Attach (recommended) or Link to PDF file [here:] Can't see how to attach a pdf here, but it is simple to create. Add a form object textbox to a pdf and make sure the option for "Multiline" is true.

Steps to reproduce the problem:
1.  Open a document with a Textbox that is set to Multiline.
2. Attempt to hit the Enter key to go to a new line.

What is the expected behavior? The cursor goes to a new line.

What went wrong? It does not go to a new line.

Link to a viewer: It can be reproduced on mozilla.github.io/pdf.js

I corrected the issue by altering the pdf.js file like this
element.addEventListener("keydown", event => { 
[...]
--} else if (event.key === "Enter") {
++ } else if (event.key === "Enter" && !this.data.multiLine) {

Our initial testing is coming through clean, and hopefully something like this code can be committed to the project in the future.

const subtype = parameters.data.annotationType;
    switch (subtype) {
      case AnnotationType.LINK:
        return new LinkAnnotationElement(parameters);
      case AnnotationType.TEXT:
        return new TextAnnotationElement(parameters);
      case AnnotationType.WIDGET:
        const fieldType = parameters.data.fieldType;
        switch (fieldType) {
          case "Tx":
            return new TextWidgetAnnotationElement(parameters);
          case "Btn":
            if (parameters.data.radioButton) {
              return new RadioButtonWidgetAnnotationElement(parameters);
            } else if (parameters.data.checkBox) {
              return new CheckboxWidgetAnnotationElement(parameters);
            }
            return new PushButtonWidgetAnnotationElement(parameters);
          case "Ch":
            return new ChoiceWidgetAnnotationElement(parameters);
        }
        return new WidgetAnnotationElement(parameters);
      case AnnotationType.POPUP:
        return new PopupAnnotationElement(parameters);
      case AnnotationType.FREETEXT:
        return new FreeTextAnnotationElement(parameters);
      case AnnotationType.LINE:
        return new LineAnnotationElement(parameters);