1 files changed, 470 insertions, 0 deletions
diff --git a/toolkit/jetpack/sdk/selection.js b/toolkit/jetpack/sdk/selection.js
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+/* 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";
+
+module.metadata = {
+  "stability": "stable",
+  "engines": {
+    "Firefox": "*",
+    "SeaMonkey": "*"
+  }
+};
+
+const { Ci, Cc } = require("chrome"),
+    { setTimeout } = require("./timers"),
+    { emit, off } = require("./event/core"),
+    { Class, obscure } = require("./core/heritage"),
+    { EventTarget } = require("./event/target"),
+    { ns } = require("./core/namespace"),
+    { when: unload } = require("./system/unload"),
+    { ignoreWindow } = require('./private-browsing/utils'),
+    { getTabs, getTabForContentWindow,
+      getAllTabContentWindows } = require('./tabs/utils'),
+    winUtils = require("./window/utils"),
+    events = require("./system/events");
+
+// The selection types
+const HTML = 0x01,
+      TEXT = 0x02,
+      DOM  = 0x03; // internal use only
+
+// A more developer-friendly message than the caught exception when is not
+// possible change a selection.
+const ERR_CANNOT_CHANGE_SELECTION =
+  "It isn't possible to change the selection, as there isn't currently a selection";
+
+const selections = ns();
+
+const Selection = Class({
+  /**
+   * Creates an object from which a selection can be set, get, etc. Each
+   * object has an associated with a range number. Range numbers are the
+   * 0-indexed counter of selection ranges as explained at
+   * https://developer.mozilla.org/en/DOM/Selection.
+   *
+   * @param rangeNumber
+   *        The zero-based range index into the selection
+   */
+  initialize: function initialize(rangeNumber) {
+    // In order to hide the private `rangeNumber` argument from API consumers
+    // while still enabling Selection getters/setters to access it, we define
+    // it as non enumerable, non configurable property. While consumers still
+    // may discover it they won't be able to do any harm which is good enough
+    // in this case.
+    Object.defineProperties(this, {
+      rangeNumber: {
+        enumerable: false,
+        configurable: false,
+        value: rangeNumber
+      }
+    });
+  },
+  get text() { return getSelection(TEXT, this.rangeNumber); },
+  set text(value) { setSelection(TEXT, value, this.rangeNumber); },
+  get html() { return getSelection(HTML, this.rangeNumber); },
+  set html(value) { setSelection(HTML, value, this.rangeNumber); },
+  get isContiguous() {
+
+    // If there are multiple non empty ranges, the selection is definitely
+    // discontiguous. It returns `false` also if there are no valid selection.
+    let count = 0;
+    for (let sel in selectionIterator)
+      if (++count > 1)
+        break;
+
+    return count === 1;
+  }
+});
+
+const selectionListener = {
+  notifySelectionChanged: function (document, selection, reason) {
+    if (!["SELECTALL", "KEYPRESS", "MOUSEUP"].some(type => reason &
+      Ci.nsISelectionListener[type + "_REASON"]) || selection.toString() == "")
+        return;
+
+    this.onSelect();
+  },
+
+  onSelect: function() {
+    emit(module.exports, "select");
+  }
+}
+
+/**
+ * Defines iterators so that discontiguous selections can be iterated.
+ * Empty selections are skipped - see `safeGetRange` for further details.
+ *
+ * If discontiguous selections are in a text field, only the first one
+ * is returned because the text field selection APIs doesn't support
+ * multiple selections.
+ */
+function* forOfIterator() {
+  let selection = getSelection(DOM);
+  let count = 0;
+
+  if (selection)
+    count = selection.rangeCount || (getElementWithSelection() ? 1 : 0);
+
+  for (let i = 0; i < count; i++) {
+    let sel = Selection(i);
+
+    if (sel.text)
+      yield Selection(i);
+  }
+}
+
+const selectionIteratorOptions = {
+  __iterator__: function() {
+      for (let item of this)
+          yield item;
+  }
+}
+selectionIteratorOptions[Symbol.iterator] = forOfIterator;
+const selectionIterator = obscure(selectionIteratorOptions);
+
+/**
+ * Returns the most recent focused window.
+ * if private browsing window is most recent and not supported,
+ * then ignore it and return `null`, because the focused window
+ * can't be targeted.
+ */
+function getFocusedWindow() {
+  let window = winUtils.getFocusedWindow();
+
+  return ignoreWindow(window) ? null : window;
+}
+
+/**
+ * Returns the focused element in the most recent focused window
+ * if private browsing window is most recent and not supported,
+ * then ignore it and return `null`, because the focused element
+ * can't be targeted.
+ */
+function getFocusedElement() {
+  let element = winUtils.getFocusedElement();
+
+  if (!element || ignoreWindow(element.ownerDocument.defaultView))
+    return null;
+
+  return element;
+}
+
+/**
+ * Returns the current selection from most recent content window. Depending on
+ * the specified |type|, the value returned can be a string of text, stringified
+ * HTML, or a DOM selection object as described at
+ * https://developer.mozilla.org/en/DOM/Selection.
