Added "add component overrides" button in volume UI

ScriptableRenderPipeline/Core/Editor/Volume/VolumeEditor.cs

                 actualTarget.isDirty = false;
             }
 
-            using (var scope = new EditorGUILayout.VerticalScope())
+            using (var vscope = new EditorGUILayout.VerticalScope())
             {
                 EditorGUILayout.PropertyField(m_IsGlobal);
 
                 else
                     EditorGUILayout.HelpBox("No override set on this volume.", MessageType.Info);
 
-                using (new EditorGUILayout.HorizontalScope())
+                EditorGUILayout.Space();
+
+                using (var hscope = new EditorGUILayout.HorizontalScope())
-                    GUILayout.FlexibleSpace();
-
-                    //if (GUILayout.Button(CoreEditorUtils.GetContent("Add Component"), GUILayout.Width(230f), GUILayout.Height(24f)))
-                    //{
-
-                    //}
-
-                    GUILayout.FlexibleSpace();
+                    if (GUILayout.Button(CoreEditorUtils.GetContent("Add component overrides..."), EditorStyles.miniButton))
+                    {
+                        var r = hscope.rect;
+                        var pos = new Vector2(r.x + r.width / 2f, r.yMax + 18f);
+                        FilterWindow.Show(pos, new VolumeComponentProvider(actualTarget, this));
+                    }
+
+                EditorGUILayout.Space();
-                    if (IsDragValid(scope.rect, e.mousePosition))
+                    if (IsDragValid(vscope.rect, e.mousePosition))
                     {
                         DragAndDrop.visualMode = DragAndDropVisualMode.Link;
                         e.Use();
                 }
                 else if (e.type == EventType.DragPerform)
                 {
-                    if (IsDragValid(scope.rect, e.mousePosition))
+                    if (IsDragValid(vscope.rect, e.mousePosition))
                     {
                         DragAndDrop.AcceptDrag();
 
                 m_Editors[index] = editor;
         }
 
-        void AddComponent(Type type)
+        internal void AddComponent(Type type)
         {
             serializedObject.Update();
 
             serializedObject.ApplyModifiedProperties();
         }
 
-        void RemoveComponent(int id)
+        internal void RemoveComponent(int id)
         {
             // Huh. Hack to keep foldout state on the next element...
             bool nextFoldoutState = false;
 
         // Reset is done by deleting and removing the object from the list and adding a new one in
         // the same spot as it was before
-        void ResetComponent(Type type, int id)
+        internal void ResetComponent(Type type, int id)
         {
             // Remove from the cached editors list
             m_Editors[id].OnDisable();
             Undo.DestroyObjectImmediate(prevSettings);
         }
 
-        void MoveComponent(int id, int offset)
+        internal void MoveComponent(int id, int offset)
         {
             // Move components
             serializedObject.Update();

ScriptableRenderPipeline/Core/Volume/VolumeComponent.cs

 
 namespace UnityEngine.Experimental.Rendering
 {
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
+    public sealed class VolumeComponentMenu : Attribute
+    {
+        public readonly string menu;
+        // TODO: Add support for component icons
+
+        public VolumeComponentMenu(string menu)
+        {
+            this.menu = menu;
+        }
+    }
+
     [Serializable]
     public class VolumeComponent : ScriptableObject
     {

ScriptableRenderPipeline/Core/Volume/VolumeManager.cs

         public VolumeStack stack { get; private set; }
 
         // Current list of tracked component types
-        IEnumerable<Type> m_BaseTypes;
+        public IEnumerable<Type> baseComponentTypes { get; private set; }
 
         // Max amount of layers available in Unity
         const int k_MaxLayerCount = 32;
         void ReloadBaseTypes()
         {
             // Grab all the component types we can find
-            m_BaseTypes = CoreUtils.GetAllAssemblyTypes()
+            baseComponentTypes = CoreUtils.GetAllAssemblyTypes()
-            foreach (var type in m_BaseTypes)
+            foreach (var type in baseComponentTypes)
             {
                 var inst = (VolumeComponent)ScriptableObject.CreateInstance(type);
                 m_ComponentsDefaultState.Add(inst);
         public VolumeStack CreateStack()
         {
-            return new VolumeStack(m_BaseTypes);
+            return new VolumeStack(baseComponentTypes);
         }
 
         public void Register(Volume volume, int layer)

