1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 | 1× 1× 4× 4× 4× 16× 4× 17× 17× 17× 17× 10× 10× 2× 17× 17× 2× 2× 14× 4× | /** * Defines the BitField class, that compactly stores multiple values as a short * series of bits. * @module montage/core/bitfield * @requires montage/core/core */ var Montage = require("./core").Montage; /** * The BitField object compactly stores multiple values as a short series of * bits. * This implementation is limited to 32 fields. * @class BitField * @classdesc Compactly stores multiple values as a short series of bits. * @extends Montage */ var BitField = exports.BitField = Montage.specialize( /** @lends BitField */ { /** * Creates a new BitField object containing the fields provided in the * propertyDescriptor parameter. * @function * @param {Object} propertyDescriptor An object containing one or more * property name/value pairs. * Each pair is added to the new BitField. * @returns {Object} A new BitField object that contains fields described * by the property descriptor. * @example * var bitField = new BitField(); * bitField = new BitField().initWithDescriptor({ * likes_golf: { * value: false * }, * likes_basketball: { * value: true * }, * likes_baseball: { * value: false * }, * }); */ initWithDescriptor: { enumerable: false, value: function (propertyDescriptor) { var fieldName; this.reset(); for (fieldName in propertyDescriptor) { this.addField(fieldName, propertyDescriptor[fieldName].value); } return this; } }, /** * Adds a new field to a BitField instance. * @function * @param {string} aFieldName The name of the field to add. * @param {Mixed} defaultValue The new field's default value. */ addField: { enumerable: false, value: function (aFieldName, defaultValue) { Iif (aFieldName in this) { return; } Iif (this._fieldCount >= 32) { throw "BitField 32 fields limit reached."; } //We try to recycle slots as limited to 32bits this._trueValue += (this._fields[aFieldName] = this._constantsToReuse.length ? this._constantsToReuse.shift() : (1 << this._fieldCount)); Montage.defineProperty(this, aFieldName, { enumerable: true, get: function () { return (this._value === this._trueValue); }, set: function (value) { value ? (this._value |= this._fields[aFieldName]) : (this._value &= ~ (this._fields[aFieldName])); if (this.value) { this.callDelegateMethod(); } } }); this._fieldCount++; Iif (!! defaultValue) { this[aFieldName] = true; } } }, _constantsToReuse: { enumerable: false, value: [] }, /** * Removes a field from the bitfield. * @function * @param {string} aFieldName The name of the field to remove. */ removeField: { enumerable: false, value: function (aFieldName) { delete this[aFieldName]; this._constantsToReuse.push(this._fields[aFieldName]); this._trueValue -= this._fields[aFieldName]; delete this._fields[aFieldName]; } }, /** * The BitField object's delegate. * @type {Property} * @default null */ delegate: { enumerable: false, value: null }, /** * @function * @returns Nothing */ callDelegateMethod: { value: function () { var delegateMethod; Iif (this.delegate && typeof (delegateMethod = this.delegate.bitFieldDidBecomeTrue) === "function") { delegateMethod.call(this.delegate, this); } }, enumerable: false }, /** * @type {Function} * @default {number} 0 */ value: { enumerable: false, get: function () { return (this._value === this._trueValue); } }, _fieldCount: { enumerable: false, value: 0 }, _value: { enumerable: false, value: 0 }, _trueValue: { enumerable: false, value: 0 }, /** * @function */ reset: { enumerable: false, value: function () { this._value = 0x0; } }, _fields: { enumerable: false, value: {} }, /** * @function */ toString: { value: function () { var fieldNames = this._fields, i, iField, result = ""; for (i = 0; (iField = fieldNames[i]); i++) { result += iField + "[" + (this._value & fieldNames[iField]) + "], "; } return result; } } }); |