+ *
+ * @param type
+ *        Specifies the return type of the selection. Valid values are the one
+ *        of the constants HTML, TEXT, or DOM.
+ *
+ * @param rangeNumber
+ *        Specifies the zero-based range index of the returned selection.
+ */
+function getSelection(type, rangeNumber) {
+  let window, selection;
+  try {
+    window = getFocusedWindow();
+    selection = window.getSelection();
+  }
+  catch (e) {
+    return null;
+  }
+
+  // Get the selected content as the specified type
+  if (type == DOM) {
+    return selection;
+  }
+  else if (type == TEXT) {
+    let range = safeGetRange(selection, rangeNumber);
+
+    if (range)
+      return range.toString();
+
+    let node = getElementWithSelection();
+
+    if (!node)
+      return null;
+
+    return node.value.substring(node.selectionStart, node.selectionEnd);
+  }
+  else if (type == HTML) {
+    let range = safeGetRange(selection, rangeNumber);
+    // Another way, but this includes the xmlns attribute for all elements in
+    // Gecko 1.9.2+ :
+    // return Cc["@mozilla.org/xmlextras/xmlserializer;1"].
+    //   createInstance(Ci.nsIDOMSerializer).serializeToSTring(range.
+    //     cloneContents());
+    if (!range)
+      return null;
+
+    let node = window.document.createElement("span");
+    node.appendChild(range.cloneContents());
+    return node.innerHTML;
+  }
+
+  throw new Error("Type " + type + " is unrecognized.");
+}
+
+/**
+ * Sets the current selection of the most recent content document by changing
+ * the existing selected text/HTML range to the specified value.
+ *
+ * @param val
+ *        The value for the new selection
+ *
+ * @param rangeNumber
+ *        The zero-based range index of the selection to be set
+ *
+ */
+function setSelection(type, val, rangeNumber) {
+  // Make sure we have a window context & that there is a current selection.
+  // Selection cannot be set unless there is an existing selection.
+  let window, selection;
+
+  try {
+    window = getFocusedWindow();
+    selection = window.getSelection();
+  }
+  catch (e) {
+    throw new Error(ERR_CANNOT_CHANGE_SELECTION);
+  }
+
+  let range = safeGetRange(selection, rangeNumber);
+
+  if (range) {
+    let fragment;
+
+    if (type === HTML)
+      fragment = range.createContextualFragment(val);
+    else {
+      fragment = range.createContextualFragment("");
+      fragment.textContent = val;
+    }
+
+    range.deleteContents();
+    range.insertNode(fragment);
+  }
+  else {
+    let node = getElementWithSelection();
+
+    if (!node)
+      throw new Error(ERR_CANNOT_CHANGE_SELECTION);
+
+    let { value, selectionStart, selectionEnd } = node;
+
+    let newSelectionEnd = selectionStart + val.length;
+
+    node.value = value.substring(0, selectionStart) +
+                  val +
+                  value.substring(selectionEnd, value.length);
+
+    node.setSelectionRange(selectionStart, newSelectionEnd);
+  }
+}
+
+/**
+ * Returns the specified range in a selection without throwing an exception.
+ *
+ * @param selection
+ *        A selection object as described at
+ *         https://developer.mozilla.org/en/DOM/Selection
+ *
+ * @param [rangeNumber]
+ *        Specifies the zero-based range index of the returned selection.
+ *        If it's not provided the function will return the first non empty
+ *        range, if any.
+ */
+function safeGetRange(selection, rangeNumber) {
+  try {
+    let { rangeCount } = selection;
+    let range = null;
+
+    if (typeof rangeNumber === "undefined")
+      rangeNumber = 0;
+    else
+      rangeCount = rangeNumber + 1;
+
+    for (; rangeNumber < rangeCount; rangeNumber++ ) {
+      range = selection.getRangeAt(rangeNumber);
+
+      if (range && range.toString())
+        break;
+
+      range = null;
+    }
+
+    return range;
+  }
+  catch (e) {
+    return null;
+  }
+}
+
+/**
+ * Returns a reference of the DOM's active element for the window given, if it
+ * supports the text field selection API and has a text selected.
