Refactor Observatory

runtime/bin/vmservice/client/lib/src/observatory/view_model.dart

-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-part of observatory;
-
-abstract class TableTreeRow extends Observable {
-  final TableTreeRow parent;
-  @observable final int depth;
-  @observable final List<TableTreeRow> children = new List<TableTreeRow>();
-  @observable final List<String> columns = [];
-
-  TableTreeRow(TableTreeRow parent) :
-      parent = parent,
-      depth = parent != null ? parent.depth+1 : 0;
-
-  bool _expanded = false;
-  bool get expanded => _expanded;
-  set expanded(bool expanded) {
-    var changed = _expanded != expanded;
-    _expanded = expanded;
-    if (changed) {
-      // If the state has changed, fire callbacks.
-      if (_expanded) {
-        onShow();
-      } else {
-        onHide();
-      }
-    }
-  }
-
-  bool toggle() {
-    expanded = !expanded;
-    return expanded;
-  }
-
-  /// Fired when the tree row is expanded. Add children rows here.
-  void onShow();
-
-  /// Fired when the tree row is collapsed.
-  void onHide();
-}
-
-class TableTree extends Observable {
-  final List<String> columnHeaders = [];
-  @observable final List<TableTreeRow> rows = toObservable([]);
-
-  /// Create a table tree with column [headers].
-  TableTree(List<String> headers) {
-    columnHeaders.addAll(headers);
-  }
-
-  /// Initialize the table tree with the list of root children.
-  void initialize(List<TableTreeRow> children) {
-    rows.clear();
-    rows.addAll(children);
-  }
-
-  /// Toggle expansion of row at [rowIndex].
-  void toggle(int rowIndex) {
-    assert(rowIndex >= 0);
-    assert(rowIndex < rows.length);
-    var row = rows[rowIndex];
-    if (row.toggle()) {
-      _expand(row);
-    } else {
-      _collapse(row);
-    }
-  }
-
-  int _index(TableTreeRow row) => rows.indexOf(row);
-
-  void _insertRow(int index, TableTreeRow row) {
-    if (index == -1) {
-      rows.add(row);
-    } else {
-      rows.insert(index, row);
-    }
-  }
-
-  void _expand(TableTreeRow row) {
-    int index = _index(row);
-    assert(index != -1);
-    for (var i = 0; i < row.children.length; i++) {
-      _insertRow(index + i + 1, row.children[i]);
-    }
-  }
-
-  void _collapse(TableTreeRow row) {
-    var childCount = row.children.length;
-    if (childCount == 0) {
-      return;
-    }
-    for (var i = 0; i < childCount; i++) {
-      // Close all inner rows.
-      if (row.children[i].expanded) {
-        _collapse(row.children[i]);
-      }
-    }
-    // Collapse this row.
-    row.expanded = false;
-    // Remove all children.
-    int index = _index(row);
-    for (var i = 0; i < childCount; i++) {
-      rows.removeAt(index + 1);
-    }
-  }
-}