/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
/* 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/. */

const {Cc, Ci, Cu, Cr} = require("chrome");

Cu.import("resource://gre/modules/Services.jsm");

var promise = require("promise");
var EventEmitter = require("devtools/shared/event-emitter");
var clipboard = require("sdk/clipboard");
var {HostType} = require("devtools/client/framework/toolbox").Toolbox;

loader.lazyGetter(this, "MarkupView", () => require("devtools/client/markupview/markup-view").MarkupView);
loader.lazyGetter(this, "HTMLBreadcrumbs", () => require("devtools/client/inspector/breadcrumbs").HTMLBreadcrumbs);
loader.lazyGetter(this, "ToolSidebar", () => require("devtools/client/framework/sidebar").ToolSidebar);
loader.lazyGetter(this, "SelectorSearch", () => require("devtools/client/inspector/selector-search").SelectorSearch);

loader.lazyGetter(this, "strings", () => {
  return Services.strings.createBundle("chrome://browser/locale/devtools/inspector.properties");
});
loader.lazyGetter(this, "toolboxStrings", () => {
  return Services.strings.createBundle("chrome://browser/locale/devtools/toolbox.properties");
});
loader.lazyGetter(this, "clipboardHelper", () => {
  return Cc["@mozilla.org/widget/clipboardhelper;1"].getService(Ci.nsIClipboardHelper);
});

loader.lazyImporter(this, "CommandUtils", "resource:///modules/devtools/client/shared/DeveloperToolbar.jsm");

const LAYOUT_CHANGE_TIMER = 250;

/**
 * Represents an open instance of the Inspector for a tab.
 * The inspector controls the breadcrumbs, the markup view, and the sidebar
 * (computed view, rule view, font view and layout view).
 *
 * Events:
 * - ready
 *      Fired when the inspector panel is opened for the first time and ready to
 *      use
 * - new-root
 *      Fired after a new root (navigation to a new page) event was fired by
 *      the walker, and taken into account by the inspector (after the markup
 *      view has been reloaded)
 * - markuploaded
 *      Fired when the markup-view frame has loaded
 * - layout-change
 *      Fired when the layout of the inspector changes
 * - breadcrumbs-updated
 *      Fired when the breadcrumb widget updates to a new node
 * - layoutview-updated
 *      Fired when the layoutview (box model) updates to a new node
 * - markupmutation
 *      Fired after markup mutations have been processed by the markup-view
 * - computed-view-refreshed
 *      Fired when the computed rules view updates to a new node
 * - computed-view-property-expanded
 *      Fired when a property is expanded in the computed rules view
 * - computed-view-property-collapsed
 *      Fired when a property is collapsed in the computed rules view
 * - computed-view-sourcelinks-updated
 *      Fired when the stylesheet source links have been updated (when switching
 *      to source-mapped files)
 * - rule-view-refreshed
 *      Fired when the rule view updates to a new node
 * - rule-view-sourcelinks-updated
 *      Fired when the stylesheet source links have been updated (when switching
 *      to source-mapped files)
 */
function InspectorPanel(iframeWindow, toolbox) {
  this._toolbox = toolbox;
  this._target = toolbox._target;
  this.panelDoc = iframeWindow.document;
  this.panelWin = iframeWindow;
  this.panelWin.inspector = this;

  this._onBeforeNavigate = this._onBeforeNavigate.bind(this);
  this._target.on("will-navigate", this._onBeforeNavigate);

  EventEmitter.decorate(this);
}

exports.InspectorPanel = InspectorPanel;

InspectorPanel.prototype = {
  /**
   * open is effectively an asynchronous constructor
   */
  open: function() {
    return this.target.makeRemote().then(() => {
      return this._getPageStyle();
    }).then(() => {
      return this._getDefaultNodeForSelection();
    }).then(defaultSelection => {
      return this._deferredOpen(defaultSelection);
    }).then(null, console.error);
  },

  get toolbox() {
    return this._toolbox;
  },

  get inspector() {
    return this._toolbox.inspector;
  },

  get walker() {
    return this._toolbox.walker;
  },

  get selection() {
    return this._toolbox.selection;
  },

  get isOuterHTMLEditable() {
    return this._target.client.traits.editOuterHTML;
  },

  get hasUrlToImageDataResolver() {
    return this._target.client.traits.urlToImageDataResolver;
  },

  get canGetUniqueSelector() {
    return this._target.client.traits.getUniqueSelector;
  },

  get canGetUsedFontFaces() {
    return this._target.client.traits.getUsedFontFaces;
  },

  get canPasteInnerOrAdjacentHTML() {
    return this._target.client.traits.pasteHTML;
  },

