ScriptableRenderPipeline/ScriptableRenderPipeline/Core/Editor/CoreEditorUtils.cs

using UnityEngine;

namespace UnityEditor.Experimental.Rendering
{
    public static class CoreEditorUtils
    {
        // UI Helpers
        public static void DrawSplitter()
        {
            var rect = GUILayoutUtility.GetRect(1f, 1f);

            // Splitter rect should be full-width
            rect.xMin = 0f;
            rect.width += 4f;

            if (Event.current.type != EventType.Repaint)
                return;

            EditorGUI.DrawRect(rect, !EditorGUIUtility.isProSkin
                ? new Color(0.6f, 0.6f, 0.6f, 1.333f)
                : new Color(0.12f, 0.12f, 0.12f, 1.333f));
        }

        public static void DrawHeader(string title)
        {
            var backgroundRect = GUILayoutUtility.GetRect(1f, 17f);

            var labelRect = backgroundRect;
            labelRect.xMin += 16f;
            labelRect.xMax -= 20f;

            var foldoutRect = backgroundRect;
            foldoutRect.y += 1f;
            foldoutRect.width = 13f;
            foldoutRect.height = 13f;

            // Background rect should be full-width
            backgroundRect.xMin = 0f;
            backgroundRect.width += 4f;

            // Background
            float backgroundTint = EditorGUIUtility.isProSkin ? 0.1f : 1f;
            EditorGUI.DrawRect(backgroundRect, new Color(backgroundTint, backgroundTint, backgroundTint, 0.2f));

            // Title
            EditorGUI.LabelField(labelRect, title, EditorStyles.boldLabel);
            EditorGUILayout.Space();
        }

        public static bool DrawHeaderFoldout(string title, bool state)
        {
            var backgroundRect = GUILayoutUtility.GetRect(1f, 17f);

            var labelRect = backgroundRect;
            labelRect.xMin += 16f;
            labelRect.xMax -= 20f;

            var foldoutRect = backgroundRect;
            foldoutRect.y += 1f;
            foldoutRect.width = 13f;
            foldoutRect.height = 13f;

            // Background rect should be full-width
            backgroundRect.xMin = 0f;
            backgroundRect.width += 4f;

            // Background
            float backgroundTint = EditorGUIUtility.isProSkin ? 0.1f : 1f;
            EditorGUI.DrawRect(backgroundRect, new Color(backgroundTint, backgroundTint, backgroundTint, 0.2f));

            // Title
            EditorGUI.LabelField(labelRect, title, EditorStyles.boldLabel);

            // Active checkbox
            state = GUI.Toggle(foldoutRect, state, GUIContent.none, EditorStyles.foldout);

            var e = Event.current;
            if (e.type == EventType.MouseDown && backgroundRect.Contains(e.mousePosition) && e.button == 0)
            {
                state = !state;
                e.Use();
            }

            return state;
        }
    }
}