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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 "use strict";

 const EventEmitter = require("devtools/toolkit/event-emitter");

 /**

  * Spectrum creates a color picker widget in any container you give it.

  *

  * Simple usage example:

  *

  * const {Spectrum} = require("devtools/shared/widgets/Spectrum");

  * let s = new Spectrum(containerElement, [255, 126, 255, 1]);

  * s.on("changed", (event, rgba, color) => {

  *   console.log("rgba(" + rgba[0] + ", " + rgba[1] + ", " + rgba[2] + ", " + rgba[3] + ")");

  * });

  * s.show();

  * s.destroy();

  *

  * Note that the color picker is hidden by default and you need to call show to

  * make it appear. This 2 stages initialization helps in cases you are creating

  * the color picker in a parent element that hasn't been appended anywhere yet

  * or that is hidden. Calling show() when the parent element is appended and

  * visible will allow spectrum to correctly initialize its various parts.

  *

  * Fires the following events:

  * - changed : When the user changes the current color

  */

 function Spectrum(parentEl, rgb) {

   EventEmitter.decorate(this);

   this.element = parentEl.ownerDocument.createElement('div');

   this.parentEl = parentEl;

   this.element.className = "spectrum-container";

   this.element.innerHTML = [

     "<div class='spectrum-top'>",

       "<div class='spectrum-fill'></div>",

       "<div class='spectrum-top-inner'>",

         "<div class='spectrum-color spectrum-box'>",

           "<div class='spectrum-sat'>",

             "<div class='spectrum-val'>",

               "<div class='spectrum-dragger'></div>",

             "</div>",

           "</div>",

         "</div>",

         "<div class='spectrum-hue spectrum-box'>",

           "<div class='spectrum-slider spectrum-slider-control'></div>",

         "</div>",

       "</div>",

     "</div>",

     "<div class='spectrum-alpha spectrum-checker spectrum-box'>",

       "<div class='spectrum-alpha-inner'>",

         "<div class='spectrum-alpha-handle spectrum-slider-control'></div>",

       "</div>",

     "</div>",

   ].join("");

   this.onElementClick = this.onElementClick.bind(this);

   this.element.addEventListener("click", this.onElementClick, false);

   this.parentEl.appendChild(this.element);

   this.slider = this.element.querySelector(".spectrum-hue");

   this.slideHelper = this.element.querySelector(".spectrum-slider");

   Spectrum.draggable(this.slider, this.onSliderMove.bind(this));

   this.dragger = this.element.querySelector(".spectrum-color");

   this.dragHelper = this.element.querySelector(".spectrum-dragger");

   Spectrum.draggable(this.dragger, this.onDraggerMove.bind(this));

   this.alphaSlider = this.element.querySelector(".spectrum-alpha");

   this.alphaSliderInner = this.element.querySelector(".spectrum-alpha-inner");

   this.alphaSliderHelper = this.element.querySelector(".spectrum-alpha-handle");

   Spectrum.draggable(this.alphaSliderInner, this.onAlphaSliderMove.bind(this));

   if (rgb) {

     this.rgb = rgb;

     this.updateUI();

   }

 }

 module.exports.Spectrum = Spectrum;

 Spectrum.hsvToRgb = function(h, s, v, a) {

   let r, g, b;

   let i = Math.floor(h * 6);

   let f = h * 6 - i;

   let p = v * (1 - s);

   let q = v * (1 - f * s);

   let t = v * (1 - (1 - f) * s);

   switch(i % 6) {

     case 0: r = v, g = t, b = p; break;

     case 1: r = q, g = v, b = p; break;

     case 2: r = p, g = v, b = t; break;

     case 3: r = p, g = q, b = v; break;

     case 4: r = t, g = p, b = v; break;

     case 5: r = v, g = p, b = q; break;

   }

   return [r * 255, g * 255, b * 255, a];

 };

 Spectrum.rgbToHsv = function(r, g, b, a) {

   r = r / 255;

   g = g / 255;

   b = b / 255;

   let max = Math.max(r, g, b), min = Math.min(r, g, b);

   let h, s, v = max;

   let d = max - min;

   s = max == 0 ? 0 : d / max;

   if(max == min) {

     h = 0; // achromatic

   }

   else {

     switch(max) {

       case r: h = (g - b) / d + (g < b ? 6 : 0); break;

       case g: h = (b - r) / d + 2; break;

       case b: h = (r - g) / d + 4; break;

     }

     h /= 6;

   }

   return [h, s, v, a];

 };

 Spectrum.getOffset = function(el) {

   let curleft = 0, curtop = 0;

   if (el.offsetParent) {

     while (el) {

       curleft += el.offsetLeft;

       curtop += el.offsetTop;

       el = el.offsetParent;

     }

   }

   return {

     left: curleft,

     top: curtop

   };

 };

 Spectrum.draggable = function(element, onmove, onstart, onstop) {

   onmove = onmove || function() {};

   onstart = onstart || function() {};

   onstop = onstop || function() {};

   let doc = element.ownerDocument;

   let dragging = false;

   let offset = {};

   let maxHeight = 0;

   let maxWidth = 0;

   function prevent(e) {

     e.stopPropagation();

     e.preventDefault();

   }

   function move(e) {

     if (dragging) {

       let pageX = e.pageX;

       let pageY = e.pageY;

       let dragX = Math.max(0, Math.min(pageX - offset.left, maxWidth));

       let dragY = Math.max(0, Math.min(pageY - offset.top, maxHeight));

       onmove.apply(element, [dragX, dragY]);

