DistanceWidget

#!/usr/bin/python3

# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkInteractionWidgets import vtkDistanceWidget
from vtkmodules.vtkRenderingCore import (
    vtkRenderWindow,
    vtkRenderWindowInteractor,
    vtkRenderer
)


def main():
    colors = vtkNamedColors()

    # A renderer and render window.
    renderer = vtkRenderer(background=colors.GetColor3d('Navy'))
    render_window = vtkRenderWindow(window_name='DistanceWidget')
    render_window.AddRenderer(renderer)
    # An interactor.
    render_window_interactor = vtkRenderWindowInteractor()
    render_window_interactor.render_window = render_window

    distance_widget = vtkDistanceWidget(interactor=render_window_interactor)
    distance_widget.CreateDefaultRepresentation()
    distance_widget.representation.label_format = '%-#6.3g mm'

    # Render an image (lights and cameras are created automatically).
    render_window.Render()

    render_window_interactor.Initialize()
    render_window.Render()
    distance_widget.On()

    # Begin mouse interaction.
    render_window_interactor.Start()


if __name__ == '__main__':
    main()