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: const {Cc, Ci, Cu} = require("chrome");
michael@0: const {rgbToHsl} = require("devtools/css-color").colorUtils;
michael@0: const {EventEmitter} = Cu.import("resource://gre/modules/devtools/event-emitter.js");
michael@0: 
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: 
michael@0: loader.lazyGetter(this, "clipboardHelper", function() {
michael@0:   return Cc["@mozilla.org/widget/clipboardhelper;1"]
michael@0:     .getService(Ci.nsIClipboardHelper);
michael@0: });
michael@0: 
michael@0: loader.lazyGetter(this, "ssService", function() {
michael@0:   return Cc["@mozilla.org/content/style-sheet-service;1"]
michael@0:     .getService(Ci.nsIStyleSheetService);
michael@0: });
michael@0: 
michael@0: loader.lazyGetter(this, "ioService", function() {
michael@0:   return Cc["@mozilla.org/network/io-service;1"]
michael@0:     .getService(Ci.nsIIOService);
michael@0: });
michael@0: 
michael@0: loader.lazyGetter(this, "DOMUtils", function () {
michael@0:   return Cc["@mozilla.org/inspector/dom-utils;1"].getService(Ci.inIDOMUtils);
michael@0: });
michael@0: 
michael@0: loader.lazyGetter(this, "XULRuntime", function() {
michael@0:   return Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULRuntime);
michael@0: });
michael@0: 
michael@0: loader.lazyGetter(this, "l10n", () => Services.strings
michael@0:   .createBundle("chrome://browser/locale/devtools/eyedropper.properties"));
michael@0: 
michael@0: const EYEDROPPER_URL = "chrome://browser/content/devtools/eyedropper.xul";
michael@0: const CROSSHAIRS_URL = "chrome://browser/content/devtools/eyedropper/crosshairs.css";
michael@0: const NOCURSOR_URL = "chrome://browser/content/devtools/eyedropper/nocursor.css";
michael@0: 
michael@0: const ZOOM_PREF = "devtools.eyedropper.zoom";
michael@0: const FORMAT_PREF = "devtools.defaultColorUnit";
michael@0: 
michael@0: const CANVAS_WIDTH = 96;
michael@0: const CANVAS_OFFSET = 3; // equals the border width of the canvas.
michael@0: const CLOSE_DELAY = 750;
michael@0: 
michael@0: const HEX_BOX_WIDTH = CANVAS_WIDTH + CANVAS_OFFSET * 2;
michael@0: const HSL_BOX_WIDTH = 158;
michael@0: 
michael@0: /**
michael@0:  * Manage instances of eyedroppers for windows. Registering here isn't
michael@0:  * necessary for creating an eyedropper, but can be used for testing.
michael@0:  */
michael@0: let EyedropperManager = {
michael@0:   _instances: new WeakMap(),
michael@0: 
michael@0:   getInstance: function(chromeWindow) {
michael@0:     return this._instances.get(chromeWindow);
michael@0:   },
michael@0: 
michael@0:   createInstance: function(chromeWindow) {
michael@0:     let dropper = this.getInstance(chromeWindow);
michael@0:     if (dropper) {
michael@0:       return dropper;
michael@0:     }
michael@0: 
michael@0:     dropper = new Eyedropper(chromeWindow);
michael@0:     this._instances.set(chromeWindow, dropper);
michael@0: 
michael@0:     dropper.on("destroy", () => {
michael@0:       this.deleteInstance(chromeWindow);
michael@0:     });
michael@0: 
michael@0:     return dropper;
michael@0:   },
michael@0: 
michael@0:   deleteInstance: function(chromeWindow) {
michael@0:     this._instances.delete(chromeWindow);
michael@0:   }
michael@0: }
michael@0: 
michael@0: exports.EyedropperManager = EyedropperManager;
michael@0: 
michael@0: /**
michael@0:  * Eyedropper widget. Once opened, shows zoomed area above current pixel and
michael@0:  * displays the color value of the center pixel. Clicking on the window will
michael@0:  * close the widget and fire a 'select' event. If 'copyOnSelect' is true, the color
michael@0:  * will also be copied to the clipboard.
