First Commit

Assets/Attributes/Editor/OnValueChangedEditor.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using Golems.Attributes;
+
+namespace Golems
+{
+    public partial class AttributesEditor
+    {
+        const BindingFlags k_OnValChangedFlags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
+
+        private Dictionary<string, object> m_Fields = new Dictionary<string, object>();
+
+        private void OnInspectorGUIOnValueChangedAttribute()
+        {
+            var targetType = target.GetType();
+            var fields = targetType.GetFields(k_OnValChangedFlags);
+            //
+            // Search for OnValueChanged Attribute on Each Field on this Object
+            //
+            for (int i = 0, counti = fields.Length; i < counti; ++i)
+            {
+                var field = fields[i];
+                var onValueChangedAttribute = field.GetCustomAttribute<OnValueChanged>();
+
+                //
+                // If we find an attribute and haven't already included it in m_Fields, include it!
+                //
+                if (onValueChangedAttribute == null || m_Fields.TryGetValue(field.Name, out var fieldValue)) continue;
+                var method = targetType.GetMethod(onValueChangedAttribute.Method, k_ButtonBindingFlags);
+
+                if (method != null)
+                {
+                    m_Fields.Add(field.Name, field.GetValue(this.target));
+                }
+            }
+
+            var changed = new List<Action>();
+
+            //
+            // Now check all our found Fields and see if a value has changed
+            //
+            foreach (var fieldValueKeypair in m_Fields)
+            {
+                //
+                // Retrieve the FieldInfo for the cached field name
+                //
+                var fieldInfo = targetType.GetField(fieldValueKeypair.Key, k_OnValChangedFlags);
+                if (fieldInfo == null) continue;
+
+                //
+                // Detect any change?
+                //
+                var currentValue = fieldInfo.GetValue(target);
+                if (currentValue != null && currentValue.Equals(fieldValueKeypair.Value) || 
+                    currentValue == null && fieldValueKeypair.Value == null) continue;
+
+                var key = fieldValueKeypair.Key;
+                changed.Add(() => { m_Fields[key] = currentValue; });
+
+                // ...a bit lazy, probably should cache this stuff but here we are :( 
+                var onValueChangedAttribute = fieldInfo.GetCustomAttribute<OnValueChanged>();
+                if (onValueChangedAttribute == null) continue;
+
+                var method = targetType.GetMethod(onValueChangedAttribute.Method, k_ButtonBindingFlags);
+                method?.Invoke(target, null);
+            }
+
+            //
+            // Update m_Fields which have been changed
+            //
+            changed.ForEach(x => x.Invoke());
+        }
+    }
+}