"""
GUI neutral widgets
===================
Widgets that are designed to work for any of the GUI backends.
All of these widgets require you to predefine a `matplotlib.axes.Axes`
instance and pass that as the first parameter. Matplotlib doesn't try to
be too smart with respect to layout -- you will have to figure out how
wide and tall you want your Axes to be to accommodate your widget.
"""
from contextlib import ExitStack
import copy
from numbers import Integral
import numpy as np
import matplotlib as mpl
from . import cbook, colors, ticker
from .lines import Line2D
from .patches import Circle, Rectangle, Ellipse
from .transforms import blended_transform_factory
[docs]class LockDraw:
"""
Some widgets, like the cursor, draw onto the canvas, and this is not
desirable under all circumstances, like when the toolbar is in zoom-to-rect
mode and drawing a rectangle. To avoid this, a widget can acquire a
canvas' lock with ``canvas.widgetlock(widget)`` before drawing on the
canvas; this will prevent other widgets from doing so at the same time (if
they also try to acquire the lock first).
"""
def __init__(self):
self._owner = None
def __call__(self, o):
"""Reserve the lock for *o*."""
if not self.available(o):
raise ValueError('already locked')
self._owner = o
[docs] def release(self, o):
"""Release the lock from *o*."""
if not self.available(o):
raise ValueError('you do not own this lock')
self._owner = None
[docs] def available(self, o):
"""Return whether drawing is available to *o*."""
return not self.locked() or self.isowner(o)
[docs] def isowner(self, o):
"""Return whether *o* owns this lock."""
return self._owner is o
[docs] def locked(self):
"""Return whether the lock is currently held by an owner."""
return self._owner is not None
[docs]class Slider(AxesWidget):
"""
A slider representing a floating point range.
Create a slider from *valmin* to *valmax* in axes *ax*. For the slider to
remain responsive you must maintain a reference to it. Call
:meth:`on_changed` to connect to the slider event.
Attributes
----------
val : float
Slider value.
"""
def __init__(self, ax, label, valmin, valmax, valinit=0.5, valfmt=None,
closedmin=True, closedmax=True, slidermin=None,
slidermax=None, dragging=True, valstep=None,
orientation='horizontal', **kwargs):
"""
Parameters
----------
ax : Axes
The Axes to put the slider in.
label : str
Slider label.
valmin : float
The minimum value of the slider.
valmax : float
The maximum value of the slider.
valinit : float, default: 0.5
The slider initial position.
valfmt : str, default: None
%-format string used to format the slider value. If None, a
`.ScalarFormatter` is used instead.
closedmin : bool, default: True
Whether the slider interval is closed on the bottom.
closedmax : bool, default: True
Whether the slider interval is closed on the top.
slidermin : Slider, default: None
Do not allow the current slider to have a value less than
the value of the Slider *slidermin*.
slidermax : Slider, default: None
Do not allow the current slider to have a value greater than
the value of the Slider *slidermax*.
dragging : bool, default: True
If True the slider can be dragged by the mouse.
valstep : float, default: None
If given, the slider will snap to multiples of *valstep*.
orientation : {'horizontal', 'vertical'}, default: 'horizontal'
The orientation of the slider.
Notes
-----
Additional kwargs are passed on to ``self.poly`` which is the
`~matplotlib.patches.Rectangle` that draws the slider knob. See the
`.Rectangle` documentation for valid property names (``facecolor``,
``edgecolor``, ``alpha``, etc.).
