5 Functions for colour handling and processing.
7 http://www.safalra.com/web-design/javascript/colour-handling-and-processing/
9 The author of this program, Safalra (Stephen Morley), irrevocably releases all
10 rights to this program, with the intention of it becoming part of the public
11 domain. Because this program is released into the public domain, it comes with
12 no warranty either expressed or implied, to the extent permitted by law.
14 For more free and public domain JavaScript code by the same author, visit:
15 http://www.safalra.com/web-design/javascript/
20 /* An abstract Colour implementation. Concrete Colour implementations should use
21 * an instance of this function as their prototype, and implement the getRGB and
22 * getHSL functions. getRGB should return an object representing the RGB
23 * components of this Colour, with the red, green, and blue components in the
24 * range [0,255] and the alpha component in the range [0,100]. getHSL should
25 * return an object representing the HSL components of this Colour, with the hue
26 * component in the range [0,360), the saturation and lightness components in
27 * the range [0,100], and the alpha component in the range [0,1].
29 Roo.lib.Colour = function(){
31 /* Returns an object representing the RGBA components of this Colour. The red,
32 * green, and blue components are converted to integers in the range [0,255].
33 * The alpha is a value in the range [0,1].
35 this.getIntegerRGB = function(){
37 // get the RGB components of this colour
38 var rgb = this.getRGB();
40 // return the integer components
42 'r' : Math.round(rgb.r),
43 'g' : Math.round(rgb.g),
44 'b' : Math.round(rgb.b),
50 /* Returns an object representing the RGBA components of this Colour. The red,
51 * green, and blue components are converted to numbers in the range [0,100].
52 * The alpha is a value in the range [0,1].
54 this.getPercentageRGB = function(){
56 // get the RGB components of this colour
57 var rgb = this.getRGB();
59 // return the percentage components
61 'r' : 100 * rgb.r / 255,
62 'g' : 100 * rgb.g / 255,
63 'b' : 100 * rgb.b / 255,
69 /* Returns a string representing this Colour as a CSS hexadecimal RGB colour
70 * value - that is, a string of the form #RRGGBB where each of RR, GG, and BB
71 * are two-digit hexadecimal numbers.
73 this.getCSSHexadecimalRGB = function(){
75 // get the integer RGB components
76 var rgb = this.getIntegerRGB();
78 // determine the hexadecimal equivalents
79 var r16 = rgb.r.toString(16);
80 var g16 = rgb.g.toString(16);
81 var b16 = rgb.b.toString(16);
83 // return the CSS RGB colour value
85 + (r16.length == 2 ? r16 : '0' + r16)
86 + (g16.length == 2 ? g16 : '0' + g16)
87 + (b16.length == 2 ? b16 : '0' + b16);
91 /* Returns a string representing this Colour as a CSS integer RGB colour
92 * value - that is, a string of the form rgb(r,g,b) where each of r, g, and b
93 * are integers in the range [0,255].
95 this.getCSSIntegerRGB = function(){
97 // get the integer RGB components
98 var rgb = this.getIntegerRGB();
100 // return the CSS RGB colour value
101 return 'rgb(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ')';
105 /* Returns a string representing this Colour as a CSS integer RGBA colour
106 * value - that is, a string of the form rgba(r,g,b,a) where each of r, g, and
107 * b are integers in the range [0,255] and a is in the range [0,1].
109 this.getCSSIntegerRGBA = function(){
111 // get the integer RGB components
112 var rgb = this.getIntegerRGB();
114 // return the CSS integer RGBA colour value
115 return 'rgb(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + rgb.a + ')';
119 /* Returns a string representing this Colour as a CSS percentage RGB colour
120 * value - that is, a string of the form rgb(r%,g%,b%) where each of r, g, and
121 * b are in the range [0,100].
123 this.getCSSPercentageRGB = function(){
125 // get the percentage RGB components
126 var rgb = this.getPercentageRGB();
128 // return the CSS RGB colour value
129 return 'rgb(' + rgb.r + '%,' + rgb.g + '%,' + rgb.b + '%)';
133 /* Returns a string representing this Colour as a CSS percentage RGBA colour
134 * value - that is, a string of the form rgba(r%,g%,b%,a) where each of r, g,
135 * and b are in the range [0,100] and a is in the range [0,1].