ScriptableRenderPipeline/Core/Editor/FilterWindow.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using UnityEngine;
+
+namespace UnityEditor.Experimental.Rendering
+{
+    [InitializeOnLoad]
+    public class FilterWindow : EditorWindow
+    {
+        public interface IProvider
+        {
+            Vector2 position { get; set; }
+
+            void CreateComponentTree(List<Element> tree);
+            bool GoToChild(Element element, bool addIfComponent);
+        }
+
+        public static readonly float DefaultWidth = 250f;
+        public static readonly float DefaultHeight = 300f;
+
+        #region BaseElements
+
+        public class Element : IComparable
+        {
+            public int level;
+            public GUIContent content;
+
+            public string name
+            {
+                get { return content.text; }
+            }
+
+            public int CompareTo(object o)
+            {
+                return name.CompareTo((o as Element).name);
+            }
+        }
+
+        [Serializable]
+        public class GroupElement : Element
+        {
+            public Vector2 scroll;
+            public int selectedIndex;
+
+            public bool WantsFocus { get; protected set; }
+
+            public virtual bool ShouldDisable
+            {
+                get { return false; }
+            }
+
+            public GroupElement(int level, string name)
+            {
+                this.level = level;
+                content = new GUIContent(name);
+            }
+
+            public virtual bool HandleKeyboard(Event evt, FilterWindow window, Action goToParent)
+            {
+                return false;
+            }
+
+            public virtual bool OnGUI(FilterWindow sFilterWindow)
+            {
+                return false;
+            }
+        }
+
+        #endregion
+
+        // Styles
+
+        class Styles
+        {
+            public GUIStyle header = (GUIStyle)typeof(EditorStyles).GetProperty("inspectorBig", BindingFlags.Static | BindingFlags.NonPublic).GetValue(null, null);
+            public GUIStyle componentButton = new GUIStyle("PR Label");
+            public GUIStyle groupButton;
+            public GUIStyle background = "grey_border";
+            public GUIStyle rightArrow = "AC RightArrow";
+            public GUIStyle leftArrow = "AC LeftArrow";
+
+            public Styles()
+            {
+                header.font = EditorStyles.boldLabel.font;
+
+                componentButton.alignment = TextAnchor.MiddleLeft;
+                componentButton.fixedHeight = 20;
+                componentButton.imagePosition = ImagePosition.ImageAbove;
+
+                groupButton = new GUIStyle(componentButton);
+            }
+        }
+
+        const int k_HeaderHeight = 30;
+        const int k_WindowHeight = 400 - 80;
+        const int k_HelpHeight = 80 * 0;
+        const string k_ComponentSearch = "NodeSearchString";
+
+        static Styles s_Styles;
+        static FilterWindow s_FilterWindow;
+        static long s_LastClosedTime;
+        static bool s_DirtyList;
+
+        IProvider m_Provider;
+        Element[] m_Tree;
+        Element[] m_SearchResultTree;
+        List<GroupElement> m_Stack = new List<GroupElement>();
+
+        float m_Anim = 1;
+        int m_AnimTarget = 1;
+        long m_LastTime;
+        bool m_ScrollToSelected;
+        string m_DelayedSearch;
+        string m_Search = "";
+
+        bool m_HasSearch { get { return !string.IsNullOrEmpty(m_Search); } }
+        GroupElement m_ActiveParent { get { return m_Stack[m_Stack.Count - 2 + m_AnimTarget]; } }
+        Element[] m_ActiveTree { get { return m_HasSearch ? m_SearchResultTree : m_Tree; } }
+        Element m_ActiveElement
+        {
+            get
+            {
+                if (m_ActiveTree == null)
+                    return null;
+
+                var children = GetChildren(m_ActiveTree, m_ActiveParent);
+                return children.Count == 0
+                    ? null
+                    : children[m_ActiveParent.selectedIndex];
+            }
+        }
+        bool m_IsAnimating { get { return !Mathf.Approximately(m_Anim, m_AnimTarget); } }
+
+        static FilterWindow()
+        {
+            s_DirtyList = true;
+        }
+
+        void OnEnable()
+        {
+            s_FilterWindow = this;
+            m_Search = "";
+        }
+
+        void OnDisable()
+        {
+            s_LastClosedTime = DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond;
+            s_FilterWindow = null;
+        }
+
+        internal static bool ValidateAddComponentMenuItem()