"""
if ax.name == '3d':
raise ValueError('Sliders cannot be added to 3D Axes')
AxesWidget.__init__(self, ax)
if slidermin is not None and not hasattr(slidermin, 'val'):
raise ValueError("Argument slidermin ({}) has no 'val'"
.format(type(slidermin)))
if slidermax is not None and not hasattr(slidermax, 'val'):
raise ValueError("Argument slidermax ({}) has no 'val'"
.format(type(slidermax)))
if orientation not in ['horizontal', 'vertical']:
raise ValueError("Argument orientation ({}) must be either"
"'horizontal' or 'vertical'".format(orientation))
self.orientation = orientation
self.closedmin = closedmin
self.closedmax = closedmax
self.slidermin = slidermin
self.slidermax = slidermax
self.drag_active = False
self.valmin = valmin
self.valmax = valmax
self.valstep = valstep
valinit = self._value_in_bounds(valinit)
if valinit is None:
valinit = valmin
self.val = valinit
self.valinit = valinit
if orientation == 'vertical':
self.poly = ax.axhspan(valmin, valinit, 0, 1, **kwargs)
self.hline = ax.axhline(valinit, 0, 1, color='r', lw=1)
else:
self.poly = ax.axvspan(valmin, valinit, 0, 1, **kwargs)
self.vline = ax.axvline(valinit, 0, 1, color='r', lw=1)
if orientation == 'vertical':
ax.set_ylim((valmin, valmax))
axis = ax.yaxis
else:
ax.set_xlim((valmin, valmax))
axis = ax.xaxis
self.valfmt = valfmt
self._fmt = axis.get_major_formatter()
if not isinstance(self._fmt, ticker.ScalarFormatter):
self._fmt = ticker.ScalarFormatter()
self._fmt.set_axis(axis)
self._fmt.set_useOffset(False) # No additive offset.
self._fmt.set_useMathText(True) # x sign before multiplicative offset.
ax.set_xticks([])
ax.set_yticks([])
ax.set_navigate(False)
self.connect_event('button_press_event', self._update)
self.connect_event('button_release_event', self._update)
if dragging:
self.connect_event('motion_notify_event', self._update)
if orientation == 'vertical':
self.label = ax.text(0.5, 1.02, label, transform=ax.transAxes,
verticalalignment='bottom',
horizontalalignment='center')
self.valtext = ax.text(0.5, -0.02, self._format(valinit),
transform=ax.transAxes,
verticalalignment='top',
horizontalalignment='center')
else:
self.label = ax.text(-0.02, 0.5, label, transform=ax.transAxes,
verticalalignment='center',
horizontalalignment='right')
self.valtext = ax.text(1.02, 0.5, self._format(valinit),
transform=ax.transAxes,
verticalalignment='center',
horizontalalignment='left')
self.cnt = 0
self.observers = {}
self.set_val(valinit)
def _value_in_bounds(self, val):
"""Makes sure *val* is with given bounds."""
if self.valstep:
val = (self.valmin
+ round((val - self.valmin) / self.valstep) * self.valstep)
if val <= self.valmin:
if not self.closedmin:
return
val = self.valmin
elif val >= self.valmax:
if not self.closedmax:
return
val = self.valmax
if self.slidermin is not None and val <= self.slidermin.val:
if not self.closedmin:
return
val = self.slidermin.val
if self.slidermax is not None and val >= self.slidermax.val:
if not self.closedmax:
return
val = self.slidermax.val
return val
def _update(self, event):
"""Update the slider position."""
if self.ignore(event) or event.button != 1:
return
if event.name == 'button_press_event' and event.inaxes == self.ax:
self.drag_active = True
event.canvas.grab_mouse(self.ax)
if not self.drag_active:
return
elif ((event.name == 'button_release_event') or
(event.name == 'button_press_event' and
event.inaxes != self.ax)):
self.drag_active = False
event.canvas.release_mouse(self.ax)
return
if self.orientation == 'vertical':
val = self._value_in_bounds(event.ydata)
else:
val = self._value_in_bounds(event.xdata)
if val not in [None, self.val]:
self.set_val(val)
def _format(self, val):
"""Pretty-print *val*."""
