Class: Keisanjaku::TerminalViewport

Inherits:
Object
  • Object
show all
Defined in:
lib/keisanjaku/terminal_viewport.rb

Constant Summary collapse

POLL_INTERVAL = 
0.25

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(width: nil, provider: nil, poll_interval: POLL_INTERVAL, platform: nil, right_margin: 0, clamp_fixed_width: false) ⇒ TerminalViewport

Returns a new instance of TerminalViewport.



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# File 'lib/keisanjaku/terminal_viewport.rb', line 11

def initialize(width: nil, provider: nil, poll_interval: POLL_INTERVAL, platform: nil, right_margin: 0, clamp_fixed_width: false)
  @requested_width = width
  @fixed = !width.nil?
  @provider = provider || -> { IO.console&.winsize&.last || Renderer::DEFAULT_WIDTH }
  @poll_interval = poll_interval
  @platform = platform || RbConfig::CONFIG["host_os"]
  @right_margin = [right_margin.to_i, 0].max
  @clamp_fixed_width = clamp_fixed_width
  @dirty = false
  @last_poll = Time.now
  @previous_winch_handler = nil
  @width = normalize_width(target_width)
end

Instance Attribute Details

#width ⇒ Object (readonly)

Returns the value of attribute width.



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# File 'lib/keisanjaku/terminal_viewport.rb', line 9

def width
  @width
end

Instance Method Details

#current_width ⇒ Object 



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# File 'lib/keisanjaku/terminal_viewport.rb', line 45

def current_width
  return width if fixed_width?

  refresh if @dirty || poll_due?
  width
end

#fixed_width? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/keisanjaku/terminal_viewport.rb', line 70

def fixed_width?
  @fixed && !@clamp_fixed_width
end

#install ⇒ Object 



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# File 'lib/keisanjaku/terminal_viewport.rb', line 25

def install
  return self if fixed_width?
  return self unless Signal.list.key?("WINCH")
  return self if windows?

  @previous_winch_handler = Signal.trap("WINCH") { @dirty = true }
  self
rescue ArgumentError
  self
end

#refresh ⇒ Object 



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# File 'lib/keisanjaku/terminal_viewport.rb', line 63

def refresh
  @width = normalize_width(target_width)
  @dirty = false
  @last_poll = Time.now
  width
end

#refresh_needed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/keisanjaku/terminal_viewport.rb', line 52

def refresh_needed?
  return false if fixed_width?

  signaled = @dirty
  return false unless signaled || poll_due?

  previous_width = @width
  refresh
  signaled || previous_width != @width
end

#restore ⇒ Object 



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# File 'lib/keisanjaku/terminal_viewport.rb', line 36

def restore
  return unless @previous_winch_handler

  Signal.trap("WINCH", @previous_winch_handler)
  @previous_winch_handler = nil
rescue ArgumentError
  nil
end