Styling PDF form fields

Implementing the WidgetAnnotation's getCustomStyles function allows you to add styling changes to particular types of widget annotations.

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

  Annotations.WidgetAnnotation.getCustomStyles = widget => {
    if (widget instanceof Annotations.TextWidgetAnnotation) {
      // can check widget properties
      if (widget.fieldName === 'f1-1') {
        return {
          'background-color': 'lightgreen'
        };
      }
      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) {
      // can check widget properties
      if (widget.fieldName === 'f1-1') {
        return {
          'background-color': 'lightgreen'
        };
      }
      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;
  };
});