class HexaPDF::Type::AcroForm::ButtonField
- See: PDF2.0 s12.7.4.2
on or off in unison.
:radios_in_unison - A group of radio buttons with the same value for the on state will turn
:push_button - The field represents a pushbutton without a permanent value.
box. Additionally, the :pushbutton flag needs to be clear.
:radio - If this flag is set, the field is a set of radio buttons. Otherwise it is a check
names.
work-around is to use multiple check box widgets with different on
Note: This deselectiong is not implemented in any tested PDF viewer. A
button deselects it.
needs to be selected at all times. Otherwise, clicking on the selected
:no_toggle_to_off -
Only used with radio buttons fields. If this flag is set, one button
== Type Specific Field Flags
no check box may be selected.
case the check box fields acts like a radio button group, with the additional feature that
Otherwise only one of those widgets will be toggled on while the others are off. In such a
those widgets have the same value, they will all be toggled on or off simultaneously.
Check boxes can be toggled on and off. One check box field may have multiple widgets. If
for this feature.no_toggle_to_off
field flag, no PDF viewer implements that; one needs to use check boxes
otherwise the widgets with the same value represent the same thing. Although there is the
may be selected at all times. Each widget must have a different value to be distinguishable;
group. Of the radio button group only one radio button (= widget of the radio button field)
Radio buttons are widgets of a single radio button field. This is also called a radio button
everything needed is automatically set up.
methods on the main Form instance (HexaPDF::Document#acro_form). By using those methods,
To create a push button, check box or radio button field, use the appropriate convenience
of these are represented with this class.
They are divided into push buttons (things to click on), check boxes and radio buttons. All
AcroForm button fields represent interactive controls to be used with the mouse.
- If this flag is set, the field is a set of radio buttons. Otherwise it is a check
- The field represents a pushbutton without a permanent value.
- A group of radio buttons with the same value for the on state will turn
def allowed_values
Note that this will only return useful values if there is at least one correctly set-up
value for check boxes or radio buttons.
Returns the array of Symbol values (minus the /Off value) that can be used for the field
def allowed_values (each_widget.with_object([]) do |widget, result| keys = widget.appearance_dict&.normal_appearance&.value&.keys result.concat(keys) if keys end - [:Off]).uniq end
def check_box?
def check_box? !push_button? && !flagged?(:radio) end
def concrete_field_type
def concrete_field_type if push_button? :push_button elsif radio_button? :radio_button else :check_box end end
def create_appearances(force: false)
AppearanceGenerator for the details.
The created appearance streams depend on the actual type of the button field. See
Creates appropriate appearances for all widgets if they don't already exist.
def create_appearances(force: false) appearance_generator_class = document.config.constantize('acro_form.appearance_generator') each_widget do |widget| normal_appearance = widget.appearance_dict&.normal_appearance next if !force && normal_appearance && ((!push_button? && normal_appearance.value.length == 2 && normal_appearance.each.all? {|_, v| v.kind_of?(HexaPDF::Stream) }) || (push_button? && normal_appearance.kind_of?(HexaPDF::Stream))) if check_box? appearance_generator_class.new(widget).create_check_box_appearances elsif radio_button? appearance_generator_class.new(widget).create_radio_button_appearances else appearance_generator_class.new(widget).create_push_button_appearances end end end
def create_widget(page, defaults: true, value: nil, **values)
be used.
The +value+ is optional for check box fields; if not specified, the default of :Yes will
be used with #field_value= to set this specific widget of the radio button set to on.
the value (a Symbol or an object responding to +#to_sym+) this widget represents. It can
If the widget is created for a radio button field, the +value+ argument needs to set to
default appearance.