137 this.getCSSPercentageRGBA = function(){
139 // get the percentage RGB components
140 var rgb = this.getPercentageRGB();
142 // return the CSS percentage RGBA colour value
143 return 'rgb(' + rgb.r + '%,' + rgb.g + '%,' + rgb.b + '%,' + rgb.a + ')';
147 /* Returns a string representing this Colour as a CSS HSL colour value - that
148 * is, a string of the form hsl(h,s%,l%) where h is in the range [0,100] and
149 * s and l are in the range [0,100].
151 this.getCSSHSL = function(){
153 // get the HSL components
154 var hsl = this.getHSL();
156 // return the CSS HSL colour value
157 return 'hsl(' + hsl.h + ',' + hsl.s + '%,' + hsl.l + '%)';
161 /* Returns a string representing this Colour as a CSS HSLA colour value - that
162 * is, a string of the form hsla(h,s%,l%,a) where h is in the range [0,100],
163 * s and l are in the range [0,100], and a is in the range [0,1].
165 this.getCSSHSLA = function(){
167 // get the HSL components
168 var hsl = this.getHSL();
170 // return the CSS HSL colour value
171 return 'hsl(' + hsl.h + ',' + hsl.s + '%,' + hsl.l + '%,' + hsl.a + ')';
175 /* Sets the colour of the specified node to this Colour. This functions sets
176 * the CSS 'color' property for the node. The parameter is:
178 * node - the node whose colour should be set
180 this.setNodeColour = function(node){
182 // set the colour of the node
183 node.style.color = this.getCSSHexadecimalRGB();
187 /* Sets the background colour of the specified node to this Colour. This
188 * functions sets the CSS 'background-color' property for the node. The
191 * node - the node whose background colour should be set
193 this.setNodeBackgroundColour = function(node){
195 // set the background colour of the node
196 node.style.backgroundColor = this.getCSSHexadecimalRGB();
199 // convert between formats..
202 var r = this.getIntegerRGB();
203 return new Roo.lib.RGBColour(r.r,r,g,r,b,r.a);
212 /* Creates a colour specified in the RGB colour space, with an optional alpha
213 * component. The parameters are:
215 * r - the red component, clipped to the range [0,255]
216 * g - the green component, clipped to the range [0,255]
217 * b - the blue component, clipped to the range [0,255]
218 * a - the alpha component, clipped to the range [0,1] - this parameter is
219 * optional and defaults to 1
221 Roo.lib.RGBColour = function (r, g, b, a){
223 // store the alpha component after clipping it if necessary
224 var alpha = (a === undefined ? 1 : Math.max(0, Math.min(1, a)));
226 // store the RGB components after clipping them if necessary
229 'r' : Math.max(0, Math.min(255, r)),
230 'g' : Math.max(0, Math.min(255, g)),
231 'b' : Math.max(0, Math.min(255, b))
234 // initialise the HSV and HSL components to null
238 /* Returns the HSV or HSL hue component of this RGBColour. The hue is in the
239 * range [0,360). The parameters are:
241 * maximum - the maximum of the RGB component values
242 * range - the range of the RGB component values
244 function getHue(maximum, range){
246 // check whether the range is zero
249 // set the hue to zero (any hue is acceptable as the colour is grey)
254 // determine which of the components has the highest value and set the hue
257 // red has the highest value
259 var hue = (rgb.g - rgb.b) / range * 60;
260 if (hue < 0) hue += 360;
263 // green has the highest value
265 var hue = (rgb.b - rgb.r) / range * 60 + 120;
268 // blue has the highest value
270 var hue = (rgb.r - rgb.g) / range * 60 + 240;
282 /* Calculates and stores the HSV components of this RGBColour so that they can
283 * be returned be the getHSV function.
285 function calculateHSV(){
287 // get the maximum and range of the RGB component values
288 var maximum = Math.max(rgb.r, rgb.g, rgb.b);
289 var range = maximum - Math.min(rgb.r, rgb.g, rgb.b);
291 // store the HSV components
294 'h' : getHue(maximum, range),
295 's' : (maximum == 0 ? 0 : 100 * range / maximum),
301 /* Calculates and stores the HSL components of this RGBColour so that they can
302 * be returned be the getHSL function.
