#

API Docs for: 3.10.3
Show: Inherited Protected Private Deprecated

# File: color/js/color-harmony.js

    /**
    Color Harmony provides methods useful for color combination discovery.

    @module color
    @submodule color-harmony
    @class Harmony
    @namespace Color
    @since 3.8.0
    */
    var HSL = 'hsl',
        RGB = 'rgb',

        SPLIT_OFFSET = 30,
        ANALOGOUS_OFFSET = 10,
        TRIAD_OFFSET = 360/3,
        TETRAD_OFFSET = 360/6,
        SQUARE_OFFSET = 360/4 ,

        DEF_COUNT = 5,
        DEF_OFFSET = 10,

        Color = Y.Color,

        Harmony = {

            // Color Groups
            /**
            Returns an Array of two colors. The first color in the Array
              will be the color passed in. The second will be the
              complementary color of the color provided
            @public
            @method getComplementary
            @param {String} str
            @param {String} [to]
            @return {Array}
            @since 3.8.0
            **/
            getComplementary: function(str, to) {
                var c = Harmony._start(str),
                    offsets = [];

                to = to || Color.findType(str);

                offsets.push({});
                offsets.push({ h: 180 });

                return Harmony._adjustOffsetAndFinish(c, offsets, to);
            },

            /**
            Returns an Array of three colors. The first color in the Array
              will be the color passed in. The second two will be split
              complementary colors.
            @public
            @method getSplit
            @param {String} str
            @param {Number} [offset]
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getSplit: function(str, offset, to) {
                var c = Harmony._start(str),
                    offsets = [];

                offset = offset || SPLIT_OFFSET;

                to = to || Color.findType(str);

                offsets.push({});
                offsets.push({ h: 180 + offset });
                offsets.push({ h: 180 - offset });

                return Harmony._adjustOffsetAndFinish(c, offsets, to);
            },

            /**
            Returns an Array of five colors. The first color in the Array
              will be the color passed in. The remaining four will be
              analogous colors two in either direction from the initially
              provided color.
            @public
            @method getAnalogous
            @param {String} str
            @param {Number} [offset]
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getAnalogous: function(str, offset, to) {
                var c = Harmony._start(str),
                    offsets = [];

                offset = offset || ANALOGOUS_OFFSET;
                to = to || Color.findType(str);

                offsets.push({});
                offsets.push({ h: offset });
                offsets.push({ h: offset * 2 });
                offsets.push({ h: -offset });
                offsets.push({ h: -offset * 2 });

                return Harmony._adjustOffsetAndFinish(c, offsets, to);
            },

            /**
            Returns an Array of three colors. The first color in the Array
              will be the color passed in. The second two will be equidistant
              from the start color and each other.
            @public
            @method getTriad
            @param {String} str
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getTriad: function(str, to) {
                var c = Harmony._start(str),
                    offsets = [];

                to = to || Color.findType(str);

                offsets.push({});
                offsets.push({ h: TRIAD_OFFSET });
                offsets.push({ h: -TRIAD_OFFSET });

                return Harmony._adjustOffsetAndFinish(c, offsets, to);
            },

            /**
            Returns an Array of four colors. The first color in the Array
              will be the color passed in. The remaining three colors are
              equidistant offsets from the starting color and each other.
            @public
            @method getTetrad
            @param {String} str
            @param {Number} [offset]
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getTetrad: function(str, offset, to) {
                var c = Harmony._start(str),
                    offsets = [];

                offset = offset || TETRAD_OFFSET;
                to = to || Color.findType(str);

                offsets.push({});
                offsets.push({ h: offset });
                offsets.push({ h: 180 });
                offsets.push({ h: 180 + offset });

                return Harmony._adjustOffsetAndFinish(c, offsets, to);
            },

            /**
            Returns an Array of four colors. The first color in the Array
              will be the color passed in. The remaining three colors are
              equidistant offsets from the starting color and each other.
            @public
            @method getSquare
            @param {String} str
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getSquare: function(str, to) {
                var c = Harmony._start(str),
                    offsets = [];

                to = to || Color.findType(str);

                offsets.push({});
                offsets.push({ h: SQUARE_OFFSET });
                offsets.push({ h: SQUARE_OFFSET * 2 });
                offsets.push({ h: SQUARE_OFFSET * 3 });

                return Harmony._adjustOffsetAndFinish(c, offsets, to);
            },

            /**
            Calculates lightness offsets resulting in a monochromatic Array
              of values.
            @public
            @method getMonochrome
            @param {String} str
            @param {Number} [count]
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getMonochrome: function(str, count, to) {
                var c = Harmony._start(str),
                    colors = [],
                    i = 0,
                    l,
                    step,
                    _c = c.concat();

                count = count || DEF_COUNT;
                to = to || Color.findType(str);

