;
using Avalonia.Interactivity;
using Avalonia.LogicalTree;
using Irihi.Avalonia.Shared.Helpers;
using Ursa.Controls.OverlayShared;

namespace Ursa.Controls;

[TemplatePart(PART_CloseButton, typeof(Button))]
[TemplatePart(PART_TitleArea, typeof(Panel))]
[PseudoClasses(PC_Modal, PC_FullScreen)]
public abstract class DialogControlBase : OverlayFeedbackElement
{
    public const string PART_CloseButton = "PART_CloseButton";
    public const string PART_TitleArea = "PART_TitleArea";
    public const string PC_Modal = ":modal";
    public const string PC_FullScreen = ":full-screen";

    public static readonly DirectProperty<DialogControlBase, bool> IsFullScreenProperty =
        AvaloniaProperty.RegisterDirect<DialogControlBase, bool>(
            nameof(IsFullScreen), o => o.IsFullScreen, (o, v) => o.IsFullScreen = v);

    public static readonly StyledProperty<bool> CanResizeProperty = AvaloniaProperty.Register<DialogControlBase, bool>(
        nameof(CanResize));

    protected internal Button? _closeButton;

    private bool _isFullScreen;
    private Panel? _titleArea;
    private bool _moveDragging;
    private Point _moveDragStartPoint;
    

    static DialogControlBase()
    {
        CanDragMoveProperty.Changed.AddClassHandler<InputElement, bool>(OnCanDragMoveChanged);
        CanCloseProperty.Changed.AddClassHandler<InputElement, bool>(OnCanCloseChanged);
        IsFullScreenProperty.AffectsPseudoClass<DialogControlBase>(PC_FullScreen);
    }

    public bool CanResize
    {
        get => GetValue(CanResizeProperty);
        set => SetValue(CanResizeProperty, value);
    }

    internal HorizontalPosition HorizontalAnchor { get; set; } = HorizontalPosition.Center;
    internal VerticalPosition VerticalAnchor { get; set; } = VerticalPosition.Center;
    internal HorizontalPosition ActualHorizontalAnchor { get; set; }
    internal VerticalPosition ActualVerticalAnchor { get; set; }
    internal double? HorizontalOffset { get; set; }
    internal double? VerticalOffset { get; set; }
    internal double? HorizontalOffsetRatio { get; set; }
    internal double? VerticalOffsetRatio { get; set; }
    internal bool CanLightDismiss { get; set; }
    internal bool? IsCloseButtonVisible { get; set; }

    public bool IsFullScreen
    {
        get => _isFullScreen;
        set => SetAndRaise(IsFullScreenProperty, ref _isFullScreen, value);
    }

    protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
    {
        base.OnApplyTemplate(e);
        _titleArea = e.NameScope.Find<Panel>(PART_TitleArea);
        if (GetCanDragMove(this))
        {
            _titleArea?.RemoveHandler(PointerMovedEvent, OnTitlePointerMove);
            _titleArea?.RemoveHandler(PointerPressedEvent, OnTitlePointerPressed);
            _titleArea?.RemoveHandler(PointerReleasedEvent, OnTitlePointerRelease);

            _titleArea?.AddHandler(PointerMovedEvent, OnTitlePointerMove, RoutingStrategies.Bubble);
            _titleArea?.AddHandler(PointerPressedEvent, OnTitlePointerPressed, RoutingStrategies.Bubble);
            _titleArea?.AddHandler(PointerReleasedEvent, OnTitlePointerRelease, RoutingStrategies.Bubble);
        }
        else
        {
            if (_titleArea is not null) _titleArea.IsHitTestVisible = false;
        }

        Button.ClickEvent.RemoveHandler(OnCloseButtonClick, _closeButton);
        _closeButton = e.NameScope.Find<Button>(PART_CloseButton);
        Button.ClickEvent.AddHandler(OnCloseButtonClick, _closeButton);
    }

    private void OnTitlePointerPressed(InputElement sender, PointerPressedEventArgs e)
    {
        //e.Source = this;
        if (ContainerPanel is OverlayDialogHost h)
        {
            if (h.IsTopLevel && this.IsFullScreen)
            {
                var top = TopLevel.GetTopLevel(this);
                if (top is Window w)
                {
                    w.BeginMoveDrag(e);
                    return;
                }
            }
        }
        if (!e.GetCurrentPoint(this).Properties.IsLeftButtonPressed) return;
        if (IsFullScreen) return;
        _moveDragging = true;
        _moveDragStartPoint = e.GetPosition(this);
    }

    private void OnTitlePointerMove(InputElement sender, PointerEventArgs e)
    {
        //e.Source = this;
        if (!_moveDragging) return;
        if (ContainerPanel is null) return;
        var p = e.GetPosition(this);
        var left = Canvas.GetLeft(this) + p.X - _moveDragStartPoint.X;
        var top = Canvas.GetTop(this) + p.Y - _moveDragStartPoint.Y;
        left = MathHelpers.SafeClamp(left, 0, ContainerPanel.Bounds.Width - Bounds.Width);
        top = MathHelpers.SafeClamp(top, 0, ContainerPanel.Bounds.Height - Bounds.Height);
        Canvas.SetLeft(this, left);
        Canvas.SetTop(this, top);
    }

    private void OnTitlePointerRelease(InputElement sender, PointerReleasedEventArgs e)
    {
        // e.Source = this;
        _moveDragging = false;
        AnchorAndUpdatePositionInfo();
    }

    private void OnCloseButtonClick(object? sender, RoutedEventArgs args)
    {
        Close();
    }

    internal void SetAsModal(bool modal)
    {
        PseudoClasses.Set(PC_Modal, modal);
    }

