Put content scripts and background scripts in separate directories, so the purpose and execution mode are more clear.

Sorry if you had patches in your local copies and this breaks them -- these renames were
a long time coming, and now is better than later.

1 files changed, 552 insertions, 0 deletions

diff --git a/content_scripts/link_hints.js b/content_scripts/link_hints.js
new file mode 100644
index 00000000..7d6b431f
--- /dev/null
+++ b/content_scripts/link_hints.js
@@ -0,0 +1,552 @@
+/*
+ * This implements link hinting. Typing "F" will enter link-hinting mode, where all clickable items on the
+ * page have a hint marker displayed containing a sequence of letters. Typing those letters will select a link.
+ *
+ * In our 'default' mode, the characters we use to show link hints are a user-configurable option. By default
+ * they're the home row.  The CSS which is used on the link hints is also a configurable option.
+ *
+ * In 'filter' mode, our link hints are numbers, and the user can narrow down the range of possibilities by
+ * typing the text of the link itself.
+ */
+var linkHints = {
+  hintMarkers: [],
+  hintMarkerContainingDiv: null,
+  shouldOpenInNewTab: false,
+  shouldOpenWithQueue: false,
+  // function that does the appropriate action on the selected link
+  linkActivator: undefined,
+  // While in delayMode, all keypresses have no effect.
+  delayMode: false,
+  // Handle the link hinting marker generation and matching. Must be initialized after settings have been
+  // loaded, so that we can retrieve the option setting.
+  markerMatcher: undefined,
+
+  /*
+   * To be called after linkHints has been generated from linkHintsBase.
+   */
+  init: function() {
+    this.onKeyDownInMode = this.onKeyDownInMode.bind(this);
+    this.markerMatcher = settings.get('filterLinkHints') ? filterHints : alphabetHints;
+  },
+
+  /*
+   * Generate an XPath describing what a clickable element is.
+   * The final expression will be something like "//button | //xhtml:button | ..."
+   * We use translate() instead of lower-case() because Chrome only supports XPath 1.0.
+   */
+  clickableElementsXPath: domUtils.makeXPath(["a", "area[@href]", "textarea", "button", "select",
+                             "input[not(@type='hidden' or @disabled or @readonly)]",
+                             "*[@onclick or @tabindex or @role='link' or @role='button' or contains(@class, 'button') or " +
+                             "@contenteditable='' or translate(@contenteditable, 'TRUE', 'true')='true']"]),
+
+  // We need this as a top-level function because our command system doesn't yet support arguments.
+  activateModeToOpenInNewTab: function() { this.activateMode(true, false, false); },
+
+  activateModeToCopyLinkUrl: function() { this.activateMode(null, false, true); },
+
+  activateModeWithQueue: function() { this.activateMode(true, true, false); },
+
+  activateMode: function(openInNewTab, withQueue, copyLinkUrl) {
+    if (!document.getElementById('vimiumLinkHintCss'))
+      // linkHintCss is declared by vimiumFrontend.js and contains the user supplied css overrides.
+      addCssToPage(linkHintCss, 'vimiumLinkHintCss');
+    this.setOpenLinkMode(openInNewTab, withQueue, copyLinkUrl);
+    this.buildLinkHints();
+    handlerStack.push({ // handlerStack is declared by vimiumFrontend.js
+      keydown: this.onKeyDownInMode,
+      // trap all key events
+      keypress: function() { return false; },
+      keyup: function() { return false; }
+    });
+  },
+
+  setOpenLinkMode: function(openInNewTab, withQueue, copyLinkUrl) {
+    this.shouldOpenInNewTab = openInNewTab;
+    this.shouldOpenWithQueue = withQueue;
+
+    if (openInNewTab || withQueue) {
+      if (openInNewTab)
+        HUD.show("Open link in new tab");
+      else if (withQueue)
+        HUD.show("Open multiple links in a new tab");
+      this.linkActivator = function(link) {
+        // When "clicking" on a link, dispatch the event with the appropriate meta key (CMD on Mac, CTRL on windows)
+        // to open it in a new tab if necessary.
