Roll Observatory packages and add a roll script

charted/lib/charts/cartesian_renderers/line_chart_renderer.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 LineChartRenderer extends CartesianRendererBase {
-  final Iterable<int> dimensionsUsingBand = const[];
-  final SubscriptionsDisposer _disposer = new SubscriptionsDisposer();
-
-  final bool alwaysAnimate;
-  final bool trackDataPoints;
-  final bool trackOnDimensionAxis;
-  final int quantitativeScaleProximity;
-
-  bool _trackingPointsCreated = false;
-  List _xPositions = [];
-
-  // Currently hovered row/column
-  int _savedOverRow = 0;
-  int _savedOverColumn = 0;
-
-  int currentDataIndex = -1;
-
-  @override
-  final String name = "line-rdr";
-
-  LineChartRenderer({
-      this.alwaysAnimate: false,
-      this.trackDataPoints: true,
-      this.trackOnDimensionAxis: false,
-      this.quantitativeScaleProximity: 5 });
-
-  /*
-   * Returns false if the number of dimension axes on the area is 0.
-   * Otherwise, the first dimension scale is used to render the chart.
-   */
-  @override
-  bool prepare(ChartArea area, ChartSeries series) {
-    _ensureAreaAndSeries(area, series);
-    if (trackDataPoints != false) {
-      _trackPointerInArea();
-    }
-    return area is CartesianArea;
-  }
-
-  @override
-  void draw(Element element, {Future schedulePostRender}) {
-    _ensureReadyToDraw(element);
-
-    var measureScale = area.measureScales(series).first,
-        dimensionScale = area.dimensionScales.first;
-
-    // Create lists of values in measure columns.
-    var lines = series.measures.map((column) {
-      return area.data.rows.map((values) => values[column]).toList();
-    }).toList();
-
-    // We only support one dimension axes, so we always use the
-    // first dimension.
-    var x = area.data.rows.map(
-        (row) => row.elementAt(area.config.dimensions.first)).toList();
-
-    var rangeBandOffset =
-        dimensionScale is OrdinalScale ? dimensionScale.rangeBand / 2 : 0;
-
-    // If tracking data points is enabled, cache location of points that
-    // represent data.
-    if (trackDataPoints) {
-      _xPositions =
-          x.map((val) => dimensionScale.scale(val) + rangeBandOffset).toList();
-    }
-
-    var line = new SvgLine(
-        xValueAccessor: (d, i) => dimensionScale.scale(x[i]) + rangeBandOffset,
-        yValueAccessor: (d, i) => measureScale.scale(d));
-
-    // Add lines and hook up hover and selection events.
-    var svgLines = root.selectAll('.line-rdr-line').data(lines);
-    svgLines.enter.append('path').each((d, i, e) {
-      e.attributes['fill'] = 'none';
-    });
-
-    svgLines.each((d, i, e) {
-      var column = series.measures.elementAt(i),
-          color = colorForColumn(column),
-          filter = filterForColumn(column),
-          styles = stylesForColumn(column);
-      e.attributes
-        ..['d'] = line.path(d, i, e)
-        ..['stroke'] = color
-        ..['class'] = styles.isEmpty
-            ? 'line-rdr-line'
-            : 'line-rdr-line ${styles.join(' ')}'
-        ..['data-column'] = '$column';
-      if (isNullOrEmpty(filter)) {
-        e.attributes.remove('filter');
-      } else {
-        e.attributes['filter'] = filter;
-      }
-    });
-
-    if (area.state != null) {
-      svgLines
-        ..on('click', (d, i, e) => _mouseClickHandler(d, i, e))
-        ..on('mouseover', (d, i, e) => _mouseOverHandler(d, i, e))
-        ..on('mouseout', (d, i, e) => _mouseOutHandler(d, i, e));
-    }
-
-    svgLines.exit.remove();
-  }
-
-  @override
-  void dispose() {
-    if (root == null) return;
-    root.selectAll('.line-rdr-line').remove();
-    root.selectAll('.line-rdr-point').remove();
-    _disposer.dispose();
-  }
-
-  @override
-  void handleStateChanges(List<ChangeRecord> changes) {
-    var lines = host.querySelectorAll('.line-rdr-line');
-    if (lines == null || lines.isEmpty) return;
-
-    for (int i = 0, len = lines.length; i < len; ++i) {
-      var line = lines.elementAt(i),
-          column = int.parse(line.dataset['column']),
-          filter = filterForColumn(column);
-      line.classes.removeAll(ChartState.COLUMN_CLASS_NAMES);
-      line.classes.addAll(stylesForColumn(column));
-      line.attributes['stroke'] = colorForColumn(column);
-
-      if (isNullOrEmpty(filter)) {
