Pull context menu related APIs from core.js to their own file.

ios/web/web_state/js/resources/context_menu.js

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @fileoverview APIs used by CRWContextMenuController.
+ */
+
+goog.provide('__crWeb.contextMenu');
+
+/** Beginning of anonymous object */
+(function() {
+
+  /**
+   * Returns the url of the image or link under the selected point. Returns an
+   * empty string if no links or images are found.
+   * @param {number} x Horizontal center of the selected point.
+   * @param {number} y Vertical center of the selected point.
+   * @return {!Object} An object of the form {
+   *     href,  // URL of the link under the point
+   *     innerText,  // innerText of the link, if the selected element is a link
+   *     src,  // src of the image, if the selected element is an image
+   *     title,  // title of the image, if the selected
+   *     referrerPolicy
+   *   }
+   *   where:
+   *     <ul>
+   *     <li>href, innerText are set if the selected element is a link.
+   *     <li>src, title are set if the selected element is an image.
+   *     <li>href is also set if the selected element is an image with a link.
+   *     <li>referrerPolicy is the referrer policy to use for navigations away
+   *         from the current page.
+   *     </ul>
+   */
+  __gCrWeb['getElementFromPoint'] = function(x, y) {
+    var hitCoordinates = spiralCoordinates_(x, y);
+    for (var index = 0; index < hitCoordinates.length; index++) {
+      var coordinates = hitCoordinates[index];
+
+      var element = elementFromPoint_(coordinates.x, coordinates.y);
+      if (!element || !element.tagName) {
+        // Nothing under the hit point. Try the next hit point.
+        continue;
+      }
+
+      if (getComputedWebkitTouchCallout_(element) === 'none')
+        continue;
+      // Also check element's ancestors. A bound on the level is used here to
+      // avoid large overhead when no links or images are found.
+      var level = 0;
+      while (++level < 8 && element && element != document) {
+        var tagName = element.tagName;
+        if (!tagName)
+          continue;
+        tagName = tagName.toLowerCase();
+
+        if (tagName === 'input' || tagName === 'textarea' ||
+            tagName === 'select' || tagName === 'option') {
+          // If the element is a known input element, stop the spiral search and
+          // return empty results.
+          return {};
+        }
+
+        if (tagName === 'a' && element.href) {
+          // Found a link.
+          return {
+            href: element.href,
+            referrerPolicy: getReferrerPolicy_(element),
+            innerText: element.innerText
+          };
+        }
+
+        if (tagName === 'img' && element.src) {
+          // Found an image.
+          var result = {
+            src: element.src,
+            referrerPolicy: getReferrerPolicy_()
+          };
+          // Copy the title, if any.
+          if (element.title) {
+            result.title = element.title;
+          }
+          // Check if the image is also a link.
+          var parent = element.parentNode;
+          while (parent) {
+            if (parent.tagName &&
+                parent.tagName.toLowerCase() === 'a' &&
+                parent.href) {
+              // This regex identifies strings like void(0),
+              // void(0)  ;void(0);, ;;;;
+              // which result in a NOP when executed as JavaScript.
+              var regex = RegExp("^javascript:(?:(?:void\\(0\\)|;)\\s*)+$");
+              if (parent.href.match(regex)) {
+                parent = parent.parentNode;
+                continue;
+              }
+              result.href = parent.href;
+              result.referrerPolicy = getReferrerPolicy_(parent);
+              break;
+            }
+            parent = parent.parentNode;
+          }
+          return result;
+        }
+        element = element.parentNode;
+      }
+    }
+    return {};
+  };
+
+  /**
+   * Suppresses the next click such that they are not handled by JS click
+   * event handlers.
+   * @type {void}
+   */
+  __gCrWeb['suppressNextClick'] = function() {
+    var suppressNextClick = function(evt) {
+      evt.preventDefault();
+      document.removeEventListener('click', suppressNextClick, false);
+    };
+    document.addEventListener('click', suppressNextClick);
+  };
+
+  /**
+   * Returns the margin in points around touchable elements (e.g. links for
+   * custom context menu).
+   * @type {number}
+   */
+  __gCrWeb['getPageWidth'] = function() {
+    var documentElement = document.documentElement;
+    var documentBody = document.body;
+    return Math.max(documentElement.clientWidth,
+                    documentElement.scrollWidth,
+                    documentElement.offsetWidth,
+                    documentBody.scrollWidth,
+                    documentBody.offsetWidth);
+  };
+
+  /**
+   * Implementation of document.elementFromPoint that is working for iOS4 and
+   * iOS5 and that also goes into frames and iframes.
+   * @private
+   */
+  var elementFromPoint_ = function(x, y) {
+    var elementFromPointIsUsingViewPortCoordinates = function(win) {
+      if (win.pageYOffset > 0) {  // Page scrolled down.
