Method: HexaPDF::Content::Canvas#form

Defined in:
lib/hexapdf/content/canvas.rb

#form(width = nil, height = nil) {|obj.canvas| ... } ⇒ Object

:call-seq:

canvas.form {|form_canvas| block }                  => form
canvas.form(width, height) {|form_canvas| block }   => form

Creates a reusable Form XObject, yields its canvas and then returns it.

If no arguments are provided, the bounding box of the form is the same as that of the context object of this canvas. Otherwise you need to provide the width and height for the form.

Once the form has been created, it can be used like an image and drawn mulitple times with the #xobject method. Note that the created form object is independent of this canvas and its context object. This means it can also be used with other canvases.

Examples:

#>pdf
form = canvas.form do |form_canvas|
  form_canvas.fill_color("hp-blue").line_width(5).
    rectangle(10, 10, 80, 80).fill_stroke
end
canvas.xobject(form, at: [0, 0])
canvas.xobject(form, width: 50, at: [100, 100])

See: HexaPDF::Type::Form

Yields:

  • (obj.canvas) 


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# File 'lib/hexapdf/content/canvas.rb', line 1479

def form(width = nil, height = nil) # :yield: canvas
  obj = if width && height
          context.document.add({Type: :XObject, Subtype: :Form, BBox: [0, 0, width, height]})
        elsif width || height
          raise ArgumentError, "Both arguments width and height need to be provided"
        else
          context.document.add({Type: :XObject, Subtype: :Form, BBox: context.box.value.dup})
        end
  yield(obj.canvas) if block_given?
  obj
end