  _deferredOpen: function(defaultSelection) {
    let deferred = promise.defer();

    this.onNewRoot = this.onNewRoot.bind(this);
    this.walker.on("new-root", this.onNewRoot);

    this.nodemenu = this.panelDoc.getElementById("inspector-node-popup");
    this.lastNodemenuItem = this.nodemenu.lastChild;
    this._setupNodeMenu = this._setupNodeMenu.bind(this);
    this._resetNodeMenu = this._resetNodeMenu.bind(this);
    this.nodemenu.addEventListener("popupshowing", this._setupNodeMenu, true);
    this.nodemenu.addEventListener("popuphiding", this._resetNodeMenu, true);

    this.onNewSelection = this.onNewSelection.bind(this);
    this.selection.on("new-node-front", this.onNewSelection);
    this.onBeforeNewSelection = this.onBeforeNewSelection.bind(this);
    this.selection.on("before-new-node-front", this.onBeforeNewSelection);
    this.onDetached = this.onDetached.bind(this);
    this.selection.on("detached-front", this.onDetached);

    this.breadcrumbs = new HTMLBreadcrumbs(this);

    this.onToolboxHostChanged = this.onToolboxHostChanged.bind(this);
    this._toolbox.on("host-changed", this.onToolboxHostChanged);

    if (this.target.isLocalTab) {
      this.browser = this.target.tab.linkedBrowser;
      this.scheduleLayoutChange = this.scheduleLayoutChange.bind(this);
      this.browser.addEventListener("resize", this.scheduleLayoutChange, true);

      // Show a warning when the debugger is paused.
      // We show the warning only when the inspector
      // is selected.
      this.updateDebuggerPausedWarning = () => {
        let notificationBox = this._toolbox.getNotificationBox();
        let notification = notificationBox.getNotificationWithValue("inspector-script-paused");
        if (!notification && this._toolbox.currentToolId == "inspector" &&
            this.target.isThreadPaused) {
          let message = strings.GetStringFromName("debuggerPausedWarning.message");
          notificationBox.appendNotification(message,
            "inspector-script-paused", "", notificationBox.PRIORITY_WARNING_HIGH);
        }

        if (notification && this._toolbox.currentToolId != "inspector") {
          notificationBox.removeNotification(notification);
        }

        if (notification && !this.target.isThreadPaused) {
          notificationBox.removeNotification(notification);
        }

      };
      this.target.on("thread-paused", this.updateDebuggerPausedWarning);
      this.target.on("thread-resumed", this.updateDebuggerPausedWarning);
      this._toolbox.on("select", this.updateDebuggerPausedWarning);
      this.updateDebuggerPausedWarning();
    }

    this._initMarkup();
    this.isReady = false;

    this.once("markuploaded", () => {
      this.isReady = true;

      // All the components are initialized. Let's select a node.
      this.selection.setNodeFront(defaultSelection, "inspector-open");

      this.markup.expandNode(this.selection.nodeFront);

      this.emit("ready");
      deferred.resolve(this);
    });

    this.setupSearchBox();
    this.setupSidebar();

    return deferred.promise;
  },

  _onBeforeNavigate: function() {
    this._defaultNode = null;
    this.selection.setNodeFront(null);
    this._destroyMarkup();
    this.isDirty = false;
    this._pendingSelection = null;
  },

  _getPageStyle: function() {
    return this._toolbox.inspector.getPageStyle().then(pageStyle => {
      this.pageStyle = pageStyle;
    });
  },

  /**
   * Return a promise that will resolve to the default node for selection.
   */
  _getDefaultNodeForSelection: function() {
    if (this._defaultNode) {
      return this._defaultNode;
    }
    let walker = this.walker;
    let rootNode = null;
    let pendingSelection = this._pendingSelection;

    // A helper to tell if the target has or is about to navigate.
    // this._pendingSelection changes on "will-navigate" and "new-root" events.
    let hasNavigated = () => pendingSelection !== this._pendingSelection;

    // If available, set either the previously selected node or the body
    // as default selected, else set documentElement
    return walker.getRootNode().then(aRootNode => {
      if (hasNavigated()) {
        return promise.reject("navigated; resolution of _defaultNode aborted");
      }

      rootNode = aRootNode;
      if (this.selectionCssSelector) {
        return walker.querySelector(rootNode, this.selectionCssSelector);
      }
    }).then(front => {
      if (hasNavigated()) {
        return promise.reject("navigated; resolution of _defaultNode aborted");
      }

      if (front) {
        return front;
      }
      return walker.querySelector(rootNode, "body");
    }).then(front => {
      if (hasNavigated()) {
        return promise.reject("navigated; resolution of _defaultNode aborted");
      }

      if (front) {
        return front;
      }
      return this.walker.documentElement();
    }).then(node => {
      if (hasNavigated()) {
        return promise.reject("navigated; resolution of _defaultNode aborted");
      }
      this._defaultNode = node;
      return node;
    });
  },

  /**
   * Target getter.
   */
  get target() {
    return this._target;
  },

  /**
   * Target setter.
   */
  set target(value) {
    this._target = value;
  },

  /**
   * Indicate that a tool has modified the state of the page.  Used to
   * decide whether to show the "are you sure you want to navigate"
   * notification.
   */
  markDirty: function() {
    this.isDirty = true;
  },

  /**
   * Hooks the searchbar to show result and auto completion suggestions.
   */
  setupSearchBox: function() {
    // Initiate the selectors search object.
    if (this.searchSuggestions) {
      this.searchSuggestions.destroy();
      this.searchSuggestions = null;
    }
    this.searchBox = this.panelDoc.getElementById("inspector-searchbox");
    this.searchSuggestions = new SelectorSearch(this, this.searchBox);
  },