michael@0:  *
michael@0:  * let eyedropper = new Eyedropper(window);
michael@0:  * eyedropper.open();
michael@0:  *
michael@0:  * eyedropper.once("select", (ev, color) => {
michael@0:  *   console.log(color);  // "rgb(20, 50, 230)"
michael@0:  * })
michael@0:  *
michael@0:  * @param {DOMWindow} chromeWindow
michael@0:  *        window to inspect
michael@0:  * @param {object} opts
michael@0:  *        optional options object, with 'copyOnSelect'
michael@0:  */
michael@0: function Eyedropper(chromeWindow, opts = { copyOnSelect: true }) {
michael@0:   this.copyOnSelect = opts.copyOnSelect;
michael@0: 
michael@0:   this._onFirstMouseMove = this._onFirstMouseMove.bind(this);
michael@0:   this._onMouseMove = this._onMouseMove.bind(this);
michael@0:   this._onMouseDown = this._onMouseDown.bind(this);
michael@0:   this._onKeyDown = this._onKeyDown.bind(this);
michael@0:   this._onFrameLoaded = this._onFrameLoaded.bind(this);
michael@0: 
michael@0:   this._chromeWindow = chromeWindow;
michael@0:   this._chromeDocument = chromeWindow.document;
michael@0: 
michael@0:   this._dragging = true;
michael@0:   this.loaded = false;
michael@0: 
michael@0:   this._mouseMoveCounter = 0;
michael@0: 
michael@0:   this.format = Services.prefs.getCharPref(FORMAT_PREF); // color value format
michael@0:   this.zoom = Services.prefs.getIntPref(ZOOM_PREF);      // zoom level - integer
michael@0: 
michael@0:   this._zoomArea = {
michael@0:     x: 0,          // the left coordinate of the center of the inspected region
michael@0:     y: 0,          // the top coordinate of the center of the inspected region
michael@0:     width: CANVAS_WIDTH,      // width of canvas to draw zoomed area onto
michael@0:     height: CANVAS_WIDTH      // height of canvas
michael@0:   };
michael@0:   EventEmitter.decorate(this);
michael@0: }
michael@0: 
michael@0: exports.Eyedropper = Eyedropper;
michael@0: 
michael@0: Eyedropper.prototype = {
michael@0:   /**
michael@0:    * Get the number of cells (blown-up pixels) per direction in the grid.
michael@0:    */
michael@0:   get cellsWide() {
michael@0:     // Canvas will render whole "pixels" (cells) only, and an even
michael@0:     // number at that. Round up to the nearest even number of pixels.
michael@0:     let cellsWide = Math.ceil(this._zoomArea.width / this.zoom);
michael@0:     cellsWide += cellsWide % 2;
michael@0: 
michael@0:     return cellsWide;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Get the size of each cell (blown-up pixel) in the grid.
michael@0:    */
michael@0:   get cellSize() {
michael@0:     return this._zoomArea.width / this.cellsWide;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Get index of cell in the center of the grid.
michael@0:    */
michael@0:   get centerCell() {
michael@0:     return Math.floor(this.cellsWide / 2);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Get color of center cell in the grid.
michael@0:    */
michael@0:   get centerColor() {
michael@0:     let x = y = (this.centerCell * this.cellSize) + (this.cellSize / 2);
michael@0:     let rgb = this._ctx.getImageData(x, y, 1, 1).data;
michael@0:     return rgb;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Start the eyedropper. Add listeners for a mouse move in the window to
michael@0:    * show the eyedropper.
michael@0:    */
michael@0:   open: function() {
michael@0:     if (this.isOpen) {
michael@0:       // the eyedropper is aready open, don't create another panel.
michael@0:       return;
michael@0:     }
michael@0:     this.isOpen = true;
michael@0: 
michael@0:     this._OS = XULRuntime.OS;
michael@0: 
michael@0:     this._chromeDocument.addEventListener("mousemove", this._onFirstMouseMove);
michael@0: 
michael@0:     this._showCrosshairs();
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Called on the first mouse move over the window. Opens the eyedropper
michael@0:    * panel where the mouse is.
