michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: const EventEmitter = require("devtools/toolkit/event-emitter");
michael@0: 
michael@0: /**
michael@0:  * Spectrum creates a color picker widget in any container you give it.
michael@0:  *
michael@0:  * Simple usage example:
michael@0:  *
michael@0:  * const {Spectrum} = require("devtools/shared/widgets/Spectrum");
michael@0:  * let s = new Spectrum(containerElement, [255, 126, 255, 1]);
michael@0:  * s.on("changed", (event, rgba, color) => {
michael@0:  *   console.log("rgba(" + rgba[0] + ", " + rgba[1] + ", " + rgba[2] + ", " + rgba[3] + ")");
michael@0:  * });
michael@0:  * s.show();
michael@0:  * s.destroy();
michael@0:  *
michael@0:  * Note that the color picker is hidden by default and you need to call show to
michael@0:  * make it appear. This 2 stages initialization helps in cases you are creating
michael@0:  * the color picker in a parent element that hasn't been appended anywhere yet
michael@0:  * or that is hidden. Calling show() when the parent element is appended and
michael@0:  * visible will allow spectrum to correctly initialize its various parts.
michael@0:  *
michael@0:  * Fires the following events:
michael@0:  * - changed : When the user changes the current color
michael@0:  */
michael@0: function Spectrum(parentEl, rgb) {
michael@0:   EventEmitter.decorate(this);
michael@0: 
michael@0:   this.element = parentEl.ownerDocument.createElement('div');
michael@0:   this.parentEl = parentEl;
michael@0: 
michael@0:   this.element.className = "spectrum-container";
michael@0:   this.element.innerHTML = [
michael@0:     "<div class='spectrum-top'>",
michael@0:       "<div class='spectrum-fill'></div>",
michael@0:       "<div class='spectrum-top-inner'>",
michael@0:         "<div class='spectrum-color spectrum-box'>",
michael@0:           "<div class='spectrum-sat'>",
michael@0:             "<div class='spectrum-val'>",
michael@0:               "<div class='spectrum-dragger'></div>",
michael@0:             "</div>",
michael@0:           "</div>",
michael@0:         "</div>",
michael@0:         "<div class='spectrum-hue spectrum-box'>",
michael@0:           "<div class='spectrum-slider spectrum-slider-control'></div>",
michael@0:         "</div>",
michael@0:       "</div>",
michael@0:     "</div>",
michael@0:     "<div class='spectrum-alpha spectrum-checker spectrum-box'>",
michael@0:       "<div class='spectrum-alpha-inner'>",
michael@0:         "<div class='spectrum-alpha-handle spectrum-slider-control'></div>",
michael@0:       "</div>",
michael@0:     "</div>",
michael@0:   ].join("");
michael@0: 
michael@0:   this.onElementClick = this.onElementClick.bind(this);
michael@0:   this.element.addEventListener("click", this.onElementClick, false);
michael@0: 
michael@0:   this.parentEl.appendChild(this.element);
michael@0: 
michael@0:   this.slider = this.element.querySelector(".spectrum-hue");
michael@0:   this.slideHelper = this.element.querySelector(".spectrum-slider");
michael@0:   Spectrum.draggable(this.slider, this.onSliderMove.bind(this));
michael@0: 
michael@0:   this.dragger = this.element.querySelector(".spectrum-color");
michael@0:   this.dragHelper = this.element.querySelector(".spectrum-dragger");
michael@0:   Spectrum.draggable(this.dragger, this.onDraggerMove.bind(this));
michael@0: 
