Bug 1055181 - CSS Filter Tooltip; r=pbrosset

Adds a new devtools tooltip type in the inspector used to edit
css filters. The widget displayed in the tooltip allows to add,
edit, remove, and re-order filters.
Changes made inside the tooltip are applied to the filter
property in the rule-view.

browser/devtools/jar.mn

@@ -141,6 +141,8 @@ browser.jar:
     content/browser/devtools/spectrum.css                              (shared/widgets/spectrum.css)
     content/browser/devtools/cubic-bezier-frame.xhtml                  (shared/widgets/cubic-bezier-frame.xhtml)
     content/browser/devtools/cubic-bezier.css                          (shared/widgets/cubic-bezier.css)
+    content/browser/devtools/filter-frame.xhtml                        (shared/widgets/filter-frame.xhtml)
+    content/browser/devtools/filter-widget.css                         (shared/widgets/filter-widget.css)
     content/browser/devtools/eyedropper.xul                            (eyedropper/eyedropper.xul)
     content/browser/devtools/eyedropper/crosshairs.css                 (eyedropper/crosshairs.css)
     content/browser/devtools/eyedropper/nocursor.css                   (eyedropper/nocursor.css)

browser/devtools/shared/moz.build

@@ -64,6 +64,7 @@ EXTRA_JS_MODULES.devtools.shared.widgets += [
     'widgets/CubicBezierPresets.js',
     'widgets/CubicBezierWidget.js',
     'widgets/FastListWidget.js',
+    'widgets/FilterWidget.js',
     'widgets/FlameGraph.js',
     'widgets/Spectrum.js',
     'widgets/TableWidget.js',

