Class FormCheckbox

  • All Implemented Interfaces:
    Cloneable

    public final class FormCheckbox
    extends FormElement

    A type of form element representing a Check Box, which can be either "checked" or "cleared" (on or off), in the same way as the HTML "checkbox" input type. In PDF, Checkboxes are almost identical to Radio Buttons - the only difference is that radio buttons require at least one annotation to be selected, whereas checkboxes don't.

    Here's an example showing how to add a set of checkboxes to the form. Each one of these boxes may be turned on or off separately.

       FormCheckbox check1 = new FormCheckbox(page, 100,100,110,110);
       form.addElement("PowerSteering", check1);
       FormCheckbox check2 = new FormCheckbox(page, 100,120,110,130);
       form.addElement("ElectricWindows", check2);
       FormCheckbox check3 = new FormCheckbox(page, 100,140,110,150);
       form.addElement("AirConditioning", check3);
     

    and here's how to determine which of those values is checked

       Form form = pdf.getForm();
       FormCheckbox check;
       check = (FormCheckbox)form.getElement("PowerSteering");
       boolean powersteering = check.getValue()!=null;
       check = (FormCheckbox)form.getElement("ElectricWindows");
       boolean electricwindows = check.getValue()!=null;
       // etc.
     
    Multiple checkboxes with the same name can be created - these will function like radio buttons except for the fact that none of the boxes has to be set.
    Since:
    1.1.23
    • Constructor Detail

      • FormCheckbox

        public FormCheckbox​(PDFPage page,
                            float x1,
                            float y1,
                            float x2,
                            float y2)
        Create a new FormCheckbox with a single annotation at the specified position. The annotation has the value of "Yes" when selected. Equivalent to calling:
          FormCheckbox box = new FormCheckbox();
          box.addAnnotation("Yes", page, x1, y1, x2, y2);
         
        Parameters:
        page - the page to place the annotation on
        x1 - the left-most X co-ordinate of the annotation
        y1 - the top-most Y co-ordinate of the annotation
        x2 - the right-most X co-ordinate of the annotation
        y2 - the bottom-most Y co-ordinate of the annotation
    • Method Detail

      • setValue

        public void setValue​(String value)
        Mark the specified annotation for the Checkbox/RadioButton as selected, and unselect any others. The specified value must be the the value of one of this field's WidgetAnnotation objects, otherwise an an IllegalArgumentException is thrown.
        Parameters:
        value - the value of the annotation to select, or null to turn them all off
      • setDefaultValue

        public void setDefaultValue​(String value)
        Set the default value for this field. Fields revert to their default value when the PDFAction.formReset() action is invoked. See setValue(java.lang.String, java.lang.String) for a discussion of which values are valid.
        Parameters:
        value - the value of the annotation to select, or null to turn them all off
      • getValue

        public String getValue()
        Get the value of this field. This will be the value of the selected RadioButton/Checkbox annotation, or null if no annotation is selected.
        Returns:
        the value of the selected annotation, or null if none is selected
      • getDefaultValue

        public String getDefaultValue()
        Return the default value of this field, or null if no default value exists.
        Returns:
        the default value of this field, or null if none is specified
      • getOptions

        public Map<String,​WidgetAnnotation> getOptions()
        Return a read-only Map containing the values (annotations) that can be selected in this RadioButton or Checkbox. As each annotation's value can be checked by iterating through the list returned from FormElement.getAnnotations(), this method is not strictly necessary, but it's a little more convenient and intuitive so we've left it in.
      • rebuild

        public void rebuild()
        Description copied from class: FormElement
        Cause the annotation list to be rebuilt. Unless you're rendering the annotation using the viewer, it's not necessary to call this method.
      • addAnnotation

        public WidgetAnnotation addAnnotation​(String value,
                                              PDFPage page,
                                              float x1,
                                              float y1,
                                              float x2,
                                              float y2)
        Add an annotation to the Checkbox or RadioButton.
        Parameters:
        value - the value of the annotation - this will be the value returned by FormElement.getValue() if this annotation is selected. Note that "Off" is not allowed as an annotation name.
        page - the page to place the annotation on
        x1 - the left-most X co-ordinate of the annotation
        y1 - the top-most Y co-ordinate of the annotation
        x2 - the right-most X co-ordinate of the annotation
        y2 - the bottom-most Y co-ordinate of the annotation
      • toString

        public String toString()