diff -r 000000000000 -r 6474c204b198 browser/devtools/shared/widgets/Spectrum.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/shared/widgets/Spectrum.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,337 @@
+/* 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;
+  }
+};