browser/devtools/shared/widgets/FilterWidget.js

@@ -0,0 +1,720 @@
+/* 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";
+
+/**
+  * This is a CSS Filter Editor widget used
+  * for Rule View's filter swatches
+  */
+
+const EventEmitter = require("devtools/toolkit/event-emitter");
+const { Cu } = require("chrome");
+const { ViewHelpers } = Cu.import("resource:///modules/devtools/ViewHelpers.jsm", {});
+const STRINGS_URI = "chrome://browser/locale/devtools/filterwidget.properties";
+const L10N = new ViewHelpers.L10N(STRINGS_URI);
+
+const DEFAULT_FILTER_TYPE = "length";
+const UNIT_MAPPING = {
+  percentage: "%",
+  length: "px",
+  angle: "deg",
+  string: ""
+};
+
+const FAST_VALUE_MULTIPLIER = 10;
+const SLOW_VALUE_MULTIPLIER = 0.1;
+const DEFAULT_VALUE_MULTIPLIER = 1;
+
+const LIST_PADDING = 7;
+const LIST_ITEM_HEIGHT = 32;
+
+const filterList = [
+  {
+    "name": "blur",
+    "range": [0, Infinity],
+    "type": "length"
+  },
+  {
+    "name": "brightness",
+    "range": [0, Infinity],
+    "type": "percentage"
+  },
+  {
+    "name": "contrast",
+    "range": [0, Infinity],
+    "type": "percentage"
+  },
+  {
+    "name": "drop-shadow",
+    "placeholder": L10N.getStr("dropShadowPlaceholder"),
+    "type": "string"
+  },
+  {
+    "name": "grayscale",
+    "range": [0, 100],
+    "type": "percentage"
+  },
+  {
+    "name": "hue-rotate",
+    "range": [0, 360],
+    "type": "angle"
+  },
+  {
+    "name": "invert",
+    "range": [0, 100],
+    "type": "percentage"
+  },
+  {
+    "name": "opacity",
+    "range": [0, 100],
+    "type": "percentage"
+  },
+  {
+    "name": "saturate",
+    "range": [0, Infinity],
+    "type": "percentage"
+  },
+  {
+    "name": "sepia",
+    "range": [0, 100],
+    "type": "percentage"
+  },
+  {
+    "name": "url",
+    "placeholder": "example.svg#c1",
+    "type": "string"
+  }
+];
+
+/**
+ * A CSS Filter editor widget used to add/remove/modify
+ * filters.
+ *
+ * Normally, it takes a CSS filter value as input, parses it
+ * and creates the required elements / bindings.
+ *
+ * You can, however, use add/remove/update methods manually.
+ * See each method's comments for more details
+ *
+ * @param {nsIDOMNode} el
+ *        The widget container.
+ * @param {String} value
+ *        CSS filter value
+ */
+function CSSFilterEditorWidget(el, value = "") {
+  this.doc = el.ownerDocument;
+  this.win = this.doc.ownerGlobal;
+  this.el = el;
+
+  this._addButtonClick = this._addButtonClick.bind(this);
+  this._removeButtonClick = this._removeButtonClick.bind(this);
+  this._mouseMove = this._mouseMove.bind(this);
+  this._mouseUp = this._mouseUp.bind(this);
+  this._mouseDown = this._mouseDown.bind(this);
+  this._input = this._input.bind(this);
+
+  this._initMarkup();
+  this._buildFilterItemMarkup();
+  this._addEventListeners();
+
+  EventEmitter.decorate(this);
+
+  this.filters = [];
+  this.setCssValue(value);
+}
+
+exports.CSSFilterEditorWidget = CSSFilterEditorWidget;
+
+CSSFilterEditorWidget.prototype = {
+  _initMarkup: function() {
+    const list = this.el.querySelector(".filters");
+    this.el.appendChild(list);
+    this.el.insertBefore(list, this.el.firstChild);
+    this.container = this.el;
+    this.list = list;
+
+    this.filterSelect = this.el.querySelector("select");
+    this._populateFilterSelect();
+  },
+
+  /**
+    * Creates <option> elements for each filter definition
+    * in filterList
+    */
+  _populateFilterSelect: function() {
+    let select = this.filterSelect;
+    filterList.forEach(filter => {
+      let option = this.doc.createElement("option");
+      option.innerHTML = option.value = filter.name;
+      select.appendChild(option);
+    });
+  },
+
+  /**
+    * Creates a template for filter elements which is cloned and used in render
+    */
+  _buildFilterItemMarkup: function() {
+    let base = this.doc.createElement("div");
+    base.className = "filter";
+
+    let name = this.doc.createElement("div");
+    name.className = "filter-name";
+
+    let value = this.doc.createElement("div");
+    value.className = "filter-value";
+
+    let drag = this.doc.createElement("i");
+    drag.title = L10N.getStr("dragHandleTooltipText");
+
+    let label = this.doc.createElement("label");
+
+    name.appendChild(drag);
+    name.appendChild(label);
+
+    let unitPreview = this.doc.createElement("span");
+    let input = this.doc.createElement("input");
+    input.classList.add("devtools-textinput");
+
+    value.appendChild(input);
+    value.appendChild(unitPreview);
+
+    let removeButton = this.doc.createElement("button");
+    removeButton.className = "remove-button";
+    value.appendChild(removeButton);
+
+    base.appendChild(name);
+    base.appendChild(value);
+
+    this._filterItemMarkup = base;
+  },
+
+  _addEventListeners: function() {
+    this.addButton = this.el.querySelector("#add-filter");
+    this.addButton.addEventListener("click", this._addButtonClick);
+    this.list.addEventListener("click", this._removeButtonClick);
+    this.list.addEventListener("mousedown", this._mouseDown);
+
+    // These events are event delegators for
+    // drag-drop re-ordering and label-dragging
+    this.win.addEventListener("mousemove", this._mouseMove);
+    this.win.addEventListener("mouseup", this._mouseUp);
+
+    // Used to workaround float-precision problems
+    this.list.addEventListener("input", this._input);
+  },
+
+  _input: function(e) {
+    let filterEl = e.target.closest(".filter"),
+        index = [...this.list.children].indexOf(filterEl),
+        filter = this.filters[index],
+        def = this._definition(filter.name);
+
+    if (def.type !== "string") {
+      e.target.value = fixFloat(e.target.value);
+    }
+    this.updateValueAt(index, e.target.value);
+  },
+
+  _mouseDown: function(e) {
+    let filterEl = e.target.closest(".filter");
+
+    // re-ordering drag handle
+    if (e.target.tagName.toLowerCase() === "i") {
+      this.isReorderingFilter = true;
+      filterEl.startingY = e.pageY;
+      filterEl.classList.add("dragging");
+
+      this.container.classList.add("dragging");
+    // label-dragging
+    } else if (e.target.classList.contains("devtools-draglabel")) {
+      let label = e.target,
+          input = filterEl.querySelector("input"),
+          index = [...this.list.children].indexOf(filterEl);
+
+      this._dragging = {
+        index, label, input,
+        startX: e.pageX
+      };
+
+      this.isDraggingLabel = true;
+    }
+  },
+
+  _addButtonClick: function() {
+    const select = this.filterSelect;
+    if (!select.value) {
+      return;
+    }
+
+    const key = select.value;
+    const def = this._definition(key);
+    // UNIT_MAPPING[string] is an empty string (falsy), so
+    // using || doesn't work here
+    const unitLabel = typeof UNIT_MAPPING[def.type] === "undefined" ?
+                             UNIT_MAPPING[DEFAULT_FILTER_TYPE] :
+                             UNIT_MAPPING[def.type];
+
+    // string-type filters have no default value but a placeholder instead
+    if (!unitLabel) {
+      this.add(key);
+    } else {
+      this.add(key, def.range[0] + unitLabel);
+    }
+
+    this.render();
+  },
+
+  _removeButtonClick: function(e) {
+    const isRemoveButton = e.target.classList.contains("remove-button");
+    if (!isRemoveButton) {
+      return;
+    }
+
+    let filterEl = e.target.closest(".filter");
+    let index = [...this.list.children].indexOf(filterEl);
+    this.removeAt(index);
+  },
+
+  _mouseMove: function(e) {
+    if (this.isReorderingFilter) {
+      this._dragFilterElement(e);
+    } else if (this.isDraggingLabel) {
+      this._dragLabel(e);
+    }
+  },
+
+  _dragFilterElement: function(e) {
+    const rect = this.list.getBoundingClientRect(),
+          top = e.pageY - LIST_PADDING,
+          bottom = e.pageY + LIST_PADDING;
+    // don't allow dragging over top/bottom of list
+    if (top < rect.top || bottom > rect.bottom) {
+      return;
+    }
+
+    const filterEl = this.list.querySelector(".dragging");
+
+    const delta = e.pageY - filterEl.startingY;
+    filterEl.style.top = delta + "px";
+
+    // change is the number of _steps_ taken from initial position
+    // i.e. how many elements we have passed
+    let change = delta / LIST_ITEM_HEIGHT;
+    change = change > 0 ? Math.floor(change) :
+             change < 0 ? Math.ceil(change) : change;
+
+    const children = this.list.children;
+    const index = [...children].indexOf(filterEl);
+    const destination = index + change;
+
+    // If we're moving out, or there's no change at all, stop and return
+    if (destination >= children.length || destination < 0 || change === 0) {
+      return;
+    }
+
+    // Re-order filter objects
+    swapArrayIndices(this.filters, index, destination);
+
+    // Re-order the dragging element in markup
+    const target = change > 0 ? children[destination + 1]
+                              : children[destination];
+    if (target) {
+      this.list.insertBefore(filterEl, target);
+    } else {
+      this.list.appendChild(filterEl);
+    }
+
+    filterEl.removeAttribute("style");
+
+    const currentPosition = change * LIST_ITEM_HEIGHT;
+    filterEl.startingY = e.pageY + currentPosition - delta;
+  },
+
+  _dragLabel: function(e) {
+    let dragging = this._dragging;
+
+    let input = dragging.input;
+
+    let multiplier = DEFAULT_VALUE_MULTIPLIER;
+
+    if (e.altKey) {
+      multiplier = SLOW_VALUE_MULTIPLIER;
+    } else if (e.shiftKey) {
+      multiplier = FAST_VALUE_MULTIPLIER;
+    }
+
+    dragging.lastX = e.pageX;
+    const delta = e.pageX - dragging.startX;