  /**
   * Build the sidebar.
   */
  setupSidebar: function() {
    let tabbox = this.panelDoc.querySelector("#inspector-sidebar");
    this.sidebar = new ToolSidebar(tabbox, this, "inspector", {
      showAllTabsMenu: true
    });

    let defaultTab = Services.prefs.getCharPref("devtools.inspector.activeSidebar");

    this._setDefaultSidebar = (event, toolId) => {
      Services.prefs.setCharPref("devtools.inspector.activeSidebar", toolId);
    };

    this.sidebar.on("select", this._setDefaultSidebar);

    this.sidebar.addTab("ruleview",
                        "chrome://devtools/content/styleinspector/cssruleview.xhtml",
                        "ruleview" == defaultTab);

    this.sidebar.addTab("computedview",
                        "chrome://devtools/content/styleinspector/computedview.xhtml",
                        "computedview" == defaultTab);

    if (Services.prefs.getBoolPref("devtools.fontinspector.enabled") && this.canGetUsedFontFaces) {
      this.sidebar.addTab("fontinspector",
                          "chrome://devtools/content/fontinspector/font-inspector.xhtml",
                          "fontinspector" == defaultTab);
    }

    this.sidebar.addTab("layoutview",
                        "chrome://devtools/content/layoutview/view.xhtml",
                        "layoutview" == defaultTab);

    if (this.target.form.animationsActor) {
      this.sidebar.addTab("animationinspector",
                          "chrome://devtools/content/animationinspector/animation-inspector.xhtml",
                          "animationinspector" == defaultTab);
    }

    this.sidebar.show();

    this.setupSidebarToggle();
  },

  /**
   * Add the expand/collapse behavior for the sidebar panel.
   */
  setupSidebarToggle: function() {
    this._paneToggleButton = this.panelDoc.getElementById("inspector-pane-toggle");
    this.onPaneToggleButtonClicked = this.onPaneToggleButtonClicked.bind(this);
    this._paneToggleButton.addEventListener("mousedown",
      this.onPaneToggleButtonClicked);
    this.updatePaneToggleButton();
  },

  /**
   * Reset the inspector on new root mutation.
   */
  onNewRoot: function() {
    this._defaultNode = null;
    this.selection.setNodeFront(null);
    this._destroyMarkup();
    this.isDirty = false;

    let onNodeSelected = defaultNode => {
      // Cancel this promise resolution as a new one had
      // been queued up.
      if (this._pendingSelection != onNodeSelected) {
        return;
      }
      this._pendingSelection = null;
      this.selection.setNodeFront(defaultNode, "navigateaway");

      this._initMarkup();
      this.once("markuploaded", () => {
        if (!this.markup) {
          return;
        }
        this.markup.expandNode(this.selection.nodeFront);
        this.setupSearchBox();
        this.emit("new-root");
      });
    };
    this._pendingSelection = onNodeSelected;
    this._getDefaultNodeForSelection().then(onNodeSelected, console.error);
  },

  _selectionCssSelector: null,

  /**
   * Set the currently selected node unique css selector.
   * Will store the current target url along with it to allow pre-selection at
   * reload
   */
  set selectionCssSelector(cssSelector = null) {
    if (this._panelDestroyer) {
      return;
    }

    this._selectionCssSelector = {
      selector: cssSelector,
      url: this._target.url
    };
  },

  /**
   * Get the current selection unique css selector if any, that is, if a node
   * is actually selected and that node has been selected while on the same url
   */
  get selectionCssSelector() {
    if (this._selectionCssSelector &&
        this._selectionCssSelector.url === this._target.url) {
      return this._selectionCssSelector.selector;
    } else {
      return null;
    }
  },

  /**
   * When a new node is selected.
   */
  onNewSelection: function(event, value, reason) {
    if (reason === "selection-destroy") {
      return;
    }

    this.cancelLayoutChange();

    // Wait for all the known tools to finish updating and then let the
    // client know.
    let selection = this.selection.nodeFront;

    // On any new selection made by the user, store the unique css selector
    // of the selected node so it can be restored after reload of the same page
    if (this.canGetUniqueSelector &&
        this.selection.isElementNode()) {
      selection.getUniqueSelector().then(selector => {
        this.selectionCssSelector = selector;
      }).then(null, e => {
        // Only log this as an error if the panel hasn't been destroyed in the
        // meantime.
        if (!this._panelDestroyer) {
          console.error(e);
        } else {
          console.warn("Could not set the unique selector for the newly "+
            "selected node, the inspector was destroyed.");
        }
      });
    }

    let selfUpdate = this.updating("inspector-panel");
    Services.tm.mainThread.dispatch(() => {
      try {
        selfUpdate(selection);
      } catch(ex) {
        console.error(ex);
      }
    }, Ci.nsIThread.DISPATCH_NORMAL);
  },

  /**
   * Delay the "inspector-updated" notification while a tool
   * is updating itself.  Returns a function that must be
   * invoked when the tool is done updating with the node
   * that the tool is viewing.
   */
  updating: function(name) {
    if (this._updateProgress && this._updateProgress.node != this.selection.nodeFront) {
      this.cancelUpdate();
    }

    if (!this._updateProgress) {
      // Start an update in progress.
      var self = this;
      this._updateProgress = {
        node: this.selection.nodeFront,
        outstanding: new Set(),
        checkDone: function() {
          if (this !== self._updateProgress) {
            return;
          }
          if (this.node !== self.selection.nodeFront) {
            self.cancelUpdate();
            return;
          }
          if (this.outstanding.size !== 0) {
            return;
          }

          self._updateProgress = null;
          self.emit("inspector-updated", name);
        },
      };
    }

    let progress = this._updateProgress;
    let done = function() {
      progress.outstanding.delete(done);
      progress.checkDone();
    };
    progress.outstanding.add(done);
    return done;
  },

