Class: Tui::Screen

Inherits:
Object
  • Object
show all
Includes:
Helpers
Defined in:
lib/tui.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Helpers

#accent, #bold, #dim, #emoji, #fill, #highlight

Constructor Details

#initialize(io: $stderr, width: nil, height: nil) ⇒ Screen

Returns a new instance of Screen.



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# File 'lib/tui.rb', line 353

def initialize(io: $stderr, width: nil, height: nil)
  @io = io
  @fixed_width = width
  @fixed_height = height
  @width = @height = nil
  refresh_size
  @header = Section.new(self)
  @body   = Section.new(self)
  @footer = Section.new(self)
  @sections = [@header, @body, @footer]
  @input_field = nil
  @cursor_row = nil
end

Instance Attribute Details

#body ⇒ Object (readonly)

Returns the value of attribute body.



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# File 'lib/tui.rb', line 351

def body
  @body
end

#footer ⇒ Object (readonly)

Returns the value of attribute footer.



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# File 'lib/tui.rb', line 351

def footer
  @footer
end

#header ⇒ Object (readonly)

Returns the value of attribute header.



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# File 'lib/tui.rb', line 351

def header
  @header
end

#height ⇒ Object (readonly)

Returns the value of attribute height.



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# File 'lib/tui.rb', line 351

def height
  @height
end

#input_field ⇒ Object (readonly)

Returns the value of attribute input_field.



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# File 'lib/tui.rb', line 351

def input_field
  @input_field
end

#width ⇒ Object (readonly)

Returns the value of attribute width.



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# File 'lib/tui.rb', line 351

def width
  @width
end

Instance Method Details

#clear ⇒ Object 



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# File 'lib/tui.rb', line 379

def clear
  @sections.each(&:clear)
  self
end

#flush ⇒ Object 



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# File 'lib/tui.rb', line 384

def flush
  refresh_size

  # Build entire frame in a single buffer to avoid flicker from partial writes
  buf = String.new(ANSI::HOME)

  cursor_row = nil
  cursor_col = nil
  current_row = 0

  # Render header at top
  @header.lines.each do |line|
    if @input_field && line.has_input?
      cursor_row = current_row + 1
      cursor_col = line.cursor_column(@input_field, @width)
    end
    line.render(buf, @width)
    current_row += 1
  end

  # Calculate available body space (total height minus header and footer)
  footer_lines = @footer.lines.length
  body_space = @height - current_row - footer_lines

  # Render body lines (limited to available space)
  body_rendered = 0
  @body.lines.each do |line|
    break if body_rendered >= body_space
    if @input_field && line.has_input?
      cursor_row = current_row + 1
      cursor_col = line.cursor_column(@input_field, @width)
    end
    line.render(buf, @width)
    current_row += 1
    body_rendered += 1
  end

  # Fill gap between body and footer with blank lines
  # Use \r to position at column 0, clear line, fill with spaces for reliability
  gap = body_space - body_rendered
  blank_line = "\r#{ANSI::CLEAR_EOL}#{' ' * (@width - 1)}\n"
  blank_line_no_newline = "\r#{ANSI::CLEAR_EOL}#{' ' * (@width - 1)}"
  gap.times do |i|
    # Last gap line without newline if no footer follows
    if i == gap - 1 && @footer.lines.empty?
      buf << blank_line_no_newline
    else
      buf << blank_line
    end
    current_row += 1
  end

  # Render footer at the bottom (sticky)
  @footer.lines.each_with_index do |line, idx|
    if @input_field && line.has_input?
      cursor_row = current_row + 1
      cursor_col = line.cursor_column(@input_field, @width)
    end
    # Last line: don't write \n to avoid scrolling
    if idx == footer_lines - 1
      line.render_no_newline(buf, @width)
    else
      line.render(buf, @width)
    end
    current_row += 1
  end

  # Position cursor at input field if present, otherwise hide cursor
  if cursor_row && cursor_col && @input_field
    buf << "\e[#{cursor_row};#{cursor_col}H"
    buf << ANSI::SHOW
  else
    buf << ANSI::HIDE
  end

  buf << ANSI::RESET

  # Single write for the entire frame - eliminates flicker
  begin
    @io.write(buf)
    @io.flush
  rescue IOError
  end
ensure
  clear
end

#input(placeholder = "", value: "", cursor: nil) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/tui.rb', line 374

def input(placeholder = "", value: "", cursor: nil)
  raise ArgumentError, "screen already has an input" if @input_field
  @input_field = InputField.new(placeholder: placeholder, text: value, cursor: cursor)
end

#refresh_size ⇒ Object 



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# File 'lib/tui.rb', line 367

def refresh_size
  rows, cols = Terminal.size(@io)
  @height = @fixed_height || rows
  @width = @fixed_width || cols
  self
end