Roll Observatory packages and add a roll script

charted/lib/svg/axis.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
-//
-
-library charted.svg.axis;
-
-import 'dart:html' show Element;
-import 'dart:math' as math;
-
-import 'package:charted/core/scales.dart';
-import 'package:charted/core/utils.dart';
-import 'package:charted/selection/selection.dart';
-
-///
-/// [SvgAxis] helps draw chart axes based on a given scale.
-///
-class SvgAxis {
-  /// Store of axis roots mapped to currently used scales
-  static final _scales = new Expando<Scale>();
-
-  /// Orientation of the axis. Defaults to [ORIENTATION_BOTTOM].
-  final String orientation;
-
-  /// Scale used on this axis
-  final Scale scale;
-
-  /// Size of all inner ticks
-  final num innerTickSize;
-
-  /// Size of the outer two ticks
-  final num outerTickSize;
-
-  /// Padding on the ticks
-  final num tickPadding;
-
-  /// List of values to be used on the ticks
-  List _tickValues;
-
-  /// Formatter for the tick labels
-  FormatFunction _tickFormat;
-
-  SvgAxis({
-      this.orientation: ORIENTATION_BOTTOM,
-      this.innerTickSize: 6,
-      this.outerTickSize: 6,
-      this.tickPadding: 3,
-      Iterable tickValues,
-      FormatFunction tickFormat,
-      Scale scale }) : scale = scale == null ? new LinearScale() : scale {
-    _tickFormat = tickFormat == null
-        ? this.scale.createTickFormatter()
-        : tickFormat;
-    _tickValues = isNullOrEmpty(tickValues) ? this.scale.ticks : tickValues;
-  }
-
-  Iterable get tickValues => _tickValues;
-
-  FormatFunction get tickFormat => _tickFormat;
-
-  /// Draw an axis on each non-null element in selection
-  draw(Selection g, {SvgAxisTicks axisTicksBuilder, bool isRTL: false}) =>
-      g.each((d, i, e) => create(
-          e, g.scope, axisTicksBuilder: axisTicksBuilder, isRTL: isRTL));
-
-  /// Create an axis on [element].
-  create(Element element, SelectionScope scope, {
-      SvgAxisTicks axisTicksBuilder, bool isRTL: false}) {
-
-    var group = scope.selectElements([element]),
-        older = _scales[element],
-        current = _scales[element] = scale.clone(),
-        isInitialRender = older == null;
-
-    var isLeft = orientation == ORIENTATION_LEFT,
-        isRight = !isLeft && orientation == ORIENTATION_RIGHT,
-        isVertical = isLeft || isRight,
-        isBottom = !isVertical && orientation == ORIENTATION_BOTTOM,
-        isTop = !(isVertical || isBottom) && orientation == ORIENTATION_TOP,
-        isHorizontal = !isVertical;
-
-    if (older == null) older = current;
-    if (axisTicksBuilder == null) {
-      axisTicksBuilder = new SvgAxisTicks();
-    }
-    axisTicksBuilder.init(this);
-
-    var values = axisTicksBuilder.ticks,
-        formatted = axisTicksBuilder.formattedTicks,
-        ellipsized = axisTicksBuilder.shortenedTicks;
-
-    var ticks = group.selectAll('.tick').data(values, current.scale),
-        exit = ticks.exit,
-        transform = isVertical ? _yAxisTransform : _xAxisTransform,
-        sign = isTop || isLeft ? -1 : 1,
-        isEllipsized = ellipsized != formatted;
-
-    var enter = ticks.enter.appendWithCallback((d, i, e) {
-      var group = Namespace.createChildElement('g', e)
-        ..attributes['class'] = 'tick'
-        ..append(Namespace.createChildElement('line',  e))
-        ..append(Namespace.createChildElement('text', e)
-            ..attributes['dy'] =
-                isVertical ? '0.32em' : (isBottom ? '0.71em' : '0'));
-      if (!isInitialRender) {
-        group.style.setProperty('opacity', EPSILON.toString());
-      }
-      return group;
-    });
-
-    // All attributes/styles/classes that may change due to theme and scale.
-    // TODO(prsd): Order elements before updating ticks.