+        {
+            return true;
+        }
+
+        internal static bool Show(Vector2 position, IProvider provider)
+        {
+            // If the window is already open, close it instead.
+            var wins = Resources.FindObjectsOfTypeAll(typeof(FilterWindow));
+            if (wins.Length > 0)
+            {
+                try
+                {
+                    ((EditorWindow)wins[0]).Close();
+                    return false;
+                }
+                catch (Exception)
+                {
+                    s_FilterWindow = null;
+                }
+            }
+
+            // We could not use realtimeSinceStartUp since it is set to 0 when entering/exitting
+            // playmode, we assume an increasing time when comparing time.
+            long nowMilliSeconds = DateTime.Now.Ticks / TimeSpan.TicksPerMillisecond;
+            bool justClosed = nowMilliSeconds < s_LastClosedTime + 50;
+
+            if (!justClosed)
+            {
+                Event.current.Use();
+
+                if (s_FilterWindow == null)
+                {
+                    s_FilterWindow = CreateInstance<FilterWindow>();
+                    s_FilterWindow.hideFlags = HideFlags.HideAndDontSave;
+                }
+
+                s_FilterWindow.Init(position, provider);
+                return true;
+            }
+            return false;
+        }
+
+        static object Invoke(Type t, object inst, string method, params object[] args)
+        {
+            var flags = (inst == null ? BindingFlags.Static : BindingFlags.Instance) | BindingFlags.NonPublic;
+            var mi = t.GetMethod(method, flags);
+            return mi.Invoke(inst, args);
+        }
+
+        void Init(Vector2 position, IProvider provider)
+        {
+            m_Provider = provider;
+            // Has to be done before calling Show / ShowWithMode
+            m_Provider.position = position;
+            position = GUIUtility.GUIToScreenPoint(position);
+            var buttonRect = new Rect(position.x - DefaultWidth / 2, position.y - 16, DefaultWidth, 1);
+
+            CreateComponentTree();
+
+            ShowAsDropDown(buttonRect, new Vector2(buttonRect.width, k_WindowHeight));
+
+            Focus();
+
+            wantsMouseMove = true;
+        }
+
+        void CreateComponentTree()
+        {
+            var tree = new List<Element>();
+            m_Provider.CreateComponentTree(tree);
+
+            m_Tree = tree.ToArray();
+
+            // Rebuild stack
+            if (m_Stack.Count == 0)
+            {
+                m_Stack.Add(m_Tree[0] as GroupElement);
+            }
+            else
+            {
+                // The root is always the match for level 0
+                var match = m_Tree[0] as GroupElement;
+                int level = 0;
+                while (true)
+                {
+                    // Assign the match for the current level
+                    var oldElement = m_Stack[level];
+                    m_Stack[level] = match;
+                    m_Stack[level].selectedIndex = oldElement.selectedIndex;
+                    m_Stack[level].scroll = oldElement.scroll;
+
+                    // See if we reached last element of stack
+                    level++;
+                    if (level == m_Stack.Count)
+                        break;
+
+                    // Try to find a child of the same name as we had before
+                    var children = GetChildren(m_ActiveTree, match);
+                    var childMatch = children.FirstOrDefault(c => c.name == m_Stack[level].name);
+
+                    if (childMatch is GroupElement)
+                    {
+                        match = childMatch as GroupElement;
+                    }
+                    else
+                    {
+                        // If we couldn't find the child, remove all further elements from the stack
+                        while (m_Stack.Count > level)
+                            m_Stack.RemoveAt(level);
+                    }
+                }
+            }
+
+            s_DirtyList = false;
+            RebuildSearch();
+        }
+
+        internal void OnGUI()
+        {
+            if (s_Styles == null)
+                s_Styles = new Styles();
+
+            GUI.Label(new Rect(0, 0, position.width, position.height), GUIContent.none, s_Styles.background);
+
+            if (s_DirtyList)
+                CreateComponentTree();
+
+            // Keyboard
+            HandleKeyboard();
+
+            GUILayout.Space(7);
+
+            // Search
+            if (!m_ActiveParent.WantsFocus)
+            {
