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Source/Editor/Modules/PrefabsModule.cs

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+using System;
+using System.Linq;
+using FlaxEditor.Actions;
+using FlaxEditor.Content;
+using FlaxEditor.SceneGraph;
+using FlaxEditor.Windows;
+using FlaxEngine;
+
+namespace FlaxEditor.Modules
+{
+    /// <summary>
+    /// Prefabs management module.
+    /// </summary>
+    /// <seealso cref="FlaxEditor.Modules.EditorModule" />
+    public sealed class PrefabsModule : EditorModule
+    {
+        /// <summary>
+        /// Occurs before prefab asset creating. Argument is a target actor.
+        /// </summary>
+        public event Action<Actor> PrefabCreating;
+
+        /// <summary>
+        /// Occurs after prefab asset creating. Arguments is created prefab asset item.
+        /// </summary>
+        public event Action<PrefabItem> PrefabCreated;
+
+        /// <summary>
+        /// Occurs before applying changes to the prefab. Arguments are prefab and the target instance.
+        /// </summary>
+        public event Action<Prefab, Actor> PrefabApplying;
+
+        /// <summary>
+        /// Occurs after applying changes to the prefab. Arguments are prefab and the target instance.
+        /// </summary>
+        public event Action<Prefab, Actor> PrefabApplied;
+
+        internal PrefabsModule(Editor editor)
+        : base(editor)
+        {
+        }
+
+        /// <summary>
+        /// Starts the creating prefab for the selected actor by showing the new item creation dialog in <see cref="ContentWindow"/>.
+        /// </summary>
+        /// <remarks>
+        /// To create prefab manually (from code) use <see cref="PrefabManager.CreatePrefab"/> method.
+        /// </remarks>
+        public void CreatePrefab()
+        {
+            // Check selection
+            var selection = Editor.SceneEditing.Selection;
+            if (selection.Count == 1 && selection[0] is ActorNode actorNode && actorNode.CanCreatePrefab)
+            {
+                CreatePrefab(actorNode.Actor);
+            }
+        }
+
+        /// <summary>
+        /// Starts the creating prefab for the given actor by showing the new item creation dialog in <see cref="ContentWindow"/>. User can specify the new asset name.
+        /// </summary>
+        /// <remarks>
+        /// To create prefab manually (from code) use <see cref="PrefabManager.CreatePrefab"/> method.
+        /// </remarks>
+        /// <param name="actor">The root prefab actor.</param>
+        public void CreatePrefab(Actor actor)
+        {
+            // Skip in invalid states
+            if (!Editor.StateMachine.CurrentState.CanEditContent)
+                return;
+
+            // Skip if cannot create assets in the given location
+            if (!Editor.Windows.ContentWin.CurrentViewFolder.CanHaveAssets)
+                return;
+
+            PrefabCreating?.Invoke(actor);
+
+            var proxy = Editor.ContentDatabase.GetProxy<Prefab>();
+            Editor.Windows.ContentWin.NewItem(proxy, actor, OnPrefabCreated);
+        }
+
+        private void OnPrefabCreated(ContentItem contentItem)
+        {
+            if (contentItem is PrefabItem prefabItem)
+            {
+                PrefabCreated?.Invoke(prefabItem);
+            }
+
+            // Skip in invalid states
+            if (!Editor.StateMachine.CurrentState.CanEditScene)
+                return;
+
+            // Record undo for prefab creating (backend links the target instance with the prefab)
+            if (Editor.Undo.Enabled)
+            {
+                var selection = Editor.SceneEditing.Selection.Where(x => x is ActorNode).ToList().BuildNodesParents();
+                if (selection.Count == 0)
+                    return;
+
+                if (selection.Count == 1)
+                {
+                    var action = BreakPrefabLinkAction.Linked(((ActorNode)selection[0]).Actor);
+                    Undo.AddAction(action);
+                }
+                else
+                {
+                    var actions = new IUndoAction[selection.Count];
+                    for (int i = 0; i < selection.Count; i++)
+                    {
+                        var action = BreakPrefabLinkAction.Linked(((ActorNode)selection[i]).Actor);
+                        actions[i] = action;
+                    }
+                    Undo.AddAction(new MultiUndoAction(actions));
+                }
+            }
+
+            Editor.Instance.Windows.PropertiesWin.Presenter.BuildLayout();
+        }
+
+        /// <summary>
+        /// Breaks any prefab links for the selected objects. Supports undo/redo.
+        /// </summary>
+        public void BreakLinks()
+        {
+            // Skip in invalid states
+            if (!Editor.StateMachine.CurrentState.CanEditScene)
+                return;
+
+            // Get valid objects (the top ones, C++ backend will process the child objects)
+            var selection = Editor.SceneEditing.Selection.Where(x => x is ActorNode actorNode && actorNode.HasPrefabLink).ToList().BuildNodesParents();
+            if (selection.Count == 0)
+                return;
+
+            // Perform action
+            if (Editor.StateMachine.CurrentState.CanUseUndoRedo)
+            {
+                if (selection.Count == 1)
+                {
+                    var action = BreakPrefabLinkAction.Break(((ActorNode)selection[0]).Actor);
+                    Undo.AddAction(action);
+                    action.Do();
+                }
+                else
+                {
+                    var actions = new IUndoAction[selection.Count];
+                    for (int i = 0; i < selection.Count; i++)
+                    {
+                        var action = BreakPrefabLinkAction.Break(((ActorNode)selection[i]).Actor);
+                        actions[i] = action;
+                        action.Do();
+                    }
+                    Undo.AddAction(new MultiUndoAction(actions));
+                }
+            }
+            else
+            {
+                for (int i = 0; i < selection.Count; i++)
+                {
+                    ((ActorNode)selection[i]).Actor.BreakPrefabLink();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Selects in Content Window the prefab asset used by the selected objects.
+        /// </summary>
+        public void SelectPrefab()
+        {
+            // Get valid objects (the top ones, C++ backend will process the child objects)
+            var selection = Editor.SceneEditing.Selection.Where(x => x is ActorNode actorNode && actorNode.HasPrefabLink).ToList().BuildNodesParents();
+            if (selection.Count == 0)
+                return;
+
+            var prefabId = ((ActorNode)selection[0]).Actor.PrefabID;
+            var prefab = FlaxEngine.Content.LoadAsync<Prefab>(prefabId);
+            Editor.Windows.ContentWin.Select(prefab);
+        }
+
+        /// <summary>
+        /// Applies the difference from the prefab object instance, saves the changes and synchronizes them with the active instances of the prefab asset.
+        /// </summary>
+        /// <remarks>
+        /// Applies all the changes from not only the given actor instance but all actors created within that prefab instance.
+        /// </remarks>
+        /// <param name="instance">The modified instance.</param>
+        public void ApplyAll(Actor instance)
+        {
+            // Validate input
+            if (!instance)
+                throw new ArgumentNullException(nameof(instance));
+            if (!instance.HasPrefabLink || instance.PrefabID == Guid.Empty)
+                throw new ArgumentException("The modified actor instance has missing prefab link.");
+
+            var prefab = FlaxEngine.Content.LoadAsync<Prefab>(instance.PrefabID);
+            if (prefab == null)
+                throw new ArgumentException("Missing prefab to apply.");
+            PrefabApplying?.Invoke(prefab, instance);
+
+            // Call backend
+            if (PrefabManager.Internal_ApplyAll(FlaxEngine.Object.GetUnmanagedPtr(instance)))
+                throw new FlaxException("Failed to apply the prefab. See log to learn more.");
+
+            PrefabApplied?.Invoke(prefab, instance);
+        }
+    }
+}