+        domUtils.simulateClick(link, { metaKey: platform == "Mac", ctrlKey: platform != "Mac" });
+      }
+    } else if (copyLinkUrl) {
+      HUD.show("Copy link URL to Clipboard");
+      this.linkActivator = function(link) {
+        chrome.extension.sendRequest({handler: 'copyToClipboard', data: link.href});
+      }
+    } else {
+      HUD.show("Open link in current tab");
+      // When we're opening the link in the current tab, don't navigate to the selected link immediately;
+      // we want to give the user some time to notice which link has received focus.
+      this.linkActivator = function(link) {
+        setTimeout(domUtils.simulateClick.bind(domUtils, link), 400);
+      }
+    }
+  },
+
+  /*
+   * Builds and displays link hints for every visible clickable item on the page.
+   */
+  buildLinkHints: function() {
+    var visibleElements = this.getVisibleClickableElements();
+    this.hintMarkers = this.markerMatcher.getHintMarkers(visibleElements);
+
+    // Note(philc): Append these markers as top level children instead of as child nodes to the link itself,
+    // because some clickable elements cannot contain children, e.g. submit buttons. This has the caveat
+    // that if you scroll the page and the link has position=fixed, the marker will not stay fixed.
+    // Also note that adding these nodes to document.body all at once is significantly faster than one-by-one.
+    this.hintMarkerContainingDiv = document.createElement("div");
+    this.hintMarkerContainingDiv.id = "vimiumHintMarkerContainer";
+    this.hintMarkerContainingDiv.className = "vimiumReset";
+    for (var i = 0; i < this.hintMarkers.length; i++)
+      this.hintMarkerContainingDiv.appendChild(this.hintMarkers[i]);
+
+    // sometimes this is triggered before documentElement is created
+    // TODO(int3): fail more gracefully?
+    if (document.documentElement)
+      document.documentElement.appendChild(this.hintMarkerContainingDiv);
+    else
+      this.deactivateMode();
+  },
+
+  /*
+   * Returns all clickable elements that are not hidden and are in the current viewport.
+   * We prune invisible elements partly for performance reasons, but moreso it's to decrease the number
+   * of digits needed to enumerate all of the links on screen.
+   */
+  getVisibleClickableElements: function() {
+    var resultSet = domUtils.evaluateXPath(this.clickableElementsXPath, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE);
+
+    var visibleElements = [];
+
+    // Find all visible clickable elements.
+    for (var i = 0, count = resultSet.snapshotLength; i < count; i++) {
+      var element = resultSet.snapshotItem(i);
+      var clientRect = domUtils.getVisibleClientRect(element, clientRect);
+      if (clientRect !== null)
+        visibleElements.push({element: element, rect: clientRect});
+
+      if (element.localName === "area") {
+        var map = element.parentElement;
+        if (!map) continue;
+        var img = document.querySelector("img[usemap='#" + map.getAttribute("name") + "']");
+        if (!img) continue;
+        var imgClientRects = img.getClientRects();
+        if (imgClientRects.length == 0) continue;
+        var c = element.coords.split(/,/);
+        var coords = [parseInt(c[0], 10), parseInt(c[1], 10), parseInt(c[2], 10), parseInt(c[3], 10)];
+        var rect = {
+          top: imgClientRects[0].top + coords[1],
+          left: imgClientRects[0].left + coords[0],
+          right: imgClientRects[0].left + coords[2],
+          bottom: imgClientRects[0].top + coords[3],
+          width: coords[2] - coords[0],
+          height: coords[3] - coords[1]
+        };
+
+        visibleElements.push({element: element, rect: rect});
+      }
+    }
+    return visibleElements;
+  },
+
+  /*
+   * Handles shift and esc keys. The other keys are passed to markerMatcher.matchHintsByKey.
