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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'use strict';
6
7
8/**
9 * The global object.
10 * @type {!Object}
11 * @const
12 */
13var global = this;
14
15
16/** Platform, package, object property, and Event support. */
17this.base = (function() {
18
19  /**
20   * Base path for modules. Used to form URLs for module 'require' requests.
21   */
22  var moduleBasePath = '.';
23  function setModuleBasePath(path) {
24    if (path[path.length - 1] == '/')
25      path = path.substring(0, path.length - 1);
26    moduleBasePath = path;
27  }
28
29
30  function mLog(text, opt_indentLevel) {
31    if (true)
32      return;
33
34    var spacing = '';
35    var indentLevel = opt_indentLevel || 0;
36    for (var i = 0; i < indentLevel; i++)
37      spacing += ' ';
38    console.log(spacing + text);
39  }
40
41  /**
42   * Builds an object structure for the provided namespace path,
43   * ensuring that names that already exist are not overwritten. For
44   * example:
45   * 'a.b.c' -> a = {};a.b={};a.b.c={};
46   * @param {string} name Name of the object that this file defines.
47   * @param {*=} opt_object The object to expose at the end of the path.
48   * @param {Object=} opt_objectToExportTo The object to add the path to;
49   *     default is {@code global}.
50   * @private
51   */
52  function exportPath(name, opt_object, opt_objectToExportTo) {
53    var parts = name.split('.');
54    var cur = opt_objectToExportTo || global;
55
56    for (var part; parts.length && (part = parts.shift());) {
57      if (!parts.length && opt_object !== undefined) {
58        // last part and we have an object; use it
59        cur[part] = opt_object;
60      } else if (part in cur) {
61        cur = cur[part];
62      } else {
63        cur = cur[part] = {};
64      }
65    }
66    return cur;
67  };
68
69  var didLoadModules = false;
70  var moduleDependencies = {};
71  var moduleStylesheets = {};
72  var moduleRawScripts = {};
73
74  function addModuleDependency(moduleName, dependentModuleName) {
75    if (!moduleDependencies[moduleName])
76      moduleDependencies[moduleName] = [];
77
78    var dependentModules = moduleDependencies[moduleName];
79    var found = false;
80    for (var i = 0; i < dependentModules.length; i++)
81      if (dependentModules[i] == dependentModuleName)
82        found = true;
83    if (!found)
84      dependentModules.push(dependentModuleName);
85  }
86
87  function addModuleRawScriptDependency(moduleName, rawScriptName) {
88    if (!moduleRawScripts[moduleName])
89      moduleRawScripts[moduleName] = [];
90
91    var dependentRawScripts = moduleRawScripts[moduleName];
92    var found = false;
93    for (var i = 0; i < moduleRawScripts.length; i++)
94      if (dependentRawScripts[i] == rawScriptName)
95        found = true;
96    if (!found)
97      dependentRawScripts.push(rawScriptName);
98  }
99
100  function addModuleStylesheet(moduleName, stylesheetName) {
101    if (!moduleStylesheets[moduleName])
102      moduleStylesheets[moduleName] = [];
103
104    var stylesheets = moduleStylesheets[moduleName];
105    var found = false;
106    for (var i = 0; i < stylesheets.length; i++)
107      if (stylesheets[i] == stylesheetName)
108        found = true;
109      if (!found)
110        stylesheets.push(stylesheetName);
111  }
112
113  function ensureDepsLoaded() {
114    if (didLoadModules)
115      return;
116    didLoadModules = true;
117
118    var req = new XMLHttpRequest();
119    var src = moduleBasePath + '/' + 'deps.js';
120    req.open('GET', src, false);
121    req.send(null);
122    if (req.status != 200)
123      throw new Error('Could not find ' + src +
124                      '. Run calcdeps.py and try again.');
125
126    base.addModuleDependency = addModuleDependency;
127    base.addModuleRawScriptDependency = addModuleRawScriptDependency;
128    base.addModuleStylesheet = addModuleStylesheet;
129    try {
130      // By construction, the deps file should call addModuleDependency.