michael@0:   this.alphaSlider = this.element.querySelector(".spectrum-alpha");
michael@0:   this.alphaSliderInner = this.element.querySelector(".spectrum-alpha-inner");
michael@0:   this.alphaSliderHelper = this.element.querySelector(".spectrum-alpha-handle");
michael@0:   Spectrum.draggable(this.alphaSliderInner, this.onAlphaSliderMove.bind(this));
michael@0: 
michael@0:   if (rgb) {
michael@0:     this.rgb = rgb;
michael@0:     this.updateUI();
michael@0:   }
michael@0: }
michael@0: 
michael@0: module.exports.Spectrum = Spectrum;
michael@0: 
michael@0: Spectrum.hsvToRgb = function(h, s, v, a) {
michael@0:   let r, g, b;
michael@0: 
michael@0:   let i = Math.floor(h * 6);
michael@0:   let f = h * 6 - i;
michael@0:   let p = v * (1 - s);
michael@0:   let q = v * (1 - f * s);
michael@0:   let t = v * (1 - (1 - f) * s);
michael@0: 
michael@0:   switch(i % 6) {
michael@0:     case 0: r = v, g = t, b = p; break;
michael@0:     case 1: r = q, g = v, b = p; break;
michael@0:     case 2: r = p, g = v, b = t; break;
michael@0:     case 3: r = p, g = q, b = v; break;
michael@0:     case 4: r = t, g = p, b = v; break;
michael@0:     case 5: r = v, g = p, b = q; break;
michael@0:   }
michael@0: 
michael@0:   return [r * 255, g * 255, b * 255, a];
michael@0: };
michael@0: 
michael@0: Spectrum.rgbToHsv = function(r, g, b, a) {
michael@0:   r = r / 255;
michael@0:   g = g / 255;
michael@0:   b = b / 255;
michael@0: 
michael@0:   let max = Math.max(r, g, b), min = Math.min(r, g, b);
michael@0:   let h, s, v = max;
michael@0: 
michael@0:   let d = max - min;
michael@0:   s = max == 0 ? 0 : d / max;
michael@0: 
michael@0:   if(max == min) {
michael@0:     h = 0; // achromatic
michael@0:   }
michael@0:   else {
michael@0:     switch(max) {
michael@0:       case r: h = (g - b) / d + (g < b ? 6 : 0); break;
michael@0:       case g: h = (b - r) / d + 2; break;
michael@0:       case b: h = (r - g) / d + 4; break;
michael@0:     }
michael@0:     h /= 6;
michael@0:   }
michael@0:   return [h, s, v, a];
michael@0: };
michael@0: 
michael@0: Spectrum.getOffset = function(el) {
michael@0:   let curleft = 0, curtop = 0;
michael@0:   if (el.offsetParent) {
michael@0:     while (el) {
michael@0:       curleft += el.offsetLeft;
michael@0:       curtop += el.offsetTop;
michael@0:       el = el.offsetParent;
michael@0:     }
michael@0:   }
michael@0:   return {
michael@0:     left: curleft,
michael@0:     top: curtop
michael@0:   };
michael@0: };
michael@0: 
michael@0: Spectrum.draggable = function(element, onmove, onstart, onstop) {
michael@0:   onmove = onmove || function() {};
michael@0:   onstart = onstart || function() {};
michael@0:   onstop = onstop || function() {};
michael@0: 
michael@0:   let doc = element.ownerDocument;
michael@0:   let dragging = false;
michael@0:   let offset = {};
michael@0:   let maxHeight = 0;
michael@0:   let maxWidth = 0;
michael@0: 
michael@0:   function prevent(e) {
michael@0:     e.stopPropagation();
michael@0:     e.preventDefault();
michael@0:   }
michael@0: 
michael@0:   function move(e) {
michael@0:     if (dragging) {
michael@0:       let pageX = e.pageX;
michael@0:       let pageY = e.pageY;
michael@0: 
michael@0:       let dragX = Math.max(0, Math.min(pageX - offset.left, maxWidth));
michael@0:       let dragY = Math.max(0, Math.min(pageY - offset.top, maxHeight));
michael@0: 