+   */
+  onKeyDownInMode: function(event) {
+    if (this.delayMode)
+      return;
+
+    if (event.keyCode == keyCodes.shiftKey && this.shouldOpenInNewTab !== null) {
+      // Toggle whether to open link in a new or current tab.
+      this.setOpenLinkMode(!this.shouldOpenInNewTab, this.shouldOpenWithQueue, false);
+      handlerStack.push({
+        keyup: function(event) {
+          if (event.keyCode !== keyCodes.shiftKey) return;
+          linkHints.setOpenLinkMode(!linkHints.shouldOpenInNewTab, linkHints.shouldOpenWithQueue, false);
+          handlerStack.pop();
+        }
+      });
+    }
+
+    // TODO(philc): Ignore keys that have modifiers.
+    if (isEscape(event)) {
+      this.deactivateMode();
+    } else {
+      var keyResult = this.markerMatcher.matchHintsByKey(event, this.hintMarkers);
+      var linksMatched = keyResult.linksMatched;
+      var delay = keyResult.delay !== undefined ? keyResult.delay : 0;
+      if (linksMatched.length == 0) {
+        this.deactivateMode();
+      } else if (linksMatched.length == 1) {
+        this.activateLink(linksMatched[0], delay);
+      } else {
+        for (var i in this.hintMarkers)
+          this.hideMarker(this.hintMarkers[i]);
+        for (var i in linksMatched)
+          this.showMarker(linksMatched[i], this.markerMatcher.hintKeystrokeQueue.length);
+      }
+    }
+  },
+
+  /*
+   * When only one link hint remains, this function activates it in the appropriate way.
+   */
+  activateLink: function(matchedLink, delay) {
+    this.delayMode = true;
+    var clickEl = matchedLink.clickableItem;
+    if (domUtils.isSelectable(clickEl)) {
+      domUtils.simulateSelect(clickEl);
+      this.deactivateMode(delay, function() { linkHints.delayMode = false; });
+    } else {
+      // TODO figure out which other input elements should not receive focus
+      if (clickEl.nodeName.toLowerCase() === 'input' && clickEl.type !== 'button')
+        clickEl.focus();
+      domUtils.flashRect(matchedLink.rect);
+      this.linkActivator(clickEl);
+      if (this.shouldOpenWithQueue) {
+        this.deactivateMode(delay, function() {
+          linkHints.delayMode = false;
+          linkHints.activateModeWithQueue();
+        });
+      } else {
+        this.deactivateMode(delay, function() { linkHints.delayMode = false; });
+      }
+    }
+  },
+
+  /*
+   * Shows the marker, highlighting matchingCharCount characters.
+   */
+  showMarker: function(linkMarker, matchingCharCount) {
+    linkMarker.style.display = "";
+    for (var j = 0, count = linkMarker.childNodes.length; j < count; j++)
+      (j < matchingCharCount) ? linkMarker.childNodes[j].classList.add("matchingCharacter") :
+                                linkMarker.childNodes[j].classList.remove("matchingCharacter");
+  },
+
+  hideMarker: function(linkMarker) {
+    linkMarker.style.display = "none";
+  },
+
+  /*
+   * If called without arguments, it executes immediately.  Othewise, it
+   * executes after 'delay' and invokes 'callback' when it is finished.
