Roll Observatory packages and add a roll script

charted/lib/core/utils/bidi_formatter.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.utils;
-
-/// Charts are always drawn with LTR context.
-BidiFormatter _bidiFormatter = new BidiFormatter.LTR();
-
-/// Fix direction of HTML using <span dir="..."> for RTL when required
-fixMarkupDirection(String markup) =>
-    _bidiFormatter.wrapWithSpan(markup, isHtml:true);
-
-/// Fix direction of text using unicode markers for RTL when required
-/// This is a simplified version of BidiFormatter.wrapWithUnicode that
-/// is meant to be used for small labels only (Eg: axis ticks).
-String fixSimpleTextDirection(String text) {
-  TextDirection direction = estimateDirectionOfSimpleText(text);
-  if (TextDirection.RTL == direction) {
-    var marker = direction == TextDirection.RTL ? Bidi.RLE : Bidi.LRE;
-    return "${marker}$text${Bidi.PDF}";
-  }
-  return text;
-}
-
-/// Estimates direction of simple text.
-/// This is a simplified version of Bidi.estimateDirectionOfText
-var _spaceRegExp = new RegExp(r'\s+');
-var _digitsRegExp = new RegExp(r'\d');
-TextDirection estimateDirectionOfSimpleText(String text) {
-  var rtlCount = 0,
-      total = 0,
-      hasWeaklyLtr = false,
-      tokens = text.split(_spaceRegExp);
-
-  for (int i = 0, len = tokens.length; i < len; ++i) {
-    var token = tokens.elementAt(i);
-    if (Bidi.startsWithRtl(token)) {
-      rtlCount++;
-      total++;
-    } else if (Bidi.hasAnyLtr(token)) {
-      total++;
-    } else if (_digitsRegExp.hasMatch(token)) {
-      hasWeaklyLtr = true;
-    }
-  }
-  if (total == 0) {
-    return hasWeaklyLtr ? TextDirection.LTR : TextDirection.UNKNOWN;
-  } else {
-    return rtlCount > 0.4 * total ? TextDirection.RTL : TextDirection.LTR;
-  }
-}