Roll Observatory packages and add a roll script

charted/lib/charts/src/chart_legend_impl.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;
-
-class DefaultChartLegendImpl implements ChartLegend {
-  static const CLASS_PREFIX = 'chart-legend';
-
-  final Element host;
-  final int visibleItemsCount;
-  final bool showValues;
-  final SubscriptionsDisposer _disposer = new SubscriptionsDisposer();
-
-  String _title;
-  SelectionScope _scope;
-  Selection _root;
-  ChartArea _area;
-
-  Iterable<ChartLegendItem> _items;
-
-  DefaultChartLegendImpl(
-      this.host, this.visibleItemsCount, this.showValues, String title)
-      : _title = title {
-    assert(host != null);
-  }
-
-  void dispose() {
-    _disposer.dispose();
-  }
-
-  /**
-   * Sets the title of the legend, if the legend is already drawn, updates the
-   * title on the legend as well.
-   */
-  void set title(String title) {
-    _title = title;
-    if (_scope == null) return;
-    _updateTitle();
-  }
-
-  String get title => _title;
-
-  /** Updates the title of the legend. */
-  void _updateTitle() {
-    if (_title.isNotEmpty) {
-      if (_root.select('.chart-legend-heading').length == 0) {
-        _root.select('.chart-legend-heading');
-        _root.append('div')
-          ..classed('chart-legend-heading')
-          ..text(_title);
-      } else {
-        _root.select('.chart-legend-heading').text(_title);
-      }
-    }
-  }
-
-  /** Updates the legend base on a new list of ChartLegendItems. */
-  update(Iterable<ChartLegendItem> items, ChartArea area) {
-    assert(items != null);
-    assert(area == _area || _area == null);
-
-    _area = area;
-    if (_area.state != null) {
-      _disposer.add(_area.state.changes.listen(_handleStateChanges));
-    }
-    if (_scope == null) {
-      _scope = new SelectionScope.element(host);
-      _root = _scope.selectElements([host]);
-    }
-
-    _updateTitle();
-    _items = items;
-    _createLegendItems();
-
-    // Add more item label if there's more items than the max display items.
-    if ((visibleItemsCount > 0) && (visibleItemsCount < items.length)) {
-      _root.select('.chart-legend-more').remove();
-      _root.append('div')
-        ..on('mouseover',
-            (d, i, e) => _displayMoreItem(items.skip(visibleItemsCount)))
-        ..on('mouseleave', (d, i, e) => _hideMoreItem())
-        ..text('${items.length - visibleItemsCount} more...')
-        ..classed('chart-legend-more');
-    }
-  }
-
-  /** Hides extra legend items. */
-  void _hideMoreItem() {
-    var tooltip = _root.select('.chart-legend-more-tooltip');
-    tooltip.style('opacity', '0');
-  }
-
-  // Displays remaining legend items as a tooltip
-  void _displayMoreItem(Iterable<ChartLegendItem> items) {
-    var tooltip = _root.select('.chart-legend-more-tooltip');
-    if (tooltip.isEmpty) {
-      tooltip = _root.select('.chart-legend-more').append('div')
-          ..classed('chart-legend-more-tooltip');
-    }
-    tooltip.style('opacity', '1');
-
-    // _createLegendItems(tooltip, 'chart-legend-more', items);
-  }
-
-  /// Creates legend items starting at the given index.
-  void _createLegendItems() {
-    var state = _area.state,
-        rows = _root.selectAll(
-            '.chart-legend-row').data(_items, (x) => x.hashCode),
-        isFirstRender = rows.length == 0;
-
-    var enter = rows.enter.appendWithCallback((d, i, e) {
-      var row = Namespace.createChildElement('div', e),
-          color = Namespace.createChildElement('div', e)
-            ..className = 'chart-legend-color',
-          label = Namespace.createChildElement('div', e)
-            ..className = 'chart-legend-label',
-          value = showValues ? (Namespace.createChildElement('div', e)
-            ..className = 'chart-legend-value') : null;
-
-      var rowStyles = ['chart-legend-row'].toList();
-
-      // If this is the first time we are adding rows,
-      // Update elements before adding them to the DOM.
-      if (isFirstRender) {
-        if (state != null) {
-          if (d.index == state.preview) {
-            rowStyles.add('chart-legend-hover');
-          }
-          if (state.isSelected(d.index)) {
-            rowStyles.add('chart-legend-selected');
-          }
-        }
-        rowStyles.addAll(
-            d.series.map((ChartSeries x) => 'type-${x.renderer.name}'));
-
-        color.style.setProperty('background-color', d.color);
-        row.append(color);
-        label.text = d.label;
-        row.append(label);
-
-        if (showValues) {
-          value.text = d.value;
-          value.style.setProperty('color', d.color);
-          row.append(value);
-        }
-      }
-      row.classes.addAll(rowStyles);
-      return row;
-    });
-
-    // We have elements in the DOM that need updating.
-    if (!isFirstRender) {
-      rows.each((ChartLegendItem d, i, Element e) {
-        var classes = e.classes;
-        if (state != null) {
-          if (d.index == state.preview) {
-            classes.add('chart-legend-hover');
-          } else {
-            classes.remove('chart-legend-hover');
-          }
-          if (state.isSelected(d.index)) {
-            classes.add('chart-legend-selected');
-          } else {
-            classes.remove('chart-legend-selected');
-          }
-        }
-        classes.addAll(d.series.map((x) => 'type-${x.renderer.name}'));
-
-        (e.children[0]).style.setProperty('background-color', d.color);
-        (e.children[1]).text = d.label;
-        if (showValues) {
-          (e.lastChild as Element)
-            ..text = d.value
-            ..style.setProperty('color', d.color);
-        }
-      });
-    }
-
-    if (state != null) {
-      enter
-        ..on('mouseover', (d, i, e) => state.preview = d.index)
-        ..on('mouseout', (d, i, e) {
-            if (state.preview == d.index) {
-              state.preview = null;
-            }
-          })
-        ..on('click', (d, i, e) {
-            if (state.isSelected(d.index)) {
-              state.unselect(d.index);
-            } else {
-              state.select(d.index);
-            }
-          });
-    }
-
-    rows.exit.remove();
-  }
-
-  /// Update legend to show chart's selection and visibility.
-  void _handleStateChanges(_) => _createLegendItems();
-}