+   */
+  deactivateMode: function(delay, callback) {
+    function deactivate() {
+      if (linkHints.markerMatcher.deactivate)
+        linkHints.markerMatcher.deactivate();
+      if (linkHints.hintMarkerContainingDiv)
+        linkHints.hintMarkerContainingDiv.parentNode.removeChild(linkHints.hintMarkerContainingDiv);
+      linkHints.hintMarkerContainingDiv = null;
+      linkHints.hintMarkers = [];
+      handlerStack.pop();
+      HUD.hide();
+    }
+    // we invoke the deactivate() function directly instead of using setTimeout(callback, 0) so that
+    // deactivateMode can be tested synchronously
+    if (!delay) {
+      deactivate();
+      if (callback) callback();
+    } else {
+      setTimeout(function() { deactivate(); if (callback) callback(); }, delay);
+    }
+  },
+
+};
+
+var alphabetHints = {
+  hintKeystrokeQueue: [],
+  logXOfBase: function(x, base) { return Math.log(x) / Math.log(base); },
+
+  getHintMarkers: function(visibleElements) {
+    var hintStrings = this.hintStrings(visibleElements.length);
+    var hintMarkers = [];
+    for (var i = 0, count = visibleElements.length; i < count; i++) {
+      var marker = hintUtils.createMarkerFor(visibleElements[i]);
+      marker.hintString = hintStrings[i];
+      marker.innerHTML = hintUtils.spanWrap(marker.hintString.toUpperCase());
+      hintMarkers.push(marker);
+    }
+
+    return hintMarkers;
+  },
+
+  /*
+   * Returns a list of hint strings which will uniquely identify the given number of links. The hint strings
+   * may be of different lengths.
+   */
+  hintStrings: function(linkCount) {
+    var linkHintCharacters = settings.get("linkHintCharacters");
+    // Determine how many digits the link hints will require in the worst case. Usually we do not need
+    // all of these digits for every link single hint, so we can show shorter hints for a few of the links.
+    var digitsNeeded = Math.ceil(this.logXOfBase(linkCount, linkHintCharacters.length));
+    // Short hints are the number of hints we can possibly show which are (digitsNeeded - 1) digits in length.
+    var shortHintCount = Math.floor(
+        (Math.pow(linkHintCharacters.length, digitsNeeded) - linkCount) /
+        linkHintCharacters.length);
+    var longHintCount = linkCount - shortHintCount;
+
+    var hintStrings = [];
+
+    if (digitsNeeded > 1)
+      for (var i = 0; i < shortHintCount; i++)
+        hintStrings.push(this.numberToHintString(i, digitsNeeded - 1, linkHintCharacters));
+
+    var start = shortHintCount * linkHintCharacters.length;
+    for (var i = start; i < start + longHintCount; i++)
+      hintStrings.push(this.numberToHintString(i, digitsNeeded, linkHintCharacters));
+
+    return this.shuffleHints(hintStrings, linkHintCharacters.length);
+  },
+
+  /*
+   * This shuffles the given set of hints so that they're scattered -- hints starting with the same character
+   * will be spread evenly throughout the array.
+   */
+  shuffleHints: function(hints, characterSetLength) {
+    var buckets = [], i = 0;
+    for (i = 0; i < characterSetLength; i++)
+      buckets[i] = []
+    for (i = 0; i < hints.length; i++)
+      buckets[i % buckets.length].push(hints[i]);
+    var result = [];
+    for (i = 0; i < buckets.length; i++)
+      result = result.concat(buckets[i]);
+    return result;
+  },
+
+  /*
+   * Converts a number like "8" into a hint string like "JK". This is used to sequentially generate all of
+   * the hint text. The hint string will be "padded with zeroes" to ensure its length is equal to numHintDigits.
+   */
+  numberToHintString: function(number, numHintDigits, characterSet) {
+    var base = characterSet.length;
+    var hintString = [];
+    var remainder = 0;
+    do {
+      remainder = number % base;
+      hintString.unshift(characterSet[remainder]);
+      number -= remainder;
+      number /= Math.floor(base);
+    } while (number > 0);
+
+    // Pad the hint string we're returning so that it matches numHintDigits.
+    // Note: the loop body changes hintString.length, so the original length must be cached!
