AIPlatform_6787/aipdev/BlackToolTip.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Media;

namespace aipdev
{
    public enum PlacementDirection
    {
        Left,
        Top,
        Right,
        Bottom
    }

    class BlackToolTip:ToolTip
    {
        public static readonly DependencyProperty TextProperty = DependencyProperty.Register(
            "Text", typeof(string), typeof(BlackToolTip), new PropertyMetadata(null));

        public static readonly DependencyProperty DirectionProperty = DependencyProperty.Register(
            "Direction", typeof(PlacementDirection), typeof(BlackToolTip), new PropertyMetadata(null));

        private readonly Border _border;
        private readonly TextBlock _textBlock;


        public string Text
        {
            get => (string)GetValue(TextProperty);
            set => SetValue(TextProperty, value);
        }
         
        public PlacementDirection Direction
        {
            get => (PlacementDirection)GetValue(DirectionProperty);
            set => SetValue(DirectionProperty, value);
        }

        public BlackToolTip()
        {
            BorderThickness = new Thickness(0);
            Padding = new Thickness(0);
            Background = Brushes.Transparent;
            Foreground = Brushes.Transparent;
            _border = new Border
            {
                Background = Brushes.Black,
                BorderBrush = Brushes.Gray,
                BorderThickness = new Thickness(0.5),
                CornerRadius = new CornerRadius(4.0),
            };
            _textBlock = new TextBlock
            {
                VerticalAlignment = VerticalAlignment.Center,
                HorizontalAlignment = HorizontalAlignment.Center,
                Background = Brushes.Transparent,
                Foreground = Brushes.White,
                FontSize = 14,
                Margin = new Thickness(8),
                TextWrapping= TextWrapping.Wrap
            };
            _border.Child = _textBlock;
            Content = _border;
        }

        protected override void OnRenderSizeChanged(SizeChangedInfo sizeInfo)
        {
            UpdateOffset();
            base.OnRenderSizeChanged(sizeInfo);
        }

        private void UpdateOffset()
        {
            if (PlacementTarget is FrameworkElement element)
            {
                if (Direction == PlacementDirection.Right || Direction == PlacementDirection.Left)
                {
                    var elementHeight = element.ActualHeight;
                    var height = ActualHeight;
                    var offset = (elementHeight - height) / 2;
                    VerticalOffset = offset;
                }
                else if (Direction == PlacementDirection.Top || Direction == PlacementDirection.Bottom)
                {
                    var elementWidth = element.ActualWidth;
                    var width = ActualWidth;
                    var offset = (elementWidth - width) / 2;
                    HorizontalOffset = offset;
                }
            }
        }

        protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
        {
            base.OnPropertyChanged(e);
            if (e.Property == TextProperty)
            {
                var text = (string) e.NewValue;
                _textBlock.Text = text;
            }
            if (e.Property == DirectionProperty)
            {
                var direction = (PlacementDirection) e.NewValue;
                if (direction == PlacementDirection.Left)
                {
                    Placement = PlacementMode.Left;
                }
                if (direction == PlacementDirection.Top)
                {
                    Placement = PlacementMode.Top;
                }
                if (direction == PlacementDirection.Right)
                {
                    Placement = PlacementMode.Right;
                }
                if (direction == PlacementDirection.Bottom)
                {
                    Placement = PlacementMode.Bottom;
                }
            }
        }
    }
}