michael@0:    */
michael@0:   _onFirstMouseMove: function(event) {
michael@0:     this._chromeDocument.removeEventListener("mousemove", this._onFirstMouseMove);
michael@0: 
michael@0:     this._panel = this._buildPanel();
michael@0: 
michael@0:     let popupSet = this._chromeDocument.querySelector("#mainPopupSet");
michael@0:     popupSet.appendChild(this._panel);
michael@0: 
michael@0:     let { panelX, panelY } = this._getPanelCoordinates(event);
michael@0:     this._panel.openPopupAtScreen(panelX, panelY);
michael@0: 
michael@0:     this._setCoordinates(event);
michael@0: 
michael@0:     this._addListeners();
michael@0: 
michael@0:     // hide cursor as we'll be showing the panel over the mouse instead.
michael@0:     this._hideCrosshairs();
michael@0:     this._hideCursor();
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Set the current coordinates to inspect from where a mousemove originated.
michael@0:    *
michael@0:    * @param {MouseEvent} event
michael@0:    *        Event for the mouse move.
michael@0:    */
michael@0:   _setCoordinates: function(event) {
michael@0:     let win = this._chromeWindow;
michael@0: 
michael@0:     let x, y;
michael@0:     if (this._OS == "Linux") {
michael@0:       // event.clientX is off on Linux, so calculate it by hand
michael@0:       let windowX = win.screenX + (win.outerWidth - win.innerWidth);
michael@0:       x = event.screenX - windowX;
michael@0: 
michael@0:       let windowY = win.screenY + (win.outerHeight - win.innerHeight);
michael@0:       y = event.screenY - windowY;
michael@0:     }
michael@0:     else {
michael@0:       x = event.clientX;
michael@0:       y = event.clientY;
michael@0:     }
michael@0: 
michael@0:     // don't let it inspect outside the browser window
michael@0:     x = Math.max(0, Math.min(x, win.outerWidth - 1));
michael@0:     y = Math.max(0, Math.min(y, win.outerHeight - 1));
michael@0: 
michael@0:     this._zoomArea.x = x;
michael@0:     this._zoomArea.y = y;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Build and add a new eyedropper panel to the window.
michael@0:    *
michael@0:    * @return {Panel}
michael@0:    *         The XUL panel holding the eyedropper UI.
michael@0:    */
michael@0:   _buildPanel: function() {
michael@0:     let panel = this._chromeDocument.createElement("panel");
michael@0:     panel.setAttribute("noautofocus", true);
michael@0:     panel.setAttribute("noautohide", true);
michael@0:     panel.setAttribute("level", "floating");
michael@0:     panel.setAttribute("class", "devtools-eyedropper-panel");
michael@0: 
michael@0:     let iframe = this._iframe = this._chromeDocument.createElement("iframe");
michael@0:     iframe.addEventListener("load", this._onFrameLoaded, true);
michael@0:     iframe.setAttribute("flex", "1");
michael@0:     iframe.setAttribute("transparent", "transparent");
michael@0:     iframe.setAttribute("allowTransparency", true);
michael@0:     iframe.setAttribute("class", "devtools-eyedropper-iframe");
michael@0:     iframe.setAttribute("src", EYEDROPPER_URL);
michael@0:     iframe.setAttribute("width", CANVAS_WIDTH);
michael@0:     iframe.setAttribute("height", CANVAS_WIDTH);
michael@0: 
michael@0:     panel.appendChild(iframe);
michael@0: 
michael@0:     return panel;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Event handler for the panel's iframe's load event. Emits
michael@0:    * a "load" event from this eyedropper object.