If +defaults+ is +true+, then default values will be set on the widget so that it uses a
Creates a widget for the button field.
def create_widget(page, defaults: true, value: nil, **values) super(page, allow_embedded: !radio_button?, **values).tap do |widget| value = :Yes if check_box? && value.nil? if radio_button? || check_box? unless value.respond_to?(:to_sym) raise ArgumentError, "Argument 'value' has to be provided for radio buttons " \ "and needs to respond to #to_sym" end widget[:AP] = {N: {value.to_sym => nil, Off: nil}} end next unless defaults widget.border_style(color: 0, width: 1, style: (push_button? ? :beveled : :solid)) widget.background_color(push_button? ? 0.5 : 255) widget.marker_style(style: check_box? ? :check : :circle) unless push_button? end end
def default_field_value
Returns the default field value.
def default_field_value normalized_field_value(:DV) end
def default_field_value=(value)
Sets the default field value.
def default_field_value=(value) normalized_field_value_set(:DV, value) end
def field_value
Radio buttons:: If no radio button is selected, +nil+ is returned. Otherwise the value (a
checked is returned. Otherwise +nil+ is returned.
Check boxes:: For check boxes that are checked the value of the specific check box that is
Push buttons:: They don't have a value, so +nil+ is always returned.
Returns the field value which depends on the concrete type.
def field_value normalized_field_value(:V) end
def field_value=(value)
the value (a Symbol or an object responding to +#to_sym+) of a radio
Radio buttons:: To turn all radio buttons off, provide +nil+ as value. Otherwise provide
toggled on.
an object responding to +#to_sym+) of the check box widget that should be
i.e. toggling it to the on state. Otherwise provide the value (a Symbol or
there is only one possible value, +true+ may be used for checking the box,
Check boxes:: Provide +nil+ or +false+ as value to toggle all check box widgets off. If
nothing is stored for them (e.g a no-op).
Push buttons:: Since push buttons don't store any value, the given value is ignored and
Sets the field value which depends on the concrete type.
def field_value=(value) normalized_field_value_set(:V, value) end
def initialize_as_check_box
This method should only be called directly after creating a new button field because it
Initializes the button field to be a check box.
def initialize_as_check_box self[:V] = :Off unflag(:push_button) unflag(:radio) end
def initialize_as_push_button
This method should only be called directly after creating a new button field because it
Initializes the button field to be a push button.
def initialize_as_push_button self[:V] = nil flag(:push_button) unflag(:radio) end
def initialize_as_radio_button
This method should only be called directly after creating a new button field because it
Initializes the button field to be a radio button.
def initialize_as_radio_button self[:V] = :Off unflag(:push_button) flag(:radio) end
def normalized_field_value(key)
Returns the normalized field value for the given key which can be :V or :DV.
def normalized_field_value(key) if push_button? nil else self[key] == :Off ? nil : self[key] end end
def normalized_field_value_set(key, value)
transformed into the expected value depending on the specific field type.
Sets the key, either :V or :DV, to the value. The given normalized value is first
def normalized_field_value_set(key, value) return if push_button? av = allowed_values self[key] = if value.nil? || value == :Off :Off elsif check_box? if value == false :Off elsif value == true && av.size == 1 av[0] elsif av.include?(value.to_sym) value.to_sym else @document.config['acro_form.on_invalid_value'].call(self, value) end elsif av.include?(value.to_sym) value.to_sym else @document.config['acro_form.on_invalid_value'].call(self, value) end update_widgets end
def perform_validation #:nodoc:
def perform_validation #:nodoc: if field_type != :Btn yield("Field /FT of AcroForm button field has to be :Btn", true) self[:FT] = :Btn end super unless key?(:V) yield("Button field has no value set, defaulting to :Off", true) self[:V] = :Off end end
def push_button?
def push_button? flagged?(:push_button) end
def radio_button?
def radio_button? !push_button? && flagged?(:radio) end
def update_widgets
def update_widgets return if push_button? create_appearances value = self[:V] each_widget do |widget| widget[:AS] = (widget.appearance_dict&.normal_appearance&.key?(value) ? value : :Off) end end