     }

   }

   function start(e) {

     let rightclick = e.which === 3;

     if (!rightclick && !dragging) {

       if (onstart.apply(element, arguments) !== false) {

         dragging = true;

         maxHeight = element.offsetHeight;

         maxWidth = element.offsetWidth;

         offset = Spectrum.getOffset(element);

         move(e);

         doc.addEventListener("selectstart", prevent, false);

         doc.addEventListener("dragstart", prevent, false);

         doc.addEventListener("mousemove", move, false);

         doc.addEventListener("mouseup", stop, false);

         prevent(e);

       }

     }

   }

   function stop() {

     if (dragging) {

       doc.removeEventListener("selectstart", prevent, false);

       doc.removeEventListener("dragstart", prevent, false);

       doc.removeEventListener("mousemove", move, false);

       doc.removeEventListener("mouseup", stop, false);

       onstop.apply(element, arguments);

     }

     dragging = false;

   }

   element.addEventListener("mousedown", start, false);

 };

 Spectrum.prototype = {

   set rgb(color) {

     this.hsv = Spectrum.rgbToHsv(color[0], color[1], color[2], color[3]);

   },

   get rgb() {

     let rgb = Spectrum.hsvToRgb(this.hsv[0], this.hsv[1], this.hsv[2], this.hsv[3]);

     return [Math.round(rgb[0]), Math.round(rgb[1]), Math.round(rgb[2]), Math.round(rgb[3]*100)/100];

   },

   get rgbNoSatVal() {

     let rgb = Spectrum.hsvToRgb(this.hsv[0], 1, 1);

     return [Math.round(rgb[0]), Math.round(rgb[1]), Math.round(rgb[2]), rgb[3]];

   },

   get rgbCssString() {

     let rgb = this.rgb;

     return "rgba(" + rgb[0] + ", " + rgb[1] + ", " + rgb[2] + ", " + rgb[3] + ")";

   },

   show: function() {

     this.element.classList.add('spectrum-show');

     this.slideHeight = this.slider.offsetHeight;

     this.dragWidth = this.dragger.offsetWidth;

     this.dragHeight = this.dragger.offsetHeight;

     this.dragHelperHeight = this.dragHelper.offsetHeight;

     this.slideHelperHeight = this.slideHelper.offsetHeight;

     this.alphaSliderWidth = this.alphaSliderInner.offsetWidth;

     this.alphaSliderHelperWidth = this.alphaSliderHelper.offsetWidth;

     this.updateUI();

   },

   onElementClick: function(e) {

     e.stopPropagation();

   },

   onSliderMove: function(dragX, dragY) {

     this.hsv[0] = (dragY / this.slideHeight);

     this.updateUI();

     this.onChange();

   },

   onDraggerMove: function(dragX, dragY) {

     this.hsv[1] = dragX / this.dragWidth;

     this.hsv[2] = (this.dragHeight - dragY) / this.dragHeight;

     this.updateUI();

     this.onChange();

   },

   onAlphaSliderMove: function(dragX, dragY) {

     this.hsv[3] = dragX / this.alphaSliderWidth;

     this.updateUI();

     this.onChange();

   },

   onChange: function() {

     this.emit("changed", this.rgb, this.rgbCssString);

   },

   updateHelperLocations: function() {

     // If the UI hasn't been shown yet then none of the dimensions will be correct

     if (!this.element.classList.contains('spectrum-show'))

       return;

     let h = this.hsv[0];

     let s = this.hsv[1];

     let v = this.hsv[2];

     // Placing the color dragger

     let dragX = s * this.dragWidth;

     let dragY = this.dragHeight - (v * this.dragHeight);

     let helperDim = this.dragHelperHeight/2;

     dragX = Math.max(

       -helperDim,

       Math.min(this.dragWidth - helperDim, dragX - helperDim)

     );

     dragY = Math.max(

       -helperDim,

       Math.min(this.dragHeight - helperDim, dragY - helperDim)

     );

     this.dragHelper.style.top = dragY + "px";

     this.dragHelper.style.left = dragX + "px";

     // Placing the hue slider

     let slideY = (h * this.slideHeight) - this.slideHelperHeight/2;

     this.slideHelper.style.top = slideY + "px";

     // Placing the alpha slider

     let alphaSliderX = (this.hsv[3] * this.alphaSliderWidth) - (this.alphaSliderHelperWidth / 2);

     this.alphaSliderHelper.style.left = alphaSliderX + "px";

   },

   updateUI: function() {

     this.updateHelperLocations();

     let rgb = this.rgb;

     let rgbNoSatVal = this.rgbNoSatVal;

     let flatColor = "rgb(" + rgbNoSatVal[0] + ", " + rgbNoSatVal[1] + ", " + rgbNoSatVal[2] + ")";

     let fullColor = "rgba(" + rgb[0] + ", " + rgb[1] + ", " + rgb[2] + ", " + rgb[3] + ")";

     this.dragger.style.backgroundColor = flatColor;

     var rgbNoAlpha = "rgb(" + rgb[0] + "," + rgb[1] + "," + rgb[2] + ")";

     var rgbAlpha0 = "rgba(" + rgb[0] + "," + rgb[1] + "," + rgb[2] + ", 0)";

     var alphaGradient = "linear-gradient(to right, " + rgbAlpha0 + ", " + rgbNoAlpha + ")";

     this.alphaSliderInner.style.background = alphaGradient;

   },

   destroy: function() {

     this.element.removeEventListener("click", this.onElementClick, false);

     this.parentEl.removeChild(this.element);

     this.slider = null;

     this.dragger = null;

     this.alphaSlider = this.alphaSliderInner = this.alphaSliderHelper = null;

     this.parentEl = null;

     this.element = null;

   }

 };