from skimage.filter import canny

from .overlayplugin import OverlayPlugin
from ..widgets import Slider, ComboBox


class CannyPlugin(OverlayPlugin):

    name = 'Canny Filter'

    def __init__(self, *args, **kwargs):
        super(CannyPlugin, self).__init__(**kwargs)

        self.add_widget(Slider('sigma', 0, 5, update_on='release'))
        self.add_widget(Slider('low threshold', 0, 255, update_on='release'))
        self.add_widget(Slider('high threshold', 0, 255, update_on='release'))
        self.add_widget(ComboBox('color', self.color_names, ptype='plugin'))

    def attach(self, image_viewer):
        super(CannyPlugin, self).attach(image_viewer)
        # Update image overlay to default slider values.
        self.filter_image()

    def image_filter(self, *args, **kwargs):
        image = canny(*args, **kwargs)
        self.overlay = image