+    const startValue = parseFloat(input.value);
+    let value = startValue + delta * multiplier;
+
+    const filter = this.filters[dragging.index];
+    const [min, max] = this._definition(filter.name).range;
+    value = value < min ? min :
+            value > max ? max : value;
+
+    input.value = fixFloat(value);
+
+    dragging.startX = e.pageX;
+
+    this.updateValueAt(dragging.index, value);
+  },
+
+  _mouseUp: function() {
+    // Label-dragging is disabled on mouseup
+    this._dragging = null;
+    this.isDraggingLabel = false;
+
+    // Filter drag/drop needs more cleaning
+    if (!this.isReorderingFilter) {
+      return;
+    }
+    let filterEl = this.list.querySelector(".dragging");
+
+    this.isReorderingFilter = false;
+    filterEl.classList.remove("dragging");
+    this.container.classList.remove("dragging");
+    filterEl.removeAttribute("style");
+
+    this.emit("updated", this.getCssValue());
+    this.render();
+  },
+
+  /**
+   * Clears the list and renders filters, binding required events.
+   * There are some delegated events bound in _addEventListeners method
+   */
+  render: function() {
+    if (!this.filters.length) {
+      this.list.innerHTML = `<p> ${L10N.getStr("emptyFilterList")} <br />
+                                 ${L10N.getStr("addUsingList")} </p>`;
+      this.emit("render");
+      return;
+    }
+
+    this.list.innerHTML = "";
+
+    let base = this._filterItemMarkup;
+
+    for (let filter of this.filters) {
+      const def = this._definition(filter.name);
+
+      let el = base.cloneNode(true);
+
+      let [name, value] = el.children,
+          label = name.children[1],
+          [input, unitPreview] = value.children;
+
+      let min, max;
+      if (def.range) {
+        [min, max] = def.range;
+      }
+
+      label.textContent = filter.name;
+      input.value = filter.value;
+
+      switch (def.type) {
+        case "percentage":
+        case "angle":
+        case "length":
+          input.type = "number";
+          input.min = min;
+          if (max !== Infinity) {
+            input.max = max;
+          }
+          input.step = "0.1";
+        break;
+        case "string":
+          input.type = "text";
+          input.placeholder = def.placeholder;
+        break;
+      }
+
+      // use photoshop-style label-dragging
+      // and show filters' unit next to their <input>
+      if (def.type !== "string") {
+        unitPreview.textContent = filter.unit;
+
+        label.classList.add("devtools-draglabel");
+        label.title = L10N.getStr("labelDragTooltipText");
+      } else {
+        // string-type filters have no unit
+        unitPreview.remove();
+      }
+
+      this.list.appendChild(el);
+    }
+
+    let el = this.list.querySelector(`.filter:last-of-type input`);
+    if (el) {
+      el.focus();
+      // move cursor to end of input
+      el.setSelectionRange(el.value.length, el.value.length);
+    }
+
+    this.emit("render");
+  },
+
+  /**
+    * returns definition of a filter as defined in filterList
+    *
+    * @param {String} name
+    *        filter name (e.g. blur)
+    * @return {Object}
+    *        filter's definition
+    */
+  _definition: function(name) {
+    return filterList.find(a => a.name === name);
+  },
+
+  /**
+    * Parses the CSS value specified, updating widget's filters
+    *
+    * @param {String} cssValue
+    *        css value to be parsed
+    */
+  setCssValue: function(cssValue) {
+    if (!cssValue) {
+      throw new Error("Missing CSS filter value in setCssValue");
+    }
+
+    this.filters = [];
+
+    if (cssValue === "none") {
+      this.emit("updated", this.getCssValue());
+      this.render();
+      return;
+    }
+
+    // Apply filter to a temporary element
+    // and get the computed value to make parsing
+    // easier
+    let tmp = this.doc.createElement("i");
+    tmp.style.filter = cssValue;
+    const computedValue = this.win.getComputedStyle(tmp).filter;
+
+    for (let {name, value} of tokenizeComputedFilter(computedValue)) {
+      this.add(name, value);
+    }
+
+    this.emit("updated", this.getCssValue());
+    this.render();
+  },
+
+  /**
+    * Creates a new [name] filter record with value
+    *
+    * @param {String} name
+    *        filter name (e.g. blur)
+    * @param {String} value
+    *        value of the filter (e.g. 30px, 20%)
+    * @return {Number}
+    *        The index of the new filter in the current list of filters
+    */
+  add: function(name, value = "") {
+    const def = this._definition(name);
+    if (!def) {
+      return false;
+    }
+
+    let unit = def.type === "string"
+               ? ""
+               : (/[a-zA-Z%]+/.exec(value) || [])[0];
+
+    if (def.type !== "string") {
+      value = parseFloat(value);
+
+      // You can omit percentage values' and use a value between 0..1
+      if (def.type === "percentage" && !unit) {
+        value = value * 100;
+        unit = "%";
+      }
+
+      const [min, max] = def.range;
+      if (value < min) {
+        value = min;
+      } else if (value > max) {
+        value = max;
+      }
+    }
+
+    const index = this.filters.push({value, unit, name: def.name}) - 1;
+    this.emit("updated", this.getCssValue());
+
+    return index;
+  },
+
+  /**
+    * returns value + unit of the specified filter
+    *
+    * @param {Number} index
+    *        filter index
+    * @return {String}
+    *        css value of filter
+    */
+  getValueAt: function(index) {
+    let filter = this.filters[index];
+    if (!filter) {
+      return null;
+    }
+
+    const {value, unit} = filter;
+
+    return value + unit;
+  },
+
+  removeAt: function(index) {
+    if (!this.filters[index]) {
+      return null;
+    }
+
+    this.filters.splice(index, 1);
+    this.emit("updated", this.getCssValue());
+    this.render();
+  },
+
+  /**
+    * Generates CSS filter value for filters of the widget
+    *
+    * @return {String}
+    *        css value of filters
+    */
+  getCssValue: function() {
+    return this.filters.map((filter, i) => {
+      return `${filter.name}(${this.getValueAt(i)})`;
+    }).join(" ") || "none";
+  },
+
+  /**
+    * Updates specified filter's value
+    *
+    * @param {Number} index
+    *        The index of the filter in the current list of filters
+    * @param {number/string} value
+    *        value to set, string for string-typed filters
+    *        number for the rest (unit automatically determined)
+    */
+  updateValueAt: function(index, value) {
+    let filter = this.filters[index];
+    if (!filter) {
+      return;
+    }
+
+    const def = this._definition(filter.name);
+
+    if (def.type !== "string") {
+      const [min, max] = def.range;
+      if (value < min) {
+        value = min;
+      } else if (value > max) {
+        value = max;
+      }
+    }
+
+    filter.value = filter.unit ? fixFloat(value, true) : value;
+
+    this.emit("updated", this.getCssValue());
+  },
+
+  _removeEventListeners: function() {
+    this.addButton.removeEventListener("click", this._addButtonClick);
+    this.list.removeEventListener("click", this._removeButtonClick);
+    this.list.removeEventListener("mousedown", this._mouseDown);
+
+    // These events are used for drag drop re-ordering
+    this.win.removeEventListener("mousemove", this._mouseMove);
+    this.win.removeEventListener("mouseup", this._mouseUp);
+
+    // Used to workaround float-precision problems
+    this.list.removeEventListener("input", this._input);
+  },
+
+  _destroyMarkup: function() {
+    this._filterItemMarkup.remove();
+    this.el.remove();
+    this.el = this.list = this.container = this._filterItemMarkup = null;
+  },
+
+  destroy: function() {
+    this._removeEventListeners();
+    this._destroyMarkup();
+  }
+};
+
+// Fixes JavaScript's float precision
+function fixFloat(a, number) {
+  let fixed = parseFloat(a).toFixed(1);
+  return number ? parseFloat(fixed) : fixed;
+}
+
+/**
+ * Used to swap two filters' indexes
+ * after drag/drop re-ordering
+ *
+ * @param {Array} array
+ *        the array to swap elements of
+ * @param {Number} a
+ *        index of first element
+ * @param {Number} b
+ *        index of second element
+ */
+function swapArrayIndices(array, a, b) {
+  array[a] = array.splice(b, 1, array[a])[0];
+}
+
+/**
+  * Tokenizes CSS Filter value and returns an array of {name, value} pairs
+  *
+  * This is only a very simple tokenizer that only works its way through
+  * parenthesis in the string to detect function names and values.
+  * It assumes that the string actually is a well-formed filter value
+  * (e.g. "blur(2px) hue-rotate(100deg)").
+  *
+  * @param {String} css
+  *        CSS Filter value to be parsed
+  * @return {Array}
+  *        An array of {name, value} pairs
+  */
+function tokenizeComputedFilter(css) {
+  let filters = [];
+  let current = "";
+  let depth = 0;
+
+  if (css === "none") {
+    return filters;
+  }
+
+  while (css.length) {
+    const char = css[0];
+
+    switch (char) {
+      case "(":
+        depth++;
+        if (depth === 1) {
+          filters.push({name: current.trim()});
+          current = "";
+        } else {
+          current += char;
+        }
+      break;
+      case ")":
+        depth--;
+        if (depth === 0) {
+          filters[filters.length - 1].value = current.trim();
+          current = "";
+        } else {
+          current += char;
+        }
+      break;
+      default:
+        current += char;
+      break;
+    }
+
+    css = css.slice(1);
+  }
+
+  return filters;
+}

