Added custom window to clean up files.

Changed the Version Handler prompts to clean up obsolete files to use
a custom editor window rather than the EditorUtility dialog which
can exceed the screen size.

Bug: 132688405
Fixes #215

Change-Id: Iefbca2ae8b7c6c0dc94758412a8cb0a48ba4ab7b

Author: Stewart Miles

source/VersionHandlerImpl/VersionHandlerImpl.csproj

@@ -55,6 +55,7 @@
     <Compile Include="src\Logger.cs" />
     <Compile Include="src\ExecutionEnvironment.cs" />
     <Compile Include="src\FileUtils.cs" />
+    <Compile Include="src\MultiSelectWindow.cs" />
     <Compile Include="src\ProjectSettings.cs" />
     <Compile Include="src\RunOnMainThread.cs" />
     <Compile Include="src\SettingsDialog.cs" />

source/VersionHandlerImpl/src/MultiSelectWindow.cs

@@ -0,0 +1,242 @@
+// <copyright file="MultiSelectWindow.cs" company="Google Inc.">
+// Copyright (C) 2019 Google Inc. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//    limitations under the License.
+// </copyright>
+
+using System;
+using System.Collections.Generic;
+using UnityEditor;
+using UnityEngine;
+
+namespace Google {
+
+    /// <summary>
+    /// Window that displays a list of optionally selected items.
+    /// </summary>
+    public class MultiSelectWindow : EditorWindow {
+
+        /// <summary>
+        /// Position of the window.
+        /// </summary>
+        private Vector2 scrollPosition = new Vector2(0, 0);
+
+        /// <summary>
+        /// Index of each item to select mapped to the sorted set of items to display.
+        /// </summary>
+        private List<KeyValuePair<int, KeyValuePair<string, string>>> sortedItems;
+
+        /// <summary>
+        /// Items to display for selection, the Key of each item is stored in the selection
+        /// the Value is rendered in the view.
+        /// </summary>
+        public List<KeyValuePair<string, string>> AvailableItems { get; set; }
+
+        /// <summary>
+        /// Set of items that have been selected.
+        /// </summary>
+        public HashSet<string> SelectedItems { get; set; }
+
+        /// <summary>
+        /// Caption for the top of the window.
+        /// </summary>
+        public string Caption { get; set; }
+
+        /// <summary>
+        /// Caption for the button to apply the selection.
+        /// </summary>
+        public string ApplyLabel { get; set; }
+
+        /// <summary>
+        /// Action to execute when the selection is applied.
+        /// </summary>
+        public Action OnApply;
+
+        /// <summary>
+        /// Caption for the button to cancel the selection.
+        /// </summary>
+        public string CancelLabel { get; set; }
+
+        /// <summary>
+        /// Action to execute when the selection is canceled.
+        /// </summary>
+        public Action OnCancel;
+
+        /// <summary>
+        /// Styles for unselected items in the list.
+        /// </summary>
+        private GUIStyle[] unselectedItemStyles;
+
+        /// <summary>
+        /// Styles for selected items in the list.
+        /// </summary>
+        private GUIStyle[] selectedItemStyles;
+
+        /// <summary>
+        /// Initialize the window.
+        /// </summary>
+        protected MultiSelectWindow() {
+            Initialize();
+        }
+
+        /// <summary>
+        /// Reset the window to its default state.
+        /// </summary>
+        public virtual void Initialize() {
+            AvailableItems = new List<KeyValuePair<string, string>>();
+            InitializeSortedItems();
+            SelectedItems = new HashSet<string>();
+            ApplyLabel = "Apply";
+            CancelLabel = "Cancel";
+            scrollPosition = new Vector2(0, 0);
+            minSize = new Vector2(300, 200);
+            unselectedItemStyles = null;
+            selectedItemStyles = null;
+        }
+
+        /// <summary>
+        /// Select all items.
+        /// </summary>
+        public virtual void SelectAll() {
+            if (AvailableItems != null) {
+                SelectedItems = new HashSet<string>();
+                foreach (var item in AvailableItems) SelectedItems.Add(item.Key);
+            } else {
+                SelectNone();
+            }
+        }
+
+        /// <summary>
+        /// Select no items.
+        /// </summary>
+        public virtual void SelectNone() {
+            SelectedItems = new HashSet<string>();
+        }
+
+        /// <summary>
+        /// Initialize the sortedItems array from the available items.
+        /// </summary>
+        private void InitializeSortedItems() {
+            sortedItems = new List<KeyValuePair<int, KeyValuePair<string, string>>>();
+            if (AvailableItems != null) {
+                for (int i = 0; i < AvailableItems.Count; ++i) {
+                    sortedItems.Add(new KeyValuePair<int, KeyValuePair<string, string>>(