  /**
   * Cancel notification of inspector updates.
   */
  cancelUpdate: function() {
    this._updateProgress = null;
  },

  /**
   * When a new node is selected, before the selection has changed.
   */
  onBeforeNewSelection: function(event, node) {
    if (this.breadcrumbs.indexOf(node) == -1) {
      // only clear locks if we'd have to update breadcrumbs
      this.clearPseudoClasses();
    }
  },

  /**
   * When a node is deleted, select its parent node or the defaultNode if no
   * parent is found (may happen when deleting an iframe inside which the
   * node was selected).
   */
  onDetached: function(event, parentNode) {
    this.cancelLayoutChange();
    this.breadcrumbs.cutAfter(this.breadcrumbs.indexOf(parentNode));
    this.selection.setNodeFront(parentNode ? parentNode : this._defaultNode, "detached");
  },

  /**
   * Destroy the inspector.
   */
  destroy: function() {
    if (this._panelDestroyer) {
      return this._panelDestroyer;
    }

    if (this.walker) {
      this.walker.off("new-root", this.onNewRoot);
      this.pageStyle = null;
    }

    this.cancelUpdate();
    this.cancelLayoutChange();

    if (this.browser) {
      this.browser.removeEventListener("resize", this.scheduleLayoutChange, true);
      this.browser = null;
    }

    this.target.off("will-navigate", this._onBeforeNavigate);

    this.target.off("thread-paused", this.updateDebuggerPausedWarning);
    this.target.off("thread-resumed", this.updateDebuggerPausedWarning);
    this._toolbox.off("select", this.updateDebuggerPausedWarning);
    this._toolbox.off("host-changed", this.onToolboxHostChanged);

    this.sidebar.off("select", this._setDefaultSidebar);
    let sidebarDestroyer = this.sidebar.destroy();
    this.sidebar = null;

    this.nodemenu.removeEventListener("popupshowing", this._setupNodeMenu, true);
    this.nodemenu.removeEventListener("popuphiding", this._resetNodeMenu, true);
    this.breadcrumbs.destroy();
    this._paneToggleButton.removeEventListener("mousedown",
      this.onPaneToggleButtonClicked);
    this._paneToggleButton = null;
    this.searchSuggestions.destroy();
    this.searchBox = null;
    this.selection.off("new-node-front", this.onNewSelection);
    this.selection.off("before-new-node", this.onBeforeNewSelection);
    this.selection.off("before-new-node-front", this.onBeforeNewSelection);
    this.selection.off("detached-front", this.onDetached);
    let markupDestroyer = this._destroyMarkup();
    this.panelWin.inspector = null;
    this.target = null;
    this.panelDoc = null;
    this.panelWin = null;
    this.breadcrumbs = null;
    this.searchSuggestions = null;
    this.lastNodemenuItem = null;
    this.nodemenu = null;
    this._toolbox = null;

    this._panelDestroyer = promise.all([
      sidebarDestroyer,
      markupDestroyer
    ]);

    return this._panelDestroyer;
  },

  /**
   * Show the node menu.
   */
  showNodeMenu: function(aButton, aPosition, aExtraItems) {
    if (aExtraItems) {
      for (let item of aExtraItems) {
        this.nodemenu.appendChild(item);
      }
    }
    this.nodemenu.openPopup(aButton, aPosition, 0, 0, true, false);
  },

  hideNodeMenu: function() {
    this.nodemenu.hidePopup();
  },

  /**
   * Returns the clipboard content if it is appropriate for pasting
   * into the current node's outer HTML, otherwise returns null.
   */
  _getClipboardContentForPaste: function() {
    let flavors = clipboard.currentFlavors;
    if (flavors.indexOf("text") != -1 ||
        (flavors.indexOf("html") != -1 && flavors.indexOf("image") == -1)) {
      let content = clipboard.get();
      if (content && content.trim().length > 0) {
        return content;
      }
    }
    return null;
  },

  /**
   * Disable the delete item if needed. Update the pseudo classes.
   */
  _setupNodeMenu: function() {
    let isSelectionElement = this.selection.isElementNode() &&
                             !this.selection.isPseudoElementNode();
    let isEditableElement = isSelectionElement &&
                            !this.selection.isAnonymousNode();
    let isScreenshotable = isSelectionElement &&
                           this.canGetUniqueSelector &&
                           this.selection.nodeFront.isTreeDisplayed;

    // Set the pseudo classes
    for (let name of ["hover", "active", "focus"]) {
      let menu = this.panelDoc.getElementById("node-menu-pseudo-" + name);

      if (isSelectionElement) {
        let checked = this.selection.nodeFront.hasPseudoClassLock(":" + name);
        menu.setAttribute("checked", checked);
        menu.removeAttribute("disabled");
      } else {
        menu.setAttribute("disabled", "true");
      }
    }

    // Disable delete item if needed
    let deleteNode = this.panelDoc.getElementById("node-menu-delete");
    if (isEditableElement) {
      deleteNode.removeAttribute("disabled");
    } else {
      deleteNode.setAttribute("disabled", "true");
    }