-    ticks.each((d, i, e) {
-      Element line = e.firstChild;
-      Element text = e.lastChild;
-      bool isRTLText = false; // FIXME(prsd)
-
-      if (isHorizontal) {
-        line.attributes['y2'] = '${sign * innerTickSize}';
-        text.attributes['y'] =
-            '${sign * (math.max(innerTickSize, 0) + tickPadding)}';
-
-        if (axisTicksBuilder.rotation != 0) {
-          text.attributes
-            ..['transform'] =
-                'rotate(${(isRTL ? -1 : 1) * axisTicksBuilder.rotation})'
-            ..['text-anchor'] = isRTL ? 'end' : 'start';
-        } else {
-          text.attributes
-            ..remove('transform')
-            ..['text-anchor'] = 'middle';
-        }
-      } else {
-        line.attributes['x2'] = '${sign * innerTickSize}';
-        text.attributes
-          ..['x'] = '${sign * (math.max(innerTickSize, 0) + tickPadding)}'
-          ..['text-anchor'] = isLeft
-              ? (isRTLText ? 'start' : 'end')
-              : (isRTLText ? 'end' : 'start');
-      }
-
-      text.text = fixSimpleTextDirection(ellipsized.elementAt(i));
-      if (isEllipsized) {
-        text.attributes['data-detail'] = formatted.elementAt(i);
-      } else {
-        text.attributes.remove('data-detail');
-      }
-
-      if (isInitialRender) {
-        var dx = current is OrdinalScale ? current.rangeBand / 2 : 0;
-        e.attributes['transform'] = isHorizontal
-            ? 'translate(${current.scale(d) + dx},0)'
-            : 'translate(0,${current.scale(d) + dx})';
-      } else {
-        e.style.setProperty('opacity', '1.0');
-      }
-    });
-
-    // Transition existing ticks to right positions
-    if (!isInitialRender) {
-      var transformFn;
-      if (current is OrdinalScale && current.rangeBand != 0) {
-        var dx = current.rangeBand / 2;
-        transformFn = (d) => current.scale(d) + dx;
-      } else if (older is OrdinalScale && older.rangeBand != 0) {
-        older = current;
-      } else {
-        transform(ticks, current.scale);
-      }
-
-      transform(enter, transformFn != null ? transformFn : older.scale);
-      transform(ticks, transformFn != null ? transformFn : current.scale);
-    }
-
-    exit.remove();
-
-    // Append the outer domain.
-    var path = element.querySelector('.domain'),
-        tickSize = sign * outerTickSize,
-        range = current.rangeExtent;
-    if (path == null) {
-      path = Namespace.createChildElement('path', element)
-          ..setAttribute('class', 'domain');
-    }
-    path.attributes['d'] = isLeft || isRight
-        ? 'M${tickSize},${range.min}H0V${range.max}H${tickSize}'
-        : 'M${range.min},${tickSize}V0H${range.max}V${tickSize}';
-    element.append(path);
-  }
-
-  _xAxisTransform(Selection selection, transformFn) {
-    selection.transition()
-      ..attrWithCallback(
-          'transform', (d, i, e) => 'translate(${transformFn(d)},0)');
-  }
-
-  _yAxisTransform(Selection selection, transformFn) {
-    selection.transition()
-      ..attrWithCallback(
-          'transform', (d, i, e) => 'translate(0,${transformFn(d)})');
-  }
-}
-
-/// Interface and the default implementation of [SvgAxisTicks].
-/// SvgAxisTicks provides strategy to handle overlapping ticks on an
-/// axis.  Default implementation assumes that the ticks don't overlap.
-class SvgAxisTicks {
-  int _rotation = 0;
-  Iterable _ticks;
-  Iterable _formattedTicks;
-
-  void init(SvgAxis axis) {
-    _ticks = axis.tickValues;
-    _formattedTicks = _ticks.map((x) => axis.tickFormat(x));
-  }
-
-  /// When non-zero, indicates the angle by which each tick value must be
-  /// rotated to avoid the overlap.
-  int get rotation => _rotation;
-
-  /// List of ticks that will be displayed on the axis.
-  Iterable get ticks => _ticks;
-
-  /// List of formatted ticks values.
-  Iterable get formattedTicks => _formattedTicks;
-
-  /// List of clipped tick values, if they had to be clipped. Must be same
-  /// as the [formattedTicks] if none of the ticks were ellipsized.
-  Iterable get shortenedTicks => _formattedTicks;
-}