Added some useful attributes from Longbow.

Author: witian

Assets/MixedRealityToolkit/Attributes/HelpAttribute.cs

@@ -0,0 +1,36 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+using UnityEngine;
+using System;
+
+namespace Microsoft.MixedReality.Toolkit
+{
+    /// <summary>
+    /// A PropertyAttribute for showing a collapsable Help section.
+    /// </summary>
+    /// <seealso cref="UnityEngine.PropertyAttribute" />
+    [AttributeUsage(AttributeTargets.Field|AttributeTargets.Property, AllowMultiple = false)]
+    public class HelpAttribute : PropertyAttribute
+    {
+        /// <summary>
+        /// The help text
+        /// </summary>
+        public string Text;
+
+        /// <summary>
+        /// The help header foldout text
+        /// </summary>
+        public string Header;
+
+        /// <summary>
+        /// Constructor
+        /// </summary>
+        /// <param name="helpText">The help text to display</param>
+        /// <param name="helpHeader">The help header foldout text</param>
+        public HelpAttribute(string helpText, string helpHeader="Help")
+        {
+            Text = helpText;
+            Header = helpHeader;
+        }
+    }
+}

Assets/MixedRealityToolkit/Attributes/HelpAttribute.cs.meta

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+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+using System;
+using UnityEngine;
+
+namespace Microsoft.MixedReality.Toolkit
+{
+    /// <summary>
+    /// Attribute to mark up an int field to be drawn using the
+    /// ScenePickPropertyDrawer
+    /// This allows the UI to display a dropdown instead of a
+    /// numeric entry field.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Field, AllowMultiple = false)]
+    public class ScenePickAttribute : PropertyAttribute
+    {
+        // Nothing to see Here, This only acts as a marker to help the editor.
+    }
+}

Assets/MixedRealityToolkit/Attributes/ScenePickAttribute.cs

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+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+using UnityEngine;
+using System;
+
+namespace Microsoft.MixedReality.Toolkit
+{
+    /// <summary>
+    /// A PropertyAttribute for Unity tags (a string field).
+    /// </summary>
+    /// <seealso cref="UnityEngine.PropertyAttribute" />
+    [AttributeUsage(AttributeTargets.Field, AllowMultiple = false)]
+    public class TagPropertyAttribute : PropertyAttribute
+    {
+        // Do nothing
+    }
+}

Assets/MixedRealityToolkit/Attributes/ScenePickAttribute.cs.meta

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+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+using UnityEngine;
+using UnityEditor;
+
+namespace Microsoft.MixedReality.Toolkit.Editor
+{
+    /// <summary>
+    /// Custom property drawer to show a foldout help section in the Inspector
+    /// </summary>
+    /// <example>
+    /// <code>
+    /// [Help("This is a multiline collapsable help section.\n • Great for providing simple instructions in Inspector.\n • Easy to use.\n • Saves space.")]
+    /// </code>
+    /// </example>
+    [CustomPropertyDrawer(typeof(HelpAttribute))]
+    public class HelpDrawer : DecoratorDrawer
+    {
+        /// <summary>
+        /// Unity calls this function to draw the GUI
+        /// </summary>
+        /// <param name="position">Rectangle to display the GUI in</param>
+        public override void OnGUI(Rect position)
+        {
+            HelpAttribute help = attribute as HelpAttribute;
+
+            HelpFoldOut = EditorGUI.Foldout(position, HelpFoldOut, help.Header);
+            if (HelpFoldOut)
+            {
+                EditorGUI.HelpBox(position, help.Text, MessageType.Info);
+            }
+        }
+
+        /// <summary>
+        /// Gets the height of the decorator
+        /// </summary>
+        /// <returns></returns>
+        public override float GetHeight()
+        {
+            HelpAttribute help = attribute as HelpAttribute;
+
+            GUIStyle helpStyle = EditorStyles.helpBox;
+            Vector2 size = helpStyle.CalcSize(new GUIContent(help.Text));
+            float lines = size.y / helpStyle.lineHeight;
+            return helpStyle.margin.top + helpStyle.margin.bottom + helpStyle.lineHeight * (HelpFoldOut ? lines : 1.0f);
+        }
+
+        #region Private
+
+        /// <summary>
+        /// The "help" foldout state
+        /// </summary>
+        private bool HelpFoldOut = false;
+
+        #endregion
+    }
+}