                if (count < 2) {
                    Y.log('Invalid value: count must be greater than 1.', 'error', 'Y.Color.getMonochrome');
                    return str;
                }

                step = 100 / (count - 1);

                for (; i <= 100; i += step) {
                    _c[2] = Math.max(Math.min(i, 100), 0);
                    colors.push(_c.concat());
                }

                l = colors.length;

                for (i=0; i<l; i++) {
                    colors[i] = Harmony._finish(colors[i], to);
                }

                return colors;
            },

            /**
            Creates an Array of similar colors. Returned Array is prepended
               with the color provided followed a number of colors decided
               by count
            @public
            @method getSimilar
            @param {String} str
            @param {Number} [offset]
            @param {Number} [count]
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getSimilar: function(str, offset, count, to) {
                var c = Harmony._start(str),
                    offsets = [],
                    slOffset,
                    s = +(c[1]),
                    sMin,
                    sMax,
                    sRand,
                    l = +(c[2]),
                    lMin,
                    lMax,
                    lRand;

                to = to || Color.findType(str);
                count = count || DEF_COUNT;
                offset = offset || DEF_OFFSET;

                slOffset = (offset > 100) ? 100 : offset;
                sMin = Math.max(0,   s - slOffset);
                sMax = Math.min(100, s + slOffset);
                lMin = Math.max(0,   l - slOffset);
                lMax = Math.min(100, l + slOffset);

                offsets.push({});
                for (i = 0; i < count; i++) {
                    sRand = ( Math.round( (Math.random() * (sMax - sMin)) + sMin ) );
                    lRand = ( Math.round( (Math.random() * (lMax - lMin)) + lMin ) );

                    offsets.push({
                        h: ( Math.random() * (offset * 2)) - offset,
                        // because getOffset adjusts from the existing color, we
                        // need to adjust it negatively to get a good number for
                        // saturation and luminance, otherwise we get a lot of white
                        s: -(s - sRand),
                        l: -(l - lRand)
                    });
                }

                return Harmony._adjustOffsetAndFinish(c, offsets, to);
            },

            /**
            Adjusts the provided color by the offset(s) given. You may
              adjust hue, saturation, and/or luminance in one step.
            @public
            @method getOffset
            @param {String} str
            @param {Object} adjust
              @param {Number} [adjust.h]
              @param {Number} [adjust.s]
              @param {Number} [adjust.l]
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getOffset: function(str, adjust, to) {
                var started = Y.Lang.isArray(str),
                    hsla,
                    type;

                if (!started) {
                    hsla = Harmony._start(str);
                    type = Color.findType(str);
                } else {
                    hsla = str;
                    type = 'hsl';
                }

                to = to || type;

                if (adjust.h) {
                    hsla[0] = ((+hsla[0]) + adjust.h) % 360;
                }

                if (adjust.s) {
                    hsla[1] = Math.max(Math.min((+hsla[1]) + adjust.s, 100), 0);
                }

                if (adjust.l) {
                    hsla[2] = Math.max(Math.min((+hsla[2]) + adjust.l, 100), 0);
                }

                if (!started) {
                    return Harmony._finish(hsla, to);
                }

                return hsla;
            },

            /**
            Returns 0 - 100 percentage of brightness from `0` (black) being the
              darkest to `100` (white) being the brightest.
            @public
            @method getBrightness
            @param {String} str
            @return {Number}
            @since 3.8.0
            **/
            getBrightness: function(str) {
                var c = Color.toArray(Color._convertTo(str, RGB)),
                    r = c[0],
                    g = c[1],
                    b = c[2],
                    weights = Y.Color._brightnessWeights;

                return Math.round(Math.sqrt(
                    (r * r * weights.r) +
                    (g * g * weights.g) +
                    (b * b * weights.b)
                ) / 255 * 100);
            },

            /**
            Returns a new color value with adjusted luminance so that the
              brightness of the return color matches the perceived brightness
              of the `match` color provided.
            @public
            @method getSimilarBrightness
            @param {String} str
            @param {String} match
            @param {String} [to]
            @return {String}
            @since 3.8.0
            **/
            getSimilarBrightness: function(str, match, to){
                var c = Color.toArray(Color._convertTo(str, HSL)),
                    b = Harmony.getBrightness(match);

                to = to || Color.findType(str);

                if (to === 'keyword') {
                    to = 'hex';
                }

                c[2] = Harmony._searchLuminanceForBrightness(c, b, 0, 100);

                str = Color.fromArray(c, Y.Color.TYPES.HSLA);

