3rdpartylibs/fastreports.wpf/FastReport.Forms.WPF/Controls/ScrollBar.cs

namespace System.Windows.Forms
{
    public class ScrollBar : Control
    {
        protected new System.Windows.Controls.Primitives.ScrollBar control { get; }

        public int LargeChange
        {
            get => (int)control.LargeChange;
            set
            {
                control.LargeChange = value;
                control.ViewportSize = value;
                UpdateMaximum();
            }
        }

        private int maximum;
        public int Maximum
        {
            get => maximum;
            set
            {
                maximum = value;
                UpdateMaximum();
            }
        }

        public int Minimum
        {
            get => (int)control.Minimum;
            set => control.Minimum = value;
        }

        public int SmallChange
        {
            get => (int)control.SmallChange;
            set => control.SmallChange = value;
        }

        public int Value
        {
            get => (int)control.Value;
            set => control.Value = value;
        }

        public event ScrollEventHandler Scroll;
        public event EventHandler ValueChanged;

        private void UpdateMaximum()
        {
            control.Maximum = maximum - control.ViewportSize;
        }

        protected virtual void OnScroll(ScrollEventArgs e) => Scroll?.Invoke(this, e);
        
        protected virtual void OnValueChanged(EventArgs e) => ValueChanged?.Invoke(this, e);

        public ScrollBar()
        {
            control = new();
            SetControl(control);

            control.Scroll += (s, e) => OnScroll(Helper.GetScrollEventArgs(e, control.Orientation == Windows.Controls.Orientation.Horizontal));
            control.ValueChanged += (s, e) => OnValueChanged(e);
        }
    }
}