XCharts/Scripts/Editor/PropertyDrawers/LocationDrawer.cs

using UnityEditor;
using UnityEngine;
using UnityEngine.UI;

namespace XCharts
{
    [CustomPropertyDrawer(typeof(Location), true)]
    public class LocationDrawer : PropertyDrawer
    {
        public override void OnGUI(Rect pos, SerializedProperty prop, GUIContent label)
        {
            Rect drawRect = pos;
            drawRect.height = EditorGUIUtility.singleLineHeight;
            SerializedProperty align = prop.FindPropertyRelative("m_Align");
            SerializedProperty left = prop.FindPropertyRelative("m_Left");
            SerializedProperty right = prop.FindPropertyRelative("m_Right");
            SerializedProperty top = prop.FindPropertyRelative("m_Top");
            SerializedProperty bottom = prop.FindPropertyRelative("m_Bottom");
            EditorGUI.PropertyField(drawRect, align, new GUIContent("Location"));
            drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
            ++EditorGUI.indentLevel;
            switch ((Location.Align)align.enumValueIndex)
            {
                case Location.Align.TopCenter:
                    EditorGUI.PropertyField(drawRect, top);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    break;
                case Location.Align.TopLeft:
                    EditorGUI.PropertyField(drawRect, top);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    EditorGUI.PropertyField(drawRect, left);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    break;
                case Location.Align.TopRight:
                    EditorGUI.PropertyField(drawRect, top);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    EditorGUI.PropertyField(drawRect, right);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    break;
                case Location.Align.BottomCenter:
                    EditorGUI.PropertyField(drawRect, bottom);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    break;
                case Location.Align.BottomLeft:
                    EditorGUI.PropertyField(drawRect, bottom);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    EditorGUI.PropertyField(drawRect, left);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    break;
                case Location.Align.BottomRight:
                    EditorGUI.PropertyField(drawRect, bottom);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    EditorGUI.PropertyField(drawRect, right);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    break;
                case Location.Align.Center:
                    break;
                case Location.Align.CenterLeft:
                    EditorGUI.PropertyField(drawRect, left);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    break;
                case Location.Align.CenterRight:
                    EditorGUI.PropertyField(drawRect, right);
                    drawRect.y += EditorGUIUtility.singleLineHeight + EditorGUIUtility.standardVerticalSpacing;
                    break;
            }
            --EditorGUI.indentLevel;
        }

        public override float GetPropertyHeight(SerializedProperty prop, GUIContent label)
        {
            SerializedProperty align = prop.FindPropertyRelative("m_Align");
            switch ((Location.Align)align.enumValueIndex)
            {
                case Location.Align.Center:
                    return 1 * EditorGUIUtility.singleLineHeight + 0 * EditorGUIUtility.standardVerticalSpacing;
                case Location.Align.TopCenter:
                case Location.Align.BottomCenter:
                case Location.Align.CenterLeft:
                case Location.Align.CenterRight:
                    return 2 * EditorGUIUtility.singleLineHeight + 1 * EditorGUIUtility.standardVerticalSpacing;
                default:
                    return 3 * EditorGUIUtility.singleLineHeight + 2 * EditorGUIUtility.standardVerticalSpacing;
            }
        }
    }
}