304 function calculateHSL(){
306 // get the maximum and range of the RGB component values
307 var maximum = Math.max(rgb.r, rgb.g, rgb.b);
308 var range = maximum - Math.min(rgb.r, rgb.g, rgb.b);
310 // determine the lightness in the range [0,1]
311 var l = maximum / 255 - range / 510;
313 // store the HSL components
316 'h' : getHue(maximum, range),
317 's' : (range == 0 ? 0 : range / 2.55 / (l < 0.5 ? l * 2 : 2 - l * 2)),
323 /* Returns the RGB and alpha components of this RGBColour as an object with r,
324 * g, b, and a properties. r, g, and b are in the range [0,255] and a is in
327 this.getRGB = function(){
329 // return the RGB components
339 /* Returns the HSV and alpha components of this RGBColour as an object with h,
340 * s, v, and a properties. h is in the range [0,360), s and v are in the range
341 * [0,100], and a is in the range [0,1].
343 this.getHSV = function(){
345 // calculate the HSV components if necessary
346 if (hsv == null) calculateHSV();
348 // return the HSV components
358 /* Returns the HSL and alpha components of this RGBColour as an object with h,
359 * s, l, and a properties. h is in the range [0,360), s and l are in the range
360 * [0,100], and a is in the range [0,1].
362 this.getHSL = function(){
364 // calculate the HSV components if necessary
365 if (hsl == null) calculateHSL();
367 // return the HSL components
378 Roo.lib.RGBColour.prototype = new Roo.lib.Colour();
381 /* Creates a colour specified in the HSV colour space, with an optional alpha
382 * component. The parameters are:
384 * h - the hue component, wrapped to the range [0,360)
385 * s - the saturation component, clipped to the range [0,100]
386 * v - the value component, clipped to the range [0,100]
387 * a - the alpha component, clipped to the range [0,1] - this parameter is
388 * optional and defaults to 1
390 Roo.lib.HSVColour = function (h, s, v, a){
392 // store the alpha component after clipping it if necessary
393 var alpha = (a === undefined ? 1 : Math.max(0, Math.min(1, a)));
395 // store the HSV components after clipping or wrapping them if necessary
398 'h' : (h % 360 + 360) % 360,
399 's' : Math.max(0, Math.min(100, s)),
400 'v' : Math.max(0, Math.min(100, v))
403 // initialise the RGB and HSL components to null
407 /* Calculates and stores the RGB components of this HSVColour so that they can
408 * be returned be the getRGB function.
410 function calculateRGB(){
412 // check whether the saturation is zero
415 // set the colour to the appropriate shade of grey
422 // set some temporary values
423 var f = hsv.h / 60 - Math.floor(hsv.h / 60);
424 var p = hsv.v * (1 - hsv.s / 100);
425 var q = hsv.v * (1 - hsv.s / 100 * f);
426 var t = hsv.v * (1 - hsv.s / 100 * (1 - f));
428 // set the RGB colour components to their temporary values
429 switch (Math.floor(hsv.h / 60)){
430 case 0: var r = hsv.v; var g = t; var b = p; break;
431 case 1: var r = q; var g = hsv.v; var b = p; break;
432 case 2: var r = p; var g = hsv.v; var b = t; break;
433 case 3: var r = p; var g = q; var b = hsv.v; break;
434 case 4: var r = t; var g = p; var b = hsv.v; break;
435 case 5: var r = hsv.v; var g = p; var b = q; break;
440 // store the RGB components
450 /* Calculates and stores the HSL components of this HSVColour so that they can
451 * be returned be the getHSL function.
453 function calculateHSL(){
455 // determine the lightness in the range [0,100]
456 var l = (2 - hsv.s / 100) * hsv.v / 2;
458 // store the HSL components
462 's' : hsv.s * hsv.v / (l < 50 ? l * 2 : 200 - l * 2),
466 // correct a division-by-zero error
467 if (isNaN(hsl.s)) hsl.s = 0;
471 /* Returns the RGB and alpha components of this HSVColour as an object with r,
472 * g, b, and a properties. r, g, and b are in the range [0,255] and a is in
475 this.getRGB = function(){
477 // calculate the RGB components if necessary
478 if (rgb == null) calculateRGB();
480 // return the RGB components
490 /* Returns the HSV and alpha components of this HSVColour as an object with h,
491 * s, v, and a properties. h is in the range [0,360), s and v are in the range
492 * [0,100], and a is in the range [0,1].
