Class: RailroadDiagrams::Choice

Inherits:
DiagramMultiContainer
  • Object
show all
Defined in:
lib/railroad_diagrams/choice.rb,
sig/generated/railroad_diagrams/choice.rbs

Overview

rubocop:disable-next Metrics/ClassLength Draws alternative paths, with one default path.

Examples:

Choice.new(0, 'yes', 'no')

Direct Known Subclasses

Optional

Instance Method Summary collapse

Constructor Details

#initialize(default, *items, id: nil, cls: nil, attrs: {}) ⇒ Choice

Returns a new instance of Choice.

Parameters:

  • default (Integer)
  • items (DiagramItem, String)
  • id: (Object) (defaults to: nil)
  • cls: (Object) (defaults to: nil)
  • attrs: (Object) (defaults to: {}) 


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# File 'lib/railroad_diagrams/choice.rb', line 13

def initialize(default, *items, id: nil, cls: nil, attrs: {})
  super('g', items, nil, nil, id: id, cls: cls, data_attrs: attrs)
  unless default.is_a?(Integer) && (0...items.size).cover?(default)
    raise InvalidArgument, "default index out of range: #{default.inspect} (0...#{items.size})"
  end

  @default = default
  @width = (AR * 4) + @items.map(&:width).max

  # The calcs are non-trivial and need to be done both here
  # and in .format(), so no reason to do it twice.
  @separators = Array.new(items.size - 1, VS)

  # If the entry or exit lines would be too close together
  # to accommodate the arcs,
  # bump up the vertical separation to compensate.
  @up = 0
  (default - 1).downto(0) do |i|
    arcs =
      if i == default - 1
        AR * 2
      else
        AR
      end

    item = @items[i]
    lower_item = @items[i + 1]

    entry_delta = lower_item.up + VS + item.down + item.height
    exit_delta = lower_item.height + lower_item.up + VS + item.down

    separator = VS
    separator += [arcs - entry_delta, arcs - exit_delta].max if entry_delta < arcs || exit_delta < arcs
    @separators[i] = separator

    @up += lower_item.up + separator + item.down + item.height
  end
  @up += @items[0].up

  @height = @items[default].height
  (default + 1...@items.size).each do |i|
    arcs =
      if i == default + 1
        AR * 2
      else
        AR
      end

    item = @items[i]
    upper_item = @items[i - 1]

    entry_delta = upper_item.height + upper_item.down + VS + item.up
    exit_delta = upper_item.down + VS + item.up + item.height

    separator = VS
    separator += [arcs - entry_delta, arcs - exit_delta].max if entry_delta < arcs || exit_delta < arcs
    @separators[i - 1] = separator

    @down += upper_item.down + separator + item.up + item.height
  end
  @down += @items[-1].down
  @needs_space = false
end

Instance Method Details

#add_downward_path(x, y, distance) ⇒ void

This method returns an undefined value.

Parameters:

  • x (Numeric)
  • y (Numeric)
  • distance (Numeric) 


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# File 'lib/railroad_diagrams/choice.rb', line 436

def add_downward_path(x, y, distance)
  Path.new(x, y)
      .arc('ne')
      .down(distance - (AR * 2))
      .arc('ws')
      .add(self)
end

#add_downward_return_path(x, y, distance, item, default) ⇒ void

This method returns an undefined value.

Parameters:



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# File 'lib/railroad_diagrams/choice.rb', line 424

def add_downward_return_path(x, y, distance, item, default)
  Path.new(x, y - distance + item.height)
      .arc('ne')
      .down(distance - item.height + default.height - (AR * 2))
      .arc('ws')
      .add(self)
end

#add_upward_path(x, y, distance) ⇒ void

This method returns an undefined value.

Parameters:

  • x (Numeric)
  • y (Numeric)
  • distance (Numeric) 


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# File 'lib/railroad_diagrams/choice.rb', line 410

def add_upward_path(x, y, distance)
  Path.new(x, y)
      .arc('se')
      .up(distance - (AR * 2))
      .arc('wn')
      .add(self)
end

#add_upward_return_path(x, y, distance, item, default) ⇒ void

This method returns an undefined value.

