Module: `wibox.widget.base`

Base class of every widgets, containers and layouts,

Class Hierarchy

gears.object
- wibox.widget.base

Info:

Copyright: 2010 Uli Schlachter
Originally authored by: Uli Schlachter
(Full contributors list available on our github project)

Constructors

wibox.widget.base.make_widget_declarative {[args]}	Create a widget from a declarative description.
wibox.widget.base.make_widget_from_value (wdg, ...)	Create a widget from an undetermined value.
wibox.widget.base.make_widget (proxy, widget_name, args)	Create an empty widget skeleton.
wibox.widget.base.empty_widget ()	Generate an empty widget which takes no space and displays nothing.

Static module functions

wibox.widget.base.rect_to_device_geometry (cr, x, y, width, height) -> (number, number, number, number)	Figure out the geometry in the device coordinate space.
wibox.widget.base.fit_widget (parent, context, widget, width, height) -> (number, number)	Fit a widget for the given available width and height.
wibox.widget.base.layout_widget (parent, context, widget, width, height) -> table	Lay out a widget for the given available width and height.
wibox.widget.base.handle_button ()	Handle a button event on a widget.
wibox.widget.base.place_widget_via_matrix (widget, mat, width, height) -> table	Create widget placement information.
wibox.widget.base.place_widget_at (widget, x, y, width, height) -> table	Create widget placement information.
wibox.widget.base.check_widget ()	Do some sanity checking on a widget.

Object properties

children	table	Get or set the children elements.
all_children	table	Get all direct and indirect children widgets.
forced_height	number or nil	Force a widget height.
forced_width	number or nil	Force a widget width.
opacity	number	The widget opacity (transparency).
visible	boolean	The widget visibility.
buttons	table	The widget buttons.

Object methods

:add_button (button)	Add a new awful.button to this widget.
:emit_signal_recursive (signal_name, ...)	Emit a signal and ensure all parent widgets in the hierarchies also forward the signal.
:index (widget, recursive, ...) -> (number, widget, table)	Get the index of a widget.
:connect_signal (name, func)	Connect to a signal.	Inherited from gears.object
:weak_connect_signal (name, func)	Connect to a signal weakly.	Inherited from gears.object
:disconnect_signal (name, func)	Disconnect from a signal.	Inherited from gears.object
:emit_signal (name, ...)	Emit a signal.	Inherited from gears.object

Signals

widget::layout_changed	When the layout (size) change.
widget::redraw_needed	When the widget content changed.
button::press	When a mouse button is pressed over the widget.
button::release	When a mouse button is released over the widget.
mouse::enter	When the mouse enter a widget.
mouse::leave	When the mouse leave a widget.

Methods

:set_widget_common (self, widget) Common implementation of the :set_widget() method exposed by many other widgets.

Constructors

🔗 wibox.widget.base.make_widget_declarative {[args]}

Create a widget from a declarative description.

See The declarative layout system.

Parameters:

Name		Type(s)	Description
args		table	A table containing the widgets disposition.

🔗 wibox.widget.base.make_widget_from_value (wdg, ...)

Create a widget from an undetermined value.

The value can be:

A widget (in which case nothing new is created)
A declarative construct
A constructor function
A metaobject

Parameters:

Name		Type(s)	Description	Default value
wdg			The value.	Not applicable
...	Optional		Arguments passed to the contructor (if any).	`nil`

Returns:

widget or nil

nil

🔗 wibox.widget.base.make_widget (proxy, widget_name, args)

Create an empty widget skeleton.

See Creating new widgets.

Parameters:

Name		Type(s)	Description	Default value
proxy	Optional	widget	If this is set, the returned widget will be a proxy for this widget. It will be equivalent to this widget. This means it looks the same on the screen.	Undefined
widget_name	Optional	string	Name of the widget. If not set, it will be set automatically via gears.object.modulename.	Undefined
args	Optional	table	Widget settings	`{}`
enable_properties	Optional	boolean	Enable automatic getter and setter methods.	`false`
class	Optional	table	The widget class	`nil`

Static module functions

🔗 wibox.widget.base.rect_to_device_geometry (cr, x, y, width, height) -> (number, number, number, number)

Figure out the geometry in the device coordinate space.

This gives only tight bounds if no rotations by non-multiples of 90° are used.

Parameters:

Name	Type(s)	Description
cr		The cairo context.
x	number	The `x` value.
y	number	The `y` value.
width	number	The `width` value.
height	number	The `height` value.

Returns:

number The new x value.
number The new y value.
number The new width value.
number The new height value.

🔗 wibox.widget.base.fit_widget (parent, context, widget, width, height) -> (number, number)

Fit a widget for the given available width and height.

This calls the widget's :fit callback and caches the result for later use. Never call :fit directly, but always through this function!

Parameters:

Name	Type(s)	Description
parent	widget	The parent widget which requests this information.
context	table	The context in which we are fit.
widget	widget	The widget to fit (this uses `widget:fit(context, width, height)`).
width	number	The available width for the widget.
height	number	The available height for the widget.

