Trigger.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;

// author: mvaganov@hotmail.com
// license: Copyfree, public domain. This is free code! Great artists, steal this code!
// latest version at: https://pastebin.com/raw/8cZ5yKSd
// requires Timer at: https://pastebin.com/raw/h61nAC3E
namespace NS {
    public class Trigger : TriggerBase {
        public float delayInSeconds = 0;
        [Tooltip("* Transform: teleport triggering object to the Transform\n"+
            "* SceneAsset: load the scene\n"+
            "* AudioClip: play audio here\n"+
            "* GameObject: SetActivate(true)\n"+
            "* Material: set this Renderer's .material property, make a note of what the previous material was\n"+
            "* <any other>: activate a \'DoActivateTrigger()\' method (if available)\n"+
            "* IEnumerable: trigger each element in the list")]
        public Object whatToTrigger;
        [Tooltip("If false, *deactivate* whatToTrigger instead")]
        public bool activate = true;

        void Start () { AddTriggers (gameObject, whatToTrigger, kind, triggerTag, activate, delayInSeconds); }

        public void DoActivateTrigger (){ DoActivateTrigger (gameObject, whatToTrigger, gameObject, activate, delayInSeconds); }
    }
    [RequireComponent(typeof(Collider))]
    public class TriggerBase : MonoBehaviour {

        public enum TKind {
            scriptedOnly,
            onTriggerEnter, onTriggerExit, onTriggerStay,
            onCollisionEnter, onCollisionExit, onCollisionStay,
            onControllerColliderHit,
            onStart, onDestroy, onEnable, onDisable, onApplicationPause, onApplicationUnpause, onApplicationQuit,
            onMouseEnter, onMouseOver, onMouseExit,
            onMouseDown, onMouseDrag, onMouseUp, onMouseUpAsButton,
            onBecameInvisible, onBecameVisible,
            // TODO add: onVREnter (can be hands or head), onVRExit, onVRPress (can be any hand control button), onVRRelease, onVRPointStart, onVRPointStop, onVRSwipe
        }
        [Tooltip("What triggers the object above")]
        public TKind kind = TKind.onTriggerEnter;
        [Tooltip("For colliders, if not empty, only trigger if the triggering collider is tagged with this value")]
        public string triggerTag;

