RangeSlider 2023.07.2

Range selection widget for Python Tkinter GUI developement in slider widget structure with two handles.

Updates and Fixes in v2023.07.2 w.r.t v2023.07.1

• Updated: Documentation, included padX and padY in widget calls to avoid confusion with errors. However, the values needs to be updated in case of non-suitability depending on system and used font size, handle size etc.
• Added: Sample ipython notebook containing code. (Visit: https://github.com/harshvinay752/RangeSlider/blob/1a068138c63ca61ccc734e71c27201e7a851c65a/sample.ipynb)

Updates and Fixes in v2023.07.1 w.r.t v2022.12.1

• Fixed: Error in updation of UI in absence of step markers.
• Fixed: Error in initialisation of handle values. (Closing the issue: https://github.com/harshvinay752/RangeSlider/issues/7#issue-1806570927)
• Added: Complimentary check for correct [step_size] parameter in case of usage of step markers.
• Fixed: Updated example code in documentation.

Updates and Fixes in v2022.12.1 w.r.t. v2021.7.4

• Added option to change font color of label (Merged from: https://github.com/RWitak)
• Improved and added option to set initial value of handles. (Merged from: https://github.com/sebasj13)

Note: In order to set the initial values -- declare initial value to the handle variable, if undeclared both handles will be set to min_val. See example in Usage section.

• Added option to set step size. (Closing the issue: https://github.com/harshvinay752/RangeSlider/issues/4#issue-1451264874)
• Added option to display step points on the bar, with added color option.
• Added option to (dis)allow the handles to cross each other.
• Added option to force(or set) handle value. (Both by value or normalised position). (Closing the issue: https://github.com/harshvinay752/RangeSlider/issues/1#issue-1050521371)

Features:

• Range selection
• Vertical as well as horizontal widget
• Option for showing current value of handle
• Customizable handle with default circular handle offering color choice or using image as handle
• Ability to bind a tkinter variable, making it easier to check for slider movement
• Custom font and position for value text
• Customizable value precision
• Custom suffix option
• Many others...

Preview

[preview.png] image file in repository.

Usage

Importing required sliders

For horizontal RangeSlider:

from RangeSlider.RangeSlider import RangeSliderH 

For vertical RangeSlider:

from RangeSlider.RangeSlider import RangeSliderV

For both horizontal and vertical RangeSlider:

from RangeSlider.RangeSlider import RangeSliderH, RangeSliderV

Creating Simple RangeSlider widget:

from tkinter.ttk import *
import tkinter as tk
 
root = tk.Tk()
 
hLeft = tk.DoubleVar(value = 0.2)  #left handle variable initialised to value 0.2
hRight = tk.DoubleVar(value = 0.85)  #right handle variable initialised to value 0.85
hSlider = RangeSliderH( root , [hLeft, hRight] , padX = 12)   #horizontal slider, [padX] value might be needed to be different depending on system, font and handle size. Usually [padX] = 12 serves,
                                                              #otherwise a recommended value will be shown through an error message
hSlider.pack()   # or grid or place method could be used

vBottom = tk.DoubleVar(value = 0)   #bottom handle variable
vTop = tk.DoubleVar(value = 1)   #top handle variable
vSlider = RangeSliderV( root, [vBottom, vTop] , padY = 12)    #vertical slider, [padY] value might be needed to be different depending on system, font and handle size. Usually [padY] = 12 serves,
                                                              #otherwise a recommended value will be shown through an error message
vSlider.pack()  # or grid or place method could be used

root.mainloop()

Getting current value

print ( hSlider.getValues() )  #return type list of format [ left handle value, right handle value ]
print ( vSlider.getValues() )  #return type list of format [ bottom handle value, top handle value ]

Force value

hSlider.forceValues([0.2, 0.67])  #returns None
vSlider.forceValues([0.62, 0.85])  #returns None

Callback on value change

def doSomething():
    print ('I was called.')

hLeft.trace_add('w', doSomething)
hRight.trace_add('w', doSomething)
vBottom.trace_add('w', doSomething)
vTop.trace_add('w', doSomething)

Attributes

For RangeSliderH:

For RangeSliderV:

Additional Notes for attributes

• if show_value is False, digit_precision, valueSide, font_family, font_size and suffix have no effect
• if auto is True, imageL, imageU, image_anchorL, image_anchorR and image_anchorU have no effect
• if auto is False, bar_radius, bar_color_inner, bar_color_outer have no effect
• if step_size is zero, step_marker will not be made

Exceptions raised

Functions

Note: The relation between value ($v_i$) and normalised value ($n_i$) of $i^{th}$ handle defined for a slider with max_val of $v_<$ and min_val of $v_>$ is given by:

$\begin{equation} n_i = \frac{v_i - v_>}{v_<-v_>} \end{equation}$

Words of Developer

This is the second version of this library. It is one of its kind widget for tkinter. When I was developing a tool for my college project I found that at the time no inbuilt or external tool is available for tkinter allowing range selection. However, range selection is a high demand tool specially for applications dealing with data visualizations. I would appreciate any developer from any community who wants to contribute to this project.

I thank RWitak and Sebastian for contributing to this project.