494 this.getHSV = function(){
496 // return the HSV components
506 /* Returns the HSL and alpha components of this HSVColour as an object with h,
507 * s, l, and a properties. h is in the range [0,360), s and l are in the range
508 * [0,100], and a is in the range [0,1].
510 this.getHSL = function(){
512 // calculate the HSL components if necessary
513 if (hsl == null) calculateHSL();
515 // return the HSL components
526 Roo.lib.HSVColour.prototype = new Roo.lib.Colour();
529 /* Creates a colour specified in the HSL colour space, with an optional alpha
530 * component. The parameters are:
532 * h - the hue component, wrapped to the range [0,360)
533 * s - the saturation component, clipped to the range [0,100]
534 * l - the lightness component, clipped to the range [0,100]
535 * a - the alpha component, clipped to the range [0,1] - this parameter is
536 * optional and defaults to 1
539 Roo.lib.HSLColour = function(h, s, l, a){
541 // store the alpha component after clipping it if necessary
542 var alpha = (a === undefined ? 1 : Math.max(0, Math.min(1, a)));
544 // store the HSL components after clipping or wrapping them if necessary
547 'h' : (h % 360 + 360) % 360,
548 's' : Math.max(0, Math.min(100, s)),
549 'l' : Math.max(0, Math.min(100, l))
552 // initialise the RGB and HSV components to null
556 /* Calculates and stores the RGB components of this HSLColour so that they can
557 * be returned be the getRGB function.
559 function calculateRGB(){
561 // check whether the saturation is zero
564 // store the RGB components representing the appropriate shade of grey
574 // set some temporary values
576 ? hsl.l * (1 + hsl.s / 100)
577 : hsl.l + hsl.s - hsl.l * hsl.s / 100;
578 var q = 2 * hsl.l - p;
580 // initialise the RGB components
583 'r' : (h + 120) / 60 % 6,
585 'b' : (h + 240) / 60 % 6
588 // loop over the RGB components
589 for (var key in rgb){
591 // ensure that the property is not inherited from the root object
592 if (rgb.hasOwnProperty(key)){
594 // set the component to its value in the range [0,100]
596 rgb[key] = q + (p - q) * rgb[key];
597 }else if (rgb[key] < 3){
599 }else if (rgb[key] < 4){
600 rgb[key] = q + (p - q) * (4 - rgb[key]);
605 // set the component to its value in the range [0,255]
616 /* Calculates and stores the HSV components of this HSLColour so that they can
617 * be returned be the getHSL function.
619 function calculateHSV(){
621 // set a temporary value
622 var t = hsl.s * (hsl.l < 50 ? hsl.l : 100 - hsl.l) / 100;
624 // store the HSV components
628 's' : 200 * t / (hsl.l + t),
632 // correct a division-by-zero error
633 if (isNaN(hsv.s)) hsv.s = 0;
637 /* Returns the RGB and alpha components of this HSLColour as an object with r,
638 * g, b, and a properties. r, g, and b are in the range [0,255] and a is in
641 this.getRGB = function(){
643 // calculate the RGB components if necessary
644 if (rgb == null) calculateRGB();
646 // return the RGB components
656 /* Returns the HSV and alpha components of this HSLColour as an object with h,
657 * s, v, and a properties. h is in the range [0,360), s and v are in the range
658 * [0,100], and a is in the range [0,1].
660 this.getHSV = function(){
662 // calculate the HSV components if necessary
663 if (hsv == null) calculateHSV();
665 // return the HSV components
675 /* Returns the HSL and alpha components of this HSLColour as an object with h,
676 * s, l, and a properties. h is in the range [0,360), s and l are in the range
677 * [0,100], and a is in the range [0,1].
679 this.getHSL = function(){
681 // return the HSL components
692 Roo.lib.HSLColour.prototype = new Roo.lib.Colour();