// Farbtastic 2.0.0-alpha.1
(function ($) {
var __debug = false;
$.fn.farbtastic = function (options) {
$.farbtastic(this, options);
return this;
};
$.farbtastic = function (container, options) {
var container = $(container)[0];
return container.farbtastic || (container.farbtastic = new $._farbtastic(container, options));
}
$._farbtastic = function (container, options) {
var fb = this;
/////////////////////////////////////////////////////
/**
* Link to the given element(s) or callback.
*/
fb.linkTo = function (callback) {
// Unbind previous nodes
if (typeof fb.callback == 'object') {
$(fb.callback).unbind('keyup', fb.updateValue);
}
// Reset color
fb.color = null;
// Bind callback or elements
if (typeof callback == 'function') {
fb.callback = callback;
}
else if (typeof callback == 'object' || typeof callback == 'string') {
fb.callback = $(callback);
fb.callback.bind('keyup', fb.updateValue);
if (fb.callback[0].value) {
fb.setColor(fb.callback[0].value);
}
}
return this;
}
fb.updateValue = function (event) {
if (this.value && this.value != fb.color) {
fb.setColor(this.value);
}
}
/**
* Change color with HTML syntax #123456
*/
fb.setColor = function (color) {
var unpack = fb.unpack(color);
if (fb.color != color && unpack) {
fb.color = color;
fb.rgb = unpack;
fb.hsl = fb.RGBToHSL(fb.rgb);
fb.updateDisplay();
}
return this;
}
/**
* Change color with HSL triplet [0..1, 0..1, 0..1]
*/
fb.setHSL = function (hsl) {
fb.hsl = hsl;
fb.rgb = fb.HSLToRGB(hsl);
fb.color = fb.pack(fb.rgb);
fb.updateDisplay();
return this;
}
/////////////////////////////////////////////////////
/**
* Initialize the color picker widget.
*/
fb.initWidget = function () {
// Insert markup and size accordingly.
var dim = {
width: options.width,
height: options.width
};
$(container)
.html(
'<div class="farbtastic" style="position: relative">' +
'<div class="farbtastic-solid"></div>' +
'<canvas class="farbtastic-mask"></canvas>' +
'<canvas class="farbtastic-overlay"></canvas>' +
'</div>'
)
.find('*').attr(dim).css(dim).end()
.find('div>*').css('position', 'absolute');
// IE Fix: Recreate canvas elements with doc.createElement and excanvas.
$.browser.msie || false && $('canvas', container).each(function () {
// Fetch info.
var attr = { 'class': $(this).attr('class'), style: this.getAttribute('style') },
e = document.createElement('canvas');
// Replace element.
$(this).before($(e).attr(attr)).remove();
// Init with explorerCanvas.
G_vmlCanvasManager && G_vmlCanvasManager.initElement(e);
// Set explorerCanvas elements dimensions and absolute positioning.
$(e).attr(dim).css(dim).css('position', 'absolute')
.find('*').attr(dim).css(dim);
});
// Determine layout
fb.radius = (options.width - options.wheelWidth) / 2 - 1;
fb.square = Math.floor((fb.radius - options.wheelWidth / 2) * 0.7) - 1;
fb.mid = Math.floor(options.width / 2);
fb.markerSize = options.wheelWidth * 0.3;
fb.solidFill = $('.farbtastic-solid', container).css({
width: fb.square * 2 - 1,
height: fb.square * 2 - 1,
left: fb.mid - fb.square,
top: fb.mid - fb.square
});
// Set up drawing context.
fb.cnvMask = $('.farbtastic-mask', container);
fb.ctxMask = fb.cnvMask[0].getContext('2d');
fb.cnvOverlay = $('.farbtastic-overlay', container);
fb.ctxOverlay = fb.cnvOverlay[0].getContext('2d');
fb.ctxMask.translate(fb.mid, fb.mid);
fb.ctxOverlay.translate(fb.mid, fb.mid);
// Draw widget base layers.
fb.drawCircle();
fb.drawMask();
}
/**
* Draw the color wheel.
*/
fb.drawCircle = function () {
var tm = +(new Date());
// Draw a hue circle with a bunch of gradient-stroked beziers.