131      eval(req.responseText);
132    } catch (e) {
133      throw new Error('When loading deps, got ' + e.stack ? e.stack : e);
134    }
135    delete base.addModuleStylesheet;
136    delete base.addModuleRawScriptDependency;
137    delete base.addModuleDependency;
138
139  }
140
141  var moduleLoadStatus = {};
142  var rawScriptLoadStatus = {};
143  function require(dependentModuleName, opt_indentLevel) {
144    var indentLevel = opt_indentLevel || 0;
145
146    if (window.FLATTENED) {
147      if (!window.FLATTENED[dependentModuleName]) {
148        throw new Error('Somehow, module ' + dependentModuleName +
149                        ' didn\'t get stored in the flattened js file! ' +
150                        'You may need to rerun build/calcdeps.py');
151      }
152      return;
153    }
154    ensureDepsLoaded();
155
156    mLog('require(' + dependentModuleName + ')', indentLevel);
157
158    if (moduleLoadStatus[dependentModuleName] == 'APPENDED')
159      return;
160    if (moduleLoadStatus[dependentModuleName] == 'RESOLVING')
161      throw new Error('Circular dependency betwen modules. Cannot continue!');
162    moduleLoadStatus[dependentModuleName] = 'RESOLVING';
163
164    // Load the module stylesheet first.
165    var stylesheets = moduleStylesheets[dependentModuleName] || [];
166    for (var i = 0; i < stylesheets.length; i++)
167      requireStylesheet(stylesheets[i]);
168
169    // Load the module raw scripts next
170    var rawScripts = moduleRawScripts[dependentModuleName] || [];
171    for (var i = 0; i < rawScripts.length; i++) {
172      var rawScriptName = rawScripts[i];
173      if (rawScriptLoadStatus[rawScriptName])
174        continue;
175
176      mLog('load(' + rawScriptName + ')', indentLevel);
177      var src = moduleBasePath + '/' + rawScriptName;
178      var text = '<script type="text/javascript" src="' + src +
179        '"></' + 'script>';
180      base.doc.write(text);
181      rawScriptLoadStatus[rawScriptName] = 'APPENDED';
182    }
183
184    // Load the module's dependent scripts after.
185    var dependentModules =
186        moduleDependencies[dependentModuleName] || [];
187    for (var i = 0; i < dependentModules.length; i++)
188      require(dependentModules[i], indentLevel + 1);
189
190    mLog('load(' + dependentModuleName + ')', indentLevel);
191    // Load the module itself.
192    var localPath = dependentModuleName.replace(/\./g, '/') + '.js';
193    var src = moduleBasePath + '/' + localPath;
194    var text = '<script type="text/javascript" src="' + src +
195        '"></' + 'script>';
196    base.doc.write(text);
197    moduleLoadStatus[dependentModuleName] = 'APPENDED';
198  }
199
200  /**
201   * Adds a dependency on a raw javascript file, e.g. a third party
202   * library.
203   * @param {String} rawScriptName The path to the script file, relative to
204   * moduleBasePath.
205   */
206  function requireRawScript(rawScriptPath) {
207    if (window.FLATTENED_RAW_SCRIPTS) {
208      if (!window.FLATTENED_RAW_SCRIPTS[rawScriptPath]) {
209        throw new Error('Somehow, ' + rawScriptPath +
210                        ' didn\'t get stored in the flattened js file! ' +
211                        'You may need to rerun build/calcdeps.py');
212      }
213      return;
214    }
215
216    if (rawScriptLoadStatus[rawScriptPath])
217      return;
218    throw new Error(rawScriptPath + ' should already have been loaded.' +
219                    ' Did you forget to run calcdeps.py?');
220  }
221
222  var stylesheetLoadStatus = {};
223  function requireStylesheet(dependentStylesheetName) {
224    if (window.FLATTENED)
225      return;
226
227    if (stylesheetLoadStatus[dependentStylesheetName])
228      return;
229    stylesheetLoadStatus[dependentStylesheetName] = true;
230    var localPath = dependentStylesheetName.replace(/\./g, '/') + '.css';
231    var stylesheetPath = moduleBasePath + '/' + localPath;
232
233    var linkEl = document.createElement('link');
234    linkEl.setAttribute('rel', 'stylesheet');
235    linkEl.setAttribute('href', stylesheetPath);
236    base.doc.head.appendChild(linkEl);
237  }
238
239  function exportTo(namespace, fn) {
240    var obj = exportPath(namespace);
241    try {
242      var exports = fn();
243    } catch (e) {
244      console.log('While running exports for ', name, ':');
245      console.log(e.stack || e);
246      return;
247    }
248
249    for (var propertyName in exports) {
250      // Maybe we should check the prototype chain here? The current usage
251      // pattern is always using an object literal so we only care about own
252      // properties.