Returns:

number The width that the widget wants to use.
number The height that the widget wants to use.

🔗 wibox.widget.base.layout_widget (parent, context, widget, width, height) -> table

Lay out a widget for the given available width and height.

This calls the widget's :layout callback and caches the result for later use. Never call :layout directly, but always through this function! However, normally there shouldn't be any reason why you need to use this function.

Parameters:

Name	Type(s)	Description
parent	widget	The parent widget which requests this information.
context	table	The context in which we are laid out.
widget	widget	The widget to layout (this uses `widget:layout(context, width, height)`).
width	number	The available width for the widget.
height	number	The available height for the widget.

Returns:

table

:layout

🔗 wibox.widget.base.handle_button ()

Handle a button event on a widget.

This is used internally and should not be called directly.

🔗 wibox.widget.base.place_widget_via_matrix (widget, mat, width, height) -> table

Create widget placement information. This should be used in a widget's :layout() callback.

Parameters:

Name	Type(s)	Description
widget	widget	The widget that should be placed.
mat		A matrix transforming from the parent widget's coordinate system. For example, use matrix.create_translate(1, 2) to draw a widget at position (1, 2) relative to the parent widget.
width	number	The width of the widget in its own coordinate system. That is, after applying the transformation matrix.
height	number	The height of the widget in its own coordinate system. That is, after applying the transformation matrix.

Returns:

table

:layout()

🔗 wibox.widget.base.place_widget_at (widget, x, y, width, height) -> table

Create widget placement information. This should be used for a widget's :layout() callback.

Parameters:

Name	Type(s)	Description
widget	widget	The widget that should be placed.
x	number	The x coordinate for the widget.
y	number	The y coordinate for the widget.
width	number	The width of the widget in its own coordinate system. That is, after applying the transformation matrix.
height	number	The height of the widget in its own coordinate system. That is, after applying the transformation matrix.

Returns:

table

:layout()

🔗 wibox.widget.base.check_widget ()

Do some sanity checking on a widget.

This function raises an error if the widget is not valid.

Object properties

🔗 children table

Get or set the children elements.

Constraints:

Default value	: `{}`
Table content	: A list of wibox.widget.

Constraints:

Default value	: `{}`
Table content	: A list of wibox.widget.

Constraints:

Default value	: `nil`
Type description:
nil	: Let the layout decide the height. Usually using the widget native height.
number	: Enforce a number of pixels.
Unit	: pixel
Negative allowed	: false

Constraints:

Default value	: `nil`
Type description:
nil	: Let the layout decide the width. Usually using the widget native width.
number	: Enforce a number of pixels.
Unit	: pixel
Negative allowed	: false

Constraints:

Default value	: `1.0`
Unit	: A gradient between transparent (`0.0`) and opaque (`1.0`).
Minimum value	: 0.0
Maximum value	: 1.0

Constraints:

Default value	: `true`
Valid values	: `true` or `false`.

Constraints:

Default value	: `{}`
Table content	: A list of awful.button.

Object methods

🔗 :add_button (button)

Add a new awful.button to this widget.

Parameters:

Name		Type(s)	Description
button		awful.button	The button to add.

🔗 :emit_signal_recursive (signal_name, ...)

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.

Note that this function has some flaws:

The signal is only forwarded once the widget tree has been built. This happens after all currently scheduled functions have been executed. Therefore, it will not start to work right away.
In case the widget is present multiple times in a single widget tree, this function will also forward the signal multiple times (once per upward tree path).
If the widget is removed from the widget tree, the signal is still forwarded for some time, similar to the first case.

Parameters:

Name		Type(s)	Description
signal_name		string
...			Other arguments

🔗 :index (widget, recursive, ...) -> (number, widget, table)

Get the index of a widget.

Parameters:

Name		Type(s)	Description
widget		widget	The widget to look for.
recursive	Optional	boolean	Recursively check accross the sub-widgets hierarchy.
...	Optional	widget	Additional widgets to add at the end of the sub-widgets hierarchy "path".

Returns:

number The widget index.
widget The parent widget.
table The hierarchy path between "self" and "widget".

🔗 :connect_signal (name, func) · Inherited from gears.object

Connect to a signal.

Usage example output:

In slot [obj]   nil nil nil
In slot [obj]   foo bar 42

Parameters:

Name		Type(s)	Description
name		string	The name of the signal.
func		function	The callback to call when the signal is emitted.

Usage:

local o = gears.object{}
-- Function can be attached to signals
local function slot(obj, a, b, c)
    print("In slot", obj, a, b, c)
end
o:connect_signal("my_signal", slot)
-- Emitting can be done without arguments. In that case, the object will be
-- implicitly added as an argument.
o:emit_signal "my_signal"
-- It is also possible to add as many random arguments are required.
o:emit_signal("my_signal", "foo", "bar", 42)
-- Finally, to allow the object to be garbage collected (the memory freed), it
-- is necessary to disconnect the signal or use weak_connect_signal
o:disconnect_signal("my_signal", slot)
-- This time, the slot wont be called as it is no longer connected.
o:emit_signal "my_signal"

🔗 :weak_connect_signal (name, func) · Inherited from gears.object

Connect to a signal weakly.

