Setting Streamlit widget values via callbacks (2 range sliders | no value overlap | clamped values)

widget_callbacks_sliders.py

# 2 range sliders | no value overlap | clamped values
import streamlit as st

state = st.session_state

def _set_x_cb():
    if state.x[1] > state.y[0]:
        state.x = (state.x[0], state.y[0])
def _set_y_cb():
    if state.y[0] < state.x[1]:
        state.y = (state.x[1], state.y[1])

message = st.info('')

x_slider = {'val': (5,20),'min': 0,'max': 100,'step': 1,}
y_slider = {'val': (30,50),'min': 0,'max': 100,'step': 1,}

x = st.slider(
    'X',
    value=x_slider['val'],
    min_value=x_slider['min'],
    max_value=x_slider['max'],
    step=x_slider['step'],
    on_change=_set_x_cb,
    key='x'
)
y = st.slider(
    'Y',
    value=y_slider['val'],
    min_value=y_slider['min'],
    max_value=y_slider['max'],
    step=y_slider['step'],
    on_change=_set_y_cb,
    key='y')

def _clamp_range(val, spec):
    val_0 = spec['min'] if val[0] < spec['min'] else val[0]
    val_0 = spec['max'] if val_0 > spec['max'] else val_0

    val_1 = spec['min'] if val[1] < spec['min'] else val[1]
    val_1 = spec['max'] if val_1 > spec['max'] else val_1

    return (val_0, val_1)

def _reset_cb():
    state.x = x_slider['val']
    state.y = y_slider['val']
def _make_same_cb():
    state.y = (state.x[1],state.x[1] + (state.x[1]-state.x[0]))
def _make_times2_cb():
    state.x = (state.x[0]*2, state.x[1]*2)
    state.x = _clamp_range(state.x, x_slider)
    state.y = (state.y[0]*2, state.y[1]*2)
    state.y = _clamp_range(state.y, y_slider)
def _make_sub2_cb():
    state.x = (state.x[0]-2, state.x[1]-2)
    state.x = _clamp_range(state.x, x_slider)
    state.y = (state.y[0]-2, state.y[1]-2)
    state.y = _clamp_range(state.y, y_slider)

c1, c2, c3, = st.columns(3)

c1.button('Join X+Y with same gap', on_click=_make_same_cb)
c2.button('Multiply by 2', on_click=_make_times2_cb)
c3.button('Subtract 2', on_click=_make_sub2_cb)
st.button('🔃', help='Reset values', on_click=_reset_cb)

message.info(f'X = {x} | Y = {y}')