+                EditorGUI.FocusTextInControl("ComponentSearch");
+                Focus();
+            }
+
+            var searchRect = GUILayoutUtility.GetRect(10, 20);
+            searchRect.x += 8;
+            searchRect.width -= 16;
+
+            GUI.SetNextControlName("ComponentSearch");
+
+            using (new EditorGUI.DisabledScope(m_ActiveParent.ShouldDisable))
+            {
+                string newSearch = (string)Invoke(typeof(EditorGUI), null, "SearchField", searchRect, m_DelayedSearch ?? m_Search);
+
+                if (newSearch != m_Search || m_DelayedSearch != null)
+                {
+                    if (!m_IsAnimating)
+                    {
+                        m_Search = m_DelayedSearch ?? newSearch;
+                        EditorPrefs.SetString(k_ComponentSearch, m_Search);
+                        RebuildSearch();
+                        m_DelayedSearch = null;
+                    }
+                    else
+                    {
+                        m_DelayedSearch = newSearch;
+                    }
+                }
+            }
+
+            // Show lists
+            ListGUI(m_ActiveTree, m_Anim, GetElementRelative(0), GetElementRelative(-1));
+            if (m_Anim < 1)
+                ListGUI(m_ActiveTree, m_Anim + 1, GetElementRelative(-1), GetElementRelative(-2));
+
+            // Animate
+            if (m_IsAnimating && Event.current.type == EventType.Repaint)
+            {
+                long now = DateTime.Now.Ticks;
+                float deltaTime = (now - m_LastTime) / (float)TimeSpan.TicksPerSecond;
+                m_LastTime = now;
+                m_Anim = Mathf.MoveTowards(m_Anim, m_AnimTarget, deltaTime * 4);
+
+                if (m_AnimTarget == 0 && Mathf.Approximately(m_Anim, 0))
+                {
+                    m_Anim = 1;
+                    m_AnimTarget = 1;
+                    m_Stack.RemoveAt(m_Stack.Count - 1);
+                }
+
+                Repaint();
+            }
+        }
+
+        void HandleKeyboard()
+        {
+            var evt = Event.current;
+
+            if (evt.type == EventType.KeyDown)
+            {
+                // Special handling when in new script panel
+                if (!m_ActiveParent.HandleKeyboard(evt, s_FilterWindow, GoToParent))
+                {
+                    // Always do these
+                    if (evt.keyCode == KeyCode.DownArrow)
+                    {
+                        m_ActiveParent.selectedIndex++;
+                        m_ActiveParent.selectedIndex = Mathf.Min(m_ActiveParent.selectedIndex, GetChildren(m_ActiveTree, m_ActiveParent).Count - 1);
+                        m_ScrollToSelected = true;
+                        evt.Use();
+                    }
+
+                    if (evt.keyCode == KeyCode.UpArrow)
+                    {
+                        m_ActiveParent.selectedIndex--;
+                        m_ActiveParent.selectedIndex = Mathf.Max(m_ActiveParent.selectedIndex, 0);
+                        m_ScrollToSelected = true;
+                        evt.Use();
+                    }
+
+                    if (evt.keyCode == KeyCode.Return || evt.keyCode == KeyCode.KeypadEnter)
+                    {
+                        GoToChild(m_ActiveElement, true);
+                        evt.Use();
+                    }
+
+                    // Do these if we're not in search mode
+                    if (!m_HasSearch)
+                    {
+                        if (evt.keyCode == KeyCode.LeftArrow || evt.keyCode == KeyCode.Backspace)
+                        {
+                            GoToParent();
+                            evt.Use();
+                        }
+
+                        if (evt.keyCode == KeyCode.RightArrow)
+                        {
+                            GoToChild(m_ActiveElement, false);
+                            evt.Use();
+                        }
+
+                        if (evt.keyCode == KeyCode.Escape)
+                        {
+                            Close();
+                            evt.Use();
+                        }
+                    }
+                }
+            }
+        }
+
+        const string k_SearchHeader = "Search";
+
+        void RebuildSearch()
+        {
+            if (!m_HasSearch)
+            {
+                m_SearchResultTree = null;
+
+                if (m_Stack[m_Stack.Count - 1].name == k_SearchHeader)
+                {
+                    m_Stack.Clear();
+                    m_Stack.Add(m_Tree[0] as GroupElement);
+                }
+
+                m_AnimTarget = 1;
