class BBS::Editor::Layout

The screen rows of a text wrapped at word boundaries: each row is [line, start, stop], the characters start...stop of line line. A row breaks after the last space that fits, or at the width when a word is longer than a row; it may end in one space beyond the width, which takes no room.

Attributes

rows [R]

The rows, an Array of [line, start, stop].

Public Class Methods

new (lines, width)

Source

# File lib/bbs/editor/layout.rb, line 15
def initialize(lines, width)
  @width = width
  @rows  = lines.each_with_index.flat_map do |text, i|
    starts = starts(text)
    starts.each_with_index.map { |s, j| [i, s, starts[j + 1] || text.length] }
  end
end

Lays lines (an Array of String) out in rows width wide.

Public Instance Methods

row_end (index)

Source

# File lib/bbs/editor/layout.rb, line 29
def row_end(index)
  line, start, stop = @rows[index]
  following = @rows[index + 1]
  following.nil? || following[0] != line ? stop : [stop - 1, start].max
end

The last cursor position on row index: its end on the last row of a line, before its last character otherwise, as that position is the next row’s start.

row_of (line, pos)

Source

# File lib/bbs/editor/layout.rb, line 24
def row_of(line, pos) = @rows.rindex { |l, start, _| l == line && start <= pos } || 0

The index of the row the cursor at line, pos is on.