// Have to use beziers, as gradient-stroked arcs don't work.
var n = 24,
r = fb.radius,
w = options.wheelWidth,
nudge = 8 / r / n * Math.PI, // Fudge factor for seams.
m = fb.ctxMask,
angle1 = 0, color1, d1;
m.save();
m.lineWidth = w / r;
m.scale(r, r);
// Each segment goes from angle1 to angle2.
for (var i = 0; i <= n; ++i) {
var d2 = i / n,
angle2 = d2 * Math.PI * 2,
// Endpoints
x1 = Math.sin(angle1), y1 = -Math.cos(angle1);
x2 = Math.sin(angle2), y2 = -Math.cos(angle2),
// Midpoint chosen so that the endpoints are tangent to the circle.
am = (angle1 + angle2) / 2,
tan = 1 / Math.cos((angle2 - angle1) / 2),
xm = Math.sin(am) * tan, ym = -Math.cos(am) * tan,
// New color
color2 = fb.pack(fb.HSLToRGB([d2, 1, 0.5]));
if (i > 0) {
if ($.browser.msie || false) {
// IE's gradient calculations mess up the colors. Correct along the diagonals.
var corr = (1 + Math.min(Math.abs(Math.tan(angle1)), Math.abs(Math.tan(Math.PI / 2 - angle1)))) / n;
color1 = fb.pack(fb.HSLToRGB([d1 - 0.15 * corr, 1, 0.5]));
color2 = fb.pack(fb.HSLToRGB([d2 + 0.15 * corr, 1, 0.5]));
// Create gradient fill between the endpoints.
var grad = m.createLinearGradient(x1, y1, x2, y2);
grad.addColorStop(0, color1);
grad.addColorStop(1, color2);
m.fillStyle = grad;
// Draw quadratic curve segment as a fill.
var r1 = (r + w / 2) / r, r2 = (r - w / 2) / r; // inner/outer radius.
m.beginPath();
m.moveTo(x1 * r1, y1 * r1);
m.quadraticCurveTo(xm * r1, ym * r1, x2 * r1, y2 * r1);
m.lineTo(x2 * r2, y2 * r2);
m.quadraticCurveTo(xm * r2, ym * r2, x1 * r2, y1 * r2);
m.fill();
}
else {
// Create gradient fill between the endpoints.
var grad = m.createLinearGradient(x1, y1, x2, y2);
grad.addColorStop(0, color1);
grad.addColorStop(1, color2);
m.strokeStyle = grad;
// Draw quadratic curve segment.
m.beginPath();
m.moveTo(x1, y1);
m.quadraticCurveTo(xm, ym, x2, y2);
m.stroke();
}
}
// Prevent seams where curves join.
angle1 = angle2 - nudge; color1 = color2; d1 = d2;
}
m.restore();
__debug && $('body').append('<div>drawCircle '+ (+(new Date()) - tm) +'ms');
};
/**
* Draw the saturation/luminance mask.
*/
fb.drawMask = function () {
var tm = +(new Date());
// Iterate over sat/lum space and calculate appropriate mask pixel values.
var size = fb.square * 2, sq = fb.square;
function calculateMask(sizex, sizey, outputPixel) {
var isx = 1 / sizex, isy = 1 / sizey;
for (var y = 0; y <= sizey; ++y) {
var l = 1 - y * isy;
for (var x = 0; x <= sizex; ++x) {
var s = 1 - x * isx;
// From sat/lum to alpha and color (grayscale)
var a = 1 - 2 * Math.min(l * s, (1 - l) * s);
var c = (a > 0) ? ((2 * l - 1 + a) * .5 / a) : 0;
outputPixel(x, y, c, a);
}
}
}
// Method #1: direct pixel access (new Canvas).
if (fb.ctxMask.getImageData) {
// Create half-resolution buffer.
var sz = Math.floor(size / 2);
var buffer = document.createElement('canvas');
buffer.width = buffer.height = sz + 1;
var ctx = buffer.getContext('2d');
var frame = ctx.getImageData(0, 0, sz + 1, sz + 1);
var i = 0;
calculateMask(sz, sz, function (x, y, c, a) {
frame.data[i++] = frame.data[i++] = frame.data[i++] = c * 255;
frame.data[i++] = a * 255;
});
ctx.putImageData(frame, 0, 0);
fb.ctxMask.drawImage(buffer, 0, 0, sz + 1, sz + 1, -sq, -sq, sq * 2, sq * 2);
}
// Method #2: drawing commands (old Canvas).