browser/devtools/shared/widgets/Tooltip.js

@@ -10,6 +10,7 @@ const IOService = Cc["@mozilla.org/network/io-service;1"]
   .getService(Ci.nsIIOService);
 const {Spectrum} = require("devtools/shared/widgets/Spectrum");
 const {CubicBezierWidget} = require("devtools/shared/widgets/CubicBezierWidget");
+const {CSSFilterEditorWidget} = require("devtools/shared/widgets/FilterWidget");
 const EventEmitter = require("devtools/toolkit/event-emitter");
 const {colorUtils} = require("devtools/css-color");
 const Heritage = require("sdk/core/heritage");
@@ -39,6 +40,7 @@ const BORDER_RE = /^border(-(top|bottom|left|right))?$/ig;
 const XHTML_NS = "http://www.w3.org/1999/xhtml";
 const SPECTRUM_FRAME = "chrome://browser/content/devtools/spectrum-frame.xhtml";
 const CUBIC_BEZIER_FRAME = "chrome://browser/content/devtools/cubic-bezier-frame.xhtml";
+const FILTER_FRAME = "chrome://browser/content/devtools/filter-frame.xhtml";
 const ESCAPE_KEYCODE = Ci.nsIDOMKeyEvent.DOM_VK_ESCAPE;
 const RETURN_KEYCODE = Ci.nsIDOMKeyEvent.DOM_VK_RETURN;
 const POPUP_EVENTS = ["shown", "hidden", "showing", "hiding"];
@@ -830,6 +832,56 @@ Tooltip.prototype = {
     return def.promise;
   },
 
