I want to make a drop-down in a custom inspector that allows me to select multiple enums from a popup, exactly like the popups you get when selecting a camera’s culling mask, a projector’s “ignore” layers, or a layermask. (see picture)
Am I missing a simple way to do this? What would the returned result of a change be? A List or array of FooEnum elements? I can jury-rig an equivalent alternative, but since this GUI element does exactly what I want, I’d love to use one if I could find out how!
I’ve written a “wrapper” function, mainly for a general PropertyDrawer, which actual uses the enum values. However, this changes the Nothing and Everything behaviour, but all enum values work fine, even combined values.
// Have to be defined somewhere in a runtime script file
// BitMaskAttribute.cs
public class BitMaskAttribute : PropertyAttribute
{
public System.Type propType;
public BitMaskAttribute(System.Type aType)
{
propType = aType;
}
}
This should go into an editor script:
// /editor/EnumBitMaskPropertyDrawer.cs
using UnityEngine;
using UnityEditor;
using System.Collections;
public static class EditorExtension
{
public static int DrawBitMaskField (Rect aPosition, int aMask, System.Type aType, GUIContent aLabel)
{
var itemNames = System.Enum.GetNames(aType);
var itemValues = System.Enum.GetValues(aType) as int[];
int val = aMask;
int maskVal = 0;
for(int i = 0; i < itemValues.Length; i++)
{
if (itemValues[i] != 0)
{
if ((val & itemValues[i]) == itemValues[i])
maskVal |= 1 << i;
}
else if (val == 0)
maskVal |= 1 << i;
}
int newMaskVal = EditorGUI.MaskField(aPosition, aLabel, maskVal, itemNames);
int changes = maskVal ^ newMaskVal;
for(int i = 0; i < itemValues.Length; i++)
{
if ((changes & (1 << i)) != 0) // has this list item changed?
{
if ((newMaskVal & (1 << i)) != 0) // has it been set?
{
if (itemValues[i] == 0) // special case: if "0" is set, just set the val to 0
{
val = 0;
break;
}
else
val |= itemValues[i];
}
else // it has been reset
{
val &= ~itemValues[i];
}
}
}
return val;
}
}
[CustomPropertyDrawer(typeof(BitMaskAttribute))]
public class EnumBitMaskPropertyDrawer : PropertyDrawer
{
public override void OnGUI (Rect position, SerializedProperty prop, GUIContent label)
{
var typeAttr = attribute as BitMaskAttribute;
// Add the actual int value behind the field name
label.text = label.text + "("+prop.intValue+")";
prop.intValue = EditorExtension.DrawBitMaskField(position, prop.intValue, typeAttr.propType, label);
}
}
Now just imagine this example:
public enum EMyEnum
{
None = 0x00,
Cow = 0x01,
Chicken = 0x02,
Cat = 0x04,
Dog = 0x08,
CowChicken = 0x03,
CatDog = 0x0C,
All = 0x0F,
}
public class Example : MonoBehaviour
{
[BitMask(typeof(EMyEnum))]
public EMyEnum someMask;
}
This will automatically draw my modified enum-mask field.
ps: I just fixed the completely broken code formatting due to the Unity Answers migration. I haven’t had the time to test if the code actually works. There were a lot of messed up things (especially [i] being replaced with italics tags).
You need to use EnumMaskField and make sure your enum is decorated with the [Flags] attribute.
@AlwaysSunny @Bunny83 @whydoidoit @Aqibsadiq :
A clean solution for current versions of Unity.
EnumFlagAttributePropertyDrawer.cs
using System;
using UnityEngine;
using UnityEditor;
[CustomPropertyDrawer(typeof(EnumFlagAttribute))]
class EnumFlagAttributePropertyDrawer : PropertyDrawer
{
public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
{
label = EditorGUI.BeginProperty(position, label, property);
var oldValue = (Enum)fieldInfo.GetValue(property.serializedObject.targetObject);
var newValue = EditorGUI.EnumFlagsField(position, label, oldValue);
if (!newValue.Equals(oldValue))
{
property.intValue = (int)Convert.ChangeType(newValue, fieldInfo.FieldType);
}
EditorGUI.EndProperty();
}
}
EnumFlagAttribute.cs
using UnityEngine;
/// <summary>
/// Display multi-select popup for Flags enum correctly.
/// </summary>
public class EnumFlagAttribute : PropertyAttribute
{
}
Usage example:
public class MyFlagHolder : MonoBehaviour
{
[SerializeField, EnumFlag]
private MyFlag flags;
}
[Flags]
public enum MyFlag
{
Flag1 = 1,
Flag2 = 2,
Flag3 = 4,
Flag4 = 8
}
@Bunny83 @AlwaysSunny @whydoidoit
Here is a simpler way
Simple 4 Steps
Step 1 : Make a new Script “EnumFlagsAttribute”
using UnityEngine;
using System.Collections;
public class EnumFlagsAttribute : PropertyAttribute
{
public EnumFlagsAttribute() { }
}
Step 2 : Make another Script “EnumFlagsAttributeDrawer”
using UnityEngine;
using System.Collections;
using System;
using UnityEditor;
[CustomPropertyDrawer(typeof(EnumFlagsAttribute))]
public class EnumFlagsAttributeDrawer : PropertyDrawer
{
public override void OnGUI(Rect _position, SerializedProperty _property, GUIContent _label)
{
_property.intValue = EditorGUI.MaskField( _position, _label, _property.intValue, _property.enumNames );
}
}
Step 3: Enum Declaration
[System.Flags]
public enum FurnitureType
{
None , SofaPrefab , Curtains , Table , Chairs
}
[EnumFlagsAttribute]
public FurnitureType enumType;
Step 4: Getting Selected Elements
List<int> ReturnSelectedElements()
{
List<int> selectedElements = new List<int>();
for (int i = 0; i < System.Enum.GetValues(typeof(FurnitureType)).Length; i++)
{
int layer = 1 << i;
if (((int) enumType & layer) != 0)
{
selectedElements.Add(i);
}
}
return selectedElements;
}
Instead of Add(i) it should be:
selectedElements.Add(
(int) Enum.GetValues( typeof(FurnitureType) ).GetValue(i)
);
can confirm aqibsadiqs solution still works. Im using it as a tag mask to destroy objects except for those chosen in the enum list, so I tweaked it to return string instead
void OnCollisionEnter2D(Collision2D collision)
{
selectedObjects = ReturnSelectedElements();
if (!selectedObjects.Contains(collision.collider.tag))
{
//action
}
}
List<string> ReturnSelectedElements()
{
List<string> selectedElements = new List<string>();
for (int i = 0; i < System.Enum.GetValues(typeof(DontDestroyOn)).Length; i++)
{
int layer = 1 << i;
if (((int)dontDestroyOn & layer) != 0)
{
selectedElements.Add(Enum.GetValues(typeof(DontDestroyOn)).GetValue(i).ToString());
}
}
return selectedElements;
}
public enum DontDestroyOn
{
Player,
Enemy,
Hazard,
Ground,
LOS
}
Id prefer to have it in the start function instead of making a list on every collision, but for whatever reason its not working there