Class: RailroadDiagrams::HorizontalChoice

Inherits:
DiagramMultiContainer show all
Defined in:
lib/railroad_diagrams/horizontal_choice.rb

Instance Attribute Summary

Attributes inherited from DiagramItem

#attrs, #children, #down, #height, #needs_space, #up, #width

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from DiagramMultiContainer

#to_str, #walk

Methods inherited from DiagramItem

#add, #to_str, #walk, #write_svg

Constructor Details

#initialize(*items) ⇒ HorizontalChoice 



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# File 'lib/railroad_diagrams/horizontal_choice.rb', line 11

def initialize(*items)
  super('g', items)
  all_but_last = @items[0...-1]
  middles = @items[1...-1]
  first = @items.first
  last = @items.last
  @needs_space = false

  @width =
    AR + # starting track
    (AR * 2 * (@items.size - 1)) + # inbetween tracks
    @items.sum { |x| x.width + (x.needs_space ? 20 : 0) } + # items
    (last.height.positive? ? AR : 0) + # needs space to curve up
    AR # ending track

  # Always exits at entrance height
  @height = 0

  # All but the last have a track running above them
  @upper_track = [AR * 2, VS, all_but_last.map(&:up).max + VS].max
  @up = [@upper_track, last.up].max

  # All but the first have a track running below them
  # Last either straight-lines or curves up, so has different calculation
  @lower_track = [
    VS,
    middles.any? ? middles.map { |x| x.height + [x.down + VS, AR * 2].max }.max : 0,
    last.height + last.down + VS
  ].max
  if first.height < @lower_track
    # Make sure there's at least 2*AR room between first exit and lower track
    @lower_track = [@lower_track, first.height + (AR * 2)].max
  end
  @down = [@lower_track, first.height + first.down].max
end

Class Method Details

.new(*items) ⇒ Object 



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# File 'lib/railroad_diagrams/horizontal_choice.rb', line 5

def self.new(*items)
  return Sequence.new(*items) if items.size <= 1

  super
end

Instance Method Details

#format(x, y, width) ⇒ Object 



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# File 'lib/railroad_diagrams/horizontal_choice.rb', line 52

def format(x, y, width)
  # Hook up the two sides if self is narrower than its stated width.
  left_gap, right_gap = determine_gaps(width, @width)
  Path.new(x, y).h(left_gap).add(self)
  Path.new(x + left_gap + @width, y + @height).h(right_gap).add(self)
  x += left_gap

  first = @items.first
  last = @items.last

  # upper track
  upper_span =
    @items[0...-1].sum { |item| item.width + (item.needs_space ? 20 : 0) } +
    ((@items.size - 2) * AR * 2) -
    AR

  Path.new(x, y)
      .arc('se')
      .up(@upper_track - (AR * 2))
      .arc('wn')
      .h(upper_span)
      .add(self)

  # lower track
  lower_span =
    @items[1..-1].sum { |item| item.width + (item.needs_space ? 20 : 0) } +
    ((@items.size - 2) * AR * 2) +
    (last.height.positive? ? AR : 0) -
    AR

  lower_start = x + AR + first.width + (first.needs_space ? 20 : 0) + (AR * 2)

  Path.new(lower_start, y + @lower_track)
      .h(lower_span)
      .arc('se')
      .up(@lower_track - (AR * 2))
      .arc('wn')
      .add(self)

  # Items
  @items.each_with_index do |item, i|
    # input track
    if i.zero?
      Path.new(x, y)
          .h(AR)
          .add(self)
      x += AR
    else
      Path.new(x, y - @upper_track)
          .arc('ne')
          .v(@upper_track - (AR * 2))
          .arc('ws')
          .add(self)
      x += AR * 2
    end

    # item
    item_width = item.width + (item.needs_space ? 20 : 0)
    item.format(x, y, item_width).add(self)
    x += item_width

    # output track
    if i == @items.size - 1
      if item.height.zero?
        Path.new(x, y).h(AR).add(self)
      else
        Path.new(x, y + item.height).arc('se').add(self)
      end
    elsif i.zero? && item.height > @lower_track
      # Needs to arc up to meet the lower track, not down.
      if item.height - @lower_track >= AR * 2
        Path.new(x, y + item.height)
            .arc('se')
            .v(@lower_track - item.height + (AR * 2))
            .arc('wn')
            .add(self)
      else
        # Not enough space to fit two arcs
        # so just bail and draw a straight line for now.
        Path.new(x, y + item.height)
            .l(AR * 2, @lower_track - item.height)
            .add(self)
      end
    else
      Path.new(x, y + item.height)
          .arc('ne')
          .v(@lower_track - item.height - (AR * 2))
          .arc('ws')
          .add(self)
    end
  end
  self
end

#text_diagram ⇒ Object 



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# File 'lib/railroad_diagrams/horizontal_choice.rb', line 146

def text_diagram
  line, line_vertical, roundcorner_bot_left, roundcorner_bot_right,
  roundcorner_top_left, roundcorner_top_right = TextDiagram.get_parts(
    %w[line line_vertical roundcorner_bot_left roundcorner_bot_right roundcorner_top_left
       roundcorner_top_right]
  )

