Module: Muxr::LayoutManager

Defined in:
lib/muxr/layout_manager.rb

Overview

Pure functions that turn (layout_name, pane_count, screen_rect) into an array of pane rectangles. No mutable state; safe to call repeatedly on every render. Following xmonad, layouts decide geometry — users never resize panes by hand.

Defined Under Namespace

Classes: Rect

Constant Summary collapse

LAYOUTS = 
%i[tall grid monocle].freeze

Class Method Summary collapse

Class Method Details

.compute(layout, count, area, focused_index: 0, master_index: 0) ⇒ Object 



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# File 'lib/muxr/layout_manager.rb', line 17

def compute(layout, count, area, focused_index: 0, master_index: 0)
  return [] if count <= 0
  master_index = master_index.clamp(0, count - 1)
  focused_index = focused_index.clamp(0, count - 1)
  case layout
  when :tall    then tall(count, area, master_index)
  when :grid    then grid(count, area)
  when :monocle then monocle(count, area, focused_index)
  else
    raise ArgumentError, "Unknown layout: #{layout.inspect}"
  end
end

.grid(count, area) ⇒ Object

Roughly square grid. Each row stretches its panes to fill the full width so an underfull bottom row doesn’t leave gaps.



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# File 'lib/muxr/layout_manager.rb', line 57

def grid(count, area)
  cols_per_row = Math.sqrt(count).ceil
  rows = (count.to_f / cols_per_row).ceil

  base_h = area.h / rows
  h_rem  = area.h - base_h * rows

  rects = []
  idx = 0
  y = area.y
  rows.times do |r|
    remaining = count - idx
    in_row = [cols_per_row, remaining].min
    row_h = base_h + (r < h_rem ? 1 : 0)
    col_w = area.w / in_row
    w_rem = area.w - col_w * in_row
    x = area.x
    in_row.times do |c|
      w = col_w + (c < w_rem ? 1 : 0)
      rects << Rect.new(x, y, w, row_h)
      x += w
      idx += 1
    end
    y += row_h
  end
  rects
end

.monocle(count, area, _focused_index = 0) ⇒ Object

All panes occupy the full area; the focused pane is the one drawn last (the Renderer is responsible for the z-order).



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# File 'lib/muxr/layout_manager.rb', line 87

def monocle(count, area, _focused_index = 0)
  Array.new(count) { Rect.new(area.x, area.y, area.w, area.h) }
end

.tall(count, area, master_index = 0) ⇒ Object

Master pane on the left taking half the width; remaining panes stack vertically on the right, dividing the remaining height evenly.



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# File 'lib/muxr/layout_manager.rb', line 32

def tall(count, area, master_index = 0)
  master_index = master_index.clamp(0, count - 1)
  return [Rect.new(area.x, area.y, area.w, area.h)] if count == 1

  master_w = [area.w / 2, 1].max
  stack_w  = [area.w - master_w, 1].max
  others   = (0...count).to_a - [master_index]
  slave_count = others.length
  base_h = area.h / slave_count
  remainder = area.h - base_h * slave_count

  rects = Array.new(count)
  rects[master_index] = Rect.new(area.x, area.y, master_w, area.h)

  y = area.y
  others.each_with_index do |idx, i|
    h = base_h + (i < remainder ? 1 : 0)
    rects[idx] = Rect.new(area.x + master_w, y, stack_w, h)
    y += h
  end
  rects
end