-        line.attributes.remove('filter');
-      } else {
-        line.attributes['filter'] = filter;
-      }
-    }
-  }
-
-  void _createTrackingCircles() {
-    var linePoints = root.selectAll('.line-rdr-point').data(series.measures);
-    linePoints.enter.append('circle').each((d, i, e) {
-      e.classes.add('line-rdr-point');
-      e.attributes['r'] = '4';
-    });
-
-    linePoints
-      ..each((d, i, e) {
-      var color = colorForColumn(d);
-      e.attributes
-        ..['r'] = '4'
-        ..['stroke'] = color
-        ..['fill'] = color
-        ..['data-column'] = '$d';
-      })
-      ..on('click', _mouseClickHandler)
-      ..on('mousemove', _mouseOverHandler)  // Ensure that we update values
-      ..on('mouseover', _mouseOverHandler)
-      ..on('mouseout', _mouseOutHandler);
-
-    linePoints.exit.remove();
-    _trackingPointsCreated = true;
-  }
-
-  void _showTrackingCircles(int row) {
-    if (_trackingPointsCreated == false) {
-      _createTrackingCircles();
-    }
-
-    var yScale = area.measureScales(series).first;
-    root.selectAll('.line-rdr-point').each((d, i, e) {
-      var x = _xPositions[row],
-          measureVal = area.data.rows.elementAt(row).elementAt(d);
-      if (measureVal != null && measureVal.isFinite) {
-        var color = colorForColumn(d),
-            filter = filterForColumn(d);
-        e.attributes
-          ..['cx'] = '$x'
-          ..['cy'] = '${yScale.scale(measureVal)}'
-          ..['fill'] = color
-          ..['stroke'] = color
-          ..['data-row'] = '$row';
-        e.style
-          ..setProperty('opacity', '1')
-          ..setProperty('visibility', 'visible');
-        if (isNullOrEmpty(filter)) {
-          e.attributes.remove('filter');
-        } else {
-          e.attributes['filter'] = filter;
-        }
-      } else {
-        e.style
-          ..setProperty('opacity', '$EPSILON')
-          ..setProperty('visibility', 'hidden');
-      }
-    });
-  }
-
-  void _hideTrackingCircles() {
-    root.selectAll('.line-rdr-point')
-      ..style('opacity', '0.0')
-      ..style('visibility', 'hidden');
-  }
-
-  int _getNearestRowIndex(double x) {
-    var lastSmallerValue = 0;
-    var chartX = x - area.layout.renderArea.x;
-    for (var i = 0; i < _xPositions.length; i++) {
-      var pos = _xPositions[i];
-      if (pos < chartX) {
-        lastSmallerValue = pos;
-      } else {
-        return i == 0 ? 0 :
-          (chartX - lastSmallerValue <= pos - chartX) ? i - 1 : i;
-      }
-    }
-    return _xPositions.length - 1;
-  }
-
-  void _trackPointerInArea() {
-    _trackingPointsCreated = false;
-    _disposer.add(area.onMouseMove.listen((ChartEvent event) {
-      if (area.layout.renderArea.contains(event.chartX, event.chartY)) {
-        var row = _getNearestRowIndex(event.chartX);
-        window.animationFrame.then((_) => _showTrackingCircles(row));
-      } else {
-        _hideTrackingCircles();
-      }
-    }));
-    _disposer.add(area.onMouseOut.listen((ChartEvent event) {
-      _hideTrackingCircles();
-    }));
-  }
-
-  void _mouseClickHandler(d, int i, Element e) {
-    if (area.state != null) {
-      area.state.select(int.parse(e.dataset['column']));
-    }
-    if (mouseClickController != null && e.tagName == 'circle') {
-      var row = int.parse(e.dataset['row']),
-          column = int.parse(e.dataset['column']);
-      mouseClickController.add(
-          new DefaultChartEventImpl(scope.event, area, series, row, column, d));
-    }
-  }
-
-  void _mouseOverHandler(d, i, e) {
-    if (area.state != null) {
-      area.state.preview = int.parse(e.dataset['column']);
-    }
-    if (mouseOverController != null && e.tagName == 'circle') {
-      _savedOverRow = int.parse(e.dataset['row']);
-      _savedOverColumn = int.parse(e.dataset['column']);
-      mouseOverController.add(new DefaultChartEventImpl(
-          scope.event, area, series, _savedOverRow, _savedOverColumn, d));
-    }
-  }
-
-  void _mouseOutHandler(d, i, e) {
-    if (area.state != null &&
-        area.state.preview == int.parse(e.dataset['column'])) {
-      area.state.preview = null;
-    }
-    if (mouseOutController != null && e.tagName == 'circle') {
-      mouseOutController.add(new DefaultChartEventImpl(
-          scope.event, area, series, _savedOverRow, _savedOverColumn, d));
-    }
-  }
-}