    // Disable / enable "Copy Unique Selector", "Copy inner HTML",
    // "Copy outer HTML", "Scroll Into View" & "Screenshot Node" as appropriate
    let unique = this.panelDoc.getElementById("node-menu-copyuniqueselector");
    let screenshot = this.panelDoc.getElementById("node-menu-screenshotnode");
    let copyInnerHTML = this.panelDoc.getElementById("node-menu-copyinner");
    let copyOuterHTML = this.panelDoc.getElementById("node-menu-copyouter");
    let scrollIntoView = this.panelDoc.getElementById("node-menu-scrollnodeintoview");
    let expandAll = this.panelDoc.getElementById("node-menu-expand");
    let collapse = this.panelDoc.getElementById("node-menu-collapse");

    expandAll.setAttribute("disabled", "true");
    collapse.setAttribute("disabled", "true");

    let markUpContainer = this.markup.importNode(this.selection.nodeFront, false);
    if (this.selection.isNode() && markUpContainer.hasChildren) {
      if (markUpContainer.expanded) {
        collapse.removeAttribute("disabled");
      }
      expandAll.removeAttribute("disabled");
    }

    this._target.actorHasMethod("domnode", "scrollIntoView").then(value => {
      scrollIntoView.hidden = !value;
    });

    if (isSelectionElement) {
      unique.removeAttribute("disabled");
      copyInnerHTML.removeAttribute("disabled");
      copyOuterHTML.removeAttribute("disabled");
      scrollIntoView.removeAttribute("disabled");
    } else {
      unique.setAttribute("disabled", "true");
      copyInnerHTML.setAttribute("disabled", "true");
      copyOuterHTML.setAttribute("disabled", "true");
      scrollIntoView.setAttribute("disabled", "true");
    }
    if (!this.canGetUniqueSelector) {
      unique.hidden = true;
    }

    if (isScreenshotable) {
      screenshot.removeAttribute("disabled");
    } else {
      screenshot.setAttribute("disabled", "true");
    }

    // Enable/Disable the link open/copy items.
    this._setupNodeLinkMenu();

    // Enable the "edit HTML" item if the selection is an element and the root
    // actor has the appropriate trait (isOuterHTMLEditable)
    let editHTML = this.panelDoc.getElementById("node-menu-edithtml");
    if (isEditableElement && this.isOuterHTMLEditable) {
      editHTML.removeAttribute("disabled");
    } else {
      editHTML.setAttribute("disabled", "true");
    }

    let pasteOuterHTML = this.panelDoc.getElementById("node-menu-pasteouterhtml");
    let pasteInnerHTML = this.panelDoc.getElementById("node-menu-pasteinnerhtml");
    let pasteBefore = this.panelDoc.getElementById("node-menu-pastebefore");
    let pasteAfter = this.panelDoc.getElementById("node-menu-pasteafter");
    let pasteFirstChild = this.panelDoc.getElementById("node-menu-pastefirstchild");
    let pasteLastChild = this.panelDoc.getElementById("node-menu-pastelastchild");

    // Is the clipboard content appropriate? Is the element editable?
    if (isEditableElement && this._getClipboardContentForPaste()) {
      pasteInnerHTML.disabled = !this.canPasteInnerOrAdjacentHTML;
      // Enable the "paste outer HTML" item if the selection is an element and
      // the root actor has the appropriate trait (isOuterHTMLEditable).
      pasteOuterHTML.disabled = !this.isOuterHTMLEditable;
      // Don't paste before / after a root or a BODY or a HEAD element.
      pasteBefore.disabled = pasteAfter.disabled =
        !this.canPasteInnerOrAdjacentHTML || this.selection.isRoot() ||
        this.selection.isBodyNode() || this.selection.isHeadNode();
      // Don't paste as a first / last child of a HTML document element.
      pasteFirstChild.disabled = pasteLastChild.disabled =
        !this.canPasteInnerOrAdjacentHTML || (this.selection.isHTMLNode() &&
        this.selection.isRoot());
    } else {
      pasteOuterHTML.disabled = true;
      pasteInnerHTML.disabled = true;
      pasteBefore.disabled = true;
      pasteAfter.disabled = true;
      pasteFirstChild.disabled = true;
      pasteLastChild.disabled = true;
    }

    // Enable the "copy image data-uri" item if the selection is previewable
    // which essentially checks if it's an image or canvas tag
    let copyImageData = this.panelDoc.getElementById("node-menu-copyimagedatauri");
    let markupContainer = this.markup.getContainer(this.selection.nodeFront);
    if (isSelectionElement && markupContainer && markupContainer.isPreviewable()) {
      copyImageData.removeAttribute("disabled");
    } else {
      copyImageData.setAttribute("disabled", "true");
    }
  },

  _resetNodeMenu: function() {
    // Remove any extra items
    while (this.lastNodemenuItem.nextSibling) {
      let toDelete = this.lastNodemenuItem.nextSibling;
      toDelete.parentNode.removeChild(toDelete);
    }
  },

  /**
   * Link menu items can be shown or hidden depending on the context and
   * selected node, and their labels can vary.
   */
  _setupNodeLinkMenu: function() {
    let linkSeparator = this.panelDoc.getElementById("node-menu-link-separator");
    let linkFollow = this.panelDoc.getElementById("node-menu-link-follow");
    let linkCopy = this.panelDoc.getElementById("node-menu-link-copy");

    // Hide all by default.
    linkSeparator.setAttribute("hidden", "true");
    linkFollow.setAttribute("hidden", "true");
    linkCopy.setAttribute("hidden", "true");

