class BBS::Widget - bbs 1.0.2

Base widget. All visual elements inherit from this.

bounds: a Rect (x, y, width, height) in screen coordinates
parent: the enclosing Container, or nil
id: an optional Symbol for lookup via Container#find

Subclasses override render and optionally handle_event.

Constants

Rect: A rectangle of screen cells: x and y are the 1-based top-left cell, width and height the size. contains?(px, py) tells whether a cell lies inside it.

Attributes

The Rect the widget occupies, its parent Container, its lookup id, and whether it is visible, has the focus, and is enabled. A new widget is visible, enabled and not focused.

enabled [RW]

The Rect the widget occupies, its parent Container, its lookup id, and whether it is visible, has the focus, and is enabled. A new widget is visible, enabled and not focused.

focused [RW]

The Rect the widget occupies, its parent Container, its lookup id, and whether it is visible, has the focus, and is enabled. A new widget is visible, enabled and not focused.

id [RW]

The Rect the widget occupies, its parent Container, its lookup id, and whether it is visible, has the focus, and is enabled. A new widget is visible, enabled and not focused.

parent [RW]

The Rect the widget occupies, its parent Container, its lookup id, and whether it is visible, has the focus, and is enabled. A new widget is visible, enabled and not focused.

theme [RW]

The BBS::Theme set on this widget, or nil to use the parent’s.

visible [RW]

The Rect the widget occupies, its parent Container, its lookup id, and whether it is visible, has the focus, and is enabled. A new widget is visible, enabled and not focused.

Public Class Methods

new (id: nil, bounds: nil, theme: nil)

Source

# File lib/bbs/widget.rb, line 35
def initialize(id: nil, bounds: nil, theme: nil)
  @id       = id
  @bounds   = bounds || Rect.new(1, 1, 0, 0)
  @parent   = nil
  @visible  = true
  @focused  = false
  @enabled  = true
  @theme    = theme
end

Creates a widget.

id: an optional Symbol for Container#find
bounds: a Rect; defaults to an empty one at 1, 1
theme: a BBS::Theme; defaults to the parent’s

Public Instance Methods

each (&) { |self| ... }

Source

# File lib/bbs/widget.rb, line 62
def each(&)
  yield self
  nil
end

Convenience: yield this widget. Subclasses override to walk a tree.

focusable? ()

Source

# File lib/bbs/widget.rb, line 46
def focusable? = false

Override in subclasses. By default a widget does not accept focus.

handle_event (_event)

Source

# File lib/bbs/widget.rb, line 59
def handle_event(_event) = nil

Handle a keyboard or mouse event. Return :halt to end the application, :handled to stop propagation, or nil/false to continue.

hit_test (x, y)

Source

# File lib/bbs/widget.rb, line 68
def hit_test(x, y)
  bounds.contains?(x, y) ? self : nil
end

Hit test: returns the deepest widget whose bounds contain (x, y).

layout (x, y, width, height)

Source

# File lib/bbs/widget.rb, line 75
def layout(x, y, width, height)
  @bounds = Rect.new(x, y, width, height)
end

Move/resize. Subclasses may override to relayout children.

on_blur ()

Source

# File lib/bbs/widget.rb, line 52
def on_blur = nil

Called when this widget loses focus.

on_focus ()

Source

# File lib/bbs/widget.rb, line 49
def on_focus = nil

Called when this widget gains focus. Subclasses may override.

redraw! ()

Source

# File lib/bbs/widget.rb, line 80
def redraw!
  @parent&.redraw!
end

Request a redraw — set by Application as a callback if needed.

render (frame)

Source

# File lib/bbs/widget.rb, line 55
def render(frame); end

Render this widget into the supplied FrameBuffer.

Protected Instance Methods

style (key)

Source

# File lib/bbs/widget.rb, line 88
def style(key)
  (@theme || parent&.theme)&.style(key)
end

Returns the SGR style for key from this widget’s theme, or from the parent’s when none is set; nil when neither has a theme.