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: #7 (comment))
• 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: #4 (comment))
• 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: #1 (comment))

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:

Attribute	Default Value	Acceptable Value(s) or Description	Release Comment
master	N/A	parent like Tk instance, TopLevel, or Frame etc.	v2021.7.4
variables	N/A	list of DoubleVar of length two in order of left handle and right handle	v2021.7.4
Width	400	width of widget in px	v2021.7.4
Height	80	height of widget in px	v2021.7.4
min_val	0	minimum value	v2021.7.4
max_val	1	maximum value	v2021.7.4
padX	3	padding from both left and right in px	v2021.7.4
image_anchorR	CENTER	anchor value for right handle if image is used as handle - N, NE, E, SE, S, SW, W, NW, CENTER	v2021.7.4
image_anchorL	CENTER	anchor value for left handle if image is used as handle - N, NE, E, SE, S, SW, W, NW, CENTER	v2021.7.4
imageL	None	PhotoImage instance for imaged left handle	v2021.7.4
imageR	None	PhotoImage instance for imaged right handle	v2021.7.4
auto	True	True for automatic circular colored handle, False for imaged handle	v2021.7.4
line_width	3	width of widget track in px	v2021.7.4
bar_radius	10	radius of outer circle of handle	v2021.7.4
bar_color_inner	'#5c8a8a'	hex value of color for inner circle in string format	v2021.7.4
bar_color_outer	'#c2d6d6'	hex value of color for inner circle in string format	v2021.7.4
line_s_color	'#0a50ff'	hex value of color for selected portion for widget track in string format	v2021.7.4
line_color	'#476b6b'	hex value of color for unselected portion for widget track in string format	v2021.7.4
bgColor	'#ffffff'	hex value of color for background of widget in string format	v2021.7.4
step_marker_color	'#ffffff'	hex value of color in string format for steps marked on widget bar	v2022.12.1
font_color	'#000000'	hex value of color for font of widget in string format	v2022.12.1
show_value	True	True if current value of handle are intended; otherwise False	v2021.7.4
digit_precision	'.1f'	precision format for shown value	v2021.7.4
valueSide	'TOP'	'TOP' if shown value intended above the handle or 'BOTTOM' if shown value intended below the handle	v2021.7.4
font_family	'Times'	font family ( all font families supported by tkinter are acceptable )	v2021.7.4
font_size	16	font size in pt	v2021.7.4
suffix	""	suffix for shown value	v2021.7.4
step_size	0	step size of handle movement, step_size equal to 0 implies continuous movement subject to system architecture floating point resolution	v2022.12.1
step_marker	False	True if to display step markers on bar; otherwise False	v2022.12.1
cross_each_other	False	True if handles can cross each other	v2022.12.1

For RangeSliderV:

Attribute	Default Value	Acceptable Value(s)	Release Comment
master	N/A	parent like Tk instance, TopLevel, or Frame etc.	v2021.7.4
variables	N/A	list of DoubleVar of length two in order of lower handle and upper handle	v2021.7.4
Width	80	width of widget in px	v2021.7.4
Height	400	height of widget in px	v2021.7.4
min_val	0	minimum value	v2021.7.4
max_val	1	maximum value	v2021.7.4
padY	3	padding from both top and bottom in px	v2021.7.4
image_anchorU	CENTER	anchor value for upper handle if image is used as handle - N, NE, E, SE, S, SW, W, NW, CENTER	v2021.7.4
image_anchorL	CENTER	anchor value for lower handle if image is used as handle - N, NE, E, SE, S, SW, W, NW, CENTER	v2021.7.4
imageL	None	PhotoImage instance for imaged lower handle	v2021.7.4
imageU	None	PhotoImage instance for imaged upper handle	v2021.7.4
auto	True	True for automatic circular colored handle, False for imaged handle	v2021.7.4
line_width	3	width of widget track in px	v2021.7.4
bar_radius	10	radius of outer circle of handle	v2021.7.4
bar_color_inner	'#5c8a8a'	hex value of color for inner circle in string format	v2021.7.4
bar_color_outer	'#c2d6d6'	hex value of color for inner circle in string format	v2021.7.4
line_s_color	'#0a50ff'	hex value of color for selected portion for widget track in string format	v2021.7.4
line_color	'#476b6b'	hex value of color for unselected portion for widget track in string format	v2021.7.4
bgColor	'#ffffff'	hex value of color for background of widget in string format	v2021.7.4
step_marker_color	'#ffffff'	hex value of color in string format for steps marked on widget bar	v2022.12.1
font_color	'#000000'	hex value of color for font of widget in string format	v2022.12.1
show_value	True	True if current value of handle are intended; otherwise False	v2021.7.4
digit_precision	'.1f'	precision format for shown value	v2021.7.4
valueSide	'TOP'	'TOP' if shown value intended above the handle or 'BOTTOM' if shown value intended below the handle	v2021.7.4
font_family	'Times'	font family ( all font families supported by tkinter are acceptable )	v2021.7.4
font_size	16	font size in pt	v2021.7.4
suffix	""	suffix for shown value	v2021.7.4
step_size	0	step size of handle movement, step_size equal to 0 implies continuous movement subject to system architecture floating point resolution	v2022.12.1
step_marker	False	True if to display step markers on bar; otherwise False	v2022.12.1
cross_each_other	False	True if handles can cross each other	v2022.12.1

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

Condition	Exception
if auto is True and either imageL or imageU or imageR or combination out of three is also given	Exception raised: "Can't decide if to use auto shape or images!"
if auto is False and one of the image handles is missing	Exception raised: "Handle for one image missing."
if auto is False and dimensions for both handles provided are not same	Exception raised : "Image dimensions incompatible, both handles should have same height and width respectively."
if Width or Height or padX or padY are not sufficient to render the widget with all features visible safely	Exception raised : $dimension$ not suitable with suggestions to avoid it

Functions

Function	Arguments	Output Format
getValues()	NIL	value of handle variables in list format in the same order as given in object definition, returned values lie between min_val and max_val
getPos()	NIL	normalised value of handle variables in list format in the same order as given in object definition, returned values lie between 0 and 1
forceValues(values)	values : a list of two values each indicating value of handle, values must be between min_val and max_val	return None
forcePos(pos)	pos : a list of two normalised values each indicating value of handle, values must be between 0 and 1	return None

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.