[DevTools] Introduce Common.List used as a backend for list controls

third_party/WebKit/Source/devtools/front_end/ui/ListModel.js

Index: third_party/WebKit/Source/devtools/front_end/ui/ListModel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/ListModel.js b/third_party/WebKit/Source/devtools/front_end/ui/ListModel.js
new file mode 100644
index 0000000000000000000000000000000000000000..770c8d166bb6228d74cd819d4e031ed4dafb1f77
--- /dev/null
+++ b/third_party/WebKit/Source/devtools/front_end/ui/ListModel.js
@@ -0,0 +1,139 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @template T
+ */
+UI.ListModel = class extends Common.Object {
+  /**
+   * @param {!Array<T>=} items
+   */
+  constructor(items) {
+    super();
+    this._items = items || [];
+  }
+
+  /**
+   * @return {number}
+   */
+  length() {
+    return this._items.length;
+  }
+
+  /**
+   * @param {number} index
+   * @return {T}
+   */
+  itemAtIndex(index) {
+    return this._items[index];
+  }
+
+  /**
+   * @param {T} item
+   */
+  pushItem(item) {
+    this.replaceItemsInRange(this._items.length, this._items.length, [item]);
+  }
+
+  /**
+   * @return {T}
+   */
+  popItem() {
+    return this.removeItemAtIndex(this._items.length - 1);
+  }
+
+  /**
+   * @param {number} index
+   * @param {T} item
+   */
+  insertItemAtIndex(index, item) {
+    this.replaceItemsInRange(index, index, [item]);
+  }
+
+  /**
+   * @param {T} item
+   * @param {function(T, T):number} comparator
+   */
+  insertItemWithComparator(item, comparator) {
+    var index = this._items.lowerBound(item, comparator);
+    this.insertItemAtIndex(index, item);
+  }
+
+  /**
+   * @param {T} item
+   * @return {number}
+   */
+  indexOfItem(item) {
+    return this._items.indexOf(item);
+  }
+
+  /**
+   * @param {number} index
+   * @return {T}
+   */
+  removeItemAtIndex(index) {
+    var result = this._items[index];
+    this.replaceItemsInRange(index, index + 1, []);
+    return result;
+  }
+
+  /**
+   * @param {T} item
+   */
+  removeItem(item) {
+    var index = this._items.indexOf(item);
+    if (index === -1) {
+      console.error('Attempt to remove non-existing item');
+      return;
+    }
+    this.removeItemAtIndex(index);
+  }
+
+  /**
+   * @param {!Array<T>} items
+   */
+  replaceAllItems(items) {
+    this.replaceItemsInRange(0, this._items.length, items);
+  }
+
+  /**
+   * @param {number} index
+   * @param {T} item
+   */
+  replaceItemAtIndex(index, item) {
+    this.replaceItemsInRange(index, index + 1, [item]);
+  }
+
+  /**
+   * @param {function(T):boolean} callback
+   * @return {number}
+   */
+  findIndex(callback) {
+    return this._items.findIndex(callback);
+  }
+
+  /**
+   * @param {number} from
+   * @param {number} to
+   * @param {!Array<T>} items
+   */
+  replaceItemsInRange(from, to, items) {
+    var removed = this._items.slice(from, to);

[caseq, 2017/06/01 01:37:57]

let's do it only in the else branch.

[dgozman, 2017/06/01 20:31:49]

Done.

+    if (items.length < 10000) {
+      this._items.splice.bind(this._items, from, to - from).apply(null, items);

[caseq, 2017/06/01 01:37:57]

removed = this._items.splice(from, to - from, ...items)

[dgozman, 2017/06/01 20:31:49]

Done.

+    } else {
+      // Splice may fail with too many arguments.
+      var before = this._items.slice(0, from);
+      var after = this._items.slice(to);
+      this._items = [].concat(before, items, after);
+    }
+    this.dispatchEventToListeners(
+        UI.ListModel.Events.ItemsReplaced, {index: from, removed: removed, inserted: items.length});
+  }
+};
+
+/** @enum {symbol} */
+UI.ListModel.Events = {
+  ItemsReplaced: Symbol('ItemsReplaced'),
+};