module Prawn::Graphics::Dash
Public Instance Methods
Sets the dash pattern for stroked lines and curves or return the current dash pattern setting if length
is nil.
There are two ways to set the dash pattern:
-
If the parameter
length
is an Integer/Float, it specifies the length of the dash and of the gap. The length of the gap can be customized by setting the :space option.Examples:
length = 3 3 on, 3 off, 3 on, 3 off, ... length = 3, :space =2 3 on, 2 off, 3 on, 2 off, ...
-
If the parameter
length
is an array, it specifies the lengths of alternating dashes and gaps. The numbers must be non-negative and not all zero. The :space option is ignored in this case.Examples:
length = [2, 1] 2 on, 1 off, 2 on, 1 off, ... length = [3, 1, 2, 3] 3 on, 1 off, 2 on, 3 off, 3 on, 1 off, ... length = [3, 0, 1] 3 on, 0 off, 1 on, 3 off, 0 on, 1 off, ...
Options may contain the keys :space and :phase
- :space
-
The space between the dashes (only used when
length
is not an array) - :phase
-
The distance into the dash pattern at which to start the dash. For example, a phase of 0 starts at the beginning of the dash; whereas, if the phase is equal to the length of the dash, then stroking will begin at the beginning of the space. Default is 0.
Integers or Floats may be used for length and the option values. Dash
units are in PDF
points (1/72 inch).
# File lib/prawn/graphics/dash.rb, line 58 def dash(length = nil, options = {}) return current_dash_state if length.nil? length = Array(length) if length.all?(&:zero?) raise ArgumentError, 'Zero length dashes are invalid. Call #undash to disable dashes.' elsif length.any?(&:negative?) raise ArgumentError, 'Negative numbers are not allowed for dash lengths.' end length = length.first if length.length == 1 self.current_dash_state = { dash: length, space: length.is_a?(Array) ? nil : options[:space] || length, phase: options[:phase] || 0 } write_stroke_dash end
Returns when stroke is dashed, false otherwise
# File lib/prawn/graphics/dash.rb, line 93 def dashed? current_dash_state != undashed_setting end
Stops dashing, restoring solid stroked lines and curves
# File lib/prawn/graphics/dash.rb, line 86 def undash self.current_dash_state = undashed_setting write_stroke_dash end
Private Instance Methods
# File lib/prawn/graphics/dash.rb, line 111 def current_dash_state graphic_state.dash end
# File lib/prawn/graphics/dash.rb, line 107 def current_dash_state=(dash_options) graphic_state.dash = dash_options end
# File lib/prawn/graphics/dash.rb, line 115 def dash_setting graphic_state.dash_setting end
# File lib/prawn/graphics/dash.rb, line 103 def undashed_setting { dash: nil, space: nil, phase: 0 } end
# File lib/prawn/graphics/dash.rb, line 99 def write_stroke_dash renderer.add_content dash_setting end