--- Get a widex index.
-- @param widget The widget to look for
-- @param[opt] recursive Also check sub-widgets
-- @param[opt] ... Aditional widgets to add at the end of the "path"
-- @return The index
-- @return The parent layout
-- @return The path between "self" and "widget"
-- @function index

--- Get all direct and indirect children widgets.
-- This will scan all containers recursively to find widgets
-- Warning: This method it prone to stack overflow id the widget, or any of its
-- children, contain (directly or indirectly) itself.
-- @treturn table The children
-- @function get_all_children

--- Set a declarative widget hierarchy description.
-- See [The declarative layout system](../documentation/03-declarative-layout.md.html)
-- @param args An array containing the widgets disposition
-- @function setup

--- Force a widget height.
-- @property forced_height
-- @tparam number|nil height The height (`nil` for automatic)

--- Force a widget width.
-- @property forced_width
-- @tparam number|nil width The width (`nil` for automatic)

--- The widget opacity (transparency).
-- @property opacity
-- @tparam[opt=1] number opacity The opacity (between 0 and 1)

--- The widget visibility.
-- @property visible
-- @param boolean

--- Set/get a widget's buttons.
-- @param _buttons The table of buttons that should bind to the widget.
-- @function buttons

--- Emit a signal and ensure all parent widgets in the hierarchies also
-- forward the signal. This is useful to track signals when there is a dynamic
-- set of containers and layouts wrapping the widget.
-- @tparam string signal_name
-- @param ... Other arguments
-- @function emit_signal_recursive

--- When the layout (size) change.
-- This signal is emitted when the previous results of `:layout()` and `:fit()`
-- are no longer valid.  Unless this signal is emitted, `:layout()` and `:fit()`
-- must return the same result when called with the same arguments.
-- @signal widget::layout_changed
-- @see widget::redraw_needed

--- When the widget content changed.
-- This signal is emitted when the content of the widget changes. The widget will
-- be redrawn, it is not re-layouted. Put differently, it is assumed that
-- `:layout()` and `:fit()` would still return the same results as before.
-- @signal widget::redraw_needed
-- @see widget::layout_changed

--- When a mouse button is pressed over the widget.
-- The position of the mouse press relative to the widget while geometry
-- contains the geometry of the widget relative to the wibox.
-- @signal button::press
-- @tparam table widget The widget
-- @tparam number lx The relative horizontal position.
-- @tparam number ly The relative vertical position.
-- @tparam number button The button number.
-- @tparam table mods The modifiers (mod4, mod1 (alt), Control, Shift)
-- @tparam table geometry
-- @tparam number geometry.x The vertical position
-- @tparam number geometry.y The horizontal position
-- @tparam number geometry.width The widget
-- @tparam number geometry.height The height
-- @tparam drawable geometry.drawable The `drawable`
-- @tparam table geometry.matrix_to_parent The relative `gears.matrix`
-- @tparam table geometry.matrix_to_device The absolute `gears.matrix`
-- @see mouse

--- When a mouse button is released over the widget.
-- The position of the mouse press relative to the widget while geometry
-- contains the geometry of the widget relative to the wibox.
-- @signal button::release
-- @tparam table widget The widget
-- @tparam number lx The relative horizontal position.
-- @tparam number ly The relative vertical position.
-- @tparam number button The button number.
-- @tparam table mods The modifiers (mod4, mod1 (alt), Control, Shift)
-- @tparam table geometry
-- @tparam number geometry.x The vertical position
-- @tparam number geometry.y The horizontal position
-- @tparam number geometry.width The widget
-- @tparam number geometry.height The height
-- @tparam drawable geometry.drawable The `drawable`
-- @tparam table geometry.matrix_to_parent The relative `gears.matrix`
-- @tparam table geometry.matrix_to_device The absolute `gears.matrix`
-- @see mouse

--- When the mouse enter a widget.
-- @signal mouse::enter
-- @tparam table widget The widget
-- @tparam table geometry
-- @tparam number geometry.x The vertical position
-- @tparam number geometry.y The horizontal position
-- @tparam number geometry.width The widget
-- @tparam number geometry.height The height
-- @tparam drawable geometry.drawable The `drawable`
-- @tparam table geometry.matrix_to_parent The relative `gears.matrix`
-- @tparam table geometry.matrix_to_device The absolute `gears.matrix`
-- @see mouse

--- When the mouse leave a widget.
-- @signal mouse::leave
-- @tparam table widget The widget
-- @tparam table geometry
-- @tparam number geometry.x The vertical position
-- @tparam number geometry.y The horizontal position
-- @tparam number geometry.width The widget
-- @tparam number geometry.height The height
-- @tparam drawable geometry.drawable The `drawable`
-- @tparam table geometry.matrix_to_parent The relative `gears.matrix`
-- @tparam table geometry.matrix_to_device The absolute `gears.matrix`
-- @see mouse