MinMaxDrawer.cs

using cmdwtf.UnityTools.Attributes;

using UnityEngine;

using UnityEditor;

namespace cmdwtf.UnityTools.Editor
{
	// Thanks, Lotte https://gist.github.com/LotteMakesStuff/0de9be35044bab97cbe79b9ced695585
	[UnityEditor.CustomPropertyDrawer(typeof(MinMaxAttribute))]
	public class MinMaxDrawer : CustomPropertyDrawer
	{
		public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
		{
			// cast the attribute to make life easier
			if (!(attribute is MinMaxAttribute minMax))
			{
				return;
			}

			// This only works on a vector2 and vector2Int! ignore on any other property type (we should probably draw an error message instead!)
			if (property.propertyType == SerializedPropertyType.Vector2)
			{
				// if we are flagged to draw in a special mode, lets modify the drawing rectangle to draw only one line at a time
				if (minMax.ShowDebugValues || minMax.ShowEditRange)
				{
					position = new Rect(position.x, position.y, position.width, EditorGUIUtility.singleLineHeight);
				}

				// pull out a bunch of helpful min/max values....
				float minValue = property.vector2Value.x; // the currently set minimum and maximum value
				float maxValue = property.vector2Value.y;
				float
					minLimit = minMax
						.MinLimit; // the limit for both min and max, min cant go lower than minLimit and maax cant top maxLimit
				float maxLimit = minMax.MaxLimit;

				// and ask unity to draw them all nice for us!
				

				var vec = Vector2.zero; // save the results into the property!
				vec.x = minValue;
				vec.y = maxValue;

				property.vector2Value = vec;

				// Do we have a special mode flagged? time to draw lines!
				if (minMax.ShowDebugValues || minMax.ShowEditRange)
				{
					bool isEditable = minMax.ShowEditRange;

					if (!isEditable)
					{
						GUI.enabled =
							false; // if were just in debug mode and not edit mode, make sure all the UI is read only!
					}

					// move the draw rect on by one line
					position.y += EditorGUIUtility.singleLineHeight;

					float[]
						vals = new float[]
						{
							minLimit, minValue, maxValue, maxLimit
						}; // shove the values and limits into a vector4 and draw them all at once
					EditorGUI.MultiFloatField(position, new GUIContent("Range"),
											  new GUIContent[]
											  {
												  new GUIContent("MinLimit"), new GUIContent("MinVal"),
												  new GUIContent("MaxVal"), new GUIContent("MaxLimit")
											  }, vals);

					GUI.enabled = false; // the range part is always read only
					position.y += EditorGUIUtility.singleLineHeight;
					EditorGUI.FloatField(position, "Selected Range", maxValue - minValue);
					GUI.enabled = true; // remember to make the UI editable again!

					if (isEditable)
					{
						property.vector2Value = new Vector2(vals[1], vals[2]); // save off any change to the value~
					}
				}
			}
			else if (property.propertyType == SerializedPropertyType.Vector2Int)
			{
				// if we are flagged to draw in a special mode, lets modify the drawing rectangle to draw only one line at a time
				if (minMax.ShowDebugValues || minMax.ShowEditRange)
				{
					position = new Rect(position.x, position.y, position.width, EditorGUIUtility.singleLineHeight);
				}

				// pull out a bunch of helpful min/max values....
				float minValue = property.vector2IntValue.x; // the currently set minimum and maximum value
				float maxValue = property.vector2IntValue.y;
				int minLimit =
					Mathf.RoundToInt(
						minMax.MinLimit); // the limit for both min and max, min cant go lower than minLimit and maax cant top maxLimit
				int maxLimit = Mathf.RoundToInt(minMax.MaxLimit);

				// and ask unity to draw them all nice for us!
				EditorGUI.MinMaxSlider(position, label, ref minValue, ref maxValue, minLimit, maxLimit);

				var vec = Vector2Int.zero; // save the results into the property!
				vec.x = Mathf.RoundToInt(minValue);
				vec.y = Mathf.RoundToInt(maxValue);

				property.vector2IntValue = vec;

				// Do we have a special mode flagged? time to draw lines!
				if (minMax.ShowDebugValues || minMax.ShowEditRange)
				{
					bool isEditable = minMax.ShowEditRange;

					if (!isEditable)
					{
						GUI.enabled =
							false; // if were just in debug mode and not edit mode, make sure all the UI is read only!
					}

					// move the draw rect on by one line
					position.y += EditorGUIUtility.singleLineHeight;

					float[]
						vals = new float[]
						{
							minLimit, minValue, maxValue, maxLimit
						}; // shove the values and limits into a vector4 and draw them all at once
					EditorGUI.MultiFloatField(position, new GUIContent("Range"),
											  new GUIContent[]
											  {
												  new GUIContent("MinLimit"), new GUIContent("MinVal"),
												  new GUIContent("MaxVal"), new GUIContent("MaxLimit")
											  }, vals);

					GUI.enabled = false; // the range part is always read only
					position.y += EditorGUIUtility.singleLineHeight;
					EditorGUI.FloatField(position, "Selected Range", maxValue - minValue);
					GUI.enabled = true; // remember to make the UI editable again!

					if (isEditable)
					{
						property.vector2IntValue =
							new Vector2Int(Mathf.RoundToInt(vals[1]),
										   Mathf.RoundToInt(vals[2])); // save off any change to the value~
					}
				}
			}
		}

		protected override int GetPropertyLineCount(SerializedProperty property, GUIContent label)
		{
			if (!(attribute is MinMaxAttribute minMax))
			{
				return 0;
			}

			int lineCount = 1;

			// if we have a special mode, add two extra lines!
			if (minMax.ShowEditRange || minMax.ShowDebugValues)
			{
				lineCount += 2;
			}

			return lineCount;
		}
	}
}