                return Color._convertTo(str, to);
            },

            //--------------------
            // PRIVATE
            //--------------------
            /**
            Converts the provided color from additive to subtractive returning
              an Array of HSLA values
            @private
            @method _start
            @param {String} str
            @return {Array}
            @since 3.8.0
            */
            _start: function(str) {
                var hsla = Color.toArray(Color._convertTo(str, HSL));
                hsla[0] = Harmony._toSubtractive(hsla[0]);

                return hsla;
            },

            /**
            Converts the provided HSLA values from subtractive to additive
              returning a converted color string
            @private
            @method _finish
            @param {Array} hsla
            @param {String} [to]
            @return {String}
            @since 3.8.0
            */
            _finish: function(hsla, to) {
                hsla[0] = Harmony._toAdditive(hsla[0]);
                hsla = 'hsla(' + hsla[0] + ', ' + hsla[1] + '%, ' + hsla[2] + '%, ' + hsla[3] + ')';

                if (to === 'keyword') {
                    to = 'hex';
                }

                return Color._convertTo(hsla, to);
            },

            /**
            Adjusts the hue degree from subtractive to additive
            @private
            @method _toAdditive
            @param {Number} hue
            @return {Number} Converted additive hue
            @since 3.8.0
            */
            _toAdditive: function(hue) {
                hue = Y.Color._constrainHue(hue);

                if (hue <= 180) {
                    hue /= 1.5;
                } else if (hue < 240) {
                    hue = 120 + (hue - 180) * 2;
                }

                return Y.Color._constrainHue(hue, 10);
            },

            /**
            Adjusts the hue degree from additive to subtractive
            @private
            @method _toSubtractive
            @param {Number} hue
            @return {Number} Converted subtractive hue
            @since 3.8.0
            */
            _toSubtractive: function(hue) {
                hue = Y.Color._constrainHue(hue);

                if (hue <= 120) {
                    hue *= 1.5;
                } else if (hue < 240) {
                    hue = 180 + (hue - 120) / 2;
                }

                return Y.Color._constrainHue(hue, 10);
            },

            /**
            Contrain the hue to a value between 0 and 360 for calculations
                and real color wheel value space. Provide a precision value
                to round return value to a decimal place
            @private
            @method _constrainHue
            @param {Number} hue
            @param {Number} [precision]
            @return {Number} Constrained hue value
            @since 3.8.0
            **/
            _constrainHue: function(hue, precision) {
                while (hue < 0) {
                    hue += 360;
                }
                hue %= 360;

                if (precision) {
                    hue = Math.round(hue * precision) / precision;
                }

                return hue;
            },

            /**
            Brightness weight factors for perceived brightness calculations

            "standard" values are listed as R: 0.241, G: 0.691, B: 0.068
            These values were changed based on grey scale comparison of hsl
              to new hsl where brightness is said to be within plus or minus 0.01.
            @private
            @property _brightnessWeights
            @since 3.8.0
            */
            _brightnessWeights: {
                r: 0.221,
                g: 0.711,
                b: 0.068
            },

            /**
            Calculates the luminance as a mid range between the min and max
              to match the brightness level provided
            @private
            @method _searchLuminanceForBrightness
            @param {Array} color HSLA values
            @param {Number} brightness Brightness to be matched
            @param {Number} min Minimum range for luminance
            @param {Number} max Maximum range for luminance
            @return {Number} Found luminance to achieve requested brightness
            @since 3.8.0
            **/
            _searchLuminanceForBrightness: function(color, brightness, min, max) {
                var luminance = (max + min) / 2,
                    b;

                color[2] = luminance;
                b = Harmony.getBrightness(Color.fromArray(color, Y.Color.TYPES.HSL));

                if (b + 2 > brightness && b - 2 < brightness) {
                    return luminance;
                } else if (b > brightness) {
                    return Harmony._searchLuminanceForBrightness(color, brightness, min, luminance);
                } else {
                    return Harmony._searchLuminanceForBrightness(color, brightness, luminance, max);
                }
            },

            /**
            Takes an HSL array, and an array of offsets and returns and array
                of colors that have been adjusted. The returned colors will
                match the array of offsets provided. If you wish you have the
                same color value returned, you can provide null or an empty
                object to the offsets. The returned array will contain color
                value strings that have been adjusted from subtractive to
                additive.
            @private
            @method _adjustOffsetAndFinish
            @param {Array} color
            @param {Array} offsets
            @param {String} to
            @return {Array}
            @since 3.8.0
            **/
            _adjustOffsetAndFinish: function(color, offsets, to) {
                var colors = [],
                    i,
                    l = offsets.length,
                    _c;

                for (i = 0; i < l; i++ ) {
                    _c = color.concat();
                    if (offsets[i]) {
                        _c = Harmony.getOffset(_c, offsets[i]);
                    }
                    colors.push(Harmony._finish(_c, to));
                }

                return colors;
            }

        };

    Y.Color = Y.mix(Y.Color, Harmony);