Parameters:



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# File 'lib/railroad_diagrams/choice.rb', line 450

def add_upward_return_path(x, y, distance, item, default)
  Path.new(x, y + distance + item.height)
      .arc('se')
      .up(distance - (AR * 2) + item.height - default.height)
      .arc('wn')
      .add(self)
end

#child_nodes ⇒ Array[DiagramItem]

Returns:



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# File 'lib/railroad_diagrams/choice.rb', line 294

def child_nodes
  @items.dup
end

#choice_layout(context) ⇒ Object

Parameters:

  • context (Object)

Returns:

  • (Object) 


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# File 'lib/railroad_diagrams/choice.rb', line 300

def choice_layout(context)
  children = @items.map { |item| context.metrics(item) }
  arc = context.options.arc_radius
  separation = context.options.vertical_separation
  width = (arc * 4) + children.map(&:width).max
  separators = Array.new(children.size - 1, separation)
  up = 0
  (@default - 1).downto(0) do |index|
    arcs = index == @default - 1 ? arc * 2 : arc
    item = children[index]
    lower = children[index + 1]
    entry_delta = lower.up + separation + item.down + item.height
    exit_delta = lower.height + lower.up + separation + item.down
    separator = separation
    separator += [arcs - entry_delta, arcs - exit_delta].max if entry_delta < arcs || exit_delta < arcs
    separators[index] = separator
    up += lower.up + separator + item.down + item.height
  end
  up += children[0].up

  height = children[@default].height
  down = 0
  (@default + 1...children.size).each do |index|
    arcs = index == @default + 1 ? arc * 2 : arc
    item = children[index]
    upper = children[index - 1]
    entry_delta = upper.height + upper.down + separation + item.up
    exit_delta = upper.down + separation + item.up + item.height
    separator = separation
    separator += [arcs - entry_delta, arcs - exit_delta].max if entry_delta < arcs || exit_delta < arcs
    separators[index - 1] = separator
    down += upper.down + separator + item.up + item.height
  end
  down += children[-1].down
  [Metrics.new(width: width, up: up, height: height, down: down, needs_space: false), separators]
end

#expand_text(diagram, left, right, line) ⇒ Object

Parameters:

  • diagram (Object)
  • left (Object)
  • right (Object)
  • line (Object)

Returns:

  • (Object) 


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# File 'lib/railroad_diagrams/choice.rb', line 341

def expand_text(diagram, left, right, line)
  rows = diagram.lines.each_with_index.map do |text, index|
    "#{index == diagram.entry ? line * left : ' ' * left}#{text}" \
      "#{index == diagram.exit ? line * right : ' ' * right}"
  end
  TextDiagram.new(diagram.entry, diagram.exit, rows)
end

#format(x, y, width) ⇒ Choice

Parameters:

  • x (Numeric)
  • y (Numeric)
  • width (Numeric)

Returns:



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# File 'lib/railroad_diagrams/choice.rb', line 87

def format(x, y, 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

  inner_width = @width - (AR * 4)
  default = @items[@default]

  format_items_above_default(x, y, inner_width, default)
  format_default_item(x, y, inner_width)
  format_items_below_default(x, y, inner_width, default)

  self
end

#format_default_item(x, y, inner_width) ⇒ void

This method returns an undefined value.

Parameters:

  • x (Numeric)
  • y (Numeric)
  • inner_width (Numeric) 


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# File 'lib/railroad_diagrams/choice.rb', line 382

def format_default_item(x, y, inner_width)
  Path.new(x, y).right(AR * 2).add(self)
  @items[@default].format(x + (AR * 2), y, inner_width).add(self)
  Path.new(x + (AR * 2) + inner_width, y + @height).right(AR * 2).add(self)
end

#format_items_above_default(x, y, inner_width, default) ⇒ void

This method returns an undefined value.

Parameters:

  • x (Numeric)
  • y (Numeric)
  • inner_width (Numeric)
  • default (DiagramItem) 


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# File 'lib/railroad_diagrams/choice.rb', line 365

def format_items_above_default(x, y, inner_width, default)
  distance_from_y = 0
  (@default - 1).downto(0) do |i|
    item = @items[i]
    lower_item = @items[i + 1]
    distance_from_y += lower_item.up + @separators[i] + item.down + item.height

    add_upward_path(x, y, distance_from_y)
    item.format(x + (AR * 2), y - distance_from_y, inner_width).add(self)
    add_downward_return_path(x + (AR * 2) + inner_width, y, distance_from_y, item, default)
  end
end

#format_items_below_default(x, y, inner_width, default) ⇒ void

This method returns an undefined value.