michael@0:    */
michael@0:   _onFrameLoaded: function() {
michael@0:     this._iframe.removeEventListener("load", this._onFrameLoaded, true);
michael@0: 
michael@0:     this._iframeDocument = this._iframe.contentDocument;
michael@0:     this._colorPreview = this._iframeDocument.querySelector("#color-preview");
michael@0:     this._colorValue = this._iframeDocument.querySelector("#color-value");
michael@0: 
michael@0:     // value box will be too long for hex values and too short for hsl
michael@0:     let valueBox = this._iframeDocument.querySelector("#color-value-box");
michael@0:     if (this.format == "hex") {
michael@0:       valueBox.style.width = HEX_BOX_WIDTH + "px";
michael@0:     }
michael@0:     else if (this.format == "hsl") {
michael@0:       valueBox.style.width = HSL_BOX_WIDTH + "px";
michael@0:     }
michael@0: 
michael@0:     this._canvas = this._iframeDocument.querySelector("#canvas");
michael@0:     this._ctx = this._canvas.getContext("2d");
michael@0: 
michael@0:     // so we preserve the clear pixel boundaries
michael@0:     this._ctx.mozImageSmoothingEnabled = false;
michael@0: 
michael@0:     this._drawWindow();
michael@0: 
michael@0:     this._addPanelListeners();
michael@0:     this._iframe.focus();
michael@0: 
michael@0:     this.loaded = true;
michael@0:     this.emit("load");
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Add key listeners to the panel.
michael@0:    */
michael@0:   _addPanelListeners: function() {
michael@0:     this._iframeDocument.addEventListener("keydown", this._onKeyDown);
michael@0: 
michael@0:     let closeCmd = this._iframeDocument.getElementById("eyedropper-cmd-close");
michael@0:     closeCmd.addEventListener("command", this.destroy.bind(this), true);
michael@0: 
michael@0:     let copyCmd = this._iframeDocument.getElementById("eyedropper-cmd-copy");
michael@0:     copyCmd.addEventListener("command", this.selectColor.bind(this), true);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Remove listeners from the panel.
michael@0:    */
michael@0:   _removePanelListeners: function() {
michael@0:     this._iframeDocument.removeEventListener("keydown", this._onKeyDown);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Add mouse event listeners to the document we're inspecting.
michael@0:    */
michael@0:   _addListeners: function() {
michael@0:     this._chromeDocument.addEventListener("mousemove", this._onMouseMove);
michael@0:     this._chromeDocument.addEventListener("mousedown", this._onMouseDown);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Remove mouse event listeners from the document we're inspecting.
michael@0:    */
michael@0:   _removeListeners: function() {
michael@0:     this._chromeDocument.removeEventListener("mousemove", this._onFirstMouseMove);
michael@0:     this._chromeDocument.removeEventListener("mousemove", this._onMouseMove);
michael@0:     this._chromeDocument.removeEventListener("mousedown", this._onMouseDown);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Hide the cursor.
michael@0:    */
michael@0:   _hideCursor: function() {
michael@0:     registerStyleSheet(NOCURSOR_URL);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Reset the cursor back to default.
michael@0:    */
michael@0:   _resetCursor: function() {
michael@0:     unregisterStyleSheet(NOCURSOR_URL);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Show a crosshairs as the mouse cursor
michael@0:    */
michael@0:   _showCrosshairs: function() {
michael@0:     registerStyleSheet(CROSSHAIRS_URL);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Reset cursor.
michael@0:    */
michael@0:   _hideCrosshairs: function() {
michael@0:     unregisterStyleSheet(CROSSHAIRS_URL);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Event handler for a mouse move over the page we're inspecting.
michael@0:    * Preview the area under the cursor, and move panel to be under the cursor.
michael@0:    *
michael@0:    * @param  {DOMEvent} event
michael@0:    *         MouseEvent for the mouse moving
michael@0:    */
michael@0:   _onMouseMove: function(event) {
michael@0:     if (!this._dragging || !this._panel || !this._canvas) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     if (this._OS == "Linux" && ++this._mouseMoveCounter % 2 == 0) {
michael@0:       // skip every other mousemove to preserve performance.
