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004b5c90 DV |
1 | // Copyright 2011 Dan Vanderkam (danvdk@gmail.com) |
2 | // All Rights Reserved. | |
dedb4f5f | 3 | |
004b5c90 DV |
4 | /** |
5 | * @fileoverview This file contains utility functions used by dygraphs. These | |
6 | * are typically static (i.e. not related to any particular dygraph). Examples | |
7 | * include date/time formatting functions, basic algorithms (e.g. binary | |
8 | * search) and generic DOM-manipulation functions. | |
9 | */ | |
dedb4f5f DV |
10 | |
11 | Dygraph.LOG_SCALE = 10; | |
12 | Dygraph.LN_TEN = Math.log(Dygraph.LOG_SCALE); | |
13 | ||
14 | /** @private */ | |
15 | Dygraph.log10 = function(x) { | |
16 | return Math.log(x) / Dygraph.LN_TEN; | |
17 | } | |
18 | ||
19 | // Various logging levels. | |
20 | Dygraph.DEBUG = 1; | |
21 | Dygraph.INFO = 2; | |
22 | Dygraph.WARNING = 3; | |
23 | Dygraph.ERROR = 3; | |
24 | ||
25 | // TODO(danvk): any way I can get the line numbers to be this.warn call? | |
26 | /** | |
27 | * @private | |
28 | * Log an error on the JS console at the given severity. | |
29 | * @param { Integer } severity One of Dygraph.{DEBUG,INFO,WARNING,ERROR} | |
30 | * @param { String } The message to log. | |
31 | */ | |
32 | Dygraph.log = function(severity, message) { | |
33 | if (typeof(console) != 'undefined') { | |
34 | switch (severity) { | |
35 | case Dygraph.DEBUG: | |
36 | console.debug('dygraphs: ' + message); | |
37 | break; | |
38 | case Dygraph.INFO: | |
39 | console.info('dygraphs: ' + message); | |
40 | break; | |
41 | case Dygraph.WARNING: | |
42 | console.warn('dygraphs: ' + message); | |
43 | break; | |
44 | case Dygraph.ERROR: | |
45 | console.error('dygraphs: ' + message); | |
46 | break; | |
47 | } | |
48 | } | |
49 | }; | |
50 | ||
51 | /** @private */ | |
52 | Dygraph.info = function(message) { | |
53 | Dygraph.log(Dygraph.INFO, message); | |
54 | }; | |
55 | /** @private */ | |
56 | Dygraph.prototype.info = Dygraph.info; | |
57 | ||
58 | /** @private */ | |
59 | Dygraph.warn = function(message) { | |
60 | Dygraph.log(Dygraph.WARNING, message); | |
61 | }; | |
62 | /** @private */ | |
63 | Dygraph.prototype.warn = Dygraph.warn; | |
64 | ||
65 | /** @private */ | |
66 | Dygraph.error = function(message) { | |
67 | Dygraph.log(Dygraph.ERROR, message); | |
68 | }; | |
69 | /** @private */ | |
70 | Dygraph.prototype.error = Dygraph.error; | |
71 | ||
72 | /** | |
73 | * @private | |
74 | * Return the 2d context for a dygraph canvas. | |
75 | * | |
76 | * This method is only exposed for the sake of replacing the function in | |
77 | * automated tests, e.g. | |
78 | * | |
79 | * var oldFunc = Dygraph.getContext(); | |
80 | * Dygraph.getContext = function(canvas) { | |
81 | * var realContext = oldFunc(canvas); | |
82 | * return new Proxy(realContext); | |
83 | * }; | |
84 | */ | |
85 | Dygraph.getContext = function(canvas) { | |
86 | return canvas.getContext("2d"); | |
87 | }; | |
88 | ||
89 | /** | |
90 | * @private | |
91 | * Add an event handler. This smooths a difference between IE and the rest of | |
92 | * the world. | |
93 | * @param { DOM element } el The element to add the event to. | |
94 | * @param { String } evt The name of the event, e.g. 'click' or 'mousemove'. | |
95 | * @param { Function } fn The function to call on the event. The function takes | |
96 | * one parameter: the event object. | |
97 | */ | |
98 | Dygraph.addEvent = function(el, evt, fn) { | |
99 | var normed_fn = function(e) { | |
100 | if (!e) var e = window.event; | |
101 | fn(e); | |
102 | }; | |
103 | if (window.addEventListener) { // Mozilla, Netscape, Firefox | |
104 | el.addEventListener(evt, normed_fn, false); | |
105 | } else { // IE | |
106 | el.attachEvent('on' + evt, normed_fn); | |
107 | } | |
108 | }; | |
109 | ||
110 | /** | |
111 | * @private | |
