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

.. only:: html

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

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

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

.. _sphx_glr_auto_examples_Interactive_plot_key_bindings.py:


Key-Press Widget Placement
==========================

Demonstrates the ``on_key`` callback API: press a key while the plot is
focused to add an overlay widget centred on the current cursor position,
or press **Backspace / Delete** to remove the last widget you clicked.

**Key bindings**

+-------------------------------+---------------------------+
| Key                           | Action                    |
+===============================+===========================+
| ``q``                         | Add a rectangle           |
+-------------------------------+---------------------------+
| ``w``                         | Add a circle              |
+-------------------------------+---------------------------+
| ``e``                         | Add an annulus            |
+-------------------------------+---------------------------+
| ``Backspace`` (macOS ⌫)       | Remove last-clicked       |
| ``Delete`` (Windows / Linux)  |                           |
+-------------------------------+---------------------------+

**Built-in 2-D shortcuts** (not overridden in this example):

+-------+---------------------------+
| Key   | Action                    |
+=======+===========================+
| ``r`` | Reset zoom / pan          |
+-------+---------------------------+
| ``c`` | Toggle colorbar           |
+-------+---------------------------+
| ``l`` | Toggle log scale          |
+-------+---------------------------+
| ``s`` | Toggle symlog scale       |
+-------+---------------------------+

The cursor coordinates reported in the event (``event.img_x``,
``event.img_y``) are in image-pixel space, so widgets are centred exactly
where the cursor was when the key was pressed.

.. note::
   Move the mouse over the image first so the plot panel receives focus,
   then press a key.  On macOS the backspace key (⌫) is used for deletion;
   on Windows / Linux use the **Delete** key.

.. GENERATED FROM PYTHON SOURCE LINES 47-123




.. raw:: html

    <div style="display:block;text-align:center;line-height:0;margin:12px 0;"><iframe src="../../_static/viewer_widgets/sphx_glr_plot_key_bindings_001.html" frameborder="0" scrolling="no" style="width:536px;height:536px;border:none;overflow:hidden;display:inline-block;max-width:100%;"></iframe></div>






.. code-block:: Python


    import numpy as np
    import anyplotlib as vw

    # ── Synthetic test image ──────────────────────────────────────────────────────
    rng = np.random.default_rng(0)
    N = 256
    x = np.linspace(0, 4 * np.pi, N)
    XX, YY = np.meshgrid(x, x)
    data = np.sin(XX) * np.cos(YY) + 0.15 * rng.standard_normal((N, N))

    # ── Figure ────────────────────────────────────────────────────────────────────
    fig, ax = vw.subplots(figsize=(520, 520))
    plot = ax.imshow(data)

    # ── Key handlers ─────────────────────────────────────────────────────────────

    @plot.on_key('q')
    def add_rectangle(event):
        """Press 'q' — add a rectangle centred on the cursor."""
        cx, cy = event.img_x, event.img_y
        half_w, half_h = N * 0.08, N * 0.08
        plot.add_widget(
            "rectangle",
            x=cx - half_w, y=cy - half_h,
            w=half_w * 2,  h=half_h * 2,
            color="#ffd54f",
        )


    @plot.on_key('w')
    def add_circle(event):
        """Press 'w' — add a circle centred on the cursor."""
        plot.add_widget(
            "circle",
            cx=event.img_x, cy=event.img_y,
            r=N * 0.07,
            color="#80cbc4",
        )


    @plot.on_key('e')
    def add_annulus(event):
        """Press 'e' — add an annulus centred on the cursor."""
        plot.add_widget(
            "annular",
            cx=event.img_x, cy=event.img_y,
            r_outer=N * 0.12,
            r_inner=N * 0.06,
            color="#ce93d8",
        )


    # macOS sends 'Backspace' for the ⌫ key; Windows/Linux send 'Delete'.
    # Register both so the example works cross-platform.
    @plot.on_key('Backspace')
    @plot.on_key('Delete')
    def delete_last(event):
        """Press Backspace/Delete — remove the last widget that was clicked."""
        wid = event.last_widget_id
        if wid and wid in {w.id for w in plot.list_widgets()}:
            plot.remove_widget(wid)


    # ── Catch-all handler (optional) — log every registered key press ─────────────

    @plot.on_key
    def log_key(event):
        img_x = getattr(event, 'img_x', None)
        img_y = getattr(event, 'img_y', None)
        pos = f"({img_x:.1f}, {img_y:.1f})" if img_x is not None else "n/a"
        print(f"[on_key] key={event.key!r}  img={pos}"
              f"  last_widget={event.last_widget_id!r}")

    fig



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

   **Total running time of the script:** (0 minutes 0.054 seconds)


.. _sphx_glr_download_auto_examples_Interactive_plot_key_bindings.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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