michael@0:       onmove.apply(element, [dragX, dragY]);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   function start(e) {
michael@0:     let rightclick = e.which === 3;
michael@0: 
michael@0:     if (!rightclick && !dragging) {
michael@0:       if (onstart.apply(element, arguments) !== false) {
michael@0:         dragging = true;
michael@0:         maxHeight = element.offsetHeight;
michael@0:         maxWidth = element.offsetWidth;
michael@0: 
michael@0:         offset = Spectrum.getOffset(element);
michael@0: 
michael@0:         move(e);
michael@0: 
michael@0:         doc.addEventListener("selectstart", prevent, false);
michael@0:         doc.addEventListener("dragstart", prevent, false);
michael@0:         doc.addEventListener("mousemove", move, false);
michael@0:         doc.addEventListener("mouseup", stop, false);
michael@0: 
michael@0:         prevent(e);
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   function stop() {
michael@0:     if (dragging) {
michael@0:       doc.removeEventListener("selectstart", prevent, false);
michael@0:       doc.removeEventListener("dragstart", prevent, false);
michael@0:       doc.removeEventListener("mousemove", move, false);
michael@0:       doc.removeEventListener("mouseup", stop, false);
michael@0:       onstop.apply(element, arguments);
michael@0:     }
michael@0:     dragging = false;
michael@0:   }
michael@0: 
michael@0:   element.addEventListener("mousedown", start, false);
michael@0: };
michael@0: 
michael@0: Spectrum.prototype = {
michael@0:   set rgb(color) {
michael@0:     this.hsv = Spectrum.rgbToHsv(color[0], color[1], color[2], color[3]);
michael@0:   },
michael@0: 
michael@0:   get rgb() {
michael@0:     let rgb = Spectrum.hsvToRgb(this.hsv[0], this.hsv[1], this.hsv[2], this.hsv[3]);
michael@0:     return [Math.round(rgb[0]), Math.round(rgb[1]), Math.round(rgb[2]), Math.round(rgb[3]*100)/100];
michael@0:   },
michael@0: 
michael@0:   get rgbNoSatVal() {
michael@0:     let rgb = Spectrum.hsvToRgb(this.hsv[0], 1, 1);
michael@0:     return [Math.round(rgb[0]), Math.round(rgb[1]), Math.round(rgb[2]), rgb[3]];
michael@0:   },
michael@0: 
michael@0:   get rgbCssString() {
michael@0:     let rgb = this.rgb;
michael@0:     return "rgba(" + rgb[0] + ", " + rgb[1] + ", " + rgb[2] + ", " + rgb[3] + ")";
michael@0:   },
michael@0: 
michael@0:   show: function() {
michael@0:     this.element.classList.add('spectrum-show');
michael@0: 
michael@0:     this.slideHeight = this.slider.offsetHeight;
michael@0:     this.dragWidth = this.dragger.offsetWidth;
michael@0:     this.dragHeight = this.dragger.offsetHeight;
michael@0:     this.dragHelperHeight = this.dragHelper.offsetHeight;
michael@0:     this.slideHelperHeight = this.slideHelper.offsetHeight;
michael@0:     this.alphaSliderWidth = this.alphaSliderInner.offsetWidth;
michael@0:     this.alphaSliderHelperWidth = this.alphaSliderHelper.offsetWidth;
michael@0: 
michael@0:     this.updateUI();
michael@0:   },
michael@0: 
michael@0:   onElementClick: function(e) {
michael@0:     e.stopPropagation();
michael@0:   },
michael@0: 
michael@0:   onSliderMove: function(dragX, dragY) {
michael@0:     this.hsv[0] = (dragY / this.slideHeight);
michael@0:     this.updateUI();
michael@0:     this.onChange();
michael@0:   },
michael@0: 
michael@0:   onDraggerMove: function(dragX, dragY) {
