| <!DOCTYPE html> |
| <!-- |
| Copyright (c) 2015 The Chromium Authors. All rights reserved. |
| Use of this source code is governed by a BSD-style license that can be |
| found in the LICENSE file. |
| --> |
| |
| <link rel="import" href="/base/range.html"> |
| |
| <script> |
| 'use strict'; |
| |
| tr.exportTo('tr.c.tracks', function() { |
| |
| /** |
| * A vertical axis for a (set of) chart series which maps an arbitrary range |
| * of values [min, max] to the unit range [0, 1]. |
| * |
| * @constructor |
| */ |
| function ChartAxis(opt_min, opt_max) { |
| this.guid_ = tr.b.GUID.allocate(); |
| this.bounds = new tr.b.Range(); |
| if (opt_min !== undefined) |
| this.bounds.addValue(opt_min); |
| if (opt_max !== undefined) |
| this.bounds.addValue(opt_max); |
| }; |
| |
| ChartAxis.prototype = { |
| get guid() { |
| return this.guid_; |
| }, |
| |
| valueToUnitRange: function(value) { |
| if (this.bounds.isEmpty) |
| throw new Error('Chart axis bounds are empty'); |
| var bounds = this.bounds; |
| if (bounds.range === 0) |
| return 0; |
| return (value - bounds.min) / bounds.range; |
| }, |
| |
| /** |
| * Automatically set the axis bounds from the range of values of all series |
| * in a list. |
| * |
| * See the description of autoSetFromRange for the optional configuration |
| * argument flags. |
| */ |
| autoSetFromSeries: function(series, opt_config) { |
| var range = new tr.b.Range(); |
| series.forEach(function(s) { |
| range.addRange(s.range); |
| }, this); |
| this.autoSetFromRange(range, opt_config); |
| }, |
| |
| /** |
| * Automatically set the axis bound from a range of values. |
| * |
| * The following four flags, which affect the behavior of this method with |
| * respect to already defined bounds, can be present in the optional |
| * configuration (a flag is assumed to be false if it is not provided or if |
| * the configuration is not provided): |
| * |
| * - expandMin: allow decreasing the min bound (if range.min < this.min) |
| * - shrinkMin: allow increasing the min bound (if range.min > this.min) |
| * - expandMax: allow increasing the max bound (if range.max > this.max) |
| * - shrinkMax: allow decreasing the max bound (if range.max < this.max) |
| * |
| * This method will ensure that the resulting bounds are defined and valid |
| * (i.e. min <= max) provided that they were valid or empty before and the |
| * value range is non-empty and valid. |
| * |
| * Note that unless expanding/shrinking a bound is explicitly enabled in |
| * the configuration, non-empty bounds will not be changed under any |
| * circumstances. |
| * |
| * Observe that if no configuration is provided (or all flags are set to |
| * false), this method will only modify the axis bounds if they are empty. |
| */ |
| autoSetFromRange: function(range, opt_config) { |
| if (range.isEmpty) |
| return; |
| |
| var bounds = this.bounds; |
| if (bounds.isEmpty) { |
| bounds.addRange(range); |
| return; |
| } |
| |
| if (!opt_config) |
| return; |
| |
| var useRangeMin = (opt_config.expandMin && range.min < bounds.min || |
| opt_config.shrinkMin && range.min > bounds.min); |
| var useRangeMax = (opt_config.expandMax && range.max > bounds.max || |
| opt_config.shrinkMax && range.max < bounds.max); |
| |
| // Neither bound is modified. |
| if (!useRangeMin && !useRangeMax) |
| return; |
| |
| // Both bounds are modified. Assuming the range argument is a valid |
| // range, no extra checks are necessary. |
| if (useRangeMin && useRangeMax) { |
| bounds.min = range.min; |
| bounds.max = range.max; |
| return; |
| } |
| |
| // Only one bound is modified. We must ensure that it doesn't go |
| // over/under the other (unmodified) bound. |
| if (useRangeMin) { |
| bounds.min = Math.min(range.min, bounds.max); |
| } else { |
| bounds.max = Math.max(range.max, bounds.min); |
| } |
| } |
| }; |
| |
| return { |
| ChartAxis: ChartAxis |
| }; |
| }); |
| </script> |