Parameters:

  • x (Numeric)
  • y (Numeric)
  • inner_width (Numeric)
  • default (DiagramItem) 


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# File 'lib/railroad_diagrams/choice.rb', line 393

def format_items_below_default(x, y, inner_width, default)
  distance_from_y = 0
  (@default + 1...@items.size).each do |i|
    item = @items[i]
    upper_item = @items[i - 1]
    distance_from_y += upper_item.height + upper_item.down + @separators[i - 1] + item.up

    add_downward_path(x, y, distance_from_y)
    item.format(x + (AR * 2), y + distance_from_y, inner_width).add(self)
    add_upward_return_path(x + (AR * 2) + inner_width, y, distance_from_y, item, default)
  end
end

#measure(context) ⇒ Metrics

Parameters:

  • context (Context)

Returns:

  • (Metrics) 


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# File 'lib/railroad_diagrams/choice.rb', line 178

def measure(context)
  choice_layout(context).first
end

#render_svg(context, x, y, width) ⇒ Svg::Element

Parameters:

  • context (Context)
  • x (Numeric)
  • y (Numeric)
  • width (Numeric)

Returns:

  • (Svg::Element) 


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# File 'lib/railroad_diagrams/choice.rb', line 187

def render_svg(context, x, y, width)
  metrics = context.metrics(self)
  separators = choice_layout(context).last
  arc = context.options.arc_radius
  left_gap, right_gap = context.gaps(width, metrics.width)
  group = Svg::Element.new('g', @attrs.dup)
  group << svg_path(Svg::PathData.new(x, y).h(left_gap))
  group << svg_path(Svg::PathData.new(x + left_gap + metrics.width, y + metrics.height).h(right_gap))
  x += left_gap
  inner_width = metrics.width - (arc * 4)
  default = context.metrics(@items[@default])

  distance = 0
  (@default - 1).downto(0) do |index|
    item = @items[index]
    child = context.metrics(item)
    lower = context.metrics(@items[index + 1])
    distance += lower.up + separators[index] + child.down + child.height
    path = Svg::PathData.new(x, y, arc_radius: arc).arc('se').v(-[0, distance - (arc * 2)].max).arc('wn')
    group << svg_path(path)
    group << context.render_svg(item, x + (arc * 2), y - distance, inner_width)
    path = Svg::PathData.new(x + (arc * 2) + inner_width, y - distance + child.height,
                             arc_radius: arc).arc('ne')
    path.v([0, distance - child.height + default.height - (arc * 2)].max).arc('ws')
    group << svg_path(path)
  end

  group << svg_path(Svg::PathData.new(x, y).h([0, arc * 2].max))
  group << context.render_svg(@items[@default], x + (arc * 2), y, inner_width)
  group << svg_path(Svg::PathData.new(x + (arc * 2) + inner_width, y + metrics.height).h([0, arc * 2].max))

  distance = 0
  (@default + 1...@items.size).each do |index|
    item = @items[index]
    child = context.metrics(item)
    upper = context.metrics(@items[index - 1])
    distance += upper.height + upper.down + separators[index - 1] + child.up
    path = Svg::PathData.new(x, y, arc_radius: arc).arc('ne').v([0, distance - (arc * 2)].max).arc('ws')
    group << svg_path(path)
    group << context.render_svg(item, x + (arc * 2), y + distance, inner_width)
    path = Svg::PathData.new(x + (arc * 2) + inner_width, y + distance + child.height,
                             arc_radius: arc).arc('se')
    path.v(-[0, distance - (arc * 2) + child.height - default.height].max).arc('wn')
    group << svg_path(path)
  end
  group
end

#render_text(context) ⇒ TextDiagram

Parameters:

  • context (Context)

Returns:

  • (TextDiagram) 


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# File 'lib/railroad_diagrams/choice.rb', line 237

def render_text(context)
  cross, line, vertical, bottom_left, bottom_right, top_left, top_right =
    context.parts.values_at('cross', 'line', 'line_vertical', 'roundcorner_bot_left',
                            'roundcorner_bot_right', 'roundcorner_top_left', 'roundcorner_top_right')
  items = @items.map { |item| expand_text(item.render_text(context), 1, 1, line) }
  max_width = items.map(&:width).max
  diagram = TextDiagram.new(0, 0, [])
  items.each_with_index do |item, index|
    left_pad, right_pad = text_gaps(context, max_width, item.width)
    item = expand_text(item, left_pad, right_pad, line)
    left_lines = [vertical] * item.height
    right_lines = [vertical] * item.height
    separator = index.positive?
    move_entry = false
    move_exit = false
    if index <= @default
      left_lines[item.entry] = top_left
      right_lines[item.exit] = top_right
      if index.zero?
        (0...item.entry).each { |row| left_lines[row] = ' ' }
        (0...item.exit).each { |row| right_lines[row] = ' ' }
      end
    end
    if index >= @default
      left_lines[item.entry] = bottom_left
      right_lines[item.exit] = bottom_right
      if index == @items.size - 1
        (item.entry + 1...item.height).each { |row| left_lines[row] = ' ' }
        (item.exit + 1...item.height).each { |row| right_lines[row] = ' ' }
      end
    end
    if index == @default
      left_lines[item.entry] = cross
      right_lines[item.exit] = cross
      move_entry = true
      move_exit = true
      if index.zero? && index == @items.size - 1
        left_lines[item.entry] = line
        right_lines[item.exit] = line
      elsif index.zero?
        left_lines[item.entry] = top_right
        right_lines[item.exit] = top_left
      elsif index == @items.size - 1
        left_lines[item.entry] = bottom_right
        right_lines[item.exit] = bottom_left
      end
    end
    left_join = TextDiagram.new(item.entry, item.entry, left_lines)
    right_join = TextDiagram.new(item.exit, item.exit, right_lines)
    item = left_join.append_right(item, '').append_right(right_join, '')
    between = separator ? [vertical + (' ' * (TextDiagram.max_width(diagram, item) - 2)) + vertical] : []
    diagram = diagram.append_below(item, between, move_entry: move_entry, move_exit: move_exit)
  end
  diagram
end