+ *
+ * Note:
+ *   we need this method because window.getSelection doesn't return a selection
+ *   for text selected in a form field (see bug 85686)
+ */
+function getElementWithSelection() {
+  let element = getFocusedElement();
+
+  if (!element)
+    return null;
+
+  try {
+    // Accessing selectionStart and selectionEnd on e.g. a button
+    // results in an exception thrown as per the HTML5 spec.  See
+    // http://www.whatwg.org/specs/web-apps/current-work/multipage/association-of-controls-and-forms.html#textFieldSelection
+
+    let { value, selectionStart, selectionEnd } = element;
+
+    let hasSelection = typeof value === "string" &&
+                      !isNaN(selectionStart) &&
+                      !isNaN(selectionEnd) &&
+                      selectionStart !== selectionEnd;
+
+    return hasSelection ? element : null;
+  }
+  catch (err) {
+    return null;
+  }
+
+}
+
+/**
+ * Adds the Selection Listener to the content's window given
+ */
+function addSelectionListener(window) {
+  let selection = window.getSelection();
+
+  // Don't add the selection's listener more than once to the same window,
+  // if the selection object is the same
+  if ("selection" in selections(window) && selections(window).selection === selection)
+    return;
+
+  // We ensure that the current selection is an instance of
+  // `nsISelectionPrivate` before working on it, in case is `null`.
+  //
+  // If it's `null` it's likely too early to add the listener, and we demand
+  // that operation to `document-shown` - it can easily happens for frames
+  if (selection instanceof Ci.nsISelectionPrivate)
+    selection.addSelectionListener(selectionListener);
+
+  // nsISelectionListener implementation seems not fire a notification if
+  // a selection is in a text field, therefore we need to add a listener to
+  // window.onselect, that is fired only for text fields.
+  // For consistency, we add it only when the nsISelectionListener is added.
+  //
+  // https://developer.mozilla.org/en/DOM/window.onselect
+  window.addEventListener("select", selectionListener.onSelect, true);
+
+  selections(window).selection = selection;
+};
+
+/**
+ * Removes the Selection Listener to the content's window given
+ */
+function removeSelectionListener(window) {
+  // Don't remove the selection's listener to a window that wasn't handled.
+  if (!("selection" in selections(window)))
+    return;
+
+  let selection = window.getSelection();
+  let isSameSelection = selection === selections(window).selection;
+
+  // Before remove the listener, we ensure that the current selection is an
+  // instance of `nsISelectionPrivate` (it could be `null`), and that is still
+  // the selection we managed for this window (it could be detached).
+  if (selection instanceof Ci.nsISelectionPrivate && isSameSelection)
+    selection.removeSelectionListener(selectionListener);
+
+  window.removeEventListener("select", selectionListener.onSelect, true);
+
+  delete selections(window).selection;
+};
+
+function onContent(event) {
+  let window = event.subject.defaultView;
+
+  // We are not interested in documents without valid defaultView (e.g. XML)
+  // that aren't in a tab (e.g. Panel); or in private windows
+   if (window && getTabForContentWindow(window) && !ignoreWindow(window)) {
+    addSelectionListener(window);
+  }
+}
+
+// Adds Selection listener to new documents
+// Note that strong reference is needed for documents that are loading slowly or
+// where the server didn't close the connection (e.g. "comet").
+events.on("document-element-inserted", onContent, true);
+
+// Adds Selection listeners to existing documents
+getAllTabContentWindows().forEach(addSelectionListener);
+
+// When a document is not visible anymore the selection object is detached, and
+// a new selection object is created when it becomes visible again.
+// That makes the previous selection's listeners added previously totally
+// useless – the listeners are not notified anymore.
+// To fix that we're listening for `document-shown` event in order to add
+// the listeners to the new selection object created.
+//
+// See bug 665386 for further details.
+
+function onShown(event) {
+  let window = event.subject.defaultView;
+
+  // We are not interested in documents without valid defaultView.
+  // For example XML documents don't have windows and we don't yet support them.
+  if (!window)
+    return;
+
+  // We want to handle only the windows where we added selection's listeners
+  if ("selection" in selections(window)) {
+    let currentSelection = window.getSelection();
+    let { selection } = selections(window);
+
+    // If the current selection for the window given is different from the one
+    // stored in the namespace, we need to add the listeners again, and replace
+    // the previous selection in our list with the new one.
+    //
+    // Notice that we don't have to remove the listeners from the old selection,
+    // because is detached. An attempt to remove the listener, will raise an
+    // error (see http://mxr.mozilla.org/mozilla-central/source/layout/generic/nsSelection.cpp#5343 )
+    //
+    // We ensure that the current selection is an instance of
+    // `nsISelectionPrivate` before working on it, in case is `null`.
+    if (currentSelection instanceof Ci.nsISelectionPrivate &&
+      currentSelection !== selection) {
+
+      window.addEventListener("select", selectionListener.onSelect, true);
+      currentSelection.addSelectionListener(selectionListener);
+      selections(window).selection = currentSelection;
+    }
+  }
+}
+
+events.on("document-shown", onShown, true);
+
+// Removes Selection listeners when the add-on is unloaded
+unload(function(){
+  getAllTabContentWindows().forEach(removeSelectionListener);
+
+  events.off("document-element-inserted", onContent);
+  events.off("document-shown", onShown);
+
+  off(exports);
+});
+
+const selection = Class({
+  extends: EventTarget,
+  implements: [ Selection, selectionIterator ]
+})();
+
+module.exports = selection;