Module: wibox.layout.align

The align layout has three slots for child widgets.

On its main axis, it will use as much space as is available to it and distribute that to its child widgets by stretching or shrinking them based on the chosen expand strategy. On its secondary axis, the biggest child widget determines the size of the layout, but smaller widgets will not be stretched to match it.

In its default configuration, the layout will give the first and third widgets only the minimum space they ask for and it aligns them to the outer edges. The remaining space between them is made available to the widget in slot two.

This layout is most commonly used to split content into left/top, center and right/bottom sections. As such, it is usually seen as the root layout in awful.wibar.

You may also fill just one or two of the widget slots, the expand algorithm will adjust accordingly.

Usage:

    wibox.widget {
        generic_widget( "first"  ),
        generic_widget( "second" ),
        generic_widget( "third"  ),
        layout  = wibox.layout.align.horizontal
    }
    

Class Hierarchy

Info:

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

Constructors

wibox.layout.align.horizontal (left, middle, right) Returns a new horizontal align layout.
wibox.layout.align.vertical (top, middle, bottom) Returns a new vertical align layout.

Object properties

first widget or nil The widget in slot one.
second widget or nil The widget in slot two.
third widget or nil The widget in slot three.
expand string Set the expand mode, which determines how child widgets expand to take up unused space.
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

:set (index, widget2) -> boolean Set a widget at a specific index, replacing the current one.
:replace_widget (widget, widget2, recursive) -> boolean Replace the first instance of widget in the layout with widget2.
:swap (index1, index2) -> boolean Swap 2 widgets in a layout.
:swap_widgets (widget1, widget2, recursive) -> boolean Swap 2 widgets in a layout.
:reset () Reset the 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.layout.align.horizontal (left, middle, right)
Returns a new horizontal align layout.

The three widget slots are aligned left, center and right.

Additionally, this creates the aliases set_left, set_middle and set_right to assign first, second and third respectively.

Parameters:

Name Type(s) Description
left Optional widget Widget to be put in slot one.
middle Optional widget Widget to be put in slot two.
right Optional widget Widget to be put in slot three.
🔗 wibox.layout.align.vertical (top, middle, bottom)
Returns a new vertical align layout.

The three widget slots are aligned top, center and bottom.

Additionally, this creates the aliases set_top, set_middle and set_bottom to assign first, second and third respectively.

Parameters:

Name Type(s) Description
top Optional widget Widget to be put in slot one.
middle Optional widget Widget to be put in slot two.
bottom Optional widget Widget to be put in slot three.

Object properties

🔗 first widget or nil · 1 signal
The widget in slot one.

This is the widget that is at the left/top.

Constraints:

Default value : nil
Type description:
nil : This spot will be empty. Depending on how large the second widget is an and the value of expand, it might mean it will leave an empty area.

Click to display more

Emit signals:

  • property::first When the first value changes.
    • self wibox.layout.align The object which changed (useful when connecting many object to the same callback).
    • new_value first The new value affected to the property.
🔗 second widget or nil · 1 signal
The widget in slot two.

This is the centered one.

Constraints:

Default value : nil
Type description:
nil : When this property is nil, then there will be an empty area.

Click to display more

Emit signals:

  • property::second When the second value changes.
    • self wibox.layout.align The object which changed (useful when connecting many object to the same callback).
    • new_value second The new value affected to the property.
🔗 third widget or nil · 1 signal
The widget in slot three.

This is the widget that is at the right/bottom.

Constraints:

Default value : nil
Type description:
nil : This spot will be empty. Depending on how large the second widget is an and the value of expand, it might mean it will leave an empty area.

Click to display more

Emit signals:

  • property::third When the third value changes.
    • self wibox.layout.align The object which changed (useful when connecting many object to the same callback).
    • new_value third The new value affected to the property.
🔗 expand string
Set the expand mode, which determines how child widgets expand to take up unused space.

Attempting to set any other value than one of those three will fall back to "inside".

Constraints:

Default value : "inside"
Valid values: : How to use unused space.
"inside" : The widgets in slot one and three are set to their minimal required size. The widget in slot two is then given the remaining space. This is the default behaviour.
"outside" : The widget in slot two is set to its minimal required size and placed in the center of the space available to the layout. The other widgets are then given the remaining space on either side. If the center widget requires all available space, the outer widgets are not drawn at all.
"none" : All widgets are given their minimal required size or the remaining space, whichever is smaller. The center widget gets priority.
🔗 children table · Inherited from wibox.widget.base
Get or set the children elements.

Constraints:

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

See also:

wibox.widget.base.all_children
🔗 all_children table · Inherited from wibox.widget.base
Get all direct and indirect children widgets. This will scan all containers recursively to find widgets Warning: This method it prone to stack overflow if there is a loop in the widgets hierarchy. A hierarchy loop is when a widget, or any of its children, contain (directly or indirectly) itself.

Constraints:

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

See also:

wibox.widget.base.children
🔗 forced_height number or nil · Inherited from wibox.widget.base
Force a widget height.

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

See also:

wibox.widget.base.forced_width
🔗 forced_width number or nil · Inherited from wibox.widget.base
Force a widget width.

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

See also:

wibox.widget.base.forced_height
🔗 opacity number · Inherited from wibox.widget.base
The widget opacity (transparency).

Constraints:

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

See also:

wibox.widget.base.visible
🔗 visible boolean · Inherited from wibox.widget.base
The widget visibility.

Constraints:

Default value : true
Valid values : true or false.

See also:

wibox.widget.base.opacity
🔗 buttons table · Inherited from wibox.widget.base
The widget buttons.

The table contains a list of awful.button objects.

Constraints:

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

See also:

awful.button Create easily new buttons objects ignoring certain modifiers. module

Object methods

🔗 :set (index, widget2) -> boolean · 1 signal
Set a widget at a specific index, replacing the current one.

Parameters:

Name Type(s) Description
index number A widget or a widget index
widget2 widget The widget to replace the previous one with

Returns:

    boolean Returns true if the widget was replaced successfully, false otherwise.

Click to display more

Emit signals:

  • widget::replaced
    • self widget The layout.
    • widget widget The inserted widget.
    • previous widget The previous widget.
    • index number The replaced index.
🔗 :replace_widget (widget, widget2, recursive) -> boolean · 1 signal
Replace the first instance of widget in the layout with widget2.

Parameters:

Name Type(s) Description Default value
widget widget The widget to replace Not applicable
widget2 widget The widget to replace widget with Not applicable
recursive Optional boolean Recurse into all compatible layouts to find the widget. false

Returns:

    boolean Returns true if the widget was replaced successfully, false otherwise.

Click to display more

Emit signals:

  • widget::replaced
    • self widget The layout.
    • widget widget index The inserted widget.
    • previous widget The previous widget.
    • index number The replaced index.
🔗 :swap (index1, index2) -> boolean · 1 signal
Swap 2 widgets in a layout.

Parameters:

Name Type(s) Description
index1 number The first widget index
index2 number The second widget index

Returns:

    boolean Returns true if the widget was replaced successfully, false otherwise.

Click to display more

Emit signals:

  • widget::swapped
    • self widget The layout.
    • widget1 widget The first widget.
    • widget2 widget The second widget.
    • index1 number The first index.
    • index1 number The second index.
🔗 :swap_widgets (widget1, widget2, recursive) -> boolean · 1 signal
Swap 2 widgets in a layout.

If widget1 is present multiple time, only the first instance is swapped.

Calls set internally, so the signal widget::replaced is emitted for both widgets as well.

Parameters:

Name Type(s) Description Default value
widget1 widget The first widget Not applicable
widget2 widget The second widget Not applicable
recursive Optional boolean Recurse into all compatible layouts to find the widget. false

Returns:

    boolean Returns true if the widget was replaced successfully, false otherwise.

See also:

set Set a widget at a specific index, replacing the current one. object methods

Click to display more

Emit signals:

  • widget::swapped
    • self widget The layout.
    • widget1 widget The first widget.
    • widget2 widget The second widget.
    • index1 number The first index.
    • index1 number The second index.
🔗 :reset () · 1 signal
Reset the layout. This removes all widgets from the layout.
Click to display more

Emit signals:

  • widget::reset
    • self widget The layout.
🔗 :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:

  1. 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.
  2. 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).
  3. 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:

  1. number The widget index.
  2. widget The parent widget.
  3. 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.

See also:

widget::redraw_needed When the widget content changed. signals
🔗 widget::redraw_needed · Inherited from wibox.widget.base
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.

See also:

widget::layout_changed When the layout (size) change. signals
🔗 button::press · Inherited from wibox.widget.base
When a mouse button is pressed over the widget.

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.

See also:

mouse Manipulate and inspect the mouse cursor. module
🔗 button::release · Inherited from wibox.widget.base
When a mouse button is released over the widget.

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.

See also:

mouse Manipulate and inspect the mouse cursor. module
🔗 mouse::enter · Inherited from wibox.widget.base
When the mouse enter a widget.

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.

See also:

mouse Manipulate and inspect the mouse cursor. module
🔗 mouse::leave · Inherited from wibox.widget.base
When the mouse leave a widget.

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.

See also:

mouse Manipulate and inspect the mouse cursor. module
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