else if (!($.browser.msie || false)) {
// Render directly at half-resolution
var sz = Math.floor(size / 2);
calculateMask(sz, sz, function (x, y, c, a) {
c = Math.round(c * 255);
fb.ctxMask.fillStyle = 'rgba(' + c + ', ' + c + ', ' + c + ', ' + a +')';
fb.ctxMask.fillRect(x * 2 - sq - 1, y * 2 - sq - 1, 2, 2);
});
}
// Method #3: vertical DXImageTransform gradient strips (IE).
else {
var cache_last, cache, w = 6; // Each strip is 6 pixels wide.
var sizex = Math.floor(size / w);
// 6 vertical pieces of gradient per strip.
calculateMask(sizex, 6, function (x, y, c, a) {
if (x == 0) {
cache_last = cache;
cache = [];
}
c = Math.round(c * 255);
a = Math.round(a * 255);
// We can only start outputting gradients once we have two rows of pixels.
if (y > 0) {
var c_last = cache_last[x][0],
a_last = cache_last[x][1],
color1 = fb.packDX(c_last, a_last),
color2 = fb.packDX(c, a),
y1 = Math.round(fb.mid + ((y - 1) * .333 - 1) * sq),
y2 = Math.round(fb.mid + (y * .333 - 1) * sq);
$('<div>').css({
position: 'absolute',
filter: "progid:DXImageTransform.Microsoft.Gradient(StartColorStr="+ color1 +", EndColorStr="+ color2 +", GradientType=0)",
top: y1,
height: y2 - y1,
// Avoid right-edge sticking out.
left: fb.mid + (x * w - sq - 1),
width: w - (x == sizex ? Math.round(w / 2) : 0)
}).appendTo(fb.cnvMask);
}
cache.push([c, a]);
});
}
__debug && $('body').append('<div>drawMask '+ (+(new Date()) - tm) +'ms');
}
/**
* Draw the selection markers.
*/
fb.drawMarkers = function () {
// Determine marker dimensions
var sz = options.width, lw = Math.ceil(fb.markerSize / 4), r = fb.markerSize - lw + 1;
var angle = fb.hsl[0] * 6.28,
x1 = Math.sin(angle) * fb.radius,
y1 = -Math.cos(angle) * fb.radius,
x2 = 2 * fb.square * (.5 - fb.hsl[1]),
y2 = 2 * fb.square * (.5 - fb.hsl[2]),
c1 = fb.invert ? '#fff' : '#000',
c2 = fb.invert ? '#000' : '#fff';
var circles = [
{ x: x1, y: y1, r: r, c: '#000', lw: lw + 1 },
{ x: x1, y: y1, r: fb.markerSize, c: '#fff', lw: lw },
{ x: x2, y: y2, r: r, c: c2, lw: lw + 1 },
{ x: x2, y: y2, r: fb.markerSize, c: c1, lw: lw },
];
// Update the overlay canvas.
fb.ctxOverlay.clearRect(-fb.mid, -fb.mid, sz, sz);
for (var i = 0; i < circles.length; i++) {
var c = circles[i];
fb.ctxOverlay.lineWidth = c.lw;
fb.ctxOverlay.strokeStyle = c.c;
fb.ctxOverlay.beginPath();
fb.ctxOverlay.arc(c.x, c.y, c.r, 0, Math.PI * 2, true);
fb.ctxOverlay.stroke();
}
}
/**
* Update the markers and styles
*/
fb.updateDisplay = function () {
// Determine whether labels/markers should invert.
fb.invert = (fb.rgb[0] * 0.3 + fb.rgb[1] * .59 + fb.rgb[2] * .11) <= 0.6;
// Update the solid background fill.
fb.solidFill.css('backgroundColor', fb.pack(fb.HSLToRGB([fb.hsl[0], 1, 0.5])));
// Draw markers
fb.drawMarkers();
// Linked elements or callback
if (typeof fb.callback == 'object') {
// Set background/foreground color
$(fb.callback).css({
backgroundColor: fb.color,
color: fb.invert ? '#fff' : '#000'
});
// Change linked value
$(fb.callback).each(function() {
if ((typeof this.value == 'string') && this.value != fb.color) {
this.value = fb.color;
}
}).change();
}
else if (typeof fb.callback == 'function') {
fb.callback.call(fb, fb.color);
}
}
/**
* Helper for returning coordinates relative to the center.