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     this._setCoordinates(event);
michael@0:     this._drawWindow();
michael@0: 
michael@0:     let { panelX, panelY } = this._getPanelCoordinates(event);
michael@0:     this._movePanel(panelX, panelY);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Get coordinates of where the eyedropper panel should go based on
michael@0:    * the current coordinates of the mouse cursor.
michael@0:    *
michael@0:    * @param {MouseEvent} event
michael@0:    *        object with properties 'screenX' and 'screenY'
michael@0:    *
michael@0:    * @return {object}
michael@0:   *          object with properties 'panelX', 'panelY'
michael@0:    */
michael@0:   _getPanelCoordinates: function({screenX, screenY}) {
michael@0:     let win = this._chromeWindow;
michael@0:     let offset = CANVAS_WIDTH / 2 + CANVAS_OFFSET;
michael@0: 
michael@0:     let panelX = screenX - offset;
michael@0:     let windowX = win.screenX + (win.outerWidth - win.innerWidth);
michael@0:     let maxX = win.screenX + win.outerWidth - offset - 1;
michael@0: 
michael@0:     let panelY = screenY - offset;
michael@0:     let windowY = win.screenY + (win.outerHeight - win.innerHeight);
michael@0:     let maxY = win.screenY + win.outerHeight - offset - 1;
michael@0: 
michael@0:     // don't let the panel move outside the browser window
michael@0:     panelX = Math.max(windowX - offset, Math.min(panelX, maxX));
michael@0:     panelY = Math.max(windowY - offset, Math.min(panelY, maxY));
michael@0: 
michael@0:     return { panelX: panelX, panelY: panelY };
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Move the eyedropper panel to the given coordinates.
michael@0:    *
michael@0:    * @param  {number} screenX
michael@0:    *         left coordinate on the screen
michael@0:    * @param  {number} screenY
michael@0:    *         top coordinate
michael@0:    */
michael@0:   _movePanel: function(screenX, screenY) {
michael@0:     this._panelX = screenX;
michael@0:     this._panelY = screenY;
michael@0: 
michael@0:     this._panel.moveTo(screenX, screenY);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Handler for the mouse down event on the inspected page. This means a
michael@0:    * click, so we'll select the color that's currently hovered.
michael@0:    *
michael@0:    * @param  {Event} event
michael@0:    *         DOM MouseEvent object
michael@0:    */
michael@0:   _onMouseDown: function(event) {
michael@0:     event.preventDefault();
michael@0:     event.stopPropagation();
michael@0: 
michael@0:     this.selectColor();
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Select the current color that's being previewed. Fire a
michael@0:    * "select" event with the color as an rgb string.
michael@0:    */
michael@0:   selectColor: function() {
michael@0:     if (this._isSelecting) {
michael@0:       return;
michael@0:     }
michael@0:     this._isSelecting = true;
michael@0:     this._dragging = false;
michael@0: 
michael@0:     this.emit("select", this._colorValue.value);
michael@0: 
michael@0:     if (this.copyOnSelect) {
michael@0:       this.copyColor(this.destroy.bind(this));
michael@0:     }
michael@0:     else {
michael@0:       this.destroy();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Copy the currently inspected color to the clipboard.
michael@0:    *
michael@0:    * @param  {Function} callback
michael@0:    *         Callback to be called when the color is in the clipboard.
michael@0:    */
michael@0:   copyColor: function(callback) {
michael@0:     Services.appShell.hiddenDOMWindow.clearTimeout(this._copyTimeout);
michael@0: 
michael@0:     let color = this._colorValue.value;
michael@0:     clipboardHelper.copyString(color);
michael@0: 
michael@0:     this._colorValue.classList.add("highlight");
michael@0:     this._colorValue.value = "✓ " + l10n.GetStringFromName("colorValue.copied");
michael@0: 
michael@0:     this._copyTimeout = Services.appShell.hiddenDOMWindow.setTimeout(() => {
michael@0:       this._colorValue.classList.remove("highlight");
michael@0:       this._colorValue.value = color;
michael@0: 
michael@0:       if (callback) {
michael@0:         callback();
michael@0:       }
michael@0:     }, CLOSE_DELAY);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Handler for the keydown event on the panel. Either copy the color
michael@0:    * or move the panel in a direction depending on the key pressed.
