Class: TerminalLayout::TerminalRenderer

Inherits:
Object
  • Object
show all
Includes:
HighLine::SystemExtensions, EventEmitter
Defined in:
lib/terminal_layout.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from EventEmitter

#_callbacks, #emit, #on, #unsubscribe

Constructor Details

#initialize(output: $stdout) ⇒ TerminalRenderer

Returns a new instance of TerminalRenderer.



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# File 'lib/terminal_layout.rb', line 526

def initialize(output: $stdout)
  @output = output
  @term_info = TermInfo.new ENV["TERM"], @output
  @previously_printed_lines = []
  @x, @y = 0, 0
end

Instance Attribute Details

#term_info ⇒ Object (readonly)

Returns the value of attribute term_info.



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# File 'lib/terminal_layout.rb', line 524

def term_info
  @term_info
end

Instance Method Details

#clear_screen ⇒ Object 



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# File 'lib/terminal_layout.rb', line 657

def clear_screen ; term_info.control "clear" ; end

#clear_screen_down ⇒ Object 



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# File 'lib/terminal_layout.rb', line 658

def clear_screen_down ; term_info.control "ed" ; end

#clear_to_beginning_of_line ⇒ Object 



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# File 'lib/terminal_layout.rb', line 656

def clear_to_beginning_of_line ; term_info.control "el1" ; end

#dumb_render(object, reset: false) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 603

def dumb_render(object, reset: false)
  if reset
    @y = 0
    @previously_printed_lines.clear
  end
  @output.print @term_info.control_string "civis"
  move_up_n_rows @y
  move_to_beginning_of_row

  object = find_top_of_tree(object)

  object_width = object.width

  rendered_content = object.render
  printable_content = rendered_content.sub(/\s*\Z/m, '')

  printable_lines = printable_content.split(/\n/).each_with_object([]) do |line, results|
    if line.empty?
      results << line
    else
      results.concat line.scan(/.{1,#{terminal_width}}/)
    end
  end

  printable_lines.zip(@previously_printed_lines) do |new_line, previous_line|
    if new_line != previous_line
      # be sure to reset the terminal at the outset of every line
      # because we don't know what state the previous line ended in
      line2print = "#{new_line}\e[0m"
      term_info.control "el"
      move_to_beginning_of_row
      term_info.control "el"
      Treefell['render'].puts "printing line=#{line2print.inspect}"
      @output.puts line2print
    else
      move_down_n_rows 1
    end
  end
  move_to_beginning_of_row
  clear_screen_down

  # calculate lines drawn so we know where we are
  lines_drawn = (printable_content.length / object_width.to_f).ceil
  @y = lines_drawn

  input_box = object.box.find_child_of_type(InputBox) do |box|
    box.focused?
  end
  render_cursor(input_box)

  @previously_printed_lines = printable_lines
end

#find_top_of_tree(object) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 595

def find_top_of_tree(object)
  loop do
    break unless object.parent
    object = object.parent
  end
  object
end

#move_down_n_rows(n) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 666

def move_down_n_rows(n) ; n.times { term_info.control "cud1" } ; end

#move_left ⇒ Object 



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# File 'lib/terminal_layout.rb', line 660

def move_left ; move_left_n_characters 1 ; end

#move_left_n_characters(n) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 661

def move_left_n_characters(n) ; n.times { term_info.control "cub1" } ; end

#move_right_n_characters(n) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 662

def move_right_n_characters(n) ; n.times { term_info.control "cuf1" } ; end

#move_to_beginning_of_row ⇒ Object 



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# File 'lib/terminal_layout.rb', line 659

def move_to_beginning_of_row ; move_to_column 0 ; end

#move_to_column(n) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 664

def move_to_column(n) ; term_info.control "hpa", n ; end

#move_to_column_and_row(column, row) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 663

def move_to_column_and_row(column, row) ; term_info.control "cup", column, row ; end

#move_up_n_rows(n) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 665

def move_up_n_rows(n) ; n.times { term_info.control "cuu1" } ; end

#render(object, reset: false) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 591

def render(object, reset: false)
  dumb_render(object, reset: reset)
end

#render_cursor(input_box) ⇒ Object 



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# File 'lib/terminal_layout.rb', line 533

def render_cursor(input_box)
  Treefell['render'].puts "render cursor at box=#{input_box.inspect} computed=#{input_box.computed.inspect}"

  move_up_n_rows @y
  move_to_beginning_of_row

  position = input_box.position

  cursor_position = input_box.cursor_position
  cursor_x = cursor_position.x
  cursor_y = cursor_position.y

  relative_position_on_row = position
  initial_offset_x = input_box.computed[:x] + (input_box.computed[:y] * terminal_width)
  cursor_x = 0
  cursor_y = 0

  absolute_position_on_row = relative_position_on_row + initial_offset_x
  loop do
    if absolute_position_on_row >= terminal_width
      # reset offset
      initial_offset_x = 0

      absolute_position_on_row -= terminal_width

      # move down a line
      cursor_y += 1
    else
      # we fit on the current line
      cursor_x = absolute_position_on_row
      break
    end
  end

  if @y < cursor_y
    # moving backwards
    move_up_n_rows(@y - cursor_y)
  elsif @y > cursor_y
    # moving forwards
    move_down_n_rows(cursor_y - @y)
  end

  move_down_n_rows cursor_y
  move_to_beginning_of_row
  move_right_n_characters cursor_x

  @x = cursor_x
  @y = cursor_y

  Treefell['render'].puts "rendering cursor at x=#{@x} y=#{@y}"

  if input_box.style[:cursor] == 'none'
    @output.print @term_info.control_string "civis"
  else
    @output.print @term_info.control_string "cnorm"
  end
end

#terminal_height ⇒ Object 



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# File 'lib/terminal_layout.rb', line 672

def terminal_height
  terminal_size[1]
end

#terminal_width ⇒ Object 



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# File 'lib/terminal_layout.rb', line 668

def terminal_width
  terminal_size[0]
end