+                m_LastTime = DateTime.Now.Ticks;
+                return;
+            }
+
+            // Support multiple search words separated by spaces.
+            var searchWords = m_Search.ToLower().Split(' ');
+
+            // We keep two lists. Matches that matches the start of an item always get first priority.
+            var matchesStart = new List<Element>();
+            var matchesWithin = new List<Element>();
+
+            foreach (var e in m_Tree)
+            {
+                if (e is GroupElement)
+                    continue;
+
+                string name = e.name.ToLower().Replace(" ", "");
+                bool didMatchAll = true;
+                bool didMatchStart = false;
+
+                // See if we match ALL the seaarch words.
+                for (int w = 0; w < searchWords.Length; w++)
+                {
+                    string search = searchWords[w];
+
+                    if (name.Contains(search))
+                    {
+                        // If the start of the item matches the first search word, make a note of that.
+                        if (w == 0 && name.StartsWith(search))
+                            didMatchStart = true;
+                    }
+                    else
+                    {
+                        // As soon as any word is not matched, we disregard this item.
+                        didMatchAll = false;
+                        break;
+                    }
+                }
+
+                // We always need to match all search words.
+                // If we ALSO matched the start, this item gets priority.
+                if (didMatchAll)
+                {
+                    if (didMatchStart)
+                        matchesStart.Add(e);
+                    else
+                        matchesWithin.Add(e);
+                }
+            }
+
+            matchesStart.Sort();
+            matchesWithin.Sort();
+
+            // Create search tree
+            var tree = new List<Element>();
+
+            // Add parent
+            tree.Add(new GroupElement(0, k_SearchHeader));
+
+            // Add search results
+            tree.AddRange(matchesStart);
+            tree.AddRange(matchesWithin);
+
+            // Create search result tree
+            m_SearchResultTree = tree.ToArray();
+            m_Stack.Clear();
+            m_Stack.Add(m_SearchResultTree[0] as GroupElement);
+
+            // Always select the first search result when search is changed (e.g. a character was typed in or deleted),
+            // because it's usually the best match.
+            if (GetChildren(m_ActiveTree, m_ActiveParent).Count >= 1)
+                m_ActiveParent.selectedIndex = 0;
+            else
+                m_ActiveParent.selectedIndex = -1;
+        }
+
+        GroupElement GetElementRelative(int rel)
+        {
+            int i = m_Stack.Count + rel - 1;
+
+            if (i < 0)
+                return null;
+
+            return m_Stack[i];
+        }
+
+        void GoToParent()
+        {
+            if (m_Stack.Count > 1)
+            {
+                m_AnimTarget = 0;
+                m_LastTime = DateTime.Now.Ticks;
+            }
+        }
+
+        void ListGUI(Element[] tree, float anim, GroupElement parent, GroupElement grandParent)
+        {
+            // Smooth the fractional part of the anim value
+            anim = Mathf.Floor(anim) + Mathf.SmoothStep(0, 1, Mathf.Repeat(anim, 1));
+
+            // Calculate rect for animated area
+            var animRect = position;
+            animRect.x = position.width * (1 - anim) + 1;
+            animRect.y = k_HeaderHeight;
+            animRect.height -= k_HeaderHeight + k_HelpHeight;
+            animRect.width -= 2;
+
+            // Start of animated area (the part that moves left and right)
+            GUILayout.BeginArea(animRect);
+
+            // Header
+            var headerRect = GUILayoutUtility.GetRect(10, 25);
+            string name = parent.name;
+            GUI.Label(headerRect, name, s_Styles.header);
+
+            // Back button
+            if (grandParent != null)
+            {
+                var arrowRect = new Rect(headerRect.x + 4, headerRect.y + 7, 13, 13);
+                var e = Event.current;
+
+                if (e.type == EventType.Repaint)
+                    s_Styles.leftArrow.Draw(arrowRect, false, false, false, false);
+
+                if (e.type == EventType.MouseDown && headerRect.Contains(e.mousePosition))
+                {
+                    GoToParent();
+                    e.Use();
+                }
+            }
+