    // Get information about the right-clicked node.
    let popupNode = this.panelDoc.popupNode;
    if (!popupNode || !popupNode.classList.contains("link")) {
      return;
    }

    let type = popupNode.dataset.type;
    if (type === "uri" || type === "cssresource" || type === "jsresource") {
      // First make sure the target can resolve relative URLs.
      this.target.actorHasMethod("inspector", "resolveRelativeURL").then(canResolve => {
        if (!canResolve) {
          return;
        }

        linkSeparator.removeAttribute("hidden");

        // Links can't be opened in new tabs in the browser toolbox.
        if (type === "uri" && !this.target.chrome) {
          linkFollow.removeAttribute("hidden");
          linkFollow.setAttribute("label", strings.GetStringFromName(
            "inspector.menu.openUrlInNewTab.label"));
        } else if (type === "cssresource") {
          linkFollow.removeAttribute("hidden");
          linkFollow.setAttribute("label", toolboxStrings.GetStringFromName(
            "toolbox.viewCssSourceInStyleEditor.label"));
        } else if (type === "jsresource") {
          linkFollow.removeAttribute("hidden");
          linkFollow.setAttribute("label", toolboxStrings.GetStringFromName(
            "toolbox.viewJsSourceInDebugger.label"));
        }

        linkCopy.removeAttribute("hidden");
        linkCopy.setAttribute("label", strings.GetStringFromName(
          "inspector.menu.copyUrlToClipboard.label"));
      }, console.error);
    } else if (type === "idref") {
      linkSeparator.removeAttribute("hidden");
      linkFollow.removeAttribute("hidden");
      linkFollow.setAttribute("label", strings.formatStringFromName(
        "inspector.menu.selectElement.label", [popupNode.dataset.link], 1));
    }
  },

  _initMarkup: function() {
    let doc = this.panelDoc;

    this._markupBox = doc.getElementById("markup-box");

    // create tool iframe
    this._markupFrame = doc.createElement("iframe");
    this._markupFrame.setAttribute("flex", "1");
    this._markupFrame.setAttribute("tooltip", "aHTMLTooltip");
    this._markupFrame.setAttribute("context", "inspector-node-popup");

    // This is needed to enable tooltips inside the iframe document.
    this._boundMarkupFrameLoad = this._onMarkupFrameLoad.bind(this);
    this._markupFrame.addEventListener("load", this._boundMarkupFrameLoad, true);

    this._markupBox.setAttribute("collapsed", true);
    this._markupBox.appendChild(this._markupFrame);
    this._markupFrame.setAttribute("src", "chrome://devtools/content/markupview/markup-view.xhtml");
    this._markupFrame.setAttribute("aria-label", strings.GetStringFromName("inspector.panelLabel.markupView"));
  },

  _onMarkupFrameLoad: function() {
    this._markupFrame.removeEventListener("load", this._boundMarkupFrameLoad, true);
    delete this._boundMarkupFrameLoad;

    this._markupFrame.contentWindow.focus();

    this._markupBox.removeAttribute("collapsed");

    let controllerWindow = this._toolbox.doc.defaultView;
    this.markup = new MarkupView(this, this._markupFrame, controllerWindow);

    this.emit("markuploaded");
  },

  _destroyMarkup: function() {
    let destroyPromise;

    if (this._boundMarkupFrameLoad) {
      this._markupFrame.removeEventListener("load", this._boundMarkupFrameLoad, true);
      this._boundMarkupFrameLoad = null;
    }

    if (this.markup) {
      destroyPromise = this.markup.destroy();
      this.markup = null;
    } else {
      destroyPromise = promise.resolve();
    }

    if (this._markupFrame) {
      this._markupFrame.parentNode.removeChild(this._markupFrame);
      this._markupFrame = null;
    }

    this._markupBox = null;

    return destroyPromise;
  },

  /**
   * When the type of toolbox host changes.
   */
  onToolboxHostChanged: function() {
    this.updatePaneToggleButton();
  },

  /**
   * When the pane toggle button is clicked, toggle the pane, change the button
   * state and tooltip.
   */
  onPaneToggleButtonClicked: function(e) {
    let sidePane = this.panelDoc.querySelector("#inspector-sidebar");
    let button = this._paneToggleButton;
    let isVisible = !button.hasAttribute("pane-collapsed");

    // Make sure the sidebar has a width attribute before collapsing because
    // ViewHelpers needs it.
    if (isVisible && !sidePane.hasAttribute("width")) {
      sidePane.setAttribute("width", sidePane.getBoundingClientRect().width);
    }

    ViewHelpers.togglePane({
      visible: !isVisible,
      animated: true,
      delayed: true
    }, sidePane);

    if (isVisible) {
      button.setAttribute("pane-collapsed", "");
      button.setAttribute("tooltiptext", strings.GetStringFromName("inspector.expandPane"));
    } else {
      button.removeAttribute("pane-collapsed");
      button.setAttribute("tooltiptext", strings.GetStringFromName("inspector.collapsePane"));
    }
  },

  /**
   * Update the pane toggle button visibility depending on the toolbox host type.
   */
  updatePaneToggleButton: function() {
    this._paneToggleButton.setAttribute("hidden",
      this._toolbox.hostType === HostType.SIDE);
  },

