.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "_gallery/events/image_data_event.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download__gallery_events_image_data_event.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr__gallery_events_image_data_event.py:


Image data event
================

Example showing how to add an event handler to an ImageGraphic to capture when the data changes.

.. GENERATED FROM PYTHON SOURCE LINES 7-56



.. image-sg:: /_gallery/events/images/sphx_glr_image_data_event_001.webp
   :alt: image data event
   :srcset: /_gallery/events/images/sphx_glr_image_data_event_001.webp
   :class: sphx-glr-single-img





.. code-block:: Python


    # test_example = false

    import fastplotlib as fpl
    import imageio.v3 as iio
    from scipy.ndimage import gaussian_filter

    rgb_weights = [0.299, 0.587, 0.114]

    # load images, convert to grayscale
    img1 = iio.imread("imageio:wikkie.png") @ rgb_weights
    img2 = iio.imread("imageio:astronaut.png") @ rgb_weights

    # Create a figure
    figure = fpl.Figure(
        shape=(1, 2),
        size=(700, 560),
        names=["image", "gaussian filtered image"]
    )

    # create image graphics
    image_raw = figure[0, 0].add_image(img1)
    image_filt = figure[0, 1].add_image(gaussian_filter(img1, sigma=5))

    # show the plot
    figure.show()


    # add event handler
    @image_raw.add_event_handler("data")
    def data_changed(ev: fpl.GraphicFeatureEvent):
        # get the new image data
        new_img = ev.info["value"]

        # set the filtered image graphic
        image_filt.data = gaussian_filter(new_img, sigma=5)


    # set the data on the first image graphic
    # this will trigger the `data_changed()` handler to be called
    image_raw.data = img2


    # NOTE: `if __name__ == "__main__"` is NOT how to use fastplotlib interactively
    # please see our docs for using fastplotlib interactively in ipython and jupyter
    if __name__ == "__main__":
        print(__doc__)
        fpl.loop.run()



.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.688 seconds)


.. _sphx_glr_download__gallery_events_image_data_event.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: image_data_event.ipynb <image_data_event.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: image_data_event.py <image_data_event.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: image_data_event.zip <image_data_event.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_