Enable use outside of play mode

scripts/DllManipulator.cs

@@ -653,6 +653,7 @@ public class DllManipulatorOptions
         public bool crashLogsStackTrace;
         public bool mockAllNativeFunctions;
         public bool onlyInEditor;
+        public bool enableInEditMode;
     }
 
     public enum DllLoadingMode

scripts/DllManipulatorScript.cs

@@ -1,12 +1,18 @@
-using System;
+using System;
 using System.Reflection;
 using System.Threading;
 using System.Linq;
 using UnityEngine;
 using UnityNativeTool.Internal;
+#if UNITY_EDITOR
+using UnityEditor;
+#endif
 
 namespace UnityNativeTool
 {
+    #if UNITY_EDITOR
+    [ExecuteInEditMode]
+    #endif
     public class DllManipulatorScript : MonoBehaviour
     {
         private static DllManipulatorScript _singletonInstance = null;
@@ -30,23 +36,45 @@ public class DllManipulatorScript : MonoBehaviour
             crashLogsStackTrace = false,
             mockAllNativeFunctions = true,
             onlyInEditor = true,
+            enableInEditMode = false
         };
 
         private void OnEnable()
         {
-#if !UNITY_EDITOR
-            if (Options.onlyInEditor)
+#if UNITY_EDITOR
+            if (_singletonInstance != null)
+            {
+                if (EditorApplication.isPlaying)
+                    Destroy(gameObject);
+                else
+                    enabled = false; //Don't destroy as the user may be editing a Prefab
+                return;
+            }
+            _singletonInstance = this;
+
+            if(EditorApplication.isPlaying)
+                DontDestroyOnLoad(gameObject);
+
+            if(EditorApplication.isPlaying || Options.enableInEditMode)
+                Initialize();
+#else
+            if (Options.onlyInEditor) 
                 return;
-#endif
 
             if (_singletonInstance != null)
             {
                 Destroy(gameObject);
                 return;
             }
             _singletonInstance = this;
-            DontDestroyOnLoad(gameObject);
 
+            DontDestroyOnLoad(gameObject);
+            Initialize();
+#endif
+        }
+
+        private void Initialize()
+        {
             var initTimer = System.Diagnostics.Stopwatch.StartNew();
 
             DllManipulator.Options = Options;
@@ -66,7 +94,8 @@ private void OnDestroy()
 
                 DllManipulator.UnloadAll();
                 DllManipulator.ForgetAllDlls();
-                DllManipulator.ClearCrashLogs();         
+                DllManipulator.ClearCrashLogs();
+                _singletonInstance = null;
             }
         }
     }

scripts/Editor/DllManipulatorEditor.cs

@@ -21,6 +21,10 @@ public class DllManipulatorEditor : Editor
             "If true, native functions will be mocked only in assembly that contains DllManipulator (usually Assembly-CSharp)");
         private static readonly GUIContent ONLY_IN_EDITOR = new GUIContent("Only in editor",
             "Whether to run only inside editor (which is recommended).");
+        private static readonly GUIContent ENABLE_IN_EDIT_MODE = new GUIContent("Enable in Edit Mode",
+            "Should the DLLs also be mocked in edit mode (i.e. even if you don't hit 'play' in editor). " +
+            "Turning this off when not needed improves performance when entering edit mode. " +
+            "Changes are currently only visible on the next time edit mode is entered (i.e. when OnEnable is called so hit 'play' then 'stop' to apply).");
         private static readonly GUIContent TARGET_ASSEMBLIES_GUI_CONTENT = new GUIContent("Target assemblies",
             "Choose from which assemblies to mock native functions");
         private static readonly GUIContent DLL_PATH_PATTERN_GUI_CONTENT = new GUIContent("DLL path pattern", 
@@ -246,6 +250,8 @@ private void DrawOptions(DllManipulatorOptions options)
             }
 
             options.onlyInEditor = EditorGUILayout.Toggle(ONLY_IN_EDITOR, options.onlyInEditor);
+
+            options.enableInEditMode = EditorGUILayout.Toggle(ENABLE_IN_EDIT_MODE, options.enableInEditMode);
 
             options.dllPathPattern = EditorGUILayout.TextField(DLL_PATH_PATTERN_GUI_CONTENT, options.dllPathPattern);
 
@@ -334,4 +340,4 @@ public static void UnloadAll()
             DllManipulator.UnloadAll();
         }
     }
-}
+}