  # Format all the child items, so we can know the maximum entry, exit, and height.
  item_tds = @items.map(&:text_diagram)

  # diagram_entry: distance from top to lowest entry, aka distance from top to diagram entry, aka final diagram entry and exit.
  diagram_entry = item_tds.map(&:entry).max
  # soil_to_baseline: distance from top to lowest entry before rightmost item, aka distance from skip-over-items line to rightmost entry, aka SOIL height.
  soil_to_baseline = item_tds[0...-1].map(&:entry).max
  # top_to_soil: distance from top to skip-over-items line.
  top_to_soil = diagram_entry - soil_to_baseline
  # baseline_to_suil: distance from lowest entry or exit after leftmost item to bottom, aka distance from entry to skip-under-items line, aka SUIL height.
  baseline_to_suil = item_tds[1..-1].map { |td| td.height - [td.entry, td.exit].min }.max - 1

  # The diagram starts with a line from its entry up to skip-over-items line:
  lines = Array.new(top_to_soil, '  ')
  lines << (roundcorner_top_left + line)
  lines += Array.new(soil_to_baseline, "#{line_vertical} ")
  lines << (roundcorner_bot_right + line)

  diagram_td = TextDiagram.new(lines.size - 1, lines.size - 1, lines)

  item_tds.each_with_index do |item_td, item_num|
    if item_num.positive?
      # All items except the leftmost start with a line from the skip-over-items line down to their entry,
      # with a joining-line across at the skip-under-items line:
      lines = ['  '] * top_to_soil
      # All such items except the rightmost also have a continuation of the skip-over-items line:
      line_to_next_item = item_num == item_tds.size - 1 ? ' ' : line
      lines << (roundcorner_top_right + line_to_next_item)
      lines += ["#{line_vertical} "] * soil_to_baseline
      lines << (roundcorner_bot_left + line)
      lines += ['  '] * baseline_to_suil
      lines << (line * 2)

      entry_td = TextDiagram.new(diagram_td.exit, diagram_td.exit, lines)
      diagram_td = diagram_td.append_right(entry_td, '')
    end

    part_td = TextDiagram.new(0, 0, [])

    if item_num < item_tds.size - 1
      # All items except the rightmost start with a segment of the skip-over-items line at the top.
      # followed by enough blank lines to push their entry down to the previous item's exit:
      lines = []
      lines << (line * item_td.width)
      lines += Array.new(soil_to_baseline - item_td.entry, ' ' * item_td.width)
      soil_segment = TextDiagram.new(0, 0, lines)
      part_td = part_td.append_below(soil_segment, [])
    end

    part_td = part_td.append_below(item_td, [], move_entry: true, move_exit: true)

    if item_num.positive?
      # All items except the leftmost end with enough blank lines to pad down to the skip-under-items
      # line, followed by a segment of the skip-under-items line:
      lines = Array.new(baseline_to_suil - (item_td.height - item_td.entry) + 1, ' ' * item_td.width)
      lines << (line * item_td.width)
      suil_segment = TextDiagram.new(0, 0, lines)
      part_td = part_td.append_below(suil_segment, [])
    end

    diagram_td = diagram_td.append_right(part_td, '')

    if item_num < item_tds.size - 1
      # All items except the rightmost have a line from their exit down to the skip-under-items line,
      # with a joining-line across at the skip-over-items line:
      lines = Array.new(top_to_soil, '  ')
      lines << (line * 2)
      lines += Array.new(diagram_td.exit - top_to_soil - 1, '  ')
      lines << (line + roundcorner_top_right)
      lines += Array.new(baseline_to_suil - (diagram_td.exit - diagram_td.entry), " #{line_vertical}")
      line_from_prev_item = item_num.positive? ? line : ' '
      lines << (line_from_prev_item + roundcorner_bot_left)

      entry = diagram_entry + 1 + (diagram_td.exit - diagram_td.entry)
      exit_td = TextDiagram.new(entry, diagram_entry + 1, lines)
    else
      # The rightmost item has a line from the skip-under-items line and from its exit up to the diagram exit:
      lines = []
      line_from_exit = diagram_td.exit == diagram_td.entry ? line : ' '
      lines << (line_from_exit + roundcorner_top_left)
      lines += Array.new(diagram_td.exit - diagram_td.entry, " #{line_vertical}")
      lines << (line + roundcorner_bot_right) if diagram_td.exit != diagram_td.entry
      lines += Array.new(baseline_to_suil - (diagram_td.exit - diagram_td.entry), " #{line_vertical}")
      lines << (line + roundcorner_bot_right)

      exit_td = TextDiagram.new(diagram_td.exit - diagram_td.entry, 0, lines)
    end
    diagram_td = diagram_td.append_right(exit_td, '')
  end

  diagram_td
end

#to_s ⇒ Object 



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# File 'lib/railroad_diagrams/horizontal_choice.rb', line 47

def to_s
  items = @items.map(&:to_s).join(', ')
  "HorizontalChoice(#{items})"
end