+    var hintStringLength = hintString.length;
+    for (var i = 0; i < numHintDigits - hintStringLength; i++)
+      hintString.unshift(characterSet[0]);
+
+    return hintString.join("");
+  },
+
+  matchHintsByKey: function(event, hintMarkers) {
+    var keyChar = getKeyChar(event);
+
+    if (event.keyCode == keyCodes.backspace || event.keyCode == keyCodes.deleteKey) {
+      if (!this.hintKeystrokeQueue.pop())
+        return { linksMatched: [] };
+    } else if (keyChar && settings.get('linkHintCharacters').indexOf(keyChar) >= 0) {
+      this.hintKeystrokeQueue.push(keyChar);
+    }
+
+    var matchString = this.hintKeystrokeQueue.join("");
+    var linksMatched = hintMarkers.filter(function(linkMarker) {
+      return linkMarker.hintString.indexOf(matchString) == 0;
+    });
+    return { linksMatched: linksMatched };
+  },
+
+  deactivate: function() {
+    this.hintKeystrokeQueue = [];
+  }
+
+};
+
+var filterHints = {
+  hintKeystrokeQueue: [],
+  linkTextKeystrokeQueue: [],
+  labelMap: {},
+
+  /*
+   * Generate a map of input element => label
+   */
+  generateLabelMap: function() {
+    var labels = document.querySelectorAll("label");
+    for (var i = 0, count = labels.length; i < count; i++) {
+      var forElement = labels[i].getAttribute("for");
+      if (forElement) {
+        var labelText = labels[i].textContent.trim();
+        // remove trailing : commonly found in labels
+        if (labelText[labelText.length-1] == ":")
+          labelText = labelText.substr(0, labelText.length-1);
+        this.labelMap[forElement] = labelText;
+      }
+    }
+  },
+
+  generateHintString: function(linkHintNumber) {
+    return (linkHintNumber + 1).toString();
+  },
+
+  generateLinkText: function(element) {
+    var linkText = "";
+    var showLinkText = false;
+    // toLowerCase is necessary as html documents return 'IMG'
+    // and xhtml documents return 'img'
+    var nodeName = element.nodeName.toLowerCase();
+
+    if (nodeName == "input") {
+      if (this.labelMap[element.id]) {
+        linkText = this.labelMap[element.id];
+        showLinkText = true;
+      } else if (element.type != "password") {
+        linkText = element.value;
+      }
+      // check if there is an image embedded in the <a> tag
+    } else if (nodeName == "a" && !element.textContent.trim()
+        && element.firstElementChild
+        && element.firstElementChild.nodeName.toLowerCase() == "img") {
+      linkText = element.firstElementChild.alt || element.firstElementChild.title;
+      if (linkText)
+        showLinkText = true;
+    } else {
+      linkText = element.textContent || element.innerHTML;
+    }
+    return { text: linkText, show: showLinkText };
+  },
+
+  renderMarker: function(marker) {
+    marker.innerHTML = hintUtils.spanWrap(marker.hintString +
+                                          (marker.showLinkText ? ": " + marker.linkText : ""));
+  },
+
+  getHintMarkers: function(visibleElements) {
+    this.generateLabelMap();
+    var hintMarkers = [];
+    for (var i = 0, count = visibleElements.length; i < count; i++) {
+      var marker = hintUtils.createMarkerFor(visibleElements[i]);
+      marker.hintString = this.generateHintString(i);
+      var linkTextObject = this.generateLinkText(marker.clickableItem);
+      marker.linkText = linkTextObject.text;
+      marker.showLinkText = linkTextObject.show;
+      this.renderMarker(marker);
+      hintMarkers.push(marker);
+    }
+    return hintMarkers;
+  },
+
+  matchHintsByKey: function(event, hintMarkers) {
+    var keyChar = getKeyChar(event);
+    var delay = 0;
+    var userIsTypingLinkText = false;
+
+    if (event.keyCode == keyCodes.enter) {
+      // activate the lowest-numbered link hint that is visible
+      for (var i = 0, count = hintMarkers.length; i < count; i++)
+        if (hintMarkers[i].style.display  != 'none') {
+          return { linksMatched: [ hintMarkers[i] ] };
+        }
+    } else if (event.keyCode == keyCodes.backspace || event.keyCode == keyCodes.deleteKey) {
+      // backspace clears hint key queue first, then acts on link text key queue.