  /**
   * Toggle a pseudo class.
   */
  togglePseudoClass: function(aPseudo) {
    if (this.selection.isElementNode()) {
      let node = this.selection.nodeFront;
      if (node.hasPseudoClassLock(aPseudo)) {
        return this.walker.removePseudoClassLock(node, aPseudo, {parents: true});
      }

      let hierarchical = aPseudo == ":hover" || aPseudo == ":active";
      return this.walker.addPseudoClassLock(node, aPseudo, {parents: hierarchical});
    }
  },

  /**
   * Show DOM properties
   */
  showDOMProperties: function() {
    this._toolbox.openSplitConsole().then(() => {
      let panel = this._toolbox.getPanel("webconsole");
      let jsterm = panel.hud.jsterm;

      jsterm.execute("inspect($0)");
      jsterm.inputNode.focus();
    });
  },

  /**
   * Use in Console.
   *
   * Takes the currently selected node in the inspector and assigns it to a
   * temp variable on the content window.  Also opens the split console and
   * autofills it with the temp variable.
   */
  useInConsole: function() {
    this._toolbox.openSplitConsole().then(() => {
      let panel = this._toolbox.getPanel("webconsole");
      let jsterm = panel.hud.jsterm;

      let evalString = `let i = 0;
        while (window.hasOwnProperty("temp" + i) && i < 1000) {
          i++;
        }
        window["temp" + i] = $0;
        "temp" + i;
      `;

      let options = {
        selectedNodeActor: this.selection.nodeFront.actorID,
      };
      jsterm.requestEvaluation(evalString, options).then((res) => {
        jsterm.setInputValue(res.result);
        this.emit("console-var-ready");
      });
    });
  },

  /**
   * Clear any pseudo-class locks applied to the current hierarchy.
   */
  clearPseudoClasses: function() {
    if (!this.walker) {
      return;
    }
    return this.walker.clearPseudoClassLocks().then(null, console.error);
  },

  /**
   * Edit the outerHTML of the selected Node.
   */
  editHTML: function() {
    if (!this.selection.isNode()) {
      return;
    }
    if (this.markup) {
      this.markup.beginEditingOuterHTML(this.selection.nodeFront);
    }
  },

  /**
   * Paste the contents of the clipboard into the selected Node's outer HTML.
   */
  pasteOuterHTML: function() {
    let content = this._getClipboardContentForPaste();
    if (!content)
      return promise.reject("No clipboard content for paste");

    let node = this.selection.nodeFront;
    return this.markup.getNodeOuterHTML(node).then(oldContent => {
      this.markup.updateNodeOuterHTML(node, content, oldContent);
    });
  },

  /**
   * Paste the contents of the clipboard into the selected Node's inner HTML.
   */
  pasteInnerHTML: function() {
    let content = this._getClipboardContentForPaste();
    if (!content)
      return promise.reject("No clipboard content for paste");

    let node = this.selection.nodeFront;
    return this.markup.getNodeInnerHTML(node).then(oldContent => {
      this.markup.updateNodeInnerHTML(node, content, oldContent);
    });
  },

  /**
   * Paste the contents of the clipboard as adjacent HTML to the selected Node.
   * @param position The position as specified for Element.insertAdjacentHTML
   *        (i.e. "beforeBegin", "afterBegin", "beforeEnd", "afterEnd").
   */
  pasteAdjacentHTML: function(position) {
    let content = this._getClipboardContentForPaste();
    if (!content)
      return promise.reject("No clipboard content for paste");

    let node = this.selection.nodeFront;
    return this.markup.insertAdjacentHTMLToNode(node, position, content);
  },

  /**
   * Copy the innerHTML of the selected Node to the clipboard.
   */
  copyInnerHTML: function() {
    if (!this.selection.isNode()) {
      return;
    }
    this._copyLongString(this.walker.innerHTML(this.selection.nodeFront));
  },

  /**
   * Copy the outerHTML of the selected Node to the clipboard.
   */
  copyOuterHTML: function() {
    if (!this.selection.isNode()) {
      return;
    }
    let node = this.selection.nodeFront;

    switch (node.nodeType) {
      case Ci.nsIDOMNode.ELEMENT_NODE :
        this._copyLongString(this.walker.outerHTML(node));
        break;
      case Ci.nsIDOMNode.COMMENT_NODE :
        this._getLongString(node.getNodeValue()).then(comment => {
          clipboardHelper.copyString("<!--" + comment + "-->");
        });
        break;
      case Ci.nsIDOMNode.DOCUMENT_TYPE_NODE :
        clipboardHelper.copyString(node.doctypeString);
        break;
    }
  },

  /**
   * Copy the data-uri for the currently selected image in the clipboard.
   */
  copyImageDataUri: function() {
    let container = this.markup.getContainer(this.selection.nodeFront);
    if (container && container.isPreviewable()) {
      container.copyImageDataUri();
    }
  },

  /**
   * Copy the content of a longString (via a promise resolving a LongStringActor) to the clipboard
   * @param  {Promise} longStringActorPromise promise expected to resolve a LongStringActor instance
   * @return {Promise} promise resolving (with no argument) when the string is sent to the clipboard
   */
  _copyLongString: function(longStringActorPromise) {
    return this._getLongString(longStringActorPromise).then(string => {
      clipboardHelper.copyString(string);
    }).catch(Cu.reportError);
  },