112 | * Cancels further processing of an event. This is useful to prevent default | |
113 | * browser actions, e.g. highlighting text on a double-click. | |
114 | * Based on the article at | |
115 | * http://www.switchonthecode.com/tutorials/javascript-tutorial-the-scroll-wheel | |
116 | * @param { Event } e The event whose normal behavior should be canceled. | |
117 | */ | |
118 | Dygraph.cancelEvent = function(e) { | |
119 | e = e ? e : window.event; | |
120 | if (e.stopPropagation) { | |
121 | e.stopPropagation(); | |
122 | } | |
123 | if (e.preventDefault) { | |
124 | e.preventDefault(); | |
125 | } | |
126 | e.cancelBubble = true; | |
127 | e.cancel = true; | |
128 | e.returnValue = false; | |
129 | return false; | |
130 | }; | |
131 | ||
132 | /** | |
133 | * Convert hsv values to an rgb(r,g,b) string. Taken from MochiKit.Color. This | |
134 | * is used to generate default series colors which are evenly spaced on the | |
135 | * color wheel. | |
136 | * @param { Number } hue Range is 0.0-1.0. | |
137 | * @param { Number } saturation Range is 0.0-1.0. | |
138 | * @param { Number } value Range is 0.0-1.0. | |
139 | * @return { String } "rgb(r,g,b)" where r, g and b range from 0-255. | |
140 | * @private | |
141 | */ | |
142 | Dygraph.hsvToRGB = function (hue, saturation, value) { | |
143 | var red; | |
144 | var green; | |
145 | var blue; | |
146 | if (saturation === 0) { | |
147 | red = value; | |
148 | green = value; | |
149 | blue = value; | |
150 | } else { | |
151 | var i = Math.floor(hue * 6); | |
152 | var f = (hue * 6) - i; | |
153 | var p = value * (1 - saturation); | |
154 | var q = value * (1 - (saturation * f)); | |
155 | var t = value * (1 - (saturation * (1 - f))); | |
156 | switch (i) { | |
157 | case 1: red = q; green = value; blue = p; break; | |
158 | case 2: red = p; green = value; blue = t; break; | |
159 | case 3: red = p; green = q; blue = value; break; | |
160 | case 4: red = t; green = p; blue = value; break; | |
161 | case 5: red = value; green = p; blue = q; break; | |
162 | case 6: // fall through | |
163 | case 0: red = value; green = t; blue = p; break; | |
164 | } | |
165 | } | |
166 | red = Math.floor(255 * red + 0.5); | |
167 | green = Math.floor(255 * green + 0.5); | |
168 | blue = Math.floor(255 * blue + 0.5); | |
169 | return 'rgb(' + red + ',' + green + ',' + blue + ')'; | |
170 | }; | |
171 | ||
172 | // The following functions are from quirksmode.org with a modification for Safari from | |
173 | // http://blog.firetree.net/2005/07/04/javascript-find-position/ | |
174 | // http://www.quirksmode.org/js/findpos.html | |
175 | ||
176 | /** @private */ | |
177 | Dygraph.findPosX = function(obj) { | |
178 | var curleft = 0; | |
179 | if(obj.offsetParent) | |
180 | while(1) | |
181 | { | |
182 | curleft += obj.offsetLeft; | |
183 | if(!obj.offsetParent) | |
184 | break; | |
185 | obj = obj.offsetParent; | |
186 | } | |
187 | else if(obj.x) | |
188 | curleft += obj.x; | |
189 | return curleft; | |
190 | }; | |
191 | ||
192 | /** @private */ | |
193 | Dygraph.findPosY = function(obj) { | |
194 | var curtop = 0; | |
195 | if(obj.offsetParent) | |
196 | while(1) | |
197 | { | |
198 | curtop += obj.offsetTop; | |
199 | if(!obj.offsetParent) | |
200 | break; | |
201 | obj = obj.offsetParent; | |
202 | } | |
203 | else if(obj.y) | |
204 | curtop += obj.y; | |
205 | return curtop; | |
206 | }; | |
207 | ||
208 | /** | |
209 | * @private | |
210 | * Returns the x-coordinate of the event in a coordinate system where the | |
211 | * top-left corner of the page (not the window) is (0,0). | |
212 | * Taken from MochiKit.Signal | |
213 | */ | |
214 | Dygraph.pageX = function(e) { | |
215 | if (e.pageX) { | |
216 | return (!e.pageX || e.pageX < 0) ? 0 : e.pageX; | |
217 | } else { | |
218 | var de = document; | |
219 | var b = document.body; | |