    #region Layer Management

    public static readonly RoutedEvent<DialogLayerChangeEventArgs> LayerChangedEvent =
        RoutedEvent.Register<CustomDialogControl, DialogLayerChangeEventArgs>(
            nameof(LayerChanged), RoutingStrategies.Bubble);

    public event EventHandler<DialogLayerChangeEventArgs> LayerChanged
    {
        add => AddHandler(LayerChangedEvent, value);
        remove => RemoveHandler(LayerChangedEvent, value);
    }

    public void UpdateLayer(object? o)
    {
        if (o is DialogLayerChangeType t) RaiseEvent(new DialogLayerChangeEventArgs(LayerChangedEvent, t));
    }

    #endregion

    #region DragMove AttachedPropert

    public static readonly AttachedProperty<bool> CanDragMoveProperty =
        AvaloniaProperty.RegisterAttached<DialogControlBase, InputElement, bool>("CanDragMove");

    public static void SetCanDragMove(InputElement obj, bool value)
    {
        obj.SetValue(CanDragMoveProperty, value);
    }

    public static bool GetCanDragMove(InputElement obj)
    {
        return obj.GetValue(CanDragMoveProperty);
    }

    private static void OnCanDragMoveChanged(InputElement arg1, AvaloniaPropertyChangedEventArgs<bool> arg2)
    {
        if (arg2.NewValue.Value)
        {
            arg1.AddHandler(PointerPressedEvent, OnPointerPressed, RoutingStrategies.Bubble);
            arg1.AddHandler(PointerMovedEvent, OnPointerMoved, RoutingStrategies.Bubble);
            arg1.AddHandler(PointerReleasedEvent, OnPointerReleased, RoutingStrategies.Bubble);
        }
        else
        {
            arg1.RemoveHandler(PointerPressedEvent, OnPointerPressed);
            arg1.RemoveHandler(PointerMovedEvent, OnPointerMoved);
            arg1.RemoveHandler(PointerReleasedEvent, OnPointerReleased);
        }

        void OnPointerPressed(InputElement sender, PointerPressedEventArgs e)
        {
            if (sender.FindLogicalAncestorOfType<DialogControlBase>() is { } dialog) e.Source = dialog;
        }

        void OnPointerMoved(InputElement sender, PointerEventArgs e)
        {
            if (sender.FindLogicalAncestorOfType<DialogControlBase>() is { } dialog) e.Source = dialog;
        }

        void OnPointerReleased(InputElement sender, PointerReleasedEventArgs e)
        {
            if (sender.FindLogicalAncestorOfType<DialogControlBase>() is { } dialog) e.Source = dialog;
        }
    }

    #endregion

    #region Close AttachedProperty

    public static readonly AttachedProperty<bool> CanCloseProperty =
        AvaloniaProperty.RegisterAttached<DialogControlBase, InputElement, bool>("CanClose");

    public static void SetCanClose(InputElement obj, bool value)
    {
        obj.SetValue(CanCloseProperty, value);
    }

    public static bool GetCanClose(InputElement obj)
    {
        return obj.GetValue(CanCloseProperty);
    }

    private static void OnCanCloseChanged(InputElement arg1, AvaloniaPropertyChangedEventArgs<bool> arg2)
    {
        if (arg2.NewValue.Value) arg1.AddHandler(PointerPressedEvent, OnPointerPressed, RoutingStrategies.Bubble);

        void OnPointerPressed(InputElement sender, PointerPressedEventArgs e)
        {
            if (sender.FindLogicalAncestorOfType<DialogControlBase>() is { } dialog) dialog.Close();
        }
    }

    #endregion
    
    protected internal override void AnchorAndUpdatePositionInfo()
    {
        if (ContainerPanel is null) return;
        ActualHorizontalAnchor = HorizontalPosition.Center;
        ActualVerticalAnchor = VerticalPosition.Center;
        double left = Canvas.GetLeft(this);
        double top = Canvas.GetTop(this);
        double right = ContainerPanel.Bounds.Width - left - Bounds.Width;
        double bottom = ContainerPanel.Bounds.Height - top - Bounds.Height;
        if (ContainerPanel is OverlayDialogHost h)
        {
            var snapThickness = h.SnapThickness;
            if(top < snapThickness.Top)
            {
                Canvas.SetTop(this, 0);
                ActualVerticalAnchor = VerticalPosition.Top;
                VerticalOffsetRatio = 0;
            }
            if(bottom < snapThickness.Bottom)
            {
                Canvas.SetTop(this, ContainerPanel.Bounds.Height - Bounds.Height);
                ActualVerticalAnchor = VerticalPosition.Bottom;
                VerticalOffsetRatio = 1;
            }
            if(left < snapThickness.Left)
            {
                Canvas.SetLeft(this, 0);
                ActualHorizontalAnchor = HorizontalPosition.Left;
                HorizontalOffsetRatio = 0;
            }
            if(right < snapThickness.Right)
            {
                Canvas.SetLeft(this, ContainerPanel.Bounds.Width - this.Bounds.Width);
                ActualHorizontalAnchor = HorizontalPosition.Right;
                HorizontalOffsetRatio = 1;
            }
        }
        left = Canvas.GetLeft(this);
        top = Canvas.GetTop(this);
        right = ContainerPanel.Bounds.Width - left - Bounds.Width;
        bottom = ContainerPanel.Bounds.Height - top - Bounds.Height;

        HorizontalOffsetRatio = (left + right) == 0 ? 0 : left / (left + right);
        VerticalOffsetRatio = (top + bottom) == 0 ? 0 : top / (top + bottom);
    }
}