  /**
   * Retrieve the content of a longString (via a promise resolving a LongStringActor)
   * @param  {Promise} longStringActorPromise promise expected to resolve a LongStringActor instance
   * @return {Promise} promise resolving with the retrieved string as argument
   */
  _getLongString: function(longStringActorPromise) {
    return longStringActorPromise.then(longStringActor => {
      return longStringActor.string().then(string => {
        longStringActor.release().catch(Cu.reportError);
        return string;
      });
    }).catch(Cu.reportError);
  },

  /**
   * Copy a unique selector of the selected Node to the clipboard.
   */
  copyUniqueSelector: function() {
    if (!this.selection.isNode()) {
      return;
    }

    this.selection.nodeFront.getUniqueSelector().then((selector) => {
      clipboardHelper.copyString(selector);
    }).then(null, console.error);
  },

  /**
   * Initiate gcli screenshot command on selected node
   */
  screenshotNode: function() {
    CommandUtils.createRequisition(this._target, {
      environment: CommandUtils.createEnvironment(this, '_target')
    }).then(requisition => {
      // Bug 1180314 -  CssSelector might contain white space so need to make sure it is
      // passed to screenshot as a single parameter.  More work *might* be needed if
      // CssSelector could contain escaped single- or double-quotes, backslashes, etc.
      requisition.updateExec("screenshot --selector '" + this.selectionCssSelector + "'");
    });
  },

  /**
   * Scroll the node into view.
   */
  scrollNodeIntoView: function() {
    if (!this.selection.isNode()) {
      return;
    }

    this.selection.nodeFront.scrollIntoView();
  },

  /**
   * Delete the selected node.
   */
  deleteNode: function() {
    if (!this.selection.isNode() ||
         this.selection.isRoot()) {
      return;
    }

    // If the markup panel is active, use the markup panel to delete
    // the node, making this an undoable action.
    if (this.markup) {
      this.markup.deleteNode(this.selection.nodeFront);
    } else {
      // remove the node from content
      this.walker.removeNode(this.selection.nodeFront);
    }
  },

  expandNode: function() {
    this.markup.expandAll(this.selection.nodeFront);
  },

  collapseNode: function() {
    this.markup.collapseNode(this.selection.nodeFront);
  },

  /**
   * This method is here for the benefit of the node-menu-link-follow menu item
   * in the inspector contextual-menu.
   */
  onFollowLink: function() {
    let type = this.panelDoc.popupNode.dataset.type;
    let link = this.panelDoc.popupNode.dataset.link;

    this.followAttributeLink(type, link);
  },

  /**
   * Given a type and link found in a node's attribute in the markup-view,
   * attempt to follow that link (which may result in opening a new tab, the
   * style editor or debugger).
   */
  followAttributeLink: function(type, link) {
    if (!type || !link) {
      return;
    }

    if (type === "uri" || type === "cssresource" || type === "jsresource") {
      // Open link in a new tab.
      // When the inspector menu was setup on click (see _setupNodeLinkMenu), we
      // already checked that resolveRelativeURL existed.
      this.inspector.resolveRelativeURL(link, this.selection.nodeFront).then(url => {
        if (type === "uri") {
          let browserWin = this.target.tab.ownerDocument.defaultView;
          browserWin.openUILinkIn(url, "tab");
        } else if (type === "cssresource") {
          return this.toolbox.viewSourceInStyleEditor(url);
        } else if (type === "jsresource") {
          return this.toolbox.viewSourceInDebugger(url);
        }
      }).catch(e => console.error(e));
    } else if (type == "idref") {
      // Select the node in the same document.
      this.walker.document(this.selection.nodeFront).then(doc => {
        return this.walker.querySelector(doc, "#" + CSS.escape(link)).then(node => {
          if (!node) {
            this.emit("idref-attribute-link-failed");
            return;
          }
          this.selection.setNodeFront(node);
        });
      }).catch(e => console.error(e));
    }
  },

  /**
   * This method is here for the benefit of the node-menu-link-copy menu item
   * in the inspector contextual-menu.
   */
  onCopyLink: function() {
    let link = this.panelDoc.popupNode.dataset.link;

    this.copyAttributeLink(link);
  },

  /**
   * This method is here for the benefit of copying links.
   */
  copyAttributeLink: function(link) {
    // When the inspector menu was setup on click (see _setupNodeLinkMenu), we
    // already checked that resolveRelativeURL existed.
    this.inspector.resolveRelativeURL(link, this.selection.nodeFront).then(url => {
      clipboardHelper.copyString(url);
    }, console.error);
  },

  /**
   * Trigger a high-priority layout change for things that need to be
   * updated immediately
   */
  immediateLayoutChange: function() {
    this.emit("layout-change");
  },

  /**
   * Schedule a low-priority change event for things like paint
   * and resize.
   */
  scheduleLayoutChange: function(event) {
    // Filter out non browser window resize events (i.e. triggered by iframes)
    if (this.browser.contentWindow === event.target) {
      if (this._timer) {
        return null;
      }
      this._timer = this.panelWin.setTimeout(() => {
        this.emit("layout-change");
        this._timer = null;
      }, LAYOUT_CHANGE_TIMER);
    }
  },

  /**
   * Cancel a pending low-priority change event if any is
   * scheduled.
   */
  cancelLayoutChange: function() {
    if (this._timer) {
      this.panelWin.clearTimeout(this._timer);
      delete this._timer;
    }
  }
};