Module: wibox.container.scroll

This container scrolls its inner widget inside of the available space.

An example usage would be a text widget that displays information about the currently playing song without using too much space for long song titles.

Please note that mouse events do not propagate to widgets inside of the scroll container. Also, if this widget is causing too high CPU usage, you can use set_fps to make it update less often.

Usage:

    wibox.widget {
   layout = wibox.container.scroll.horizontal,
   max_size = 100,
   step_function = wibox.container.scroll.step_functions
                   .waiting_nonlinear_back_and_forth,
   speed = 100,
   {
       widget = wibox.widget.textbox,
       text = "This is a " .. string.rep("very, ", 10) ..  " very long text",
   },
}

Class Hierarchy

Info:

  • Copyright: 2015 Uli Schlachter
  • Originally authored by: Uli Schlachter (based on ideas from Saleur Geoffrey)
    (Full contributors list available on our github project)

Constructors

wibox.container.scroll.horizontal (widget, fps, speed, extra_space, expand, max_size, step_function, space_for_scrolling) Get a new horizontal scrolling container.
wibox.container.scroll.vertical (widget, fps, speed, extra_space, expand, max_size, step_function, space_for_scrolling) Get a new vertical scrolling container.

Object properties

widget widget or nil The widget to be scrolled.
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

:pause () Pause the scrolling animation.
:continue () Continue the scrolling animation.
:reset_scrolling () Reset the scrolling state to its initial condition.
:set_direction (dir) Set the direction in which this widget scroll.
:set_expand (expand) Specify the expand mode that is used for extra space.
:set_fps (fps) Set the number of frames per second that this widget should draw.
:set_extra_space (extra_space) Set the amount of extra space that should be included in the scrolling.
:set_speed (speed) Set the speed of the scrolling animation.
:set_max_size (max_size) Set the maximum size of this widget in the direction set by set_direction.
:set_step_function (step_function) Set the step function that determines the exact behaviour of the scrolling animation.
:set_space_for_scrolling (space_for_scrolling) Set an upper limit for the space for scrolling.
: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

Callback functions prototype

scroll.step_functions.linear_increase () A step function that scrolls the widget in an increasing direction with constant speed.
scroll.step_functions.linear_decrease () A step function that scrolls the widget in an decreasing direction with constant speed.
scroll.step_functions.linear_back_and_forth () A step function that scrolls the widget to its end and back to its beginning, then back to its end, etc.
scroll.step_functions.nonlinear_back_and_forth () A step function that scrolls the widget to its end and back to its beginning, then back to its end, etc.
scroll.step_functions.waiting_nonlinear_back_and_forth () A step function that scrolls the widget to its end and back to its beginning, then back to its end, etc.

Tables

scroll.step_functions A selection of step functions

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.scroll.horizontal (widget, fps, speed, extra_space, expand, max_size, step_function, space_for_scrolling)
Get a new horizontal scrolling container.

Parameters:

Name Type(s) Description Default value
widget Optional The widget that should be scrolled Undefined
fps Optional The number of frames per second 20
speed Optional The speed of the animation 10
extra_space Optional The amount of extra space to include 0
expand Optional boolean Should the widget be expanded to include the extra space? false
max_size Optional The maximum size of the child widget Undefined
step_function Optional The step function to be used step_functions.linear_increase
space_for_scrolling Optional The space for scrolling 2^1024
🔗 wibox.container.scroll.vertical (widget, fps, speed, extra_space, expand, max_size, step_function, space_for_scrolling)
Get a new vertical scrolling container.

Parameters:

Name Type(s) Description Default value
widget Optional The widget that should be scrolled Undefined
fps Optional The number of frames per second 20
speed Optional The speed of the animation 10
extra_space Optional The amount of extra space to include 0
expand Optional boolean Should the widget be expanded to include the extra space? false
max_size Optional The maximum size of the child widget Undefined
step_function Optional The step function to be used step_functions.linear_increase
space_for_scrolling Optional The space for scrolling 2^1024

Object properties

🔗 widget widget or nil
The widget to be scrolled.

