Class: TuiTui::Widget::List

Inherits:
Object
  • Object
show all
Defined in:
lib/tui_tui/widget/list.rb

Overview

Drawing companion for ScrollList. Row content comes from the caller, keeping the list domain-agnostic.

Instance Method Summary collapse

Constructor Details

#initialize(scroll) ⇒ List

Returns a new instance of List.



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# File 'lib/tui_tui/widget/list.rb', line 12

def initialize(scroll)
  @scroll = scroll
end

Instance Method Details

#draw(canvas, rect, highlight: nil, scrollbar: nil, auto: false) ⇒ Object 



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# File 'lib/tui_tui/widget/list.rb', line 16

def draw(canvas, rect, highlight: nil, scrollbar: nil, auto: false)
  # With auto:, reserve the gutter only when the content overflows the rect.
  show_bar = scrollbar && !(auto && @scroll.count <= rect.rows)
  body, gutter = show_bar ? rect.split_gutter : [rect, nil]
  @scroll.ensure_visible(body.rows)
  @scroll.each_visible(body.rows) do |index, offset|
    row = body.row + offset
    selected = index == @scroll.cursor
    canvas.fill(Rect.new(row: row, col: body.col, rows: 1, cols: body.cols), highlight) if highlight && selected
    canvas.line(row, body.col, Line.coerce(yield(index, selected)).truncate(body.cols))
  end

  draw_scrollbar(canvas, gutter, scrollbar) if gutter
  canvas
end

#index_at(rect, event, scrollbar: nil) ⇒ Object

Map a MouseEvent to the list index under it, or nil. Pass the same rect and scrollbar: used for draw so the gutter column is excluded and the scroll offset matches what was rendered. Returns nil for clicks outside the body or below the last item.



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# File 'lib/tui_tui/widget/list.rb', line 36

def index_at(rect, event, scrollbar: nil)
  body = scrollbar ? rect.split_gutter.first : rect
  return nil unless body.hit?(event)

  index = @scroll.top + (event.row - body.row)
  index < @scroll.count ? index : nil
end