Styling PDF form fields

Starting in WebViewer 11 you can style widgets by modifying their annotation properties directly. These styles are serialized and therefore saved to the PDF document.

In earlier versions, styles could only be modified by using the Widget.getCustomStyles or Widget.getCustomContainerStyles functions and were not serialized or saved to the document.

WebViewer(...)
.then(instance => {
  // This method of styling widgets is not available in WebViewer 8.
  // See sections below for usage on getCustomStyles()
  // and getCustomContainerStyles().
});

Implementing the WidgetAnnotation's getCustomStyles function allows you to add styling changes to particular types of widget annotations. This function gets called for every annotation but in the sample below we show how to filter for all widgets, and style specific widgets based on their type.

WebViewer(...)
.then(instance => {
  const { Annotations } = instance.Core;

  Annotations.WidgetAnnotation.getCustomStyles = widget => {
    if (widget instanceof Annotations.TextWidgetAnnotation) {
      return {
        'background-color': 'lightblue',
        color: 'brown'
      };
    } else if (widget instanceof Annotations.PushButtonWidgetAnnotation) {
      return {
        'background-color': 'black',
        color: 'white'
      };
    } else if (widget instanceof Annotations.CheckButtonWidgetAnnotation) {
      return {
        'background-color': 'lightgray',
        opacity: 0.8
      };
    }
  };
});

Implementing the WidgetAnnotation's getContainerCustomStyles function allows you to add styling changes to the container element of the widget annotation.

WebViewer(...)
.then(instance => {
  const { Annotations } = instance.Core;

  Annotations.WidgetAnnotation.getContainerCustomStyles = widget => {
    if (widget instanceof Annotations.TextWidgetAnnotation) {
      return {
        'background-color': 'lightblue',
        color: 'brown'
      };
    } else if (widget instanceof Annotations.PushButtonWidgetAnnotation) {
      return {
        'background-color': 'black',
        color: 'white'
      };
    } else if (widget instanceof Annotations.CheckButtonWidgetAnnotation) {
      return {
        'background-color': 'lightgray',
        opacity: 0.8
      };
    }
  };
});

You can also extend the createInnerElement function on widget annotations. This allows you to use your own DOM elements for the display or just to add your own event handlers.

WebViewer(...)
.then(instance => {
  const { Annotations } = instance.Core;

  const createInnerElement = Annotations.CheckButtonWidgetAnnotation.prototype.createInnerElement;
  Annotations.CheckButtonWidgetAnnotation.prototype.createInnerElement = function() {
    const button = this;

    const el = createInnerElement.apply(this, arguments);
    el.addEventListener('click', () => {
      console.log('check button clicked', button.fieldName);
    });

    return el;
  };
});