class BBS::Windows::Stream

A live stream window: scrollable history + single-line input + poll.

BBS::Windows::Stream.open(app,
  title: ' Live Chat ',
  initial_lines: services[:chat].history.map { |l| fmt(l) },
  placeholder: 'Type a message and press Enter…',
  on_submit: ->(text, app) {
    services[:chat].broadcast(username, text.strip)
  },
  on_poll: ->(app) {
    services[:chat].drain(app.session_id).map { |l| fmt(l) }
  }
)

on_submit(text, app) is called when the user presses Enter on a non-empty input. The input is cleared automatically afterwards unless the handler returns :keep.

on_poll(app) is invoked from the application’s idle tick (~1s). It should return an Array of new lines to append (or nil/[]).

Constants

OPTIONS: The options of ::new and their defaults.

Attributes

history [R]

The BBS::Widgets::ScrollView of past lines and the BBS::Widgets::TextInput under it.

input [R]

The BBS::Widgets::ScrollView of past lines and the BBS::Widgets::TextInput under it.

Public Class Methods

new (app:, title:, **options)

Source

# File lib/bbs/windows/stream.rb, line 66
def initialize(app:, title:, **options)
  unknown = options.keys - OPTIONS.keys
  raise ArgumentError, "unknown stream options: #{unknown.inspect}" unless unknown.empty?

  @options = OPTIONS.merge(options)
  super(title: title, modal: false, maximizable: @options[:maximizable])
  self.theme = app.theme
  @app = app
  build
end

Creates the window and its widgets, centred on app‘s screen. It is not opened; see attach.

app: the BBS::Application
title: the window title

The options (OPTIONS):

initial_lines: the lines the history starts with
placeholder: the text the empty input shows
on_submit: called with (text, app) on Enter
on_poll: called with app on each tick; returns new lines
buffer_size: the most lines the history keeps (default 500)
width: the window width; by default the screen less 8
height: the window height; by default the screen less 6
close_button: adds a Close button (default true)
close_label: the Close button’s label
maximizable: gives the window the zoom gadget

Raises ArgumentError for an unknown option.

Calls superclass method BBS::Window::new

open (app, **kw)

Source

# File lib/bbs/windows/stream.rb, line 34
def self.open(app, **kw)
  new(app: app, **kw).tap(&:attach)
end

Creates a stream window with the keywords of Stream.new and opens it on app.

Returns the Stream window.

Public Instance Methods

attach ()

Source

# File lib/bbs/windows/stream.rb, line 80
def attach
  @app.open_window(self)
  reset_focus
  focus_manager.focus(@input)
  self
end

Opens the window on the application and focuses the input.

Returns self.

normal_rect ()

Source

# File lib/bbs/windows/stream.rb, line 104
def normal_rect
  w = @options[:width]  || (@app.cols - 8)
  h = @options[:height] || (@app.rows - 6)
  [((@app.cols - w) / 2) + 1, ((@app.rows - h) / 2) + 1, w, h]
end

Returns the un-maximized bounds as [x, y, width, height]: the requested size, or the screen less 8 columns and 6 rows, centred.

place (x, y, width, height)

Source

# File lib/bbs/windows/stream.rb, line 112
def place(x, y, width, height)
  layout(x, y, width, height)
  @history.layout(x + 2, y + 1, width - 4, [height - 4, 1].max)
  scroll_to_end
  @input.layout(x + 2, y + height - 3, width - 4, 1)
  @input.send(:adjust_scroll)
  ButtonBar.place(self, @bar[:widgets], @bar_descriptors) if @bar
end

History on top, the input line under it, the button row at the bottom; the history stays scrolled to its end.

resizable? ()

Source

# File lib/bbs/windows/stream.rb, line 99
def resizable? = true

A stream window can be resized; place lays it out again.

tick (_app)

Source

# File lib/bbs/windows/stream.rb, line 90
def tick(_app)
  new_lines = @options[:on_poll]&.call(@app)
  return if new_lines.nil? || new_lines.empty?

  @history.lines = (@history.lines + Array(new_lines)).last(@options[:buffer_size])
  scroll_to_end
end

Called on the application’s idle tick: appends the lines on_poll returns to the history, drops the oldest beyond buffer_size, and scrolls to the end. Does nothing without on_poll or new lines.