This allows the callback function to be garbage collected and automatically disconnects the signal when that happens. Warning: Only use this function if you really, really, really know what you are doing.

Parameters:

Name		Type(s)	Description
name		string	The name of the signal.
func		function	The callback to call when the signal is emitted.

🔗 :disconnect_signal (name, func) · Inherited from gears.object

Disconnect from a signal.

Parameters:

Name		Type(s)	Description
name		string	The name of the signal.
func		function	The callback that should be disconnected.

🔗 :emit_signal (name, ...) · Inherited from gears.object

Emit a signal.

Parameters:

Name		Type(s)	Description
name		string	The name of the signal
...			Extra arguments for the callback functions. Each connected function receives the object as first argument and then any extra arguments that are given to emit_signal()

Signals

🔗 widget::layout_changed

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.

Arguments:

Name	Type(s)	Description
self	table	The current object instance itself.
lx	number	The horizontal position relative to the (0,0) position in the widget.
ly	number	The vertical position relative to the (0,0) position in the widget.
button	number	The button number.
mods	table	The modifiers (mod4, mod1 (alt), Control, Shift)
find_widgets_result	table	The entry from the result of wibox:find_widgets for the position that the mouse hit.
drawable	wibox.drawable	The drawable containing the widget.
widget	widget	The widget being displayed.
hierarchy	wibox.hierarchy	The hierarchy managing the widget's geometry.
x	number	An approximation of the X position that the widget is visible at on the surface.
y	number	An approximation of the Y position that the widget is visible at on the surface.
width	number	An approximation of the width that the widget is visible at on the surface.
height	number	An approximation of the height that the widget is visible at on the surface.
widget_width	number	The exact width of the widget in its local coordinate system.
widget_height	number	The exact height of the widget in its local coordinate system.

Arguments:

Name	Type(s)	Description
self	table	The current object instance itself.
lx	number	The horizontal position relative to the (0,0) position in the widget.
ly	number	The vertical position relative to the (0,0) position in the widget.
button	number	The button number.
mods	table	The modifiers (mod4, mod1 (alt), Control, Shift)
find_widgets_result	table	The entry from the result of wibox:find_widgets for the position that the mouse hit.
drawable	wibox.drawable	The drawable containing the widget.
widget	widget	The widget being displayed.
hierarchy	wibox.hierarchy	The hierarchy managing the widget's geometry.
x	number	An approximation of the X position that the widget is visible at on the surface.
y	number	An approximation of the Y position that the widget is visible at on the surface.
width	number	An approximation of the width that the widget is visible at on the surface.
height	number	An approximation of the height that the widget is visible at on the surface.
widget_width	number	The exact width of the widget in its local coordinate system.
widget_height	number	The exact height of the widget in its local coordinate system.

Arguments:

Name	Type(s)	Description
self	table	The current object instance itself.
find_widgets_result	table	The entry from the result of wibox:find_widgets for the position that the mouse hit.
drawable	wibox.drawable	The drawable containing the widget.
widget	widget	The widget being displayed.
hierarchy	wibox.hierarchy	The hierarchy managing the widget's geometry.
x	number	An approximation of the X position that the widget is visible at on the surface.
y	number	An approximation of the Y position that the widget is visible at on the surface.
width	number	An approximation of the width that the widget is visible at on the surface.
height	number	An approximation of the height that the widget is visible at on the surface.
widget_width	number	The exact width of the widget in its local coordinate system.
widget_height	number	The exact height of the widget in its local coordinate system.

Arguments:

Name	Type(s)	Description
self	table	The current object instance itself.
find_widgets_result	table	The entry from the result of wibox:find_widgets for the position that the mouse hit.
drawable	wibox.drawable	The drawable containing the widget.
widget	widget	The widget being displayed.
hierarchy	wibox.hierarchy	The hierarchy managing the widget's geometry.
x	number	An approximation of the X position that the widget is visible at on the surface.
y	number	An approximation of the Y position that the widget is visible at on the surface.
width	number	An approximation of the width that the widget is visible at on the surface.
height	number	An approximation of the height that the widget is visible at on the surface.
widget_width	number	The exact width of the widget in its local coordinate system.
widget_height	number	The exact height of the widget in its local coordinate system.

Methods

🔗 :set_widget_common (self, widget)

Common implementation of the :set_widget() method exposed by many other widgets.

Use this if your widget has no custom logic when setting the widget.

Parameters:

Name		Type(s)	Description
self
widget

Usage:

rawset(my_custom_widget, "set_widget", wibox.widget.base.set_widget_common)

awesome

Contents

Classes

Core components

Input handling

Declarative rules

Widgets

Widget containers

Widget layouts

Popups and bars

Utility libraries

Theme related libraries

Libraries

Sample files

Documentation

Module: wibox.widget.base

Class Hierarchy

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Module: `wibox.widget.base`