Fix for Tooltips for Unity 4.2

Unity v4.3 fixed an issue where "Editor: PropertyDrawers can now call
EditorGUI.PropertyField to get the default implementation instead of
getting infinite recursion."
(http://unity3d.com/unity/whats-new/unity-4.3).
Added work around for previous versions that doesn’t use
EditorGUI.PropertyField

Fixes #3

source/Plugins/Editor/TooltipDrawer.cs

@@ -14,19 +14,93 @@ You may obtain a copy of the License at
   limitations under the License.
 */
 
+#if UNITY_4_0 || UNITY_4_0_1 || UNITY_4_1 || UNITY_4_2
+#define PRE_UNITY_4_3
+#endif
+
+using System;
+using System.Reflection;
 using UnityEngine;
 using UnityEditor;
 
+
 /*
   Custom Property Drawer to enable Tooltips for Inspector properties
 */
+
 [CustomPropertyDrawer(typeof(TooltipAttribute))]
 public class TooltipDrawer : PropertyDrawer
 {
-  public override void OnGUI(Rect position, SerializedProperty prop, GUIContent label)
-  {
+
+#if PRE_UNITY_4_3
+  private GUIContent _newTooltipContent = null;
+  private GUIContent previousTooltipContent = null;
+  private Type fieldType = null;
+
+  public override void OnGUI(Rect position, SerializedProperty property, GUIContent tooltipContent) {
+    previousTooltipContent = tooltipContent;
+    EditorGUI.BeginProperty(position, newTooltipContent, property);
+    EditorGUI.BeginChangeCheck();
+    switch(property.propertyType)
+    {
+      case SerializedPropertyType.Boolean:
+        bool newBoolValue = EditorGUI.Toggle(position, newTooltipContent, property.boolValue);
+        if(EditorGUI.EndChangeCheck()) property.boolValue = newBoolValue;
+        break;
+      case SerializedPropertyType.Enum:
+        int newEnumValueIndex = (int)(object)EditorGUI.EnumPopup(position, newTooltipContent, Enum.Parse(GetFieldType(property), property.enumNames[property.enumValueIndex]) as Enum);
+        if(EditorGUI.EndChangeCheck()) property.enumValueIndex = newEnumValueIndex;
+        break;
+      case SerializedPropertyType.Float:
+        float newFloatValue = EditorGUI.FloatField(position, newTooltipContent, property.floatValue);
+        if(EditorGUI.EndChangeCheck()) property.floatValue = newFloatValue;
+        break;
+      case SerializedPropertyType.Integer:
+        int newIntValue = EditorGUI.IntField(position, newTooltipContent, property.intValue);
+        if(EditorGUI.EndChangeCheck()) property.intValue = newIntValue;
+        break;
+      case SerializedPropertyType.String:
+        string newStringValue = EditorGUI.TextField(position, newTooltipContent, property.stringValue);
+        if(EditorGUI.EndChangeCheck()) property.stringValue = newStringValue;
+        break;
+      default:
+        Debug.LogWarning("TooltipDrawer: Unsupported Type: " + property.propertyType);
+        break;
+    }
+  }
+
+  private GUIContent newTooltipContent {
+    get {
+      if(_newTooltipContent == null) {
+        TooltipAttribute tooltipAttribute = attribute as TooltipAttribute;
+        _newTooltipContent = new GUIContent(previousTooltipContent.text, tooltipAttribute.text);
+      }
+      return _newTooltipContent;
+    }
+  }
+
+  private Type GetFieldType(SerializedProperty property) {
+    if (fieldType == null) {
+        Type parentClassType = property.serializedObject.targetObject.GetType();
+        FieldInfo fieldInfo = parentClassType.GetField(property.name,
+            BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public);
+
+        if (fieldInfo == null) {
+            Debug.LogWarning("TooltipDrawer: No field info found.");
+            return null;
+        }
+        fieldType = fieldInfo.FieldType;
+    }
+    return fieldType;
+  }
+
+#else
+
+  public override void OnGUI(Rect position, SerializedProperty property, GUIContent tooltipContent) {
     var atr = (TooltipAttribute) attribute;
-    var content = new GUIContent(label.text, atr.text);
-    EditorGUI.PropertyField(position, prop, content);
+    var content = new GUIContent(tooltipContent.text, atr.text);
+    EditorGUI.PropertyField(position, property, content);
   }
-}
+
+#endif
+}