253      var propertyDescriptor = Object.getOwnPropertyDescriptor(exports,
254                                                               propertyName);
255      if (propertyDescriptor) {
256        Object.defineProperty(obj, propertyName, propertyDescriptor);
257        mLog('  +' + propertyName);
258      }
259    }
260  };
261
262  /**
263   * Fires a property change event on the target.
264   * @param {EventTarget} target The target to dispatch the event on.
265   * @param {string} propertyName The name of the property that changed.
266   * @param {*} newValue The new value for the property.
267   * @param {*} oldValue The old value for the property.
268   */
269  function dispatchPropertyChange(target, propertyName, newValue, oldValue) {
270    var e = new base.Event(propertyName + 'Change');
271    e.propertyName = propertyName;
272    e.newValue = newValue;
273    e.oldValue = oldValue;
274    target.dispatchEvent(e);
275  }
276
277  /**
278   * Converts a camelCase javascript property name to a hyphenated-lower-case
279   * attribute name.
280   * @param {string} jsName The javascript camelCase property name.
281   * @return {string} The equivalent hyphenated-lower-case attribute name.
282   */
283  function getAttributeName(jsName) {
284    return jsName.replace(/([A-Z])/g, '-$1').toLowerCase();
285  }
286
287  /**
288   * The kind of property to define in {@code defineProperty}.
289   * @enum {number}
290   * @const
291   */
292  var PropertyKind = {
293    /**
294     * Plain old JS property where the backing data is stored as a 'private'
295     * field on the object.
296     */
297    JS: 'js',
298
299    /**
300     * The property backing data is stored as an attribute on an element.
301     */
302    ATTR: 'attr',
303
304    /**
305     * The property backing data is stored as an attribute on an element. If the
306     * element has the attribute then the value is true.
307     */
308    BOOL_ATTR: 'boolAttr'
309  };
310
311  /**
312   * Helper function for defineProperty that returns the getter to use for the
313   * property.
314   * @param {string} name The name of the property.
315   * @param {base.PropertyKind} kind The kind of the property.
316   * @return {function():*} The getter for the property.
317   */
318  function getGetter(name, kind) {
319    switch (kind) {
320      case PropertyKind.JS:
321        var privateName = name + '_';
322        return function() {
323          return this[privateName];
324        };
325      case PropertyKind.ATTR:
326        var attributeName = getAttributeName(name);
327        return function() {
328          return this.getAttribute(attributeName);
329        };
330      case PropertyKind.BOOL_ATTR:
331        var attributeName = getAttributeName(name);
332        return function() {
333          return this.hasAttribute(attributeName);
334        };
335    }
336  }
337
338  /**
339   * Helper function for defineProperty that returns the setter of the right
340   * kind.
341   * @param {string} name The name of the property we are defining the setter
342   *     for.
343   * @param {base.PropertyKind} kind The kind of property we are getting the
344   *     setter for.
345   * @param {function(*):void} opt_setHook A function to run after the property
346   *     is set, but before the propertyChange event is fired.
347   * @return {function(*):void} The function to use as a setter.
