firefox/toolkit/components/tooltiptext/TooltipTextProvider.sys.mjs

/* 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/. */

export function TooltipTextProvider() {}

function getFileInputTitleText(tipElement) {
  let files = tipElement.files;
  let bundle = Services.strings.createBundle(
    "chrome://global/locale/layout/HtmlForm.properties"
  );
  if (!files.length) {
    return bundle.GetStringFromName(
      tipElement.multiple ? "NoFilesSelected" : "NoFileSelected"
    );
  }
  let titleText = files[0].name;
  // For UX and performance (jank) reasons we cap the number of
  // files that we list in the tooltip to 20 plus a "and xxx more"
  // line, or to 21 if exactly 21 files were picked.
  const TRUNCATED_FILE_COUNT = 20;
  let count = Math.min(files.length, TRUNCATED_FILE_COUNT);
  for (let i = 1; i < count; ++i) {
    titleText += "\n" + files[i].name;
  }
  if (files.length == TRUNCATED_FILE_COUNT + 1) {
    titleText += "\n" + files[TRUNCATED_FILE_COUNT].name;
  } else if (files.length > TRUNCATED_FILE_COUNT + 1) {
    const l10n = new Localization(["toolkit/global/htmlForm.ftl"], true);
    const andXMoreStr = l10n.formatValueSync("input-file-and-more-files", {
      fileCount: files.length - TRUNCATED_FILE_COUNT,
    });
    titleText += "\n" + andXMoreStr;
  }
  return titleText;
}

TooltipTextProvider.prototype = {
  getNodeText(tipElement, textOut, directionOut) {
    // Don't show the tooltip if the tooltip node is a document or browser.
    // Caller should ensure the node is in (composed) document.
    if (
      !tipElement ||
      !tipElement.ownerDocument ||
      tipElement.localName == "browser"
    ) {
      return false;
    }

    var defView = tipElement.ownerGlobal;
    // XXX Work around bug 350679:
    // "Tooltips can be fired in documents with no view".
    if (!defView) {
      return false;
    }

    const XLinkNS = "http://www.w3.org/1999/xlink";
    const XUL_NS =
      "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";

    var titleText = null;
    var XLinkTitleText = null;
    var lookingForSVGTitle = true;
    var direction = tipElement.ownerDocument.dir;

    for (; tipElement; tipElement = tipElement.flattenedTreeParentNode) {
      if (tipElement.nodeType != defView.Node.ELEMENT_NODE) {
        continue;
      }
      if (tipElement.namespaceURI == XUL_NS) {
        lookingForSVGTitle = false;
        titleText = tipElement.getAttribute("tooltiptext");
      } else if (!defView.SVGElement.isInstance(tipElement)) {
        lookingForSVGTitle = false;
        titleText = tipElement.getAttribute("title");
      }

      if (
        (defView.HTMLAnchorElement.isInstance(tipElement) ||
          defView.HTMLAreaElement.isInstance(tipElement) ||
          defView.HTMLLinkElement.isInstance(tipElement) ||
          defView.SVGAElement.isInstance(tipElement)) &&
        tipElement.href
      ) {
        XLinkTitleText = tipElement.getAttributeNS(XLinkNS, "title");
      }

      // If the element is invalid per HTML5 Forms specifications and has no title,
      // show the constraint validation error message.
      if (
        titleText == null &&
        (defView.HTMLInputElement.isInstance(tipElement) ||
          defView.HTMLTextAreaElement.isInstance(tipElement) ||
          defView.HTMLSelectElement.isInstance(tipElement) ||
          defView.HTMLButtonElement.isInstance(tipElement)) &&
        !tipElement.form?.noValidate
      ) {
        // If the element is barred from constraint validation or valid,
        // the validation message will be the empty string.
        titleText = tipElement.validationMessage || null;
      }

      // If the element is an <input type='file'> without a title, we should show
      // the current file selection.
      if (
        titleText == null &&
        defView.HTMLInputElement.isInstance(tipElement) &&
        tipElement.type == "file"
      ) {
        try {
          titleText = getFileInputTitleText(tipElement);
        } catch (ex) {}
      }

      if (
        lookingForSVGTitle &&
        tipElement.parentNode.nodeType != defView.Node.DOCUMENT_NODE
      ) {
        for (let childNode of tipElement.childNodes) {
          if (defView.SVGTitleElement.isInstance(childNode)) {
            titleText = childNode.textContent;
            break;
          }
        }
      }

      // Check texts against null so that title="" can be used to undefine a
      // title on a child element.
      if (titleText != null || XLinkTitleText != null) {
        break;
      }
    }

    return [titleText, XLinkTitleText].some(function (t) {
      if (t && /\S/.test(t)) {
        // Make CRLF and CR render one line break each.
        textOut.value = t.replace(/\r\n?/g, "\n");

        if (tipElement) {
          direction = defView
            .getComputedStyle(tipElement)
            .getPropertyValue("direction");
        }

        directionOut.value = direction;
        return true;
      }

      return false;
    });
  },

  classID: Components.ID("{f376627f-0bbc-47b8-887e-fc92574cc91f}"),
  QueryInterface: ChromeUtils.generateQI(["nsITooltipTextProvider"]),
};