+  /**
+   * Fill the tooltip with a new instance of the CSSFilterEditorWidget
+   * widget initialized with the given filter value, and return a promise
+   * that resolves to the instance of the widget when ready.
+   */
+  setFilterContent: function(filter) {
+    let def = promise.defer();
+
+    // Create an iframe to host the filter widget
+    let iframe = this.doc.createElementNS(XHTML_NS, "iframe");
+    iframe.setAttribute("transparent", true);
+    iframe.setAttribute("width", "350");
+    iframe.setAttribute("flex", "1");
+    iframe.setAttribute("class", "devtools-tooltip-iframe");
+
+    let panel = this.panel;
+
+    function onLoad() {
+      iframe.removeEventListener("load", onLoad, true);
+      let win = iframe.contentWindow.wrappedJSObject,
+          doc = win.document.documentElement;
+
+      let container = win.document.getElementById("container");
+      let widget = new CSSFilterEditorWidget(container, filter);
+
+      iframe.height = doc.offsetHeight
+
+      widget.on("render", e => {
+        iframe.height = doc.offsetHeight
+      });
+
+      // Resolve to the widget instance whenever the popup becomes visible
+      if (panel.state == "open") {
+        def.resolve(widget);
+      } else {
+        panel.addEventListener("popupshown", function shown() {
+          panel.removeEventListener("popupshown", shown, true);
+          def.resolve(widget);
+        }, true);
+      }
+    }
+    iframe.addEventListener("load", onLoad, true);
+    iframe.setAttribute("src", FILTER_FRAME);
+
+    // Put the iframe in the tooltip
+    this.content = iframe;
+
+    return def.promise;
+  },
+
   /**
    * Set the content of the tooltip to display a font family preview.
    * This is based on Lea Verou's Dablet. See https://github.com/LeaVerou/dabblet
@@ -1446,7 +1498,7 @@ SwatchCubicBezierTooltip.prototype = Heritage.extend(SwatchBasedEditorTooltip.pr
    * bezier curve in the widget
    */
   show: function() {
-    // Call then parent class' show function
+    // Call the parent class' show function
     SwatchBasedEditorTooltip.prototype.show.call(this);
     // Then set the curve and listen to changes to preview them
     if (this.activeSwatch) {
@@ -1479,6 +1531,61 @@ SwatchCubicBezierTooltip.prototype = Heritage.extend(SwatchBasedEditorTooltip.pr
   }
 });
 
+/**
+ * The swatch-based css filter tooltip class is a specific class meant to be used
+ * along with rule-view's generated css filter swatches.
+ * It extends the parent SwatchBasedEditorTooltip class.
+ * It just wraps a standard Tooltip and sets its content with an instance of a
+ * CSSFilterEditorWidget.
+ *
+ * @param {XULDocument} doc
+ */
+function SwatchFilterTooltip(doc) {
+  SwatchBasedEditorTooltip.call(this, doc);
+
+  // Creating a filter editor instance.
+  // this.widget will always be a promise that resolves to the widget instance
+  this.widget = this.tooltip.setFilterContent("none");
+  this._onUpdate = this._onUpdate.bind(this);
+}
+
+exports.SwatchFilterTooltip = SwatchFilterTooltip;
+
+SwatchFilterTooltip.prototype = Heritage.extend(SwatchBasedEditorTooltip.prototype, {
+  show: function() {
+    // Call the parent class' show function
+    SwatchBasedEditorTooltip.prototype.show.call(this);
+    // Then set the filter value and listen to changes to preview them
+    if (this.activeSwatch) {
+      this.currentFilterValue = this.activeSwatch.nextSibling;
+      this.widget.then(widget => {
+        widget.off("updated", this._onUpdate);
+        widget.on("updated", this._onUpdate);
+        widget.setCssValue(this.currentFilterValue.textContent);
+        widget.render();
+      });
+    }
+  },
+
+  _onUpdate: function(event, filters) {
+    if (!this.activeSwatch) {
+      return;
+    }
+
+    this.currentFilterValue.textContent = filters;
+    this.preview();
+  },
+
+  destroy: function() {
+    SwatchBasedEditorTooltip.prototype.destroy.call(this);
+    this.currentFilterValue = null;
+    this.widget.then(widget => {
+      widget.off("updated", this._onUpdate);
+      widget.destroy();
+    });
+  }
+});
+
 /**
  * L10N utility class
  */

browser/devtools/shared/widgets/filter-frame.xhtml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- 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/. -->
+<!DOCTYPE html [
+  <!ENTITY % filterwidgetDTD SYSTEM "chrome://browser/locale/devtools/filterwidget.dtd" >
+  %filterwidgetDTD;
+]>
+<html xmlns="http://www.w3.org/1999/xhtml">
+  <head>
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
+    <link rel="stylesheet" href="chrome://browser/content/devtools/filter-widget.css" type="text/css"/>
+    <link rel="stylesheet" href="chrome://browser/skin/devtools/common.css" type="text/css"/>
+    <script type="application/javascript;version=1.8" src="theme-switching.js"></script>
+  </head>
+  <body>
+
+    <div id="container">
+      <div class="filters">
+      </div>
+      <div id="editor-footer">
+        <select value="">
+          <option value="">&filterListSelectPlaceholder;</option>
+        </select>
+        <button id="add-filter">&addNewFilterButton;</button>
+      </div>
+    </div>
+  </body>
+</html>

