.. 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

        Click :ref:`here <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 5-152



.. 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:: default


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

    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:

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

        def __init__(self, pathpatch: matplotlib.patches.PathPatch):
            """Path editor class. ``t`` toggle vertex markers on and off.
            When vertex markers are on, you can move them, delete them. 

            Args:
                pathpatch (matplotlib.patches.PathPatch): PathPatch instance
            """

            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 vert

            canvas.mpl_connect("draw_event", self.draw_callback)
            canvas.mpl_connect("button_press_event", self.button_press_callback)
            canvas.mpl_connect("key_press_event", self.key_press_callback)
            canvas.mpl_connect("button_release_event", self.button_release_callback)
            canvas.mpl_connect("motion_notify_event", self.motion_notify_callback)
            self.canvas = canvas

        def draw_callback(self, event: matplotlib.backend_bases.DrawEvent):
            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 pathpatch_changed(self, pathpatch: matplotlib.patches.PathPatch):
            "this method is called whenever the pathpatchgon object is called"
            # only copy the artist props to the line (except visibility)
            vis = self.line.get_visible()
            plt.Artist.update_from(self.line, pathpatch)
            self.line.set_visible(vis)  # don't use the pathpatch visibility state

        def get_ind_under_point(self, event):
            "get the index of the vertex under point if within epsilon tolerance"

            # 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 button_press_callback(self, event):
            "whenever a mouse button is pressed"
            if not self.showverts:
                return
            if event.inaxes is None:
                return
            if event.button != 1:
                return
            self._ind = self.get_ind_under_point(event)

        def button_release_callback(self, event):
            "whenever a mouse button is released"
            if not self.showverts:
                return
            if event.button != 1:
                return
            self._ind = None

        def key_press_callback(self, event):
            "whenever a key is pressed"
            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 motion_notify_callback(self, event):
            "on mouse movement"
            if not self.showverts:
                return
            if self._ind is None:
                return
            if event.inaxes is None:
                return
            if event.button != 1:
                return
            x, y = event.xdata, event.ydata

            vertices = self.pathpatch.get_path().vertices

            vertices[self._ind] = x, y
            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  0.096 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-python

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

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

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