ColorPicker

See the ColorPickerDemo.cs.

using Gridrand.Contracts;
using Gridrand.RimGui.Manual;
using System;

namespace Gridrand.RimGui.Extensions.Manual
{
    /// <summary>
    /// Demonstrates the color picker.
    /// </summary>
    class ColorPickerDemo : ManualBase, IManual
    {
        HsvColor hsv = new(240d, 0.8d, 0.8d, 0.8d);

        public ColorPickerDemo(ManualBaseResource p) : base(p)
        {
        }

        public void Draw()
        {
            using (ExStyle.RectInnerPointHandle.Colors.Begin(new Color32(220, 220, 220, 255)))
            using (ExStyle.VerticalBarHandle.Colors.Begin(new Color32(220, 220, 220, 255)))
            using (Style.SpacingXs.Begin(5f))
            using (var rects = LayoutBuilder
                .Fixed(200f)
                .Fixed(20f)
                .Fixed(20f)
                .Fit(1f)
                .BuildAllocatedHorizontal(height: 200f))
            {
                var isHandledSVPanel = DrawSVPanel(rects.R0);
                DrawHue(rects.R1);
                DrawAlpha(rects.R2);

                // color preview
                Gui.NextRect(rects.R3).ColorPreview(hsv.ToRgb());

                var color = (Color32)hsv.ToRgb();
                var r = color.r;
                var g = color.g;
                var b = color.b;
                var a = color.a;
                var changedRgba = false;
                // Allow direct editing of R, G, B, A color components
                if (Gui.LabelNext("R").SliderInputNumeric<byte>(ref r, 0, 255)) changedRgba = true;
                if (Gui.LabelNext("G").SliderInputNumeric<byte>(ref g, 0, 255)) changedRgba = true;
                if (Gui.LabelNext("B").SliderInputNumeric<byte>(ref b, 0, 255)) changedRgba = true;
                if (Gui.LabelNext("A").SliderInputNumeric<byte>(ref a, 0, 255)) changedRgba = true;
                if (changedRgba)
                    hsv = new(new Color32(r, g, b, a));

                Gui.SmallSpacing();

                var h = hsv.H;
                var s = hsv.S;
                var v = hsv.V;
                var changedHsv = false;
                // Allow direct editing of R, G, B, A color components
                if (Gui.LabelNext("H").SliderInputNumeric(ref h, 0d, HsvColor.HMax)) changedHsv = true;
                if (Gui.LabelNext("S").SliderInputNumeric(ref s, 0d, 1d)) changedHsv = true;
                if (Gui.LabelNext("V").SliderInputNumeric(ref v, 0d, 1d)) changedHsv = true;
                if (changedHsv)
                    hsv = new HsvColor(h, s, v, hsv.A);
            }
        }

        bool DrawSVPanel(Rect svPanelRect)
        {
            // Draw SV panel and handle user interaction
            Gui.NextRect(svPanelRect).CustomDelegate(hsv.H, (shaper, widget) => shaper.AddSVPanel(widget.Rect, widget.State));

            // Update HSV values even when any part of the SV panel is clicked
            var v01 = Gui.SnapRectInnerPointHandle(svPanelRect, new Vector2((float)hsv.S, (float)hsv.V));
            hsv = new HsvColor(hsv.H, v01.x, v01.y, hsv.A);
            return Ctx.IsLastPressed();
        }

        // Draw Hue bar and handle vertical slider input
        void DrawHue(Rect barHandleRect)
        {
            // Draw Hue bar and handle vertical slider input
            Gui.NextRect(barHandleRect).CustomDelegate((shaper, widget) => shaper.AddHueBar(widget.Rect));
            var hue01 = Gui.SnapVerticalBarHandle(barHandleRect, (float)hsv.H01);
            hsv = new HsvColor(Math.Min(hue01 * HsvColor.HMax, HsvColor.HMax), hsv.S, hsv.V, hsv.A);
        }

        // Show RGB preview with alpha gradient
        void DrawAlpha(Rect rect)
        {
            // Show RGB preview with alpha gradient
            Gui.NextRect(rect).ColorPreview(new());
            var rgb0 = hsv.ToRgb();
            var bottom = rgb0.ChangeAlpha(0);
            var top = rgb0.ChangeAlpha(255);
            Gui.NextRect(rect).Gradient(bottom, bottom, top, top);

            // Handle alpha channel adjustment
            var alpha = Gui.SnapVerticalBarHandle(rect, (float)hsv.A);
            hsv = new HsvColor(hsv.H, hsv.S, hsv.V, alpha);
        }

    }
}