Roll Observatory packages and add a roll script

charted/lib/core/scales/time_scale.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.core.scales;
-
-/// TimeScale is a linear scale that operates on time.
-class TimeScale extends LinearScale {
-  static const _scaleSteps = const [
-    1e3,    // 1-second
-    5e3,    // 5-second
-    15e3,   // 15-second
-    3e4,    // 30-second
-    6e4,    // 1-minute
-    3e5,    // 5-minute
-    9e5,    // 15-minute
-    18e5,   // 30-minute
-    36e5,   // 1-hour
-    108e5,  // 3-hour
-    216e5,  // 6-hour
-    432e5,  // 12-hour
-    864e5,  // 1-day
-    1728e5, // 2-day
-    6048e5, // 1-week
-    2592e6, // 1-month
-    7776e6, // 3-month
-    31536e6 // 1-year
-  ];
-
-  static final _scaleLocalMethods = [
-    [TimeInterval.second, 1],
-    [TimeInterval.second, 5],
-    [TimeInterval.second, 15],
-    [TimeInterval.second, 30],
-    [TimeInterval.minute, 1],
-    [TimeInterval.minute, 5],
-    [TimeInterval.minute, 15],
-    [TimeInterval.minute, 30],
-    [TimeInterval.hour,   1],
-    [TimeInterval.hour,   3],
-    [TimeInterval.hour,   6],
-    [TimeInterval.hour,   12],
-    [TimeInterval.day,    1],
-    [TimeInterval.day,    2],
-    [TimeInterval.week,   1],
-    [TimeInterval.month,  1],
-    [TimeInterval.month,  3],
-    [TimeInterval.year,   1]
-  ];
-
-  static TimeFormatFunction _scaleLocalFormat = new TimeFormat().multi([
-      [".%L",   (DateTime d) => d.millisecond > 0],
-      [":%S",   (DateTime d) => d.second > 0],
-      ["%I:%M", (DateTime d) => d.minute > 0],
-      ["%I %p", (DateTime d) => d.hour > 0],
-      ["%a %d", (DateTime d) => (d.weekday % 7) > 0 && d.day != 1],
-      ["%b %d", (DateTime d) => d.day != 1],
-      ["%B",    (DateTime d) => d.month > 1],
-      ["%Y",    (d) => true]
-  ]);
-
-  TimeScale();
-  TimeScale._clone(TimeScale source) : super._clone(source);
-
-  @override
-  scale(dynamic val) =>
-      super.scale(val is DateTime ? val.millisecondsSinceEpoch : val);
-
-  @override
-  set domain(Iterable value) {
-    super.domain = value.map(
-        (d) => d is DateTime ? d.millisecondsSinceEpoch : d).toList();
-  }
-
-  @override
-  FormatFunction createTickFormatter([String format]) => _scaleLocalFormat;
-
-  @override
-  TimeScale clone() => new TimeScale._clone(this);
-
-  List _getTickMethod(Extent extent, int count) {
-    var target  = (extent.max - extent.min) / count,
-        i = ScaleUtils.bisect(_scaleSteps, target);
-
-    return i == _scaleSteps.length
-        ? [ TimeInterval.year, _linearTickRange(
-            new Extent(extent.min / 31536e6, extent.max / 31536e6)).step ]
-        : i == 0
-            ? [ new ScaleMilliSeconds(), _linearTickRange(extent).step ]
-            : _scaleLocalMethods[
-                target / _scaleSteps[i - 1] < _scaleSteps[i] / target ? i - 1 : i];
-  }
-
-  List niceInterval(int ticksCount, [int skip = 1]) {
-    var extent = ScaleUtils.extent(domain),
-        method = _getTickMethod(extent, ticksCount),
-        interval;
-
-    if (method != null) {
-      interval = method[0];
-      skip = method[1];
-    }
-
-    bool skipped(var date) {
-      if (date is DateTime) date = date.millisecondsSinceEpoch;
-      return (interval as TimeInterval)
-          .range(date, date + 1, skip).length == 0;
-    }
-
-    if (skip > 1) {
-      domain = ScaleUtils.nice(domain, new RoundingFunctions(
-        (date) {
-          while (skipped(date = (interval as TimeInterval).floor(date))) {
-            date = new DateTime.fromMillisecondsSinceEpoch(
-                date.millisecondsSinceEpoch - 1);
-          }
-          return date.millisecondsSinceEpoch;
-        },
-        (date) {
-          while (skipped(date = (interval as TimeInterval).ceil(date))) {
-            date = new DateTime.fromMillisecondsSinceEpoch(
-                date.millisecondsSinceEpoch + 1);
-          }
-          return date.millisecondsSinceEpoch;
-        }
-      ));
-    } else {
-      domain = ScaleUtils.nice(
-          domain, new RoundingFunctions(
-              (date) => interval.floor(date).millisecondsSinceEpoch,
-              (date) => interval.ceil(date).millisecondsSinceEpoch));
-    }
-    return domain;
-  }
-
-  @override
-  set nice(bool value) {
-    assert(value != null);
-    if (value != null && _nice != value) {
-      _nice = value;
-      domain = niceInterval(_ticksCount);
-    }
-  }
-
-  List ticksInterval(int ticksCount, [int skip]) {
-    var extent = ScaleUtils.extent(domain),
-        method = _getTickMethod(extent, ticksCount),
-        interval;
-    if (method != null) {
-      interval = method[0];
-      skip = method[1];
-    }
-    return interval.range(extent.min, extent.max + 1, skip < 1 ? 1 : skip);
-  }
-
-  @override
-  List get ticks => ticksInterval(ticksCount);
-}
-
-class ScaleMilliSeconds implements TimeInterval {
-  DateTime _toDateTime(x) {
-    assert (x is int || x is DateTime);
-    return x is num ? new DateTime.fromMillisecondsSinceEpoch(x) : x;
-  }
-  DateTime floor(dynamic val) => _toDateTime(val);
-  DateTime ceil(dynamic val) => _toDateTime(val);
-  DateTime round(dynamic val) => _toDateTime(val);
-
-  DateTime offset(dynamic val, num dt) {
-    assert(val is int || val is DateTime);
-    return new DateTime.fromMillisecondsSinceEpoch(
-        val is int ? val + dt : (val as DateTime).millisecondsSinceEpoch + dt);
-  }
-
-  List range(var t0, var t1, int step) {
-    int start = t0 is DateTime ? t0.millisecondsSinceEpoch : t0,
-        stop = t1 is DateTime ? t1.millisecondsSinceEpoch : t1;
-    return new Range((start / step).ceil() * step, stop, step).map(
-        (d) => new DateTime.fromMillisecondsSinceEpoch(d)).toList();
-  }
-}