michael@0:    *
michael@0:    * @param  {Event} event
michael@0:    *         DOM KeyboardEvent object
michael@0:    */
michael@0:   _onKeyDown: function(event) {
michael@0:     if (event.metaKey && event.keyCode === event.DOM_VK_C) {
michael@0:       this.copyColor();
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     let offsetX = 0;
michael@0:     let offsetY = 0;
michael@0:     let modifier = 1;
michael@0: 
michael@0:     if (event.keyCode === event.DOM_VK_LEFT) {
michael@0:       offsetX = -1;
michael@0:     }
michael@0:     if (event.keyCode === event.DOM_VK_RIGHT) {
michael@0:       offsetX = 1;
michael@0:     }
michael@0:     if (event.keyCode === event.DOM_VK_UP) {
michael@0:       offsetY = -1;
michael@0:     }
michael@0:     if (event.keyCode === event.DOM_VK_DOWN) {
michael@0:       offsetY = 1;
michael@0:     }
michael@0:     if (event.shiftKey) {
michael@0:       modifier = 10;
michael@0:     }
michael@0: 
michael@0:     offsetY *= modifier;
michael@0:     offsetX *= modifier;
michael@0: 
michael@0:     if (offsetX !== 0 || offsetY !== 0) {
michael@0:       this._zoomArea.x += offsetX;
michael@0:       this._zoomArea.y += offsetY;
michael@0: 
michael@0:       this._drawWindow();
michael@0: 
michael@0:       this._movePanel(this._panelX + offsetX, this._panelY + offsetY);
michael@0: 
michael@0:       event.preventDefault();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Draw the inspected area onto the canvas using the zoom level.
michael@0:    */
michael@0:   _drawWindow: function() {
michael@0:     let { width, height, x, y } = this._zoomArea;
michael@0: 
michael@0:     let zoomedWidth = width / this.zoom;
michael@0:     let zoomedHeight = height / this.zoom;
michael@0: 
michael@0:     let drawX = x - (zoomedWidth / 2);
michael@0:     let drawY = y - (zoomedHeight / 2);
michael@0: 
michael@0:     // draw the portion of the window we're inspecting
michael@0:     this._ctx.drawWindow(this._chromeWindow, drawX, drawY, zoomedWidth,
michael@0:                         zoomedHeight, "white");
michael@0: 
michael@0:     // now scale it
michael@0:     let sx = 0;
michael@0:     let sy = 0;
michael@0:     let sw = zoomedWidth;
michael@0:     let sh = zoomedHeight;
michael@0:     let dx = 0;
michael@0:     let dy = 0;
michael@0:     let dw = width;
michael@0:     let dh = height;
michael@0: 
michael@0:     this._ctx.drawImage(this._canvas, sx, sy, sw, sh, dx, dy, dw, dh);
michael@0: 
michael@0:     let rgb = this.centerColor;
michael@0:     this._colorPreview.style.backgroundColor = toColorString(rgb, "rgb");
michael@0:     this._colorValue.value = toColorString(rgb, this.format);
michael@0: 
michael@0:     if (this.zoom > 2) {
michael@0:       // grid at 2x is too busy
michael@0:       this._drawGrid();
michael@0:     }
michael@0:     this._drawCrosshair();
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Draw a grid on the canvas representing pixel boundaries.
michael@0:    */
michael@0:   _drawGrid: function() {
michael@0:     let { width, height } = this._zoomArea;
michael@0: 
michael@0:     this._ctx.lineWidth = 1;
michael@0:     this._ctx.strokeStyle = "rgba(143, 143, 143, 0.2)";
michael@0: 
michael@0:     for (let i = 0; i < width; i += this.cellSize) {
michael@0:       this._ctx.beginPath();
michael@0:       this._ctx.moveTo(i - .5, 0);
michael@0:       this._ctx.lineTo(i - .5, height);
michael@0:       this._ctx.stroke();
michael@0: 
michael@0:       this._ctx.beginPath();
michael@0:       this._ctx.moveTo(0, i - .5);
michael@0:       this._ctx.lineTo(width, i - .5);
michael@0:       this._ctx.stroke();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Draw a box on the canvas to highlight the center cell.