220 | return e.clientX + | |
221 | (de.scrollLeft || b.scrollLeft) - | |
222 | (de.clientLeft || 0); | |
223 | } | |
224 | }; | |
225 | ||
226 | /** | |
227 | * @private | |
228 | * Returns the y-coordinate of the event in a coordinate system where the | |
229 | * top-left corner of the page (not the window) is (0,0). | |
230 | * Taken from MochiKit.Signal | |
231 | */ | |
232 | Dygraph.pageY = function(e) { | |
233 | if (e.pageY) { | |
234 | return (!e.pageY || e.pageY < 0) ? 0 : e.pageY; | |
235 | } else { | |
236 | var de = document; | |
237 | var b = document.body; | |
238 | return e.clientY + | |
239 | (de.scrollTop || b.scrollTop) - | |
240 | (de.clientTop || 0); | |
241 | } | |
242 | }; | |
243 | ||
244 | /** | |
245 | * @private | |
246 | * @param { Number } x The number to consider. | |
247 | * @return { Boolean } Whether the number is zero or NaN. | |
248 | */ | |
249 | // TODO(danvk): rename this function to something like 'isNonZeroNan'. | |
250 | Dygraph.isOK = function(x) { | |
251 | return x && !isNaN(x); | |
252 | }; | |
253 | ||
254 | /** | |
255 | * Number formatting function which mimicks the behavior of %g in printf, i.e. | |
256 | * either exponential or fixed format (without trailing 0s) is used depending on | |
257 | * the length of the generated string. The advantage of this format is that | |
258 | * there is a predictable upper bound on the resulting string length, | |
259 | * significant figures are not dropped, and normal numbers are not displayed in | |
260 | * exponential notation. | |
261 | * | |
262 | * NOTE: JavaScript's native toPrecision() is NOT a drop-in replacement for %g. | |
263 | * It creates strings which are too long for absolute values between 10^-4 and | |
264 | * 10^-6, e.g. '0.00001' instead of '1e-5'. See tests/number-format.html for | |
265 | * output examples. | |
266 | * | |
267 | * @param {Number} x The number to format | |
268 | * @param {Number} opt_precision The precision to use, default 2. | |
269 | * @return {String} A string formatted like %g in printf. The max generated | |
270 | * string length should be precision + 6 (e.g 1.123e+300). | |
271 | */ | |
272 | Dygraph.floatFormat = function(x, opt_precision) { | |
273 | // Avoid invalid precision values; [1, 21] is the valid range. | |
274 | var p = Math.min(Math.max(1, opt_precision || 2), 21); | |
275 | ||
276 | // This is deceptively simple. The actual algorithm comes from: | |
277 | // | |
278 | // Max allowed length = p + 4 | |
279 | // where 4 comes from 'e+n' and '.'. | |
280 | // | |
281 | // Length of fixed format = 2 + y + p | |
282 | // where 2 comes from '0.' and y = # of leading zeroes. | |
283 | // | |
284 | // Equating the two and solving for y yields y = 2, or 0.00xxxx which is | |
285 | // 1.0e-3. | |
286 | // | |
287 | // Since the behavior of toPrecision() is identical for larger numbers, we | |
288 | // don't have to worry about the other bound. | |
289 | // | |
290 | // Finally, the argument for toExponential() is the number of trailing digits, | |
291 | // so we take off 1 for the value before the '.'. | |
292 | return (Math.abs(x) < 1.0e-3 && x != 0.0) ? | |
293 | x.toExponential(p - 1) : x.toPrecision(p); | |
294 | }; | |
295 | ||
296 | /** | |
297 | * @private | |
298 | * Converts '9' to '09' (useful for dates) | |
299 | */ | |
300 | Dygraph.zeropad = function(x) { | |
301 | if (x < 10) return "0" + x; else return "" + x; | |
302 | }; | |
303 | ||
304 | /** | |
305 | * Return a string version of the hours, minutes and seconds portion of a date. | |
306 | * @param {Number} date The JavaScript date (ms since epoch) | |
307 | * @return {String} A time of the form "HH:MM:SS" | |
308 | * @private | |
309 | */ | |
310 | Dygraph.hmsString_ = function(date) { | |
311 | var zeropad = Dygraph.zeropad; | |
312 | var d = new Date(date); | |