browser/devtools/shared/widgets/filter-widget.css

@@ -0,0 +1,122 @@
+/* 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/. */
+
+#container {
+  color: var(--theme-body-color);
+  padding: 5px;
+  font: message-box;
+}
+
+#container.dragging {
+  -moz-user-select: none;
+}
+
+.theme-light #add-filter,
+.theme-light .remove-button {
+  filter: invert(1);
+}
+
+.filter {
+  display: flex;
+  margin-bottom: 10px;
+}
+
+.filter-name,
+.filter-value {
+  display: flex;
+  align-items: center;
+}
+
+.filter-name {
+  padding-right: 10px;
+  flex: 1;
+}
+
+.filter-value {
+  min-width: 150px;
+  flex: 2;
+}
+
+.remove-button {
+  width: 16px;
+  height: 16px;
+  background: url(chrome://browser/skin/devtools/close@2x.png);
+  background-size: 16px;
+  font-size: 0;
+  border: none;
+  cursor: pointer;
+}
+
+/* drag/drop handle */
+#container i {
+  width: 10px;
+  margin-right: 15px;
+  padding: 10px 0;
+  cursor: grab;
+}
+
+#container i::before {
+  content: '';
+  display: block;
+  width: 10px;
+  height: 1px;
+  background: currentColor;
+  box-shadow: 0 3px 0 0 currentColor,
+              0 -3px 0 0 currentColor;
+}
+
+#container .dragging {
+  position: relative;
+  z-index: 1;
+  cursor: grab;
+}
+
+.filter-name label {
+  -moz-user-select: none;
+  flex-grow: 1;
+}
+
+.filter-name label.devtools-draglabel {
+  cursor: ew-resize;
+}
+
+.filter-value input {
+  min-width: 50%;
+  flex-grow: 1;
+}
+
+.filter-value span {
+  max-width: 20px;
+  width: 20px;
+}
+
+/* message shown when there's no filter specified */
+#container p {
+  text-align: center;
+  line-height: 20px;
+}
+
+#editor-footer {
+  display: flex;
+  justify-content: flex-end;
+}
+
+#editor-footer select {
+  flex-grow: 1;
+  box-sizing: border-box;
+  font: inherit;
+  margin: 0 3px;
+}
+
+#add-filter {
+  -moz-appearance: none;
+  background: url(chrome://browser/skin/devtools/add.svg);
+  background-size: 18px;
+  border: none;
+  width: 16px;
+  height: 16px;
+  font-size: 0;
+  vertical-align: middle;
+  cursor: pointer;
+}

browser/devtools/styleinspector/rule-view.js

@@ -2612,15 +2612,19 @@ TextPropertyEditor.prototype = {
       this.element.removeAttribute("dirty");
     }
 
-    let colorSwatchClass = "ruleview-colorswatch";
-    let bezierSwatchClass = "ruleview-bezierswatch";
+    const sharedSwatchClass = "ruleview-swatch ";
+    const colorSwatchClass = "ruleview-colorswatch";
+    const bezierSwatchClass = "ruleview-bezierswatch";
+    const filterSwatchClass = "ruleview-filterswatch";
 
     let outputParser = this.ruleEditor.ruleView._outputParser;
     let frag = outputParser.parseCssProperty(name, val, {
-      colorSwatchClass: colorSwatchClass,
+      colorSwatchClass: sharedSwatchClass + colorSwatchClass,
       colorClass: "ruleview-color",
-      bezierSwatchClass: bezierSwatchClass,
+      bezierSwatchClass: sharedSwatchClass + bezierSwatchClass,
       bezierClass: "ruleview-bezier",
+      filterSwatchClass: sharedSwatchClass + filterSwatchClass,
+      filterClass: "ruleview-filter",
       defaultColorType: !propDirty,
       urlClass: "theme-link",
       baseURI: this.sheetURI
@@ -2658,6 +2662,20 @@ TextPropertyEditor.prototype = {
       }
     }
 
+    // Attach the filter editor tooltip to the filter swatch
+    let span = this.valueSpan.querySelector("." + filterSwatchClass);
+    if (this.ruleEditor.isEditable) {
+      if(span) {
+        let originalValue = this.valueSpan.textContent;
+
+        this.ruleEditor.ruleView.tooltips.filterEditor.addSwatch(span, {
+          onPreview: () => this._previewValue(this.valueSpan.textContent),
+          onCommit: () => this._applyNewValue(this.valueSpan.textContent),
+          onRevert: () => this._applyNewValue(originalValue, false)
+        });
+      }
+    }
+
     // Populate the computed styles.
     this._updateComputed();
   },

browser/devtools/styleinspector/style-inspector-overlays.js

@@ -16,7 +16,8 @@ const {Cc, Ci, Cu} = require("chrome");
 const {
   Tooltip,
   SwatchColorPickerTooltip,
-  SwatchCubicBezierTooltip
+  SwatchCubicBezierTooltip,
+  SwatchFilterTooltip
 } = require("devtools/shared/widgets/Tooltip");
 const {CssLogic} = require("devtools/styleinspector/css-logic");
 const {Promise:promise} = Cu.import("resource://gre/modules/Promise.jsm", {});
@@ -239,7 +240,8 @@ TooltipsOverlay.prototype = {
   get isEditing() {
     return this.colorPicker.tooltip.isShown() ||
            this.colorPicker.eyedropperOpen ||
-           this.cubicBezier.tooltip.isShown();
+           this.cubicBezier.tooltip.isShown() ||
+           this.filterEditor.tooltip.isShown();
   },
 