+            if (!parent.OnGUI(s_FilterWindow))
+                ListGUI(tree, parent);
+
+            GUILayout.EndArea();
+        }
+
+        void GoToChild(Element e, bool addIfComponent)
+        {
+            if (m_Provider.GoToChild(e, addIfComponent))
+            {
+                Close();
+            }
+            else if (!m_HasSearch)
+            {
+                m_LastTime = DateTime.Now.Ticks;
+
+                if (m_AnimTarget == 0)
+                {
+                    m_AnimTarget = 1;
+                }
+                else if (Mathf.Approximately(m_Anim, 1f))
+                {
+                    m_Anim = 0;
+                    m_Stack.Add(e as GroupElement);
+                }
+            }
+        }
+
+        void ListGUI(Element[] tree, GroupElement parent)
+        {
+            // Start of scroll view list
+            parent.scroll = GUILayout.BeginScrollView(parent.scroll);
+
+            EditorGUIUtility.SetIconSize(new Vector2(16, 16));
+
+            var children = GetChildren(tree, parent);
+            var selectedRect = new Rect();
+            var evt = Event.current;
+
+            // Iterate through the children
+            for (int i = 0; i < children.Count; i++)
+            {
+                var e = children[i];
+                var r = GUILayoutUtility.GetRect(16, 20, GUILayout.ExpandWidth(true));
+
+                // Select the element the mouse cursor is over.
+                // Only do it on mouse move - keyboard controls are allowed to overwrite this until the next time the mouse moves.
+                if (evt.type == EventType.MouseMove || evt.type == EventType.MouseDown)
+                {
+                    if (parent.selectedIndex != i && r.Contains(evt.mousePosition))
+                    {
+                        parent.selectedIndex = i;
+                        Repaint();
+                    }
+                }
+
+                bool selected = false;
+
+                // Handle selected item
+                if (i == parent.selectedIndex)
+                {
+                    selected = true;
+                    selectedRect = r;
+                }
+
+                // Draw element
+                if (evt.type == EventType.Repaint)
+                {
+                    var labelStyle = (e is GroupElement) ? s_Styles.groupButton : s_Styles.componentButton;
+                    labelStyle.Draw(r, e.content, false, false, selected, selected);
+
+                    if (e is GroupElement)
+                    {
+                        var arrowRect = new Rect(r.x + r.width - 13, r.y + 4, 13, 13);
+                        s_Styles.rightArrow.Draw(arrowRect, false, false, false, false);
+                    }
+                }
+
+                if (evt.type == EventType.MouseDown && r.Contains(evt.mousePosition))
+                {
+                    evt.Use();
+                    parent.selectedIndex = i;
+                    GoToChild(e, true);
+                }
+            }
+
+            EditorGUIUtility.SetIconSize(Vector2.zero);
+
+            GUILayout.EndScrollView();
+
+            // Scroll to show selected
+            if (m_ScrollToSelected && evt.type == EventType.Repaint)
+            {
+                m_ScrollToSelected = false;
+                var scrollRect = GUILayoutUtility.GetLastRect();
+
+                if (selectedRect.yMax - scrollRect.height > parent.scroll.y)
+                {
+                    parent.scroll.y = selectedRect.yMax - scrollRect.height;
+                    Repaint();
+                }
+
+                if (selectedRect.y < parent.scroll.y)
+                {
+                    parent.scroll.y = selectedRect.y;
+                    Repaint();
+                }
+            }
+        }
+
+        List<Element> GetChildren(Element[] tree, Element parent)
+        {
+            var children = new List<Element>();
+            int level = -1;
+            int i;
+
+            for (i = 0; i < tree.Length; i++)
+            {
+                if (tree[i] == parent)
+                {
+                    level = parent.level + 1;
+                    i++;
+                    break;
+                }
+            }
+
+            if (level == -1)
+                return children;
+
+            for (; i < tree.Length; i++)
+            {
+                var e = tree[i];
+
+                if (e.level < level)
+                    break;
+
+                if (e.level > level && !m_HasSearch)
+                    continue;
+
+                children.Add(e);
+            }
+
+            return children;
+        }
+    }
+}