michael@0:    */
michael@0:   _drawCrosshair: function() {
michael@0:     let x = y = this.centerCell * this.cellSize;
michael@0: 
michael@0:     this._ctx.lineWidth = 1;
michael@0:     this._ctx.lineJoin = 'miter';
michael@0:     this._ctx.strokeStyle = "rgba(0, 0, 0, 1)";
michael@0:     this._ctx.strokeRect(x - 1.5, y - 1.5, this.cellSize + 2, this.cellSize + 2);
michael@0: 
michael@0:     this._ctx.strokeStyle = "rgba(255, 255, 255, 1)";
michael@0:     this._ctx.strokeRect(x - 0.5, y - 0.5, this.cellSize, this.cellSize);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Destroy the eyedropper and clean up. Emits a "destroy" event.
michael@0:    */
michael@0:   destroy: function() {
michael@0:     this._resetCursor();
michael@0:     this._hideCrosshairs();
michael@0: 
michael@0:     if (this._panel) {
michael@0:       this._panel.hidePopup();
michael@0:       this._panel.remove();
michael@0:       this._panel = null;
michael@0:     }
michael@0:     this._removePanelListeners();
michael@0:     this._removeListeners();
michael@0: 
michael@0:     this.isOpen = false;
michael@0:     this._isSelecting = false;
michael@0: 
michael@0:     this.emit("destroy");
michael@0:   }
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Add a user style sheet that applies to all documents.
michael@0:  */
michael@0: function registerStyleSheet(url) {
michael@0:   var uri = ioService.newURI(url, null, null);
michael@0:   if (!ssService.sheetRegistered(uri, ssService.AGENT_SHEET)) {
michael@0:     ssService.loadAndRegisterSheet(uri, ssService.AGENT_SHEET);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Remove a user style sheet.
michael@0:  */
michael@0: function unregisterStyleSheet(url) {
michael@0:   var uri = ioService.newURI(url, null, null);
michael@0:   if (ssService.sheetRegistered(uri, ssService.AGENT_SHEET)) {
michael@0:     ssService.unregisterSheet(uri, ssService.AGENT_SHEET);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Get a formatted CSS color string from a color value.
michael@0:  *
michael@0:  * @param {array} rgb
michael@0:  *        Rgb values of a color to format
michael@0:  * @param {string} format
michael@0:  *        Format of string. One of "hex", "rgb", "hsl", "name"
michael@0:  *
michael@0:  * @return {string}
michael@0:  *        Formatted color value, e.g. "#FFF" or "hsl(20, 10%, 10%)"
michael@0:  */
michael@0: function toColorString(rgb, format) {
michael@0:   let [r,g,b] = rgb;
michael@0: 
michael@0:   switch(format) {
michael@0:     case "hex":
michael@0:       return hexString(rgb);
michael@0:     case "rgb":
michael@0:       return "rgb(" + r + ", " + g + ", " + b + ")";
michael@0:     case "hsl":
michael@0:       let [h,s,l] = rgbToHsl(rgb);
michael@0:       return "hsl(" + h + ", " + s + "%, " + l + "%)";
michael@0:     case "name":
michael@0:       let str;
michael@0:       try {
michael@0:         str = DOMUtils.rgbToColorName(r, g, b);
michael@0:       } catch(e) {
michael@0:         str = hexString(rgb);
michael@0:       }
michael@0:       return str;
michael@0:     default:
michael@0:       return hexString(rgb);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Produce a hex-formatted color string from rgb values.
michael@0:  *
michael@0:  * @param {array} rgb
michael@0:  *        Rgb values of color to stringify
michael@0:  *
michael@0:  * @return {string}
michael@0:  *        Hex formatted string for color, e.g. "#FFEE00"
michael@0:  */
michael@0: function hexString([r,g,b]) {
michael@0:   let val = (1 << 24) + (r << 16) + (g << 8) + (b << 0);
michael@0:   return "#" + val.toString(16).substr(-6).toUpperCase();
michael@0: }