Constraints:

Default value : nil
🔗 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

🔗 :pause ()
Pause the scrolling animation.

See also:

continue Continue the scrolling animation. object methods
🔗 :continue ()
Continue the scrolling animation.

See also:

pause Pause the scrolling animation. object methods
🔗 :reset_scrolling ()
Reset the scrolling state to its initial condition. For must scroll step functions, the effect of this function should be to display the widget without any scrolling applied. This function does not undo the effect of pause.
🔗 :set_direction (dir)
Set the direction in which this widget scroll.

Parameters:

Name Type(s) Description
dir Either "h" for horizontal scrolling or "v" for vertical scrolling
🔗 :set_expand (expand)
Specify the expand mode that is used for extra space.

Parameters:

Name Type(s) Description
expand boolean If true, the widget is expanded to include the extra space. If false, the extra space is simply left empty.

See also:

set_extra_space Set the amount of extra space that should be included in the scrolling. object methods
🔗 :set_fps (fps)
Set the number of frames per second that this widget should draw.

Parameters:

Name Type(s) Description
fps number The number of frames per second
🔗 :set_extra_space (extra_space)
Set the amount of extra space that should be included in the scrolling. This extra space will likely be left empty between repetitions of the widgets.

Parameters:

Name Type(s) Description
extra_space number The amount of extra space

See also:

set_expand Specify the expand mode that is used for extra space. object methods
🔗 :set_speed (speed)
Set the speed of the scrolling animation. The exact meaning depends on the step function that is used, but for the simplest step functions, this will be in pixels per second.

Parameters:

Name Type(s) Description
speed number The speed for the animation
🔗 :set_max_size (max_size)
Set the maximum size of this widget in the direction set by set_direction. If the child widget is smaller than this size, no scrolling is done. If the child widget is larger, then only this size will be visible and the rest is made visible via scrolling.

Parameters:

Name Type(s) Description
max_size number The maximum size of this widget or nil for unlimited.
🔗 :set_step_function (step_function)
Set the step function that determines the exact behaviour of the scrolling animation. The step function is called with five arguments:

  • The time in seconds since the state of the animation
  • The size of the child widget
  • The size of the visible part of the widget
  • The speed of the animation. This should have a linear effect on this function's behaviour.
  • The extra space configured by set_extra_space. This was not yet added to the size of the child widget, but should likely be added to it in most cases.

The step function should return a single number. This number is the offset at which the widget is drawn and should be between 0 and size+extra_space.

Parameters:

Name Type(s) Description
step_function function A step function.

See also:

step_functions A selection of step functions tables
🔗 :set_space_for_scrolling (space_for_scrolling)
Set an upper limit for the space for scrolling. This restricts the child widget's maximal size.

Parameters:

Name Type(s) Description
space_for_scrolling number The space for scrolling
🔗 :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()

Callback functions prototype

🔗 scroll.step_functions.linear_increase ()
A step function that scrolls the widget in an increasing direction with constant speed.
🔗 scroll.step_functions.linear_decrease ()
A step function that scrolls the widget in an decreasing direction with constant speed.
🔗 scroll.step_functions.linear_back_and_forth ()
A step function that scrolls the widget to its end and back to its beginning, then back to its end, etc. The speed is constant.
🔗 scroll.step_functions.nonlinear_back_and_forth ()
A step function that scrolls the widget to its end and back to its beginning, then back to its end, etc. The speed is null at the ends and maximal in the middle.
🔗 scroll.step_functions.waiting_nonlinear_back_and_forth ()
A step function that scrolls the widget to its end and back to its beginning, then back to its end, etc. The speed is null at the ends and maximal in the middle. At both ends the widget stands still for a moment.

Tables

🔗 scroll.step_functions
A selection of step functions

See also:

set_step_function Set the step function that determines the exact behaviour of the scrolling animation. object methods

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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