michael@0:     this.hsv[1] = dragX / this.dragWidth;
michael@0:     this.hsv[2] = (this.dragHeight - dragY) / this.dragHeight;
michael@0:     this.updateUI();
michael@0:     this.onChange();
michael@0:   },
michael@0: 
michael@0:   onAlphaSliderMove: function(dragX, dragY) {
michael@0:     this.hsv[3] = dragX / this.alphaSliderWidth;
michael@0:     this.updateUI();
michael@0:     this.onChange();
michael@0:   },
michael@0: 
michael@0:   onChange: function() {
michael@0:     this.emit("changed", this.rgb, this.rgbCssString);
michael@0:   },
michael@0: 
michael@0:   updateHelperLocations: function() {
michael@0:     // If the UI hasn't been shown yet then none of the dimensions will be correct
michael@0:     if (!this.element.classList.contains('spectrum-show'))
michael@0:       return;
michael@0: 
michael@0:     let h = this.hsv[0];
michael@0:     let s = this.hsv[1];
michael@0:     let v = this.hsv[2];
michael@0: 
michael@0:     // Placing the color dragger
michael@0:     let dragX = s * this.dragWidth;
michael@0:     let dragY = this.dragHeight - (v * this.dragHeight);
michael@0:     let helperDim = this.dragHelperHeight/2;
michael@0: 
michael@0:     dragX = Math.max(
michael@0:       -helperDim,
michael@0:       Math.min(this.dragWidth - helperDim, dragX - helperDim)
michael@0:     );
michael@0:     dragY = Math.max(
michael@0:       -helperDim,
michael@0:       Math.min(this.dragHeight - helperDim, dragY - helperDim)
michael@0:     );
michael@0: 
michael@0:     this.dragHelper.style.top = dragY + "px";
michael@0:     this.dragHelper.style.left = dragX + "px";
michael@0: 
michael@0:     // Placing the hue slider
michael@0:     let slideY = (h * this.slideHeight) - this.slideHelperHeight/2;
michael@0:     this.slideHelper.style.top = slideY + "px";
michael@0: 
michael@0:     // Placing the alpha slider
michael@0:     let alphaSliderX = (this.hsv[3] * this.alphaSliderWidth) - (this.alphaSliderHelperWidth / 2);
michael@0:     this.alphaSliderHelper.style.left = alphaSliderX + "px";
michael@0:   },
michael@0: 
michael@0:   updateUI: function() {
michael@0:     this.updateHelperLocations();
michael@0: 
michael@0:     let rgb = this.rgb;
michael@0:     let rgbNoSatVal = this.rgbNoSatVal;
michael@0: 
michael@0:     let flatColor = "rgb(" + rgbNoSatVal[0] + ", " + rgbNoSatVal[1] + ", " + rgbNoSatVal[2] + ")";
michael@0:     let fullColor = "rgba(" + rgb[0] + ", " + rgb[1] + ", " + rgb[2] + ", " + rgb[3] + ")";
michael@0: 
michael@0:     this.dragger.style.backgroundColor = flatColor;
michael@0: 
michael@0:     var rgbNoAlpha = "rgb(" + rgb[0] + "," + rgb[1] + "," + rgb[2] + ")";
michael@0:     var rgbAlpha0 = "rgba(" + rgb[0] + "," + rgb[1] + "," + rgb[2] + ", 0)";
michael@0:     var alphaGradient = "linear-gradient(to right, " + rgbAlpha0 + ", " + rgbNoAlpha + ")";
michael@0:     this.alphaSliderInner.style.background = alphaGradient;
michael@0:   },
michael@0: 
michael@0:   destroy: function() {
michael@0:     this.element.removeEventListener("click", this.onElementClick, false);
michael@0: 
michael@0:     this.parentEl.removeChild(this.element);
michael@0: 
michael@0:     this.slider = null;
michael@0:     this.dragger = null;
michael@0:     this.alphaSlider = this.alphaSliderInner = this.alphaSliderHelper = null;
michael@0:     this.parentEl = null;
michael@0:     this.element = null;
michael@0:   }
michael@0: };