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

.. only:: html

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

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

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

.. _sphx_glr_gallery_demo.py:


Demo
----

An example that uses events to trigger some canvas functionality.

A nice demo, and very convenient to test the different backends.

* Can be closed with Escape or by pressing the window close button.
* In both cases, it should print "Close detected" exactly once.
* Hit "f" to spend 2 seconds doing direct draws.

.. GENERATED FROM PYTHON SOURCE LINES 14-77

.. code-block:: Python


    import time

    from rendercanvas.auto import RenderCanvas, loop
    from rendercanvas.utils.cube import setup_drawing_sync
    import rendercanvas


    canvas = RenderCanvas(
        size=(640, 480),
        title="Canvas events with $backend on $loop - $fps fps",
        max_fps=10,
        update_mode="continuous",
        present_method="",
    )


    draw_frame = setup_drawing_sync(canvas)
    canvas.request_draw(draw_frame)

    # Note: in this demo we listen to all events (using '*'). In general
    # you want to select one or more specific events to handle.

    cursor_index = 0


    @canvas.add_event_handler("*")
    def process_event(event):
        global cursor_index

        if event["event_type"] not in ["pointer_move", "before_draw", "animate"]:
            print(event)

        if event["event_type"] == "key_down":
            if event["key"] == "Escape":
                canvas.close()
            elif event["key"] in " f":
                # Force draw for 2 secs
                print("force-drawing ...")
                etime = time.time() + 2
                i = 0
                while time.time() < etime:
                    i += 1
                    canvas.force_draw()
                print(f"Drew {i} frames in 2s.")
            elif event["key"] == "c":
                # Swap cursor
                shapes = list(rendercanvas.CursorShape)
                cursor_index += 1
                if cursor_index >= len(shapes):
                    cursor_index = 0
                cursor = shapes[cursor_index]
                canvas.set_cursor(cursor)
                print(f"Cursor: {cursor!r}")
        elif event["event_type"] == "close":
            # Should see this exactly once, either when pressing escape, or
            # when pressing the window close button.
            print("Close detected!")
            assert canvas.get_closed()


    if __name__ == "__main__":
        loop.run()


.. _sphx_glr_download_gallery_demo.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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