313 | if (d.getSeconds()) { | |
314 | return zeropad(d.getHours()) + ":" + | |
315 | zeropad(d.getMinutes()) + ":" + | |
316 | zeropad(d.getSeconds()); | |
317 | } else { | |
318 | return zeropad(d.getHours()) + ":" + zeropad(d.getMinutes()); | |
319 | } | |
320 | }; | |
321 | ||
322 | /** | |
323 | * Convert a JS date (millis since epoch) to YYYY/MM/DD | |
324 | * @param {Number} date The JavaScript date (ms since epoch) | |
325 | * @return {String} A date of the form "YYYY/MM/DD" | |
326 | * @private | |
327 | */ | |
328 | Dygraph.dateString_ = function(date) { | |
329 | var zeropad = Dygraph.zeropad; | |
330 | var d = new Date(date); | |
331 | ||
332 | // Get the year: | |
333 | var year = "" + d.getFullYear(); | |
334 | // Get a 0 padded month string | |
335 | var month = zeropad(d.getMonth() + 1); //months are 0-offset, sigh | |
336 | // Get a 0 padded day string | |
337 | var day = zeropad(d.getDate()); | |
338 | ||
339 | var ret = ""; | |
340 | var frac = d.getHours() * 3600 + d.getMinutes() * 60 + d.getSeconds(); | |
341 | if (frac) ret = " " + Dygraph.hmsString_(date); | |
342 | ||
343 | return year + "/" + month + "/" + day + ret; | |
344 | }; | |
345 | ||
346 | /** | |
347 | * Round a number to the specified number of digits past the decimal point. | |
348 | * @param {Number} num The number to round | |
349 | * @param {Number} places The number of decimals to which to round | |
350 | * @return {Number} The rounded number | |
351 | * @private | |
352 | */ | |
353 | Dygraph.round_ = function(num, places) { | |
354 | var shift = Math.pow(10, places); | |
355 | return Math.round(num * shift)/shift; | |
356 | }; | |
357 | ||
358 | /** | |
359 | * @private | |
360 | * Implementation of binary search over an array. | |
361 | * Currently does not work when val is outside the range of arry's values. | |
362 | * @param { Integer } val the value to search for | |
363 | * @param { Integer[] } arry is the value over which to search | |
364 | * @param { Integer } abs If abs > 0, find the lowest entry greater than val | |
365 | * If abs < 0, find the highest entry less than val. | |
366 | * if abs == 0, find the entry that equals val. | |
367 | * @param { Integer } [low] The first index in arry to consider (optional) | |
368 | * @param { Integer } [high] The last index in arry to consider (optional) | |
369 | */ | |
370 | Dygraph.binarySearch = function(val, arry, abs, low, high) { | |
371 | if (low == null || high == null) { | |
372 | low = 0; | |
373 | high = arry.length - 1; | |
374 | } | |
375 | if (low > high) { | |
376 | return -1; | |
377 | } | |
378 | if (abs == null) { | |
379 | abs = 0; | |
380 | } | |
381 | var validIndex = function(idx) { | |
382 | return idx >= 0 && idx < arry.length; | |
383 | } | |
384 | var mid = parseInt((low + high) / 2); | |
385 | var element = arry[mid]; | |
386 | if (element == val) { | |
387 | return mid; | |
388 | } | |
389 | if (element > val) { | |
390 | if (abs > 0) { | |
391 | // Accept if element > val, but also if prior element < val. | |
392 | var idx = mid - 1; | |
393 | if (validIndex(idx) && arry[idx] < val) { | |
394 | return mid; | |
395 | } | |
396 | } | |
397 | return Dygraph.binarySearch(val, arry, abs, low, mid - 1); | |
398 | } | |
399 | if (element < val) { | |
400 | if (abs < 0) { | |
401 | // Accept if element < val, but also if prior element > val. | |
402 | var idx = mid + 1; | |
403 | if (validIndex(idx) && arry[idx] > val) { | |
404 | return mid; | |
405 | } | |
406 | } | |
407 | return Dygraph.binarySearch(val, arry, abs, mid + 1, high); | |
408 | } | |
409 | }; | |
410 | ||
411 | /** | |
412 | * @private | |
413 | * Parses a date, returning the number of milliseconds since epoch. This can be | |
414 | * passed in as an xValueParser in the Dygraph constructor. | |
415 | * TODO(danvk): enumerate formats that this understands. | |
