Roll Observatory packages and add a roll script

charted/lib/charts/data_transformers/transpose_transformer.dart

-/*
- * Copyright 2014 Google Inc. All rights reserved.
- *
- * Use of this source code is governed by a BSD-style
- * license that can be found in the LICENSE file or at
- * https://developers.google.com/open-source/licenses/bsd
- */
-
-part of charted.charts;
-
-/**
- * Transforms the ChartData by transposing the columns and rows.  A label column
- * index in the original data will need to be specified (default to 0), all
- * values in the specified label column will be used as the label for the
- * transformed data, all the labels in the original Chart data columns will be
- * populated in the label column as values of that column.
- *
- * All values in the data except for the data in the label column must have the
- * same type; All columns except for the label column must have the same
- * formatter if a formatter exist for columns.
- */
-class TransposeTransformer extends ChangeNotifier
-    implements ChartDataTransform, ChartData {
-  final SubscriptionsDisposer _dataSubscriptions = new SubscriptionsDisposer();
-  ObservableList<ChartColumnSpec> columns = new ObservableList();
-  ObservableList<Iterable> rows = new ObservableList();
-
-  // If specified, this values of this column in the input chart data will be
-  // used as labels of the transposed column label.  Defaults to first column.
-  int _labelColumn;
-  ChartData _data;
-
-  TransposeTransformer([this._labelColumn = 0]);
-
-  /**
-   * Transforms the input data with the specified label column in the
-   * constructor.  If the ChartData is Observable, changes fired by the input
-   * data will trigger transform to be performed again to update the output rows
-   * and columns.
-   */
-  ChartData transform(ChartData data) {
-    _data = data;
-    _registerListeners();
-    _transform();
-    return this;
-  }
-
-  /** Registers listeners if input ChartData is Observable. */
-  _registerListeners() {
-    _dataSubscriptions.dispose();
-
-    if(_data is Observable) {
-      var observable = (_data as Observable);
-      _dataSubscriptions.add(observable.changes.listen((records) {
-        _transform();
-
-        // NOTE: Currently we're only passing the first change because the chart
-        // area just draw with the updated data.  When we add partial update
-        // to chart area, we'll need to handle this better.
-        notifyChange(records.first);
-      }));
-    }
-  }
-
-  /**
-   * Performs the transpose transform with _data.  This is called on transform
-   * and on changes if ChartData is Observable.
-   */
-  _transform() {
-    // Assert all columns are of the same type and formatter, excluding the
-    // label column.
-    var type;
-    var formatter;
-    for (var i = 0; i < _data.columns.length; i++) {
-      if (i != _labelColumn) {
-        if (type == null) {
-          type = _data.columns.elementAt(i).type;
-        } else {
-          assert(type == _data.columns.elementAt(i).type);
-        }
-        if (formatter == null) {
-          formatter = _data.columns.elementAt(i).formatter;
-        } else {
-          assert(formatter == _data.columns.elementAt(i).formatter);
-        }
-      }
-    }
-
-    columns.clear();
-    rows.clear();
-    rows.addAll(new List<Iterable>.generate(_data.columns.length - 1, (i) => []));
-
-    // Populate the transposed rows' data, excluding the label column, visit
-    // each value in the original data once.
-    var columnLabels = [];
-    for (var row in _data.rows) {
-      for (var i = 0; i < row.length; i++) {
-        var columnOffset = (i < _labelColumn) ? 0 : 1;
-        if (i != _labelColumn) {
-          (rows.elementAt(i - columnOffset) as List).add(row.elementAt(i));
-        } else {
-          columnLabels.add(row.elementAt(i));
-        }
-      }
-    }
-
-    // Transpose the ColumnSpec's label into the column where the original
-    // column that is used as the new label.
-    for (var i = 0; i < rows.length; i++) {
-      var columnOffset = (i < _labelColumn) ? 0 : 1;
-      (rows.elementAt(i) as List).insert(_labelColumn,
-          _data.columns.elementAt(i + columnOffset).label);
-
-    }
-
-    // Construct new ColumnSpaces base on the label column.
-    for (var label in columnLabels) {
-      columns.add(new ChartColumnSpec(type: type, label: label,
-          formatter: formatter));
-    }
-    columns.insert(_labelColumn,
-        new ChartColumnSpec(type: ChartColumnSpec.TYPE_STRING, label:
-        _data.columns.elementAt(_labelColumn).label));
-  }
-}