        public static void DoActivateTrigger(object triggeringObject, object whatToTrigger, GameObject triggeredGameObject, bool activate, float delayInSeconds) {
            if (delayInSeconds <= 0) {
                DoActivateTrigger (triggeringObject, whatToTrigger, triggeredGameObject, activate);
            } else {
                NS.Timer.setTimeout (() => {
                    DoActivateTrigger (triggeringObject, whatToTrigger, triggeredGameObject, activate);
                }, (long)(delayInSeconds * 1000));
            }
        }
        public static void DoActivateTrigger(object triggeringObject, object whatToTrigger, GameObject triggeredGameObject, bool activate) {
            if (whatToTrigger == null) { Debug.LogError ("Don't know how to trigger null"); return; }
            System.Type type = whatToTrigger.GetType ();
            if (typeof(System.Action).IsAssignableFrom (type)) {
                System.Action a = whatToTrigger as System.Action;
                a.Invoke ();
            } else if (typeof(UnityEngine.Events.UnityEvent).IsAssignableFrom (type)) {
                UnityEngine.Events.UnityEvent a = whatToTrigger as UnityEngine.Events.UnityEvent;
                a.Invoke ();
            } else if (type == typeof(Transform)) {
                Transform t = whatToTrigger as Transform;
                Transform toMove = triggeringObject as Transform;
                if (toMove == null) {
                    GameObject go = triggeringObject as GameObject;
                    if (go != null) {
                        toMove = go.transform;
                    }
                }
                if (toMove != null) {
                    toMove.position = t.position;
                }
            } else if (type == typeof(UnityEditor.SceneAsset)) {
                UnityEditor.SceneAsset scene = whatToTrigger as UnityEditor.SceneAsset;
                LoadLevel (scene.name, activate);
            } else if (type == typeof(AudioClip) || type == typeof(AudioSource)) {
                AudioSource asource = null;
                if (type == typeof(AudioSource)) {
                    asource = whatToTrigger as AudioSource;
                }
                if (asource == null) {
                    asource = triggeredGameObject.AddComponent<AudioSource> ();
                }
                if (type == typeof(AudioClip)) {
                    asource.clip = whatToTrigger as AudioClip;
                }
                if (activate) {
                    asource.Play ();
                } else {
                    asource.Stop ();
                }
            } else if (type == typeof(ParticleSystem)) {
                ParticleSystem ps = whatToTrigger as ParticleSystem;
                if (activate) {
                    Transform t = ps.transform;
                    t.position = triggeredGameObject.transform.position;
                    t.rotation = triggeredGameObject.transform.rotation;
                    ParticleSystem.ShapeModule sm = ps.shape;
                    if (sm.shapeType == ParticleSystemShapeType.Mesh) {
                        sm.mesh = triggeredGameObject.GetComponent<MeshFilter> ().mesh;
                        sm.scale = triggeredGameObject.transform.lossyScale;
                    } else if (sm.shapeType == ParticleSystemShapeType.MeshRenderer) {
                        sm.meshRenderer = triggeredGameObject.GetComponent<MeshRenderer> ();
                    }
                    ps.Play ();
                } else {
                    ps.Stop ();
                }
            } else if (type == typeof(GameObject)) {
                (whatToTrigger as GameObject).SetActive (activate);
            } else if (type == typeof(UnityEngine.Material)) {
                RememberedOriginalMaterial r = triggeredGameObject.GetComponent<RememberedOriginalMaterial> ();
                if (activate) {
                    Material m = whatToTrigger as Material;
                    if (r == null) {
                        r = triggeredGameObject.AddComponent<RememberedOriginalMaterial> ();
                        r.oldMaterial = triggeredGameObject.GetComponent<Renderer> ().material;
                        triggeredGameObject.GetComponent<Renderer> ().material = m;
                    }
                } else {
                    if (r != null) {
                        triggeredGameObject.GetComponent<Renderer> ().material = r.oldMaterial;
                        Destroy (r);
                    }
                }
            } else if (typeof(IEnumerable).IsAssignableFrom (type)) {
                IEnumerable ienum = whatToTrigger as IEnumerable;
                IEnumerator iter = ienum.GetEnumerator ();
                while (iter.MoveNext ()) {
                    DoActivateTrigger (triggeringObject, iter.Current, triggeredGameObject, activate);
                }
            } else if (type == typeof(Animation)) {
                if (activate) {
                    (whatToTrigger as Animation).Play ();
                } else {
                    (whatToTrigger as Animation).Stop();
                }
            } else {
                System.Reflection.MethodInfo[] m = type.GetMethods ();
                bool invoked = false;
                for (int i = 0; i < m.Length; ++i) {
                    if (m[i].Name == "DoActivateTrigger" && m[i].GetParameters().Length == 0) {
                        m[i].Invoke (whatToTrigger, new object[]{ });
                        invoked = true;
                        break;
                    }
                }
                if(!invoked) {
                    Debug.LogError ("Don't know how to "+((activate)?"activate":"deactivate")+" a \'" + type + "\'");
                }
            }
        }
        /// <summary>Loads or unloads the level.</summary>
        /// <param name="sceneName">scene name.</param>
        /// <param name="load">If set to <c>true</c> load (or unload current and reload), otherwise unload (if there are multiple levels)</param>
        public static void LoadLevel(string sceneName, bool load = true) {
            if (load) {
                int currentSceneIndex = -1;
                for (int i = 0; i < SceneManager.sceneCount; ++i) {
                    if (SceneManager.GetSceneAt (i).name == sceneName) {
                        currentSceneIndex = i; break;
                    }
                }
                if (SceneManager.sceneCount > 1 && currentSceneIndex >= 0) {
                    // if the scene is already loaded, unload it. then load it once it is unloaded
                    AsyncOperation op = SceneManager.UnloadSceneAsync(sceneName);
                    op.completed += (AsyncOperation o)=>{ SceneManager.LoadScene (sceneName, LoadSceneMode.Additive); };
                } else {
                    SceneManager.LoadScene (sceneName);
                }
            } else {
                SceneManager.UnloadSceneAsync (sceneName);
            }
        }
        public class RememberedOriginalMaterial : MonoBehaviour { public Material oldMaterial; }

        private static void ColToTrig(GameObject g) {
            Collider c = g.GetComponent<Collider> ();      if (c) { c.isTrigger = true; }
            Collider2D c2 = g.GetComponent<Collider2D> (); if (c2) { c2.isTrigger = true; }
        }