ScriptableRenderPipeline/Core/Editor/FilterWindow.cs.meta

+fileFormatVersion: 2
+guid: e1dbde6eddba87f4ea272a5d3af5b7ac
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

ScriptableRenderPipeline/Core/Editor/Volume/VolumeComponentProvider.cs

+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using UnityEngine.Experimental.Rendering;
+
+namespace UnityEditor.Experimental.Rendering
+{
+    using IProvider = FilterWindow.IProvider;
+    using Element = FilterWindow.Element;
+    using GroupElement = FilterWindow.GroupElement;
+
+    class VolumeComponentProvider : IProvider
+    {
+        class VolumeComponentElement : Element
+        {
+            public Type type;
+
+            public VolumeComponentElement(int level, string label, Type type)
+            {
+                this.level = level;
+                this.type = type;
+                // TODO: Add support for custom icons
+                content = new GUIContent(label);
+            }
+        }
+
+        class PathNode : IComparable<PathNode>
+        {
+            public List<PathNode> nodes =  new List<PathNode>();
+            public string name;
+            public Type type;
+
+            public int CompareTo(PathNode other)
+            {
+                return name.CompareTo(other.name);
+            }
+        }
+
+        public Vector2 position { get; set; }
+
+        Volume m_Target;
+        VolumeEditor m_TargetEditor;
+
+        public VolumeComponentProvider(Volume target, VolumeEditor targetEditor)
+        {
+            m_Target = target;
+            m_TargetEditor = targetEditor;
+        }
+
+        public void CreateComponentTree(List<Element> tree)
+        {
+            tree.Add(new GroupElement(0, "Volume Components"));
+
+            var attrType = typeof(VolumeComponentMenu);
+            var types = VolumeManager.instance.baseComponentTypes;
+            var rootNode = new PathNode();
+
+            foreach (var t in types)
+            {
+                // Skip components that have already been added to the volume
+                if (m_Target.Has(t))
+                    continue;
+
+                string path = string.Empty;
+
+                // Look for a VolumeComponentMenu attribute
+                var attrs = t.GetCustomAttributes(attrType, false);
+                if (attrs.Length > 0)
+                {
+                    var attr = attrs[0] as VolumeComponentMenu;
+                    if (attr != null)
+                        path = attr.menu;
+                }
+
+                // If no attribute or in case something went wrong when grabbing it, fallback to a
+                // beautified class name
+                if (string.IsNullOrEmpty(path))
+                    path = ObjectNames.NicifyVariableName(t.Name);
+
+                // Prep the categories & types tree
+                AddNode(rootNode, path, t);
+            }
+
+            // Recursively add all elements to the tree
+            Traverse(rootNode, 1, tree);
+        }
+
+        public bool GoToChild(Element element, bool addIfComponent)
+        {
+            if (element is VolumeComponentElement)
+            {
+                var e = (VolumeComponentElement)element;
+                m_TargetEditor.AddComponent(e.type);
+                return true;
+            }
+
+            return false;
+        }
+
+        void AddNode(PathNode root, string path, Type type)
+        {
+            var current = root;
+            var parts = path.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
+
+            foreach (var part in parts)
+            {
+                var child = current.nodes.Find(x => x.name == part);
+
+                if (child == null)
+                {
+                    child = new PathNode { name = part, type = type };
+                    current.nodes.Add(child);
+                }
+
+                current = child;
+            }
+        }
+
+        void Traverse(PathNode node, int depth, List<Element> tree)
+        {
+            node.nodes.Sort();
+
+            foreach (var n in node.nodes)
+            {
+                if (n.nodes.Count > 0) // Group
+                {
+                    tree.Add(new GroupElement(depth, n.name));
+                    Traverse(n, depth + 1, tree);
+                }
+                else // Element
+                {
+                    tree.Add(new VolumeComponentElement(depth, n.name, n.type));
+                }
+            }
+        }
+    }
+}

ScriptableRenderPipeline/Core/Editor/Volume/VolumeComponentProvider.cs.meta

+fileFormatVersion: 2
+guid: 7d7e09e271ad3fd4c9ceb1873a5fb59e
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: