Module: `wibox.container.constraint`

Restrict a widget size using one of multiple available strategies.

Class Hierarchy

gears.object
- wibox.widget.base
- - wibox.container.constraint

Info:

Copyright: 2012 Lukáš Hrázký
Originally authored by: Lukáš Hrázký
(Full contributors list available on our github project)

Constructors

wibox.container.constraint (widget, strategy, width, height)

Returns a new constraint container.

Object properties

widget	widget or nil	The widget to be constrained.
strategy	string	Set the strategy to use for the constraining.
width	number or nil	Set the maximum width to val.
height	number or nil	Set the maximum height to val.
children	table	Get or set the children elements.	Inherited from wibox.widget.base
all_children	table	Get all direct and indirect children widgets.	Inherited from wibox.widget.base
forced_height	number or nil	Force a widget height.	Inherited from wibox.widget.base
forced_width	number or nil	Force a widget width.	Inherited from wibox.widget.base
opacity	number	The widget opacity (transparency).	Inherited from wibox.widget.base
visible	boolean	The widget visibility.	Inherited from wibox.widget.base
buttons	table	The widget buttons.	Inherited from wibox.widget.base

Object methods

:reset ()	Reset this layout.
:add_button (button)	Add a new awful.button to this widget.	Inherited from wibox.widget.base
:emit_signal_recursive (signal_name, ...)	Emit a signal and ensure all parent widgets in the hierarchies also forward the signal.	Inherited from wibox.widget.base
:index (widget, recursive, ...) -> (number, widget, table)	Get the index of a widget.	Inherited from wibox.widget.base
: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.	Inherited from wibox.widget.base
widget::redraw_needed	When the widget content changed.	Inherited from wibox.widget.base
button::press	When a mouse button is pressed over the widget.	Inherited from wibox.widget.base
button::release	When a mouse button is released over the widget.	Inherited from wibox.widget.base
mouse::enter	When the mouse enter a widget.	Inherited from wibox.widget.base
mouse::leave	When the mouse leave a widget.	Inherited from wibox.widget.base

Constructors

🔗 wibox.container.constraint (widget, strategy, width, height)

Returns a new constraint container.

This container will constraint the size of a widget according to the strategy. Note that this will only work for layouts that respect the widget's size, eg. fixed layout. In layouts that don't (fully) respect widget's requested size, the inner widget still might get drawn with a size that does not fit the constraint, eg. in flex layout.

Parameters:

Name		Description
widget	Optional	A widget to use.
strategy	Optional	How to constraint the size. 'max' (default), 'min' or 'exact'.
width	Optional	The maximum width of the widget. nil for no limit.
height	Optional	The maximum height of the widget. nil for no limit.

Returns:

table

Object properties

🔗 widget widget or nil

The widget to be constrained.

Constraints:

Default value : nil

🔗 strategy string · 1 signal

Set the strategy to use for the constraining.

Constraints:

Default value	: `"max"`
Valid values:
`"max"`	: Never allow the size to be larger than the limit.
`"min"`	: Never allow the size to tbe below the limit.
`"exact"`	: Force the widget size.

Click to display more

Emit signals:

property::strategy When the strategy value changes.

self wibox.container.constraint The object which changed (useful when connecting many object to the same callback).
new_value strategy The new value affected to the property.

🔗 width number or nil · 1 signal

Set the maximum width to val. nil for no width limit.

Constraints:

Default value	: `nil`
Type description:
nil	: Do not set a width limit.
number	: Set a width limit.
Unit	: pixel
Negative allowed	: false

Click to display more

Emit signals:

property::width When the width value changes.

self wibox.container.constraint The object which changed (useful when connecting many object to the same callback).
new_value width The new value affected to the property.

🔗 height number or nil · 1 signal

Set the maximum height to val. nil for no height limit.

Constraints:

Default value	: `nil`
Type description:
nil	: Do not set a height limit.
number	: Set a height limit.
Unit	: pixel
Negative allowed	: false

Click to display more

Emit signals:

property::height When the height value changes.

self wibox.container.constraint The object which changed (useful when connecting many object to the same callback).
new_value height The new value affected to the property.

🔗 children table · Inherited from wibox.widget.base

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

🔗 :reset ()

Reset this layout.

The widget will be unreferenced, strategy set to "max" and the constraints set to nil.

🔗 :add_button (button) · Inherited from wibox.widget.base

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, ...) · Inherited from wibox.widget.base

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) · Inherited from wibox.widget.base

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 · Inherited from wibox.widget.base

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.

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Documentation

Module: wibox.container.constraint

Class Hierarchy

Info:

Constructors

Object properties

Object methods

Signals

Constructors

Parameters:

Returns:

Object properties

Constraints:

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Module: `wibox.container.constraint`