color_sliders#
An interactive plot of colors. This example demonstrates adding widgets and
CustomJS
callbacks that can update a plot.
Details
- Bokeh APIs:
figure.text
,bokeh.layouts.column
,bokeh.models.ColumnDataSource
,bokeh.models.CustomJS
,bokeh.models.Slider
,bokeh.themes.Theme
- More info:
- Keywords:
hover, javascript callback, theme, tooltip
# noqa: E501
from bokeh.layouts import column
from bokeh.models import ColumnDataSource, CustomJS, Slider
from bokeh.plotting import curdoc, figure, show
from bokeh.themes import Theme
color = R, G, B = (75, 125, 125)
text_color = (255, 255, 255)
# create a data source to enable refreshing of fill & text color
source = ColumnDataSource(data=dict(color=[color], text_color=[text_color]))
# create first plot, as a rect() glyph and centered text label, with fill and text color taken from source
p = figure(x_range=(-8, 8), y_range=(-4, 4),
width=400, height=300,
title='move sliders to change', tools='')
p.rect(0, 0, width=18, height=10, fill_color='color',
line_color = 'black', source=source)
p.text(0, 0, text='color', text_color='text_color',
alpha=0.6667, text_font_size='48px', text_baseline='middle',
text_align='center', source=source)
red = Slider(title="R", start=0, end=255, value=R, step=1)
green = Slider(title="G", start=0, end=255, value=G, step=1)
blue = Slider(title="B", start=0, end=255, value=B, step=1)
callback = CustomJS(args=dict(source=source, red=red, blue=blue, green=green), code="""
function toHex(c) {
const hex = c.toString(16)
return hex.length == 1 ? "0" + hex : hex
}
const R = red.value | 0
const G = green.value | 0
const B = blue.value | 0
const color = "#" + toHex(R) + toHex(G) + toHex(B)
const text_color = ((R > 127) || (G > 127) || (B > 127)) ? '#000000' : '#ffffff'
source.data = { color: [color], text_color: [text_color] }
""")
red.js_on_change('value', callback)
blue.js_on_change('value', callback)
green.js_on_change('value', callback)
# theme everything for a cleaner look
curdoc().theme = Theme(json={
"attrs": {
"Plot": { "toolbar_location": None },
"Grid": { "grid_line_color": None },
"Axis": {
"axis_line_color": None,
"major_label_text_color": None,
"major_tick_line_color": None,
"minor_tick_line_color": None,
},
},
})
show(column(red, green, blue, p))