+      // if both queues are empty. exit hinting mode
+      if (!this.hintKeystrokeQueue.pop() && !this.linkTextKeystrokeQueue.pop())
+          return { linksMatched: [] };
+    } else if (keyChar) {
+      if (/[0-9]/.test(keyChar))
+        this.hintKeystrokeQueue.push(keyChar);
+      else {
+        // since we might renumber the hints, the current hintKeyStrokeQueue
+        // should be rendered invalid (i.e. reset).
+        this.hintKeystrokeQueue = [];
+        this.linkTextKeystrokeQueue.push(keyChar);
+        userIsTypingLinkText = true;
+      }
+    }
+
+    // at this point, linkTextKeystrokeQueue and hintKeystrokeQueue have been updated to reflect the latest
+    // input. use them to filter the link hints accordingly.
+    var linksMatched = this.filterLinkHints(hintMarkers);
+    var matchString = this.hintKeystrokeQueue.join("");
+    linksMatched = linksMatched.filter(function(linkMarker) {
+      return !linkMarker.filtered && linkMarker.hintString.indexOf(matchString) == 0;
+    });
+
+    if (linksMatched.length == 1 && userIsTypingLinkText) {
+      // In filter mode, people tend to type out words past the point
+      // needed for a unique match. Hence we should avoid passing
+      // control back to command mode immediately after a match is found.
+      var delay = 200;
+    }
+
+    return { linksMatched: linksMatched, delay: delay };
+  },
+
+  /*
+   * Marks the links that do not match the linkText search string with the 'filtered' DOM property. Renumbers
+   * the remainder if necessary.
+   */
+  filterLinkHints: function(hintMarkers) {
+    var linksMatched = [];
+    var linkSearchString = this.linkTextKeystrokeQueue.join("");
+
+    for (var i = 0; i < hintMarkers.length; i++) {
+      var linkMarker = hintMarkers[i];
+      var matchedLink = linkMarker.linkText.toLowerCase().indexOf(linkSearchString.toLowerCase()) >= 0;
+
+      if (!matchedLink) {
+        linkMarker.filtered = true;
+      } else {
+        linkMarker.filtered = false;
+        var oldHintString = linkMarker.hintString;
+        linkMarker.hintString = this.generateHintString(linksMatched.length);
+        if (linkMarker.hintString != oldHintString)
+          this.renderMarker(linkMarker);
+        linksMatched.push(linkMarker);
+      }
+    }
+    return linksMatched;
+  },
+
+  deactivate: function(delay, callback) {
+    this.hintKeystrokeQueue = [];
+    this.linkTextKeystrokeQueue = [];
+    this.labelMap = {};
+  }
+
+};
+
+var hintUtils = {
+  /*
+   * Make each hint character a span, so that we can highlight the typed characters as you type them.
+   */
+  spanWrap: function(hintString) {
+    var innerHTML = [];
+    for (var i = 0; i < hintString.length; i++)
+      innerHTML.push("<span class='vimiumReset'>" + hintString[i] + "</span>");
+    return innerHTML.join("");
+  },
+
+  /*
+   * Creates a link marker for the given link.
+   */
+  createMarkerFor: function(link) {
+    var marker = document.createElement("div");
+    marker.className = "vimiumReset internalVimiumHintMarker vimiumHintMarker";
+    marker.clickableItem = link.element;
+
+    var clientRect = link.rect;
+    marker.style.left = clientRect.left + window.scrollX + "px";
+    marker.style.top = clientRect.top  + window.scrollY  + "px";
+
+    marker.rect = link.rect;
+
+    return marker;
+  }
+};