348   */
349  function getSetter(name, kind, opt_setHook) {
350    switch (kind) {
351      case PropertyKind.JS:
352        var privateName = name + '_';
353        return function(value) {
354          var oldValue = this[privateName];
355          if (value !== oldValue) {
356            this[privateName] = value;
357            if (opt_setHook)
358              opt_setHook.call(this, value, oldValue);
359            dispatchPropertyChange(this, name, value, oldValue);
360          }
361        };
362
363      case PropertyKind.ATTR:
364        var attributeName = getAttributeName(name);
365        return function(value) {
366          var oldValue = this[attributeName];
367          if (value !== oldValue) {
368            if (value == undefined)
369              this.removeAttribute(attributeName);
370            else
371              this.setAttribute(attributeName, value);
372            if (opt_setHook)
373              opt_setHook.call(this, value, oldValue);
374            dispatchPropertyChange(this, name, value, oldValue);
375          }
376        };
377
378      case PropertyKind.BOOL_ATTR:
379        var attributeName = getAttributeName(name);
380        return function(value) {
381          var oldValue = this[attributeName];
382          if (value !== oldValue) {
383            if (value)
384              this.setAttribute(attributeName, name);
385            else
386              this.removeAttribute(attributeName);
387            if (opt_setHook)
388              opt_setHook.call(this, value, oldValue);
389            dispatchPropertyChange(this, name, value, oldValue);
390          }
391        };
392    }
393  }
394
395  /**
396   * Defines a property on an object. When the setter changes the value a
397   * property change event with the type {@code name + 'Change'} is fired.
398   * @param {!Object} obj The object to define the property for.
399   * @param {string} name The name of the property.
400   * @param {base.PropertyKind=} opt_kind What kind of underlying storage to
401   * use.
402   * @param {function(*):void} opt_setHook A function to run after the
403   *     property is set, but before the propertyChange event is fired.
404   */
405  function defineProperty(obj, name, opt_kind, opt_setHook) {
406    if (typeof obj == 'function')
407      obj = obj.prototype;
408
409    var kind = opt_kind || PropertyKind.JS;
410
411    if (!obj.__lookupGetter__(name))
412      obj.__defineGetter__(name, getGetter(name, kind));
413
414    if (!obj.__lookupSetter__(name))
415      obj.__defineSetter__(name, getSetter(name, kind, opt_setHook));
416  }
417
418  /**
419   * Counter for use with createUid
420   */
421  var uidCounter = 1;
422
423  /**
424   * @return {number} A new unique ID.
425   */
426  function createUid() {
427    return uidCounter++;
428  }
429
430  /**
431   * Returns a unique ID for the item. This mutates the item so it needs to be
432   * an object
433   * @param {!Object} item The item to get the unique ID for.
434   * @return {number} The unique ID for the item.
435   */
436  function getUid(item) {
437    if (item.hasOwnProperty('uid'))
438      return item.uid;
439    return item.uid = createUid();
440  }
441
442  /**
443   * Dispatches a simple event on an event target.
444   * @param {!EventTarget} target The event target to dispatch the event on.
445   * @param {string} type The type of the event.
446   * @param {boolean=} opt_bubbles Whether the event bubbles or not.
447   * @param {boolean=} opt_cancelable Whether the default action of the event
448   *     can be prevented.
449   * @return {boolean} If any of the listeners called {@code preventDefault}
450   *     during the dispatch this will return false.
451   */
452  function dispatchSimpleEvent(target, type, opt_bubbles, opt_cancelable) {
453    var e = new base.Event(type, opt_bubbles, opt_cancelable);
454    return target.dispatchEvent(e);
455  }
456
457  /**
458   * Adds a {@code getInstance} static method that always return the same
459   * instance object.
460   * @param {!Function} ctor The constructor for the class to add the static
461   *     method to.
462   */
463  function addSingletonGetter(ctor) {
464    ctor.getInstance = function() {
465      return ctor.instance_ || (ctor.instance_ = new ctor());
466    };
467  }
468
469  /**
470   * Creates a new event to be used with base.EventTarget or DOM EventTarget
471   * objects.
472   * @param {string} type The name of the event.
473   * @param {boolean=} opt_bubbles Whether the event bubbles.