+        return (win.document.elementFromPoint(
+            0, win.pageYOffset + win.innerHeight - 1) === null);
+      }
+      if (win.pageXOffset > 0) {  // Page scrolled to the right.
+        return (win.document.elementFromPoint(
+            win.pageXOffset + win.innerWidth - 1, 0) === null);
+      }
+      return false;  // No scrolling, don't care.
+    };
+
+    var newCoordinate = function(x, y) {
+      var coordinates = {
+          x: x, y: y,
+          viewPortX: x - window.pageXOffset, viewPortY: y - window.pageYOffset,
+          useViewPortCoordinates: false,
+          window: window
+      };
+      return coordinates;
+    };
+
+    // Returns the coordinates of the upper left corner of |obj| in the
+    // coordinates of the window that |obj| is in.
+    var getPositionInWindow = function(obj) {
+      var coord = { x: 0, y: 0 };
+      while (obj.offsetParent) {
+        coord.x += obj.offsetLeft;
+        coord.y += obj.offsetTop;
+        obj = obj.offsetParent;
+      }
+      return coord;
+    };
+
+    var elementsFromCoordinates = function(coordinates) {
+      coordinates.useViewPortCoordinates = coordinates.useViewPortCoordinates ||
+          elementFromPointIsUsingViewPortCoordinates(coordinates.window);
+
+      var currentElement = null;
+      if (coordinates.useViewPortCoordinates) {
+        currentElement = coordinates.window.document.elementFromPoint(
+            coordinates.viewPortX, coordinates.viewPortY);
+      } else {
+        currentElement = coordinates.window.document.elementFromPoint(
+            coordinates.x, coordinates.y);
+      }
+      // We have to check for tagName, because if a selection is made by the
+      // UIWebView, the element we will get won't have one.
+      if (!currentElement || !currentElement.tagName) {
+        return null;
+      }
+      if (currentElement.tagName.toLowerCase() === 'iframe' ||
+          currentElement.tagName.toLowerCase() === 'frame') {
+        // The following condition is true if the iframe is in a different
+        // domain; no further information is accessible.
+        if (typeof(currentElement.contentWindow.document) == 'undefined') {
+          return currentElement;
+        }
+        var framePosition = getPositionInWindow(currentElement);
+        coordinates.viewPortX -=
+            framePosition.x - coordinates.window.pageXOffset;
+        coordinates.viewPortY -=
+            framePosition.y - coordinates.window.pageYOffset;
+        coordinates.window = currentElement.contentWindow;
+        coordinates.x -= framePosition.x + coordinates.window.pageXOffset;
+        coordinates.y -= framePosition.y + coordinates.window.pageYOffset;
+        return elementsFromCoordinates(coordinates);
+      }
+      return currentElement;
+    };
+
+    return elementsFromCoordinates(newCoordinate(x, y));
+  };
+
+  /** @private */
+  var spiralCoordinates_ = function(x, y) {
+    var MAX_ANGLE = Math.PI * 2.0 * 3.0;
+    var POINT_COUNT = 30;
+    var ANGLE_STEP = MAX_ANGLE / POINT_COUNT;
+    var TOUCH_MARGIN = 25;
+    var SPEED = TOUCH_MARGIN / MAX_ANGLE;
+
+    var coordinates = [];
+    for (var index = 0; index < POINT_COUNT; index++) {
+      var angle = ANGLE_STEP * index;
+      var radius = angle * SPEED;
+
+      coordinates.push({x: x + Math.round(Math.cos(angle) * radius),
+                        y: y + Math.round(Math.sin(angle) * radius)});
+    }
+
+    return coordinates;
+  };
+
+  /** @private */
+  var getComputedWebkitTouchCallout_ = function(element) {
+    return window.getComputedStyle(element, null)['webkitTouchCallout'];
+  };
+
+  /**
+   * Gets the referrer policy to use for navigations away from the current page.
+   * If a link element is passed, and it includes a rel=noreferrer tag, that
+   * will override the page setting.
+   * @param {HTMLElement=} opt_linkElement The link triggering the navigation.
+   * @return {string} The policy string.
+   * @private
+   */
+  var getReferrerPolicy_ = function(opt_linkElement) {
+    if (opt_linkElement) {
+      var rel = opt_linkElement.getAttribute('rel');
+      if (rel && rel.toLowerCase() == 'noreferrer') {
+        return 'never';
+      }
+    }
+
+    var metaTags = document.getElementsByTagName('meta');
+    for (var i = 0; i < metaTags.length; ++i) {
+      if (metaTags[i].name.toLowerCase() == 'referrer') {
+        return metaTags[i].content.toLowerCase();
+      }
+    }
+    return 'default';
+  };
+
+}());  // End of anonymouse object