+                        i, new KeyValuePair<string, string>(AvailableItems[i].Key,
+                                                            AvailableItems[i].Value)));
+                }
+            }
+        }
+
+        /// <summary>
+        /// Sort the set of items.
+        /// </summary>
+        /// <param name="direction">1 to sort ascending, -1 to sort descending.</param>
+        public virtual void Sort(int direction) {
+            if (AvailableItems != null) {
+                InitializeSortedItems();
+                sortedItems.Sort((lhs, rhs) => {
+                        return direction > 0 ?
+                            String.Compare(lhs.Value.Value, rhs.Value.Value) :
+                            String.Compare(rhs.Value.Value, lhs.Value.Value);
+                    });
+            }
+        }
+
+        /// <summary>
+        /// Lazily configure the styles used to draw items in the window.
+        /// Default styles in some versions of Unity are not accessible until OnGUI().
+        /// </summary>
+        protected virtual void InitializeStyles() {
+            // Configure unselected styles with alternating normal states.
+            if (unselectedItemStyles == null) {
+                unselectedItemStyles = new GUIStyle[2];
+                unselectedItemStyles[0] = EditorStyles.label;
+                unselectedItemStyles[1] = EditorStyles.textField;
+            }
+            if (selectedItemStyles == null && unselectedItemStyles != null) {
+                // Configure selected styles by overriding the font style.
+                selectedItemStyles = new GUIStyle[unselectedItemStyles.Length];
+                for (int i = 0; i < unselectedItemStyles.Length; ++i) {
+                    var style = new GUIStyle(unselectedItemStyles[i]);
+                    style.font = EditorStyles.boldLabel.font;
+                    selectedItemStyles[i] = style;
+                }
+            }
+            if (AvailableItems != null && sortedItems.Count != AvailableItems.Count) {
+                InitializeSortedItems();
+            }
+        }
+
+        /// <summary>
+        /// Draw the window.
+        /// </summary>
+        protected virtual void OnGUI() {
+            InitializeStyles();
+            if (!String.IsNullOrEmpty(Caption)) {
+                EditorGUILayout.BeginHorizontal();
+                EditorGUILayout.SelectableLabel(Caption);
+                EditorGUILayout.EndHorizontal();
+                EditorGUILayout.Space();
+            }
+            EditorGUILayout.BeginVertical();
+            scrollPosition = EditorGUILayout.BeginScrollView(scrollPosition);
+            int displayIndex = 0;
+            foreach (var indexAndItem in sortedItems) {
+                var item = indexAndItem.Value.Key;
+                var display = indexAndItem.Value.Value;
+                bool selected = SelectedItems.Contains(item);
+                EditorGUILayout.BeginHorizontal(
+                    selected ? selectedItemStyles[displayIndex % selectedItemStyles.Length] :
+                        unselectedItemStyles[displayIndex % unselectedItemStyles.Length]);
+                bool currentlySelected = EditorGUILayout.ToggleLeft(display, selected);
+                if (currentlySelected != selected) {
+                    if (currentlySelected) {
+                        SelectedItems.Add(item);
+                    } else {
+                        SelectedItems.Remove(item);
+                    }
+                }
+                EditorGUILayout.EndHorizontal();
+                displayIndex++;
+            }
+            EditorGUILayout.EndScrollView();
+            EditorGUILayout.EndVertical();
+            EditorGUILayout.BeginHorizontal();
+            if (GUILayout.Button("All")) SelectAll();
+            if (GUILayout.Button("None")) SelectNone();
+            EditorGUILayout.Space();
+            EditorGUILayout.Space();
+            bool cancel = GUILayout.Button(CancelLabel);
+            bool apply = GUILayout.Button(ApplyLabel);
+            EditorGUILayout.EndHorizontal();
+            EditorGUILayout.Space();
+            if (cancel || apply) {
+                if (cancel && OnCancel != null) OnCancel();
+                if (apply && OnApply != null) OnApply();
+                Close();
+            }
+        }
+
+        /// <summary>
+        /// Get the existing multi-select window or create a new one.
+        /// </summary>
+        /// <param name="title">Title to display on the window.</param>
+        /// <returns>Reference to this class</returns>
+        public static MultiSelectWindow CreateMultiSelectWindow(string title) {
+            MultiSelectWindow window = (MultiSelectWindow)EditorWindow.GetWindow(
+                typeof(MultiSelectWindow), true, title, true);
+            window.Initialize();
+            return window;
+        }
+    }
+}