474   *     Default is false.
475   * @param {boolean=} opt_preventable Whether the default action of the event
476   *     can be prevented.
477   * @constructor
478   * @extends {Event}
479   */
480  function Event(type, opt_bubbles, opt_preventable) {
481    var e = base.doc.createEvent('Event');
482    e.initEvent(type, !!opt_bubbles, !!opt_preventable);
483    e.__proto__ = global.Event.prototype;
484    return e;
485  };
486
487  /**
488   * Initialization which must be deferred until run-time.
489   */
490  function initialize() {
491    // If 'document' isn't defined, then we must be being pre-compiled,
492    // so set a trap so that we're initialized on first access at run-time.
493    if (!global.document) {
494      var originalCr = cr;
495
496      Object.defineProperty(global, 'cr', {
497        get: function() {
498          Object.defineProperty(global, 'cr', {value: originalCr});
499          originalBase.initialize();
500          return originalCr;
501        },
502        configurable: true
503      });
504
505      return;
506    }
507
508    Event.prototype = {__proto__: global.Event.prototype};
509
510    base.doc = document;
511
512    base.isMac = /Mac/.test(navigator.platform);
513    base.isWindows = /Win/.test(navigator.platform);
514    base.isChromeOS = /CrOS/.test(navigator.userAgent);
515    base.isLinux = /Linux/.test(navigator.userAgent);
516    base.isGTK = /GTK/.test(chrome.toolkit);
517    base.isViews = /views/.test(chrome.toolkit);
518
519    setModuleBasePath('/src');
520  }
521
522  function asArray(arrayish) {
523    var values = [];
524    for (var i = 0; i < arrayish.length; i++)
525      values.push(arrayish[i]);
526    return values;
527  }
528
529  function concatenateArrays(/*arguments*/) {
530    var values = [];
531    for (var i = 0; i < arguments.length; i++) {
532      if(!(arguments[i] instanceof Array))
533        throw new Error('Arguments ' + i + 'is not an array');
534      values.push.apply(values, arguments[i]);
535    }
536    return values;
537  }
538
539  function dictionaryKeys(dict) {
540    var keys = [];
541    for (var key in dict)
542      keys.push(key);
543    return keys;
544  }
545
546  function dictionaryValues(dict) {
547    var values = [];
548    for (var key in dict)
549      values.push(dict[key]);
550    return values;
551  }
552
553  /**
554   * Maps types to a given value.
555   * @constructor
556   */
557  function TypeMap() {
558    this.types = [];
559    this.values = [];
560  }
561  TypeMap.prototype = {
562    __proto__: Object.prototype,
563
564    add: function(type, value) {
565      this.types.push(type);
566      this.values.push(value);
567    },
568
569    get: function(instance) {
570      for (var i = 0; i < this.types.length; i++) {
571        if (instance instanceof this.types[i])
572          return this.values[i];
573      }
574      return undefined;
575    }
576  };
577
578  return {
579    set moduleBasePath(path) {
580      setModuleBasePath(path);
581    },
582
583    get moduleBasePath() {
584      return moduleBasePath;
585    },
586
587    require: require,
588    requireStylesheet: requireStylesheet,
589    requireRawScript: requireRawScript,
590    exportTo: exportTo,
591
592    addSingletonGetter: addSingletonGetter,
593    createUid: createUid,
594    defineProperty: defineProperty,
595    dispatchPropertyChange: dispatchPropertyChange,
596    dispatchSimpleEvent: dispatchSimpleEvent,
597    Event: Event,
598    getUid: getUid,
599    initialize: initialize,
600    PropertyKind: PropertyKind,
601    asArray: asArray,
602    concatenateArrays: concatenateArrays,
603    dictionaryKeys: dictionaryKeys,
604    dictionaryValues: dictionaryValues,
605    TypeMap: TypeMap,
606  };
607})();
608
609
610/**
611 * TODO(kgr): Move this to another file which is to be loaded last.
612 * This will be done as part of future work to make this code pre-compilable.
613 */
614base.initialize();
615