Module: Prawn::Graphics::Transparency

Included in:
Prawn::Graphics
Defined in:
lib/prawn/graphics/transparency.rb

Overview

This module is used to place transparent content on the page. It has the capacity for separate transparency values for stroked content and all other content.

Stable API collapse

Instance Method Details

#transparent(opacity, stroke_opacity = opacity) { ... } ⇒ void

This method returns an undefined value.

Set opacity.

Examples:

Both the fill and stroke will be at 50% opacity.

pdf.transparent(0.5) do
  pdf.text("hello world")
  pdf.fill_and_stroke_circle([x, y], 25)
end

The fill will be at 50% opacity, but the stroke will be at 75% opacity.

pdf.transparent(0.5, 0.75) do
  pdf.text("hello world")
  pdf.fill_and_stroke_circle([x, y], 25)
end

Parameters:

  • opacity (Number) —

    Fill opacity. Clipped to the 0.0 to 1.0 range.

  • stroke_opacity (Number) (defaults to: opacity) —

    Stroke opacity. Clipped to the 0.0 to 1.0 range.

Yields:



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# File 'lib/prawn/graphics/transparency.rb', line 30

def transparent(opacity, stroke_opacity = opacity)
  renderer.min_version(1.4)

  opacity = opacity.clamp(0.0, 1.0)
  stroke_opacity = stroke_opacity.clamp(0.0, 1.0)

  save_graphics_state
  renderer.add_content(
    "/#{opacity_dictionary_name(opacity, stroke_opacity)} gs",
  )
  yield
  restore_graphics_state
end