        public static void AddTriggers(GameObject g, object w, TKind kind, string triggerTag, bool a, float s) {
            bool is2D = false;
            switch(kind){
            case TKind.onTriggerEnter: case TKind.onTriggerExit: case TKind.onTriggerStay:
                is2D = g.GetComponent<Collider2D> () != null;
                break;
            }
            switch (kind) {
            case TKind.onTriggerEnter:if(is2D) AddTaggedTrigger<OnTriggerEnter2D_> (g,w,triggerTag,a,s);
                                      else     AddTaggedTrigger<OnTriggerEnter_>   (g,w,triggerTag,a,s); ColToTrig (g); break;
            case TKind.onTriggerExit: if(is2D) AddTaggedTrigger<OnTriggerExit2D_>  (g,w,triggerTag,a,s);
                                      else     AddTaggedTrigger<OnTriggerExit_>    (g,w,triggerTag,a,s); ColToTrig (g); break;
            case TKind.onTriggerStay: if(is2D) AddTaggedTrigger<OnTriggerStay2D_>  (g,w,triggerTag,a,s);
                                      else     AddTaggedTrigger<OnTriggerStay_>    (g,w,triggerTag,a,s); ColToTrig (g); break;
            case TKind.onCollisionEnter:if(is2D) AddTaggedTrigger<OnCollisionEnter2D_> (g,w,triggerTag,a,s);
                                        else     AddTaggedTrigger<OnCollisionEnter_>   (g,w,triggerTag,a,s); ColToTrig (g); break;
            case TKind.onCollisionExit: if(is2D) AddTaggedTrigger<OnCollisionExit2D_>  (g,w,triggerTag,a,s);
                                        else     AddTaggedTrigger<OnCollisionExit_>    (g,w,triggerTag,a,s); ColToTrig (g); break;
            case TKind.onCollisionStay: if(is2D) AddTaggedTrigger<OnCollisionStay2D_>  (g,w,triggerTag,a,s);
                                        else     AddTaggedTrigger<OnCollisionStay_>    (g,w,triggerTag,a,s); ColToTrig (g); break;
            case TKind.onControllerColliderHit:AddTaggedTrigger<OnControllerColliderHit_> (g,w,triggerTag,a,s); break;
            case TKind.onStart:             AddTrigger<OnStart_>    (g,w,a,s); break;
            case TKind.onDestroy:           AddTrigger<OnDestroy_>  (g,w,a,s); break;
            case TKind.onEnable:            AddTrigger<OnEnable_>   (g,w,a,s); break;
            case TKind.onDisable:           AddTrigger<OnDisable_>  (g,w,a,s); break;
            case TKind.onApplicationPause:  AddTrigger<OnApplicationPause_>   (g,w,a,s); break;
            case TKind.onApplicationUnpause:AddTrigger<OnApplicationUnpause_> (g,w,a,s); break;
            case TKind.onApplicationQuit:   AddTrigger<OnApplicationQuit_>    (g,w,a,s); break;
            case TKind.onMouseEnter:        AddTrigger<OnMouseEnter_>(g,w,a,s); break;
            case TKind.onMouseOver:         AddTrigger<OnMouseOver_> (g,w,a,s); break;
            case TKind.onMouseExit:         AddTrigger<OnMouseExit_> (g,w,a,s); break;
            case TKind.onMouseDown:         AddTrigger<OnMouseDown_> (g,w,a,s); break;
            case TKind.onMouseDrag:         AddTrigger<OnMouseDrag_> (g,w,a,s); break;
            case TKind.onMouseUp:           AddTrigger<OnMouseUp_>   (g,w,a,s); break;
            case TKind.onMouseUpAsButton:   AddTrigger<OnMouseUpAsButton_> (g,w,a,s); break;
            case TKind.onBecameInvisible:   AddTrigger<OnBecameInvisible_> (g,w,a,s); break;
            case TKind.onBecameVisible:     AddTrigger<OnBecameVisible_> (g,w,a,s); break;
            }
        }

        public class _TriggerBase : MonoBehaviour {
            public object whatToTrigger;
            public float delayInSeconds = 0;
            public bool activate = true;
            public void DoActivateTrigger () {
                Trigger.DoActivateTrigger (gameObject, whatToTrigger, gameObject, activate, delayInSeconds);
            }
            public void DoTriggerMouse() { Trigger.DoActivateTrigger (Input.mousePosition, whatToTrigger, gameObject, activate); }
        }
        private static void AddTrigger<T>(GameObject gameObject, object whatToTrigger, bool activate, float s) where T : _TriggerBase {
            T t = gameObject.AddComponent<T> ();
            t.whatToTrigger = whatToTrigger;
            t.activate = activate;
            t.delayInSeconds = s;
        }

        public class OnStart_ : _TriggerBase { void Start() { DoActivateTrigger(); }}
        public class OnDestroy_ : _TriggerBase { void OnDestroy() { DoActivateTrigger(); }}
        public class OnEnable_ : _TriggerBase { void OnEnable() { DoActivateTrigger(); }}
        public class OnDisable_ : _TriggerBase { void OnDisable() { DoActivateTrigger(); }}
        public class OnBecameInvisible_ : _TriggerBase { void OnBecameInvisible() { DoActivateTrigger(); }}
        public class OnBecameVisible_ : _TriggerBase { void OnBecameVisible() { DoActivateTrigger(); }}
        public class OnMouseEnter_ : _TriggerBase { void OnMouseEnter() { DoTriggerMouse (); }}
        public class OnMouseOver_ : _TriggerBase { void OnMouseOver() { DoTriggerMouse (); }}
        public class OnMouseExit_ : _TriggerBase { void OnMouseExit() { DoTriggerMouse (); }}
        public class OnMouseDown_ : _TriggerBase { void OnMouseDown() { DoTriggerMouse (); }}
        public class OnMouseDrag_ : _TriggerBase { void OnMouseDrag() { DoTriggerMouse (); }}
        public class OnMouseUp_ : _TriggerBase { void OnMouseUp() { DoTriggerMouse (); }}
        public class OnMouseUpAsButton_ : _TriggerBase { void OnMouseMouseUpAsButton() { DoTriggerMouse (); }}

