Function getLocalHintsForElement

content_scripts/link_hints.js:1073–1294

(element)

  // one part of element which is clickable (for example, if it's an image); if so, each LocalHint
  // represents one of the clickable rectangles of the element.
  getLocalHintsForElement(element) {
    // Get the tag name. However, `element.tagName` can be an element (not a string, see #2035), so
    // we guard against that.
    const tagName = element.tagName.toLowerCase?.() || "";
    let isClickable = false;
    let onlyHasTabIndex = false;
    let possibleFalsePositive = false;
    const hints = [];
    const imageMapAreas = [];
    let reason = null;

    // Insert area elements that provide click functionality to an img.
    if (tagName === "img") {
      let mapName = element.getAttribute("usemap");
      if (mapName) {
        const imgClientRects = element.getClientRects();
        mapName = mapName.replace(/^#/, "").replace('"', '\\"');
        const map = document.querySelector(`map[name=\"${mapName}\"]`);
        if (map && (imgClientRects.length > 0)) {
          isClickable = true;
          const areas = map.getElementsByTagName("area");
          let areasAndRects = DomUtils.getClientRectsForAreas(imgClientRects[0], areas);
          // We use this image property when detecting overlapping links.
          areasAndRects = areasAndRects.map((o) => Object.assign(o, { image: element }));
          imageMapAreas.push(...areasAndRects);
        }
      }
    }

    // Check aria properties to see if the element should be ignored.
    // Note that we're showing hints for elements with aria-hidden=true. See #3501 for discussion.
    const ariaDisabled = element.getAttribute("aria-disabled");
    if (ariaDisabled && ["", "true"].includes(ariaDisabled.toLowerCase())) {
      return []; // This element should never have a link hint.
    }

    // Check for AngularJS listeners on the element.
    if (!this.checkForAngularJs) {
      this.checkForAngularJs = (function () {
        const angularElements = document.getElementsByClassName("ng-scope");
        if (angularElements.length === 0) {
          return () => false;
        } else {
          const ngAttributes = [];
          for (const prefix of ["", "data-", "x-"]) {
            for (const separator of ["-", ":", "_"]) {
              ngAttributes.push(`${prefix}ng${separator}click`);
            }
          }
          return function (element) {
            for (const attribute of ngAttributes) {
              if (element.hasAttribute(attribute)) return true;
            }
            return false;
          };
        }
      })();
    }