Slider

(Contains a tkinter.Scale object)

__init__(self, master, start=0, end=100, horizontal=True, command=None, grid=None, align=None)

What is it?

The Slider object displays a bar and selector which can be used to specify a value in a range.

The above code looks like this on Windows: Slider on Windows

How do I make one?

Create a Slider object like this:

from guizero import App, Slider
app = App()
slider = Slider(app)
app.display()

Starting paramters

When you create a Slider object, you must specify a master and you can specify any of the the optional parameters. Specify parameters in the brackets, like this: slider = Slider(app, horizontal=False)

Parameter Takes Default Compulsory Description
master App or Box - Yes The container to which this widget belongs
align string None - Alignment of this widget within its grid location. Possible values: "top", "bottom", "left", "right". This parameter is only required if the master object has a grid layout.
command function name None - The name of a function to call when the slider value is changed
end int 100 - The largest value selectable on the slider
grid List [int, int] None - [x,y] coordinates of this widget. This parameter is only required if the master object has a grid layout.
horizontal Boolean True - Whether you wish to display your slider horizontally or vertically (defaults to horizontal)
start int 0 - The smallest value selectable on the slider
visible boolean True No If the widget should be visible.
enabled boolean True No If the widget should be enabled.

Methods

You can call the following methods on a Slider object.

Method Takes Returns Description
the function specified in command
after(time, command) time (int), command (function name) - Schedules a single call to command after time milliseconds. (To repeatedly call the same command, use repeat())
cancel(command) command (function name) - Cancels a scheduled call to command
destroy() - - Destroys the widget
disable() - - Disables the widget so that it is "greyed out" and cannot be interacted with
enable() - - Enables the widget
focus() - - Gives focus to the widget (e.g. focusing a TextBox so that the user can type inside it)
hide() - - Hides the widget from view. This method will unpack the widget from the layout manager.
repeat(time, command) time (int), command (function name) - Repeats command every time milliseconds. This is useful for scheduling a function to be regularly called, for example updating a value read from a sensor.
show() - - Displays the widget if it was previously hidden
update_command(command) command (function name) - Updates the function to call when the slider value is changed
add_command(command) command (function name) - Sets the function called when the slider value is changed to

Methods in italics will still work but are deprecated - this means you should stop using them because they may not work in future versions of guizero

Properties

You can set and get the following properties:

Method Data type Description
align string The alignment of this widget within its grid location
bg color The background colour of the widget
enabled boolean True if the widget is enabled
font string The font of the text
grid List [x,y] coordinates of this widget. This parameter is only required if the master object has a grid
height size Sets the height of the widget
master App or Box The container to which this widget belongs
text_size int The size of the text
text_color color The colour of the text
value string The current value of the slider
visible boolean If this widget is visible
width size Sets the width of the widget

Examples

Calling a function when the slider value changes

You can specify a function to call when the slider value changes. Your function MUST have a minimum of one parameter as it will automatically receive a string containing the value of the slider (called slider_value in the example) when it is called.

This code has a slider and a text box, and the text box updates automatically to display the current value of the slider.

Text box and slider

from guizero import App, Slider, TextBox
def slider_changed(slider_value):
    textbox.value = slider_value

app = App()
slider = Slider(app, command=slider_changed)
textbox = TextBox(app)
app.display()