Canvas Color Bars

We can draw directly into the Jupyter Lab canvas by using the Canvas drawing component.

The following draws several horizontal bars of different color.

from ipycanvas import Canvas

canvas = Canvas(width=400, height=170)

# draw a some lines of different colors and widths

canvas.translate(10,10)

canvas.fill_style = 'red';
canvas.fill_rect(0, 0, 400, 10)

canvas.fill_style = 'orange';
canvas.fill_rect(0, 25, 400, 10)

canvas.fill_style = 'yellow';
canvas.fill_rect(0, 50, 400, 10)

canvas.fill_style = 'green';
canvas.fill_rect(0, 75, 400, 10)

canvas.fill_style = 'blue';
canvas.fill_rect(0, 100, 400, 10)

canvas.fill_style = 'purple';
canvas.fill_rect(0, 125, 400, 10)

canvas.fill_style = 'pink';
canvas.fill_rect(0, 150, 400, 10)

canvas

Experiments

Can you modify the above to use a list of colors and a for loop? The color list might be:

Using Lists

from ipycanvas import Canvas
canvas = Canvas(width=400, height=250)

colors =['red', 'orange', 'yellow', 'green', 'blue', 'purple', 'brown',
         'cyan', 'lightgreen', 'lightblue']
canvas.font = '16px serif'

# draw some boxes of different colors

canvas.translate(10,10)
for i in range(len(colors)):
   canvas.fill_style = colors[i];
   canvas.fill_text(colors[i], 0, 25*i + 10)
   canvas.fill_rect(70, i*25, 400, 15)

canvas