This Unity custom property drawer provides a user-friendly min-max slider for integer values in the inspector. It is useful for developers who need to set a range of values. The custom attribute and property drawer handle MinMaxInt class, ensuring that values are clamped within specified limits and displayed as a slider with editable fields for …

MinMaxRangeAttribute.cs

using UnityEditor;
using UnityEngine;

[System.Serializable]
public class MinMaxInt
{
    public int Min;
    public int Max;
}

public class MinMaxRangeAttribute : PropertyAttribute
{
    public int minLimit;
    public int maxLimit;

    public MinMaxRangeAttribute(int minLimit, int maxLimit)
    {
        this.minLimit = minLimit;
        this.maxLimit = maxLimit;
    }
}

[CustomPropertyDrawer(typeof(MinMaxRangeAttribute))]
public class MinMaxRangeDrawer : PropertyDrawer
{
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
        MinMaxRangeAttribute range = (MinMaxRangeAttribute)attribute;

        if (property.type == nameof(MinMaxInt))
        {
            SerializedProperty minProperty = property.FindPropertyRelative("Min");
            SerializedProperty maxProperty = property.FindPropertyRelative("Max");

            if (minProperty != null && maxProperty != null)
            {
                int min = minProperty.intValue;
                int max = maxProperty.intValue;

                float minFloat = min;
                float maxFloat = max;

                EditorGUI.BeginChangeCheck();

                // Calculate rectangles
                Rect labelRect = new Rect(position.x, position.y, position.width, EditorGUIUtility.singleLineHeight);
                Rect sliderRect = new Rect(position.x, position.y + EditorGUIUtility.singleLineHeight + 2, position.width, EditorGUIUtility.singleLineHeight);
                Rect minLabelRect = new Rect(position.x, position.y + 2 * EditorGUIUtility.singleLineHeight + 4, position.width / 2 - 10, EditorGUIUtility.singleLineHeight);
                Rect maxLabelRect = new Rect(position.x + position.width / 2 + 10, position.y + 2 * EditorGUIUtility.singleLineHeight + 4, position.width / 2 - 10, EditorGUIUtility.singleLineHeight);

                // Draw the label
                EditorGUI.LabelField(labelRect, label);

                // Draw the slider
                EditorGUI.MinMaxSlider(sliderRect, ref minFloat, ref maxFloat, range.minLimit, range.maxLimit);

                // Convert float back to int
                min = Mathf.RoundToInt(minFloat);
                max = Mathf.RoundToInt(maxFloat);

                // Draw the min and max labels
                min = EditorGUI.IntField(minLabelRect, "Min", min);
                max = EditorGUI.IntField(maxLabelRect, "Max", max);

                // Clamp values to ensure they stay within range
                min = Mathf.Clamp(min, range.minLimit, range.maxLimit);
                max = Mathf.Clamp(max, range.minLimit, range.maxLimit);

                // Ensure min is not greater than max
                if (min > max) max = min;

                if (EditorGUI.EndChangeCheck())
                {
                    minProperty.intValue = min;
                    maxProperty.intValue = max;
                }
            }
            else
            {
                EditorGUI.LabelField(position, label.text, "Use only with MinMaxInt");
            }
        }
        else
        {
            EditorGUI.LabelField(position, label.text, "Use only with MinMaxInt");
        }
    }

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
    {
        return EditorGUIUtility.singleLineHeight * 3 + 6;
    }
}

//  Usage:
//  [MinMaxRange(0, 15)]
//  public MinMaxInt ivHealthRange;