   /**
@@ -261,6 +263,8 @@ TooltipsOverlay.prototype = {
       this.colorPicker = new SwatchColorPickerTooltip(this.view.inspector.panelDoc);
       // Cubic bezier tooltip
       this.cubicBezier = new SwatchCubicBezierTooltip(this.view.inspector.panelDoc);
+      // Filter editor tooltip
+      this.filterEditor = new SwatchFilterTooltip(this.view.inspector.panelDoc);
     }
 
     this._isStarted = true;
@@ -286,6 +290,10 @@ TooltipsOverlay.prototype = {
       this.cubicBezier.destroy();
     }
 
+    if (this.filterEditor) {
+      this.filterEditor.destroy();
+    }
+
     this._isStarted = false;
   },
 
@@ -345,6 +353,11 @@ TooltipsOverlay.prototype = {
       this.cubicBezier.hide();
     }
 
+    if (this.isRuleView && this.filterEditor.tooltip.isShown()) {
+      this.filterEditor.revert();
+      this.filterEdtior.hide();
+    }
+
     let inspector = this.view.inspector;
 
     if (type === TOOLTIP_IMAGE_TYPE) {
@@ -373,6 +386,10 @@ TooltipsOverlay.prototype = {
     if (this.cubicBezier) {
       this.cubicBezier.hide();
     }
+
+    if (this.filterEditor) {
+      this.filterEditor.hide();
+    }
   },
 
   /**

browser/locales/en-US/chrome/browser/devtools/filterwidget.dtd

@@ -0,0 +1,14 @@
+<!-- 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/. -->
+
+<!-- LOCALIZATION NOTE : FILE These strings are used in the CSS Filter Editor Widget
+   - which can be found in a tooltip that appears in the Rule View when clicking
+   - on a filter swatch displayed next to CSS declarations like 'filter: blur(2px)'. -->
+
+<!-- LOCALIZATION NOTE (filterListSelectPlaceholder): This string is used as
+   - a preview option in the list of possible filters <select> -->
+<!ENTITY filterListSelectPlaceholder "Select a Filter">
+
+<!-- LOCALIZATION NOTE (addNewFilterButton): This string is displayed on a button used to add new filters -->
+<!ENTITY addNewFilterButton "Add">

browser/locales/en-US/chrome/browser/devtools/filterwidget.properties

@@ -0,0 +1,33 @@
+# 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/.
+
+# LOCALIZATION NOTE These strings are used in the CSS Filter Editor Widget
+# which can be found in a tooltip that appears in the Rule View when clicking
+# on a filter swatch displayed next to CSS declarations like 'filter: blur(2px)'.
+
+# LOCALIZATION NOTE (emptyFilterList):
+# This string is displayed when filter's list is empty
+# (no filter specified / all removed)
+emptyFilterList=No filter specified
+
+# LOCALIZATION NOTE (addUsingList):
+# This string is displayed under [emptyFilterList] when filter's
+# list is empty, guiding user to add a filter using the list below it
+addUsingList=Add a filter using the list below
+
+# LOCALIZATION NOTE (dropShadowPlaceholder):
+# This string is used as a placeholder for drop-shadow's input
+# in the filter list (shown when <input> is empty)
+dropShadowPlaceholder=x y radius color
+
+# LOCALIZATION NOTE (dragHandleTooltipText):
+# This string is used as a tooltip text (shown on mouse hover) on the
+# drag handles of filters which are used to re-order filters
+dragHandleTooltipText=Drag up or down to re-order filter
+
+# LOCALIZATION NOTE (labelDragTooltipText):
+# This string is used as a tooltip text (shown on mouse hover) on the
+# filters' labels which can be dragged left/right to increase/decrease
+# the filter's value (like photoshop)
+labelDragTooltipText=Drag left or right to decrease or increase the value

browser/locales/jar.mn

@@ -34,6 +34,8 @@
     locale/browser/devtools/debugger.dtd              (%chrome/browser/devtools/debugger.dtd)
     locale/browser/devtools/debugger.properties       (%chrome/browser/devtools/debugger.properties)
     locale/browser/devtools/device.properties         (%chrome/browser/devtools/device.properties)
+    locale/browser/devtools/filterwidget.properties   (%chrome/browser/devtools/filterwidget.properties)
+    locale/browser/devtools/filterwidget.dtd          (%chrome/browser/devtools/filterwidget.dtd)
     locale/browser/devtools/netmonitor.dtd            (%chrome/browser/devtools/netmonitor.dtd)
     locale/browser/devtools/netmonitor.properties     (%chrome/browser/devtools/netmonitor.properties)
     locale/browser/devtools/shadereditor.dtd          (%chrome/browser/devtools/shadereditor.dtd)

browser/themes/linux/jar.mn

@@ -226,7 +226,9 @@ browser.jar:
 * skin/classic/browser/devtools/common.css            (../shared/devtools/common.css)
 * skin/classic/browser/devtools/dark-theme.css        (../shared/devtools/dark-theme.css)
 * skin/classic/browser/devtools/light-theme.css       (../shared/devtools/light-theme.css)
+  skin/classic/browser/devtools/add.svg               (../shared/devtools/images/add.svg)
   skin/classic/browser/devtools/filters.svg           (../shared/devtools/filters.svg)
+  skin/classic/browser/devtools/filter-swatch.svg     (../shared/devtools/images/filter-swatch.svg)
   skin/classic/browser/devtools/controls.png          (../shared/devtools/images/controls.png)
   skin/classic/browser/devtools/controls@2x.png       (../shared/devtools/images/controls@2x.png)
   skin/classic/browser/devtools/performance-icons.svg  (../shared/devtools/images/performance-icons.svg)

