.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "11_demos\python_packages\matplotlib\demo_path_editor.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_11_demos_python_packages_matplotlib_demo_path_editor.py>`
        to download the full example code.

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

.. _sphx_glr_11_demos_python_packages_matplotlib_demo_path_editor.py:

Path editor
==============

.. GENERATED FROM PYTHON SOURCE LINES 5-143



.. image-sg:: /11_demos/python_packages/matplotlib/images/sphx_glr_demo_path_editor_001.png
   :alt: drag vertices to update path
   :srcset: /11_demos/python_packages/matplotlib/images/sphx_glr_demo_path_editor_001.png
   :class: sphx-glr-single-img





.. code-block:: Python


    import numpy as np
    import matplotlib
    import matplotlib.path as mpath
    import matplotlib.patches as mpatches
    import matplotlib.pyplot as plt
    from matplotlib.backend_bases import MouseButton

    Path = mpath.Path

    fig, ax = plt.subplots()

    pathdata = [
        (Path.MOVETO, (1.58, -2.57)),
        (Path.CURVE4, (0.35, -1.1)),
        (Path.CURVE4, (-1.75, 2.0)),
        (Path.CURVE4, (0.375, 2.0)),
        (Path.LINETO, (0.85, 1.15)),
        (Path.CURVE4, (2.2, 3.2)),
        (Path.CURVE4, (3, 0.05)),
        (Path.CURVE4, (2.0, -0.5)),
        (Path.CLOSEPOLY, (1.58, -2.57)),
    ]

    codes, verts = zip(*pathdata)
    path = mpath.Path(verts, codes)
    patch = mpatches.PathPatch(path, facecolor="green", edgecolor="yellow", alpha=0.5)
    ax.add_patch(patch)


    class PathInteractor:
        """
        An path editor.

        Press 't' to toggle vertex markers on and off.  When vertex markers are on,
        they can be dragged with the mouse.
        """

        showverts = True
        epsilon = 5  # max pixel distance to count as a vertex hit

        def __init__(self, pathpatch):
            self.ax = pathpatch.axes
            canvas = self.ax.figure.canvas
            self.pathpatch = pathpatch
            self.pathpatch.set_animated(True)

            x, y = zip(*self.pathpatch.get_path().vertices)

            (self.line,) = ax.plot(x, y, marker="o", markerfacecolor="r", animated=True)

            self._ind = None  # the active vertex

            canvas.mpl_connect("draw_event", self.on_draw)
            canvas.mpl_connect("button_press_event", self.on_button_press)
            canvas.mpl_connect("key_press_event", self.on_key_press)
            canvas.mpl_connect("button_release_event", self.on_button_release)
            canvas.mpl_connect("motion_notify_event", self.on_mouse_move)
            self.canvas = canvas

        def get_ind_under_point(self, event):
            """
            Return the index of the point closest to the event position or *None*
            if no point is within ``self.epsilon`` to the event position.
            """
            # display coords
            xy = np.asarray(self.pathpatch.get_path().vertices)
            xyt = self.pathpatch.get_transform().transform(xy)
            xt, yt = xyt[:, 0], xyt[:, 1]
            d = np.sqrt((xt - event.x) ** 2 + (yt - event.y) ** 2)
            ind = d.argmin()

            if d[ind] >= self.epsilon:
                ind = None

            return ind

        def on_draw(self, event):
            """Callback for draws."""
            self.background = self.canvas.copy_from_bbox(self.ax.bbox)
            self.ax.draw_artist(self.pathpatch)
            self.ax.draw_artist(self.line)
            self.canvas.blit(self.ax.bbox)

        def on_button_press(self, event):
            """Callback for mouse button presses."""
            if (
                event.inaxes is None
                or event.button != MouseButton.LEFT
                or not self.showverts
            ):
                return
            self._ind = self.get_ind_under_point(event)

        def on_button_release(self, event):
            """Callback for mouse button releases."""
            if event.button != MouseButton.LEFT or not self.showverts:
                return
            self._ind = None

        def on_key_press(self, event):
            """Callback for key presses."""
            if not event.inaxes:
                return
            if event.key == "t":
                self.showverts = not self.showverts
                self.line.set_visible(self.showverts)
                if not self.showverts:
                    self._ind = None
            self.canvas.draw()

        def on_mouse_move(self, event):
            """Callback for mouse movements."""
            if (
                self._ind is None
                or event.inaxes is None
                or event.button != MouseButton.LEFT
                or not self.showverts
            ):
                return

            vertices = self.pathpatch.get_path().vertices

            vertices[self._ind] = event.xdata, event.ydata
            self.line.set_data(zip(*vertices))

            self.canvas.restore_region(self.background)
            self.ax.draw_artist(self.pathpatch)
            self.ax.draw_artist(self.line)
            self.canvas.blit(self.ax.bbox)


    interactor = PathInteractor(patch)
    ax.set_title("drag vertices to update path")
    ax.set_xlim(-3, 4)
    ax.set_ylim(-3, 4)

    plt.show()


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

   **Total running time of the script:** (0 minutes 0.042 seconds)


.. _sphx_glr_download_11_demos_python_packages_matplotlib_demo_path_editor.py:

.. only:: html

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

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

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

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

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

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

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