*/
fb.widgetCoords = function (event) {
return {
x: event.pageX - fb.offset.left - fb.mid,
y: event.pageY - fb.offset.top - fb.mid
};
}
/**
* Mousedown handler
*/
fb.mousedown = function (event) {
// Capture mouse
if (!$._farbtastic.dragging) {
$(document).bind('mousemove', fb.mousemove).bind('mouseup', fb.mouseup);
$._farbtastic.dragging = true;
}
// Update the stored offset for the widget.
fb.offset = $(container).offset();
// Check which area is being dragged
var pos = fb.widgetCoords(event);
fb.circleDrag = Math.max(Math.abs(pos.x), Math.abs(pos.y)) > (fb.square + 2);
// Process
fb.mousemove(event);
return false;
}
/**
* Mousemove handler
*/
fb.mousemove = function (event) {
// Get coordinates relative to color picker center
var pos = fb.widgetCoords(event);
// Set new HSL parameters
if (fb.circleDrag) {
var hue = Math.atan2(pos.x, -pos.y) / 6.28;
fb.setHSL([(hue + 1) % 1, fb.hsl[1], fb.hsl[2]]);
}
else {
var sat = Math.max(0, Math.min(1, -(pos.x / fb.square / 2) + .5));
var lum = Math.max(0, Math.min(1, -(pos.y / fb.square / 2) + .5));
fb.setHSL([fb.hsl[0], sat, lum]);
}
return false;
}
/**
* Mouseup handler
*/
fb.mouseup = function () {
// Uncapture mouse
$(document).unbind('mousemove', fb.mousemove);
$(document).unbind('mouseup', fb.mouseup);
$._farbtastic.dragging = false;
}
/* Various color utility functions */
fb.dec2hex = function (x) {
return (x < 16 ? '0' : '') + x.toString(16);
}
fb.packDX = function (c, a) {
return '#' + fb.dec2hex(a) + fb.dec2hex(c) + fb.dec2hex(c) + fb.dec2hex(c);
};
fb.pack = function (rgb) {
var r = Math.round(rgb[0] * 255);
var g = Math.round(rgb[1] * 255);
var b = Math.round(rgb[2] * 255);
return '#' + fb.dec2hex(r) + fb.dec2hex(g) + fb.dec2hex(b);
};
fb.unpack = function (color) {
if (color.length == 7) {
function x(i) {
return parseInt(color.substring(i, i + 2), 16) / 255;
}
return [ x(1), x(3), x(5) ];
}
else if (color.length == 4) {
function x(i) {
return parseInt(color.substring(i, i + 1), 16) / 15;
}
return [ x(1), x(2), x(3) ];
}
};
fb.HSLToRGB = function (hsl) {
var m1, m2, r, g, b;
var h = hsl[0], s = hsl[1], l = hsl[2];
m2 = (l <= 0.5) ? l * (s + 1) : l + s - l * s;
m1 = l * 2 - m2;
return [
this.hueToRGB(m1, m2, h + 0.33333),
this.hueToRGB(m1, m2, h),
this.hueToRGB(m1, m2, h - 0.33333)
];
};
fb.hueToRGB = function (m1, m2, h) {
h = (h + 1) % 1;
if (h * 6 < 1) return m1 + (m2 - m1) * h * 6;
if (h * 2 < 1) return m2;
if (h * 3 < 2) return m1 + (m2 - m1) * (0.66666 - h) * 6;
return m1;
};
fb.RGBToHSL = function (rgb) {
var r = rgb[0], g = rgb[1], b = rgb[2],
min = Math.min(r, g, b),
max = Math.max(r, g, b),
delta = max - min,
h = 0,
s = 0,
l = (min + max) / 2;
if (l > 0 && l < 1) {
s = delta / (l < 0.5 ? (2 * l) : (2 - 2 * l));
}
if (delta > 0) {
if (max == r && max != g) h += (g - b) / delta;
if (max == g && max != b) h += (2 + (b - r) / delta);
if (max == b && max != r) h += (4 + (r - g) / delta);
h /= 6;
}
return [h, s, l];
};
// Parse options.
if (!options.callback) {
options = { callback: options };
}
options = $.extend({
width: 300,
wheelWidth: (options.width || 300) / 10,
callback: null
}, options);
// Initialize.
fb.initWidget();
// Install mousedown handler (the others are set on the document on-demand)
$('canvas.farbtastic-overlay', container).mousedown(fb.mousedown);
// Set linked elements/callback
if (options.callback) {
fb.linkTo(options.callback);
}
// Set to gray.
if (!fb.color) fb.setColor('#808080');
}
})(jQuery);