browser/themes/osx/jar.mn

@@ -356,7 +356,9 @@ browser.jar:
 * skin/classic/browser/devtools/common.css                  (../shared/devtools/common.css)
 * skin/classic/browser/devtools/dark-theme.css              (../shared/devtools/dark-theme.css)
 * skin/classic/browser/devtools/light-theme.css             (../shared/devtools/light-theme.css)
+  skin/classic/browser/devtools/add.svg                     (../shared/devtools/images/add.svg)
   skin/classic/browser/devtools/filters.svg                 (../shared/devtools/filters.svg)
+  skin/classic/browser/devtools/filter-swatch.svg           (../shared/devtools/images/filter-swatch.svg)
   skin/classic/browser/devtools/controls.png                (../shared/devtools/images/controls.png)
   skin/classic/browser/devtools/controls@2x.png             (../shared/devtools/images/controls@2x.png)
   skin/classic/browser/devtools/performance-icons.svg       (../shared/devtools/images/performance-icons.svg)

browser/themes/shared/devtools/dark-theme.css

@@ -204,9 +204,8 @@
   color: black;
 }
 
-.ruleview-colorswatch,
-.computedview-colorswatch,
-.ruleview-bezierswatch {
+.ruleview-swatch,
+.computedview-colorswatch {
   box-shadow: 0 0 0 1px #818181;
 }
 

browser/themes/shared/devtools/images/add.svg

@@ -0,0 +1,3 @@
+<svg width="18" height="18" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+  <polygon fill="#EEF0F2" points="4,7 8,7 8,3 10,3 10,7 14,7 14,9 10,9 10,13 8,13 8,9 4,9 4,7"></polygon>
+</svg>

browser/themes/shared/devtools/images/filter-swatch.svg

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- 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/. -->
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 12 12" width="12px" height="12px">
+  <defs>
+    <mask id="mask">
+      <rect width="100%" height="100%" fill="white"/>
+      <polygon points="12,0 0,0 0,12"/>
+    </mask>
+  </defs>
+
+  <g id="addpage-shape">
+    <circle cx="6" cy="6" r="6" fill="white"/>
+    <circle cx="6" cy="6" r="6" mask="url(#mask)" fill="#AEB0B1" />
+  </g>
+</svg>

browser/themes/shared/devtools/light-theme.css

@@ -202,9 +202,8 @@
   border-color: var(--theme-splitter-color);
 }
 
-.ruleview-colorswatch,
-.computedview-colorswatch,
-.ruleview-bezierswatch {
+.ruleview-swatch,
+.computedview-colorswatch {
   box-shadow: 0 0 0 1px #c4c4c4;
 }
 

browser/themes/shared/devtools/ruleview.css

@@ -67,8 +67,7 @@
   visibility: hidden;
 }
 
-.ruleview-rule[uneditable=true] .ruleview-colorswatch,
-.ruleview-rule[uneditable=true] .ruleview-bezierswatch {
+.ruleview-rule[uneditable=true] .ruleview-swatch {
   cursor: default;
 }
 
@@ -149,8 +148,7 @@
   -moz-margin-start: 35px;
 }
 
-.ruleview-colorswatch,
-.ruleview-bezierswatch {
+.ruleview-swatch {
   cursor: pointer;
   border-radius: 50%;
   width: 1em;
@@ -182,6 +180,11 @@
   background-size: 1em;
 }
 
+.ruleview-filterswatch {
+  background: url("chrome://browser/skin/devtools/filter-swatch.svg");
+  background-size: 1em;
+}
+
 @media (min-resolution: 2dppx) {
   .ruleview-bezierswatch {
     background: url("chrome://browser/skin/devtools/cubic-bezier-swatch@2x.png");

browser/themes/windows/jar.mn

@@ -307,7 +307,9 @@ browser.jar:
 *       skin/classic/browser/devtools/common.css                    (../shared/devtools/common.css)
 *       skin/classic/browser/devtools/dark-theme.css                (../shared/devtools/dark-theme.css)
 *       skin/classic/browser/devtools/light-theme.css               (../shared/devtools/light-theme.css)
+        skin/classic/browser/devtools/add.svg                       (../shared/devtools/images/add.svg)
         skin/classic/browser/devtools/filters.svg                   (../shared/devtools/filters.svg)
+        skin/classic/browser/devtools/filter-swatch.svg             (../shared/devtools/images/filter-swatch.svg)
         skin/classic/browser/devtools/controls.png                  (../shared/devtools/images/controls.png)
         skin/classic/browser/devtools/controls@2x.png               (../shared/devtools/images/controls@2x.png)
         skin/classic/browser/devtools/performance-icons.svg         (../shared/devtools/images/performance-icons.svg)

toolkit/devtools/output-parser.js

@@ -103,6 +103,8 @@ OutputParser.prototype = {
     options.expectCubicBezier = ["transition", "transition-timing-function",
       "animation", "animation-timing-function"].indexOf(name) !== -1;
 
+    options.expectFilter = name === "filter";
+
     if (this._cssPropertySupportsValue(name, value)) {
       return this._parse(value, options);
     }
@@ -184,6 +186,11 @@ OutputParser.prototype = {
         break;
       }
 
+      if (options.expectFilter) {
+        this._appendFilter(text, options);
+        break;
+      }
+
       matched = text.match(REGEX_QUOTES);
       if (matched) {
         let match = matched[0];
@@ -408,6 +415,26 @@ OutputParser.prototype = {
     return false;
   },
 
+  _appendFilter: function(filters, options={}) {
+    let container = this._createNode("span", {
+      "data-filters": filters
+    });
+
+    if (options.filterSwatchClass) {
+      let swatch = this._createNode("span", {
+        class: options.filterSwatchClass
+      });
+      container.appendChild(swatch);
+    }
+
+    let value = this._createNode("span", {
+      class: options.filterClass
+    }, filters);
+
+    container.appendChild(value);
+    this.parsed.push(container);
+  },
+
    /**
     * Append a URL to the output.
     *