416 | * @param {String} A date in YYYYMMDD format. | |
417 | * @return {Number} Milliseconds since epoch. | |
418 | */ | |
419 | Dygraph.dateParser = function(dateStr) { | |
420 | var dateStrSlashed; | |
421 | var d; | |
422 | if (dateStr.search("-") != -1) { // e.g. '2009-7-12' or '2009-07-12' | |
423 | dateStrSlashed = dateStr.replace("-", "/", "g"); | |
424 | while (dateStrSlashed.search("-") != -1) { | |
425 | dateStrSlashed = dateStrSlashed.replace("-", "/"); | |
426 | } | |
427 | d = Dygraph.dateStrToMillis(dateStrSlashed); | |
428 | } else if (dateStr.length == 8) { // e.g. '20090712' | |
429 | // TODO(danvk): remove support for this format. It's confusing. | |
430 | dateStrSlashed = dateStr.substr(0,4) + "/" + dateStr.substr(4,2) | |
431 | + "/" + dateStr.substr(6,2); | |
432 | d = Dygraph.dateStrToMillis(dateStrSlashed); | |
433 | } else { | |
434 | // Any format that Date.parse will accept, e.g. "2009/07/12" or | |
435 | // "2009/07/12 12:34:56" | |
436 | d = Dygraph.dateStrToMillis(dateStr); | |
437 | } | |
438 | ||
439 | if (!d || isNaN(d)) { | |
440 | Dygraph.error("Couldn't parse " + dateStr + " as a date"); | |
441 | } | |
442 | return d; | |
443 | }; | |
444 | ||
445 | /** | |
446 | * @private | |
447 | * This is identical to JavaScript's built-in Date.parse() method, except that | |
448 | * it doesn't get replaced with an incompatible method by aggressive JS | |
449 | * libraries like MooTools or Joomla. | |
450 | * @param { String } str The date string, e.g. "2011/05/06" | |
451 | * @return { Integer } millis since epoch | |
452 | */ | |
453 | Dygraph.dateStrToMillis = function(str) { | |
454 | return new Date(str).getTime(); | |
455 | }; | |
456 | ||
457 | // These functions are all based on MochiKit. | |
458 | /** | |
459 | * Copies all the properties from o to self. | |
460 | * | |
461 | * @private | |
462 | */ | |
463 | Dygraph.update = function (self, o) { | |
464 | if (typeof(o) != 'undefined' && o !== null) { | |
465 | for (var k in o) { | |
466 | if (o.hasOwnProperty(k)) { | |
467 | self[k] = o[k]; | |
468 | } | |
469 | } | |
470 | } | |
471 | return self; | |
472 | }; | |
473 | ||
474 | /** | |
475 | * @private | |
476 | */ | |
477 | Dygraph.isArrayLike = function (o) { | |
478 | var typ = typeof(o); | |
479 | if ( | |
480 | (typ != 'object' && !(typ == 'function' && | |
481 | typeof(o.item) == 'function')) || | |
482 | o === null || | |
483 | typeof(o.length) != 'number' || | |
484 | o.nodeType === 3 | |
485 | ) { | |
486 | return false; | |
487 | } | |
488 | return true; | |
489 | }; | |
490 | ||
491 | /** | |
492 | * @private | |
493 | */ | |
494 | Dygraph.isDateLike = function (o) { | |
495 | if (typeof(o) != "object" || o === null || | |
496 | typeof(o.getTime) != 'function') { | |
497 | return false; | |
498 | } | |
499 | return true; | |
500 | }; | |
501 | ||
502 | /** | |
503 | * @private | |
504 | */ | |
505 | Dygraph.clone = function(o) { | |
506 | // TODO(danvk): figure out how MochiKit's version works | |
507 | var r = []; | |
508 | for (var i = 0; i < o.length; i++) { | |
509 | if (Dygraph.isArrayLike(o[i])) { | |
510 | r.push(Dygraph.clone(o[i])); | |
511 | } else { | |
512 | r.push(o[i]); | |
513 | } | |
514 | } | |
515 | return r; | |
516 | }; | |
517 | ||
518 | /** | |
519 | * @private | |
520 | * Create a new canvas element. This is more complex than a simple | |
521 | * document.createElement("canvas") because of IE and excanvas. | |
522 | */ | |
523 | Dygraph.createCanvas = function() { | |
524 | var canvas = document.createElement("canvas"); | |
525 | ||
526 | isIE = (/MSIE/.test(navigator.userAgent) && !window.opera); | |
527 | if (isIE && (typeof(G_vmlCanvasManager) != 'undefined')) { | |
528 | canvas = G_vmlCanvasManager.initElement(canvas); | |
529 | } | |
530 | ||
531 | return canvas; | |
532 | }; |