Assets/MixedRealityToolkit/Attributes/TagPropertyAttribute.cs

@@ -0,0 +1,119 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+using UnityEngine;
+using UnityEditor;
+
+namespace Microsoft.MixedReality.Toolkit.Editor
+{
+    /// <summary>
+    /// Creates a custom picker based on the list of scene in the build settings.
+    /// </summary>
+    /// <example>
+    /// <code>
+    /// [ScenePick]
+    /// public int SceneId;
+    /// </code>
+    /// </example>
+    [CustomPropertyDrawer(typeof(ScenePickAttribute))]
+    public class ScenePickPropertyDrawer : PropertyDrawer
+    {
+        /// <summary>
+        /// List of Options extracted from the Editor
+        /// </summary>
+        private static GUIContent[] Options;
+
+        /// <summary>
+        /// List of Scene GUIDS for the scenes
+        /// </summary>
+        private static string[] PropertyData;
+
+        /// <summary>
+        /// Select this option to remove the event string
+        /// </summary>
+        private static readonly string UnselectedText = "-- None --";
+
+        /// <summary>
+        /// Text to display when an entry is missing
+        /// </summary>
+        private static readonly string MissingText = "-- Missing --";
+
+        /// <summary>
+        /// Function called by unity to draw the GUI for this property
+        /// We are replacing the int value of the backing field with a dropdown list of scene names
+        /// </summary>
+        /// <param name="position">See base class</param>
+        /// <param name="property">See base class</param>
+        /// <param name="label">See base class</param>
+        public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
+        {
+            BuildOptions();
+
+            var currentGuid = property.stringValue.Split(';')[0];
+
+            var currentId = System.Array.FindIndex(PropertyData, (x) => x.Contains(currentGuid));
+
+            if (currentId == -1)
+            {
+                // Not found, display the missing text
+                currentId = Options.Length - 1;
+            }
+            else if (currentId > 0 && property.stringValue != PropertyData[currentId])
+            {
+                // If the string has changed, update the property.
+                // This will happen if the scene is renamed.
+                property.stringValue = PropertyData[currentId];
+                EditorUtility.SetDirty(property.serializedObject.targetObject);
+            }
+
+            EditorGUI.BeginProperty(position, new GUIContent(property.name), property);
+            var newId = EditorGUI.Popup(position, label, currentId, Options);
+
+            if (newId != currentId)
+            {
+                property.stringValue = PropertyData[newId];
+                EditorUtility.SetDirty(property.serializedObject.targetObject);
+            }
+
+            EditorGUI.EndProperty();
+
+        }
+
+        /// <summary>
+        /// Build the list of scene names
+        /// Note: Scene 0 is the no-scene option.
+        /// </summary>
+        private static void BuildOptions()
+        {
+            var scenes = EditorBuildSettings.scenes;
+
+            if (scenes.Length > 0)
+            {
+                Options = new GUIContent[scenes.Length + 2];
+                PropertyData = new string[scenes.Length + 2];
+
+                Options[0] = new GUIContent(UnselectedText);
+                PropertyData[0] = string.Empty;
+
+                for (int i = 0; i < scenes.Length; i++)
+                {
+                    // Right, replace '/' with '\' otherwise the list displays like a menu where '/' denotes a sub-menu.
+                    Options[i + 1] = new GUIContent(scenes[i].path.Replace("/", "\\"));
+                    PropertyData[i + 1] = scenes[i].guid.ToString() + ";" + scenes[i].path;
+                }
+
+                Options[scenes.Length + 1] = new GUIContent(MissingText);
+                PropertyData[scenes.Length + 1] = MissingText;
+            }
+            else
+            {
+                Options = new GUIContent[2];
+                PropertyData = new string[2];
+
+                Options[0] = new GUIContent(UnselectedText);
+                PropertyData[0] = string.Empty;
+                Options[1] = new GUIContent(MissingText);
+                PropertyData[1] = MissingText;
+            }
+        }
+    }
+}