Until now when I wanted to make a field appear in the inspector I made a custom inspector, but I got tired of it, so I decided to make an attribute.
The files needed:
1. First of all, I used something that I posted about in another please. You can find it here, get it before you get the attribute.
2. Put this enum wherever you want:
/// <summary>
/// Types of comperisons.
/// </summary>
public enum ComparisonType
{
Equals = 1,
NotEqual = 2,
GreaterThan = 3,
SmallerThan = 4,
SmallerOrEqual = 5,
GreaterOrEqual = 6
}
3. Put this enum wherever you want as well:
/// <summary>
/// Types of comperisons.
/// </summary>
public enum DisablingType
{
ReadOnly = 2,
DontDraw = 3
}
4. Put this inside of a CSharp file wherever you want in your project:
using UnityEngine;
using System;
/// <summary>
/// Draws the field/property ONLY if the copared property compared by the comparison type with the value of comparedValue returns true.
/// </summary>
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field, AllowMultiple = true)]
public class DrawIfAttribute : PropertyAttribute
{
public string comparedPropertyName { get; private set; }
public object comparedValue { get; private set; }
public ComparisonType comparisonType { get; private set; }
public DisablingType disablingType { get; private set; }
/// <summary>
/// Only draws the field only if a condition is met.
/// </summary>
/// <param name="comparedPropertyName">The name of the property that is being compared (case sensitive).</param>
/// <param name="comparedValue">The value the property is being compared to.</param>
/// <param name="comparisonType">The type of comperison the values will be compared by.</param>
/// <param name="disablingType">The type of disabling that should happen if the condition is NOT met. Defaulted to DisablingType.DontDraw.</param>
public DrawIfAttribute(string comparedPropertyName, object comparedValue, ComparisonType comparisonType, DisablingType disablingType = DisablingType.DontDraw)
{
this.comparedPropertyName = comparedPropertyName;
this.comparedValue = comparedValue;
this.comparisonType = comparisonType;
this.disablingType = disablingType;
}
}
5. Put this wherever you want, just make sure it’s either directly or indirectly in a folder called “Editor”:
using UnityEditor;
using UnityEngine;
[CustomPropertyDrawer(typeof(DrawIfAttribute))]
public class DrawIfPropertyDrawer : PropertyDrawer
{
// Reference to the attribute on the property.
DrawIfAttribute drawIf;
// Field that is being compared.
SerializedProperty comparedField;
// Height of the property.
private float propertyHeight;
public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
{
return propertyHeight;
}
public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
{
// Set the global variables.
drawIf = attribute as DrawIfAttribute;
comparedField = property.serializedObject.FindProperty(drawIf.comparedPropertyName);
// Get the value of the compared field.
object comparedFieldValue = comparedField.GetValue<object>();
// References to the values as numeric types.
NumericType numericComparedFieldValue = null;
NumericType numericComparedValue = null;
try
{
// Try to set the numeric types.
numericComparedFieldValue = new NumericType(comparedFieldValue);
numericComparedValue = new NumericType(drawIf.comparedValue);
}
catch (NumericTypeExpectedException)
{
// This place will only be reached if the type is not a numeric one. If the comparison type is not valid for the compared field type, log an error.
if (drawIf.comparisonType != ComparisonType.Equals && drawIf.comparisonType != ComparisonType.NotEqual)
{
Debug.LogError("The only comparsion types available to type '" + comparedFieldValue.GetType() + "' are Equals and NotEqual. (On object '" + property.serializedObject.targetObject.name + "')");
return;
}
}
// Is the condition met? Should the field be drawn?
bool conditionMet = false;
// Compare the values to see if the condition is met.
switch (drawIf.comparisonType)
{
case ComparisonType.Equals:
if (comparedFieldValue.Equals(drawIf.comparedValue))
conditionMet = true;
break;
case ComparisonType.NotEqual:
if (!comparedFieldValue.Equals(drawIf.comparedValue))
conditionMet = true;
break;
case ComparisonType.GreaterThan:
if (numericComparedFieldValue > numericComparedValue)
conditionMet = true;
break;
case ComparisonType.SmallerThan:
if (numericComparedFieldValue < numericComparedValue)
conditionMet = true;
break;
case ComparisonType.SmallerOrEqual:
if (numericComparedFieldValue <= numericComparedValue)
conditionMet = true;
break;
case ComparisonType.GreaterOrEqual:
if (numericComparedFieldValue >= numericComparedValue)
conditionMet = true;
break;
}
// The height of the property should be defaulted to the default height.
propertyHeight = base.GetPropertyHeight(property, label);
// If the condition is met, simply draw the field. Else...
if (conditionMet)
{
EditorGUI.PropertyField(position, property);
}
else
{
//...check if the disabling type is read only. If it is, draw it disabled, else, set the height to zero.
if (drawIf.disablingType == DisablingType.ReadOnly)
{
GUI.enabled = false;
EditorGUI.PropertyField(position, property);
GUI.enabled = true;
}
else
{
propertyHeight = 0f;
}
}
}
}
This is how you can use it:
This is just an example script I put on one of the game objects:
using UnityEngine;
public class Test : MonoBehaviour
{
[Range(0, 2)]
public float someFloat;
[DrawIf("someFloat", 1f, ComparisonType.GreaterOrEqual)]
public int someInt;
public bool someBool;
[DrawIf("someBool", true, ComparisonType.Equals, DisablingType.ReadOnly)]
public int anotherInt;
}
This is the result:
Just keep in mind a few things:
- When the condition isn’t met and it doesn’t draw the field, when it is met and it draws it it will take a very little bit of time to update the height (you can see it in the GIF).
- When you spell the name of the compared field incorrectly, it won’t give you an error. So make sure the spelling is correct and the capital letters are correct as well (it’s case sensitive).
EDIT:
I originally wrote “comperison”, instead of “comparison”. I tried to fix it in all of the places, but if anyone found any more mistakes (since I think I missed some), please tell me.
For anyone who doesn’t want to copy the code, you download it here. Just get the “Hide If Attribute” folder. You can also try the numeric type one: Free Assets - Google Drive
