chrome/browser/resources/print_preview/data/measurement_system.js

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 cr.define('print_preview', function() {
   6   'use strict';
   7
   8   /**
   9    * Measurement system of the print preview. Used to parse and serialize point
  10    * measurements into the system's local units (e.g. millimeters, inches).
  11    * @param {string} thousandsDelimeter Delimeter between thousands digits.
  12    * @param {string} decimalDelimeter Delimeter between integers and decimals.
  13    * @param {!print_preview.MeasurementSystem.UnitType} unitType Measurement
  14    *     unit type of the system.
  15    * @constructor
  16    */
  17   function MeasurementSystem(thousandsDelimeter, decimalDelimeter, unitType) {
  18     this.thousandsDelimeter_ = thousandsDelimeter || ',';
  19     this.decimalDelimeter_ = decimalDelimeter || '.';
  20     this.unitType_ = unitType;
  21   };
  22
  23   /**
  24    * Parses |numberFormat| and extracts the symbols used for the thousands point
  25    * and decimal point.
  26    * @param {string} numberFormat The formatted version of the number 12345678.
  27    * @return {!Array<string>} The extracted symbols in the order
  28    *     [thousandsSymbol, decimalSymbol]. For example,
  29    *     parseNumberFormat("123,456.78") returns [",", "."].
  30    */
  31   MeasurementSystem.parseNumberFormat = function(numberFormat) {
  32     if (!numberFormat) {
  33       return [',', '.'];
  34     }
  35     var regex = /^(\d+)(\W?)(\d+)(\W?)(\d+)$/;
  36     var matches = numberFormat.match(regex) || ['', '', ',', '', '.'];
  37     return [matches[2], matches[4]];
  38   };
  39
  40   /**
  41    * Enumeration of measurement unit types.
  42    * @enum {number}
  43    */
  44   MeasurementSystem.UnitType = {
  45     METRIC: 0, // millimeters
  46     IMPERIAL: 1 // inches
  47   };
  48
  49   /**
  50    * Maximum resolution of local unit values.
  51    * @type {!Object<!print_preview.MeasurementSystem.UnitType, number>}
  52    * @private
  53    */
  54   MeasurementSystem.Precision_ = {};
  55   MeasurementSystem.Precision_[MeasurementSystem.UnitType.METRIC] = 0.5;
  56   MeasurementSystem.Precision_[MeasurementSystem.UnitType.IMPERIAL] = 0.01;
  57
  58   /**
  59    * Maximum number of decimal places to keep for local unit.
  60    * @type {!Object<!print_preview.MeasurementSystem.UnitType, number>}
  61    * @private
  62    */
  63   MeasurementSystem.DecimalPlaces_ = {};
  64   MeasurementSystem.DecimalPlaces_[MeasurementSystem.UnitType.METRIC] = 1;
  65   MeasurementSystem.DecimalPlaces_[MeasurementSystem.UnitType.IMPERIAL] = 2;
  66
  67   /**
  68    * Number of points per inch.
  69    * @type {number}
  70    * @const
  71    * @private
  72    */
  73   MeasurementSystem.PTS_PER_INCH_ = 72.0;
  74
  75   /**
  76    * Number of points per millimeter.
  77    * @type {number}
  78    * @const
  79    * @private
  80    */
  81   MeasurementSystem.PTS_PER_MM_ = MeasurementSystem.PTS_PER_INCH_ / 25.4;
  82
  83   MeasurementSystem.prototype = {
  84     /** @return {string} The unit type symbol of the measurement system. */
  85     get unitSymbol() {
  86       if (this.unitType_ == MeasurementSystem.UnitType.METRIC) {
  87         return 'mm';
  88       } else if (this.unitType_ == MeasurementSystem.UnitType.IMPERIAL) {
  89         return '"';
  90       } else {
  91         throw Error('Unit type not supported: ' + this.unitType_);
  92       }
  93     },
  94
  95     /**
  96      * @return {string} The thousands delimeter character of the measurement
  97      *     system.
  98      */
  99     get thousandsDelimeter() {
 100       return this.thousandsDelimeter_;
 101     },
 102
 103     /**
 104      * @return {string} The decimal delimeter character of the measurement
 105      *     system.
 106      */
 107     get decimalDelimeter() {
 108       return this.decimalDelimeter_;
 109     },
 110
 111     setSystem: function(thousandsDelimeter, decimalDelimeter, unitType) {
 112       this.thousandsDelimeter_ = thousandsDelimeter;
 113       this.decimalDelimeter_ = decimalDelimeter;
 114       this.unitType_ = unitType;
 115     },
 116
 117     /**
 118      * Rounds a value in the local system's units to the appropriate precision.
 119      * @param {number} value Value to round.
 120      * @return {number} Rounded value.
 121      */
 122     roundValue: function(value) {
 123       var precision = MeasurementSystem.Precision_[this.unitType_];
 124       var roundedValue = Math.round(value / precision) * precision;
 125       // Truncate
 126       return +roundedValue.toFixed(
 127           MeasurementSystem.DecimalPlaces_[this.unitType_]);
 128     },
 129
 130     /**
 131      * @param {number} pts Value in points to convert to local units.
 132      * @return {number} Value in local units.
 133      */
 134     convertFromPoints: function(pts) {
 135       if (this.unitType_ == MeasurementSystem.UnitType.METRIC) {
 136         return pts / MeasurementSystem.PTS_PER_MM_;
 137       } else {
 138         return pts / MeasurementSystem.PTS_PER_INCH_;
 139       }
 140     },
 141
 142     /**
 143      * @param {number} localUnits Value in local units to convert to points.
 144      * @return {number} Value in points.
 145      */
 146     convertToPoints: function(localUnits) {
 147       if (this.unitType_ == MeasurementSystem.UnitType.METRIC) {
 148         return localUnits * MeasurementSystem.PTS_PER_MM_;
 149       } else {
 150         return localUnits * MeasurementSystem.PTS_PER_INCH_;
 151       }
 152     }
 153   };
 154
 155   // Export
 156   return {
 157     MeasurementSystem: MeasurementSystem
 158   };
 159 });