        public delegate void BooleanAction(bool b);
        public static void EquateUnityEditorPauseWithApplicationPause(BooleanAction b) {
            #if UNITY_EDITOR
            // This method is run whenever the playmode state is changed.
            UnityEditor.EditorApplication.pauseStateChanged += (UnityEditor.PauseState ps) => {
                b(ps == UnityEditor.PauseState.Paused);
            };
            #endif
        }
        public class OnApplicationPause_ : _TriggerBase { void OnApplicationPause(bool pauseStatus) {
            if (pauseStatus == true) { DoActivateTrigger (); }
        } void Start() { EquateUnityEditorPauseWithApplicationPause (OnApplicationPause); }}
        public class OnApplicationUnpause_ : _TriggerBase { void OnApplicationPause(bool pauseStatus) {
            if (pauseStatus == false) { DoActivateTrigger (); }
        } void Start() { EquateUnityEditorPauseWithApplicationPause (OnApplicationPause); }}

        public class OnApplicationQuit_ : _TriggerBase { void OnApplicationQuit() { DoActivateTrigger(); }}
        //onTriggerEnter, onTriggerExit, onTriggerStay,
        public class _TriggerAreaBase : _TriggerBase {
            public string triggerTag;
            public bool IsTriggeringObject(GameObject o){ return triggerTag == "" || o.tag == triggerTag || o.tag == ""; }
            public void DoActivateTrigger (GameObject tobj) {
                if (IsTriggeringObject(tobj)) {
                    Trigger.DoActivateTrigger (tobj, whatToTrigger, gameObject, activate, delayInSeconds); }
            }
        }
        private static void AddTaggedTrigger<T>(GameObject gameObject, object whatToTrigger, string triggerTag, bool activate, float s) where T : _TriggerAreaBase {
            T t = gameObject.AddComponent<T> ();
            t.whatToTrigger = whatToTrigger;
            t.triggerTag = triggerTag;
            t.activate = activate;
            t.delayInSeconds = s;
        }

        public class OnTriggerEnter_ : _TriggerAreaBase { void OnTriggerEnter (Collider col) { DoActivateTrigger (col.gameObject); }}
        public class OnTriggerExit_ : _TriggerAreaBase { void OnTriggerExit (Collider col) { DoActivateTrigger (col.gameObject); }}
        public class OnTriggerStay_ : _TriggerAreaBase { void OnTriggerStay (Collider col) { DoActivateTrigger (col.gameObject); }}
        public class OnTriggerEnter2D_ : _TriggerAreaBase { void OnTriggerEnter2D (Collider2D col) { DoActivateTrigger (col.gameObject); }}
        public class OnTriggerExit2D_ : _TriggerAreaBase { void OnTriggerExit2D (Collider2D col) { DoActivateTrigger (col.gameObject); }}
        public class OnTriggerStay2D_ : _TriggerAreaBase { void OnTriggerStay2D (Collider2D col) { DoActivateTrigger (col.gameObject); }}
        public class OnCollisionEnter_ : _TriggerAreaBase { void OnCollisionEnter (Collider col) { DoActivateTrigger (col.gameObject); }}
        public class OnCollisionExit_ : _TriggerAreaBase { void OnCollisionExit (Collider col) { DoActivateTrigger (col.gameObject); }}
        public class OnCollisionStay_ : _TriggerAreaBase { void OnCollisionStay (Collider col) { DoActivateTrigger (col.gameObject); }}
        public class OnCollisionEnter2D_ : _TriggerAreaBase { void OnCollisionEnter2D (Collider2D col) { DoActivateTrigger (col.gameObject); }}
        public class OnCollisionExit2D_ : _TriggerAreaBase { void OnCollisionExit2D (Collider2D col) { DoActivateTrigger (col.gameObject); }}
        public class OnCollisionStay2D_ : _TriggerAreaBase { void OnCollisionStay2D (Collider2D col) { DoActivateTrigger (col.gameObject); }}
        public class OnControllerColliderHit_ : _TriggerAreaBase { void OnControllerColliderHit(CharacterController col) { DoActivateTrigger (col.gameObject); }}
    }
}