#svg_path(data) ⇒ Object

Parameters:

  • data (Object)

Returns:

  • (Object) 


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# File 'lib/railroad_diagrams/choice.rb', line 337

def svg_path(data)
  Svg::Element.new('path', { 'd' => data }, self_closing: true)
end

#text_diagram ⇒ TextDiagram

Returns:

  • (TextDiagram) 


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# File 'lib/railroad_diagrams/choice.rb', line 104

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

  item_tds = @items.map { |item| item.text_diagram.expand(1, 1, 0, 0) }
  max_item_width = item_tds.map(&:width).max
  diagram_td = TextDiagram.new(0, 0, [])
  item_tds.each_with_index do |item_td, i|
    left_pad, right_pad = TextDiagram.gaps(max_item_width, item_td.width)
    item_td = item_td.expand(left_pad, right_pad, 0, 0)
    has_separator = true
    left_lines = [line_vertical] * item_td.height
    right_lines = [line_vertical] * item_td.height
    move_entry = false
    move_exit = false
    if i <= @default
      left_lines[item_td.entry] = roundcorner_top_left
      right_lines[item_td.exit] = roundcorner_top_right
      if i.zero?
        has_separator = false
        (0...item_td.entry).each { |j| left_lines[j] = ' ' }
        (0...item_td.exit).each { |j| right_lines[j] = ' ' }
      end
    end
    if i >= @default
      left_lines[item_td.entry] = roundcorner_bot_left
      right_lines[item_td.exit] = roundcorner_bot_right
      if i.zero?
        has_separator = false
      end
      if i == @items.size - 1
        (item_td.entry + 1...item_td.height).each { |j| left_lines[j] = ' ' }
        (item_td.exit + 1...item_td.height).each { |j| right_lines[j] = ' ' }
      end
    end
    if i == @default
      left_lines[item_td.entry] = cross
      right_lines[item_td.exit] = cross
      move_entry = true
      move_exit = true
      if i.zero? && i == @items.size - 1
        left_lines[item_td.entry] = line
        right_lines[item_td.exit] = line
      elsif i.zero?
        left_lines[item_td.entry] = roundcorner_top_right
        right_lines[item_td.exit] = roundcorner_top_left
      elsif i == @items.size - 1
        left_lines[item_td.entry] = roundcorner_bot_right
        right_lines[item_td.exit] = roundcorner_bot_left
      end
    end
    left_join_td = TextDiagram.new(item_td.entry, item_td.entry, left_lines)
    right_join_td = TextDiagram.new(item_td.exit, item_td.exit, right_lines)
    item_td = left_join_td.append_right(item_td, '').append_right(right_join_td, '')
    separator =
      if has_separator
        [
          line_vertical +
            (' ' * (TextDiagram.max_width(diagram_td, item_td) - 2)) + line_vertical
        ]
      else
        []
      end
    diagram_td = diagram_td.append_below(item_td, separator, move_entry: move_entry, move_exit: move_exit)
  end
  diagram_td
end

#text_gaps(context, outer, inner) ⇒ Object

Parameters:

  • context (Object)
  • outer (Object)
  • inner (Object)

Returns:

  • (Object) 


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# File 'lib/railroad_diagrams/choice.rb', line 349

def text_gaps(context, outer, inner)
  difference = outer - inner
  case context.options.internal_alignment
  when :left then [0, difference]
  when :right then [difference, 0]
  else
    left = difference / 2
    [left, difference - left]
  end
end

#to_s ⇒ String

Returns:

  • (String) 


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# File 'lib/railroad_diagrams/choice.rb', line 78

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