if self.valfmt is not None:
return self.valfmt % val
else:
_, s, _ = self._fmt.format_ticks([self.valmin, val, self.valmax])
# fmt.get_offset is actually the multiplicative factor, if any.
return s + self._fmt.get_offset()
[docs] def set_val(self, val):
"""
Set slider value to *val*
Parameters
----------
val : float
"""
xy = self.poly.xy
if self.orientation == 'vertical':
xy[1] = 0, val
xy[2] = 1, val
else:
xy[2] = val, 1
xy[3] = val, 0
self.poly.xy = xy
self.valtext.set_text(self._format(val))
if self.drawon:
self.ax.figure.canvas.draw_idle()
self.val = val
if not self.eventson:
return
for cid, func in self.observers.items():
func(val)
[docs] def on_changed(self, func):
"""
When the slider value is changed call *func* with the new
slider value
Parameters
----------
func : callable
Function to call when slider is changed.
The function must accept a single float as its arguments.
Returns
-------
int
Connection id (which can be used to disconnect *func*)
"""
cid = self.cnt
self.observers[cid] = func
self.cnt += 1
return cid
[docs] def disconnect(self, cid):
"""
Remove the observer with connection id *cid*
Parameters
----------
cid : int
Connection id of the observer to be removed
"""
try:
del self.observers[cid]
except KeyError:
pass
[docs] def reset(self):
"""Reset the slider to the initial value"""
if self.val != self.valinit:
self.set_val(self.valinit)
[docs]class TextBox(AxesWidget):
"""
A GUI neutral text input box.
For the text box to remain responsive you must keep a reference to it.
Call `.on_text_change` to be updated whenever the text changes.
Call `.on_submit` to be updated whenever the user hits enter or
leaves the text entry field.
Attributes
----------
ax : `~matplotlib.axes.Axes`
The parent axes for the widget.
label : `.Text`
color : color
The color of the text box when not hovering.
hovercolor : color
The color of the text box when hovering.
"""
@cbook.deprecated("3.3")
@property
def params_to_disable(self):
return [key for key in mpl.rcParams if 'keymap' in key]
def __init__(self, ax, label, initial='',
color='.95', hovercolor='1', label_pad=.01):
"""
Parameters
----------
ax : `~matplotlib.axes.Axes`
The `~.axes.Axes` instance the button will be placed into.
label : str
Label for this text box.
initial : str
Initial value in the text box.
color : color
The color of the box.
hovercolor : color
The color of the box when the mouse is over it.
label_pad : float
The distance between the label and the right side of the textbox.
"""
AxesWidget.__init__(self, ax)
self.DIST_FROM_LEFT = .05
self.label = ax.text(
-label_pad, 0.5, label, transform=ax.transAxes,
verticalalignment='center', horizontalalignment='right')
self.text_disp = self.ax.text(
self.DIST_FROM_LEFT, 0.5, initial, transform=self.ax.transAxes,
verticalalignment='center', horizontalalignment='left')
self.cnt = 0
self.change_observers = {}
self.submit_observers = {}
ax.set(
xlim=(0, 1), ylim=(0, 1), # s.t. cursor appears from first click.
navigate=False, facecolor=color,
xticks=[], yticks=[])
self.cursor_index = 0
self.cursor = ax.vlines(0, 0, 0, visible=False,
transform=mpl.transforms.IdentityTransform())
self.connect_event('button_press_event', self._click)
self.connect_event('button_release_event', self._release)
self.connect_event('motion_notify_event', self._motion)
self.connect_event('key_press_event', self._keypress)
self.connect_event('resize_event', self._resize)
self.color = color
self.hovercolor = hovercolor
self.capturekeystrokes = False
@property
def text(self):
return self.text_disp.get_text()
def _rendercursor(self):
# this is a hack to figure out where the cursor should go.
# we draw the text up to where the cursor should go, measure
# and save its dimensions, draw the real text, then put the cursor
# at the saved dimensions
# This causes a single extra draw if the figure has never been rendered
# yet, which should be fine as we're going to repeatedly re-render the
# figure later anyways.
if self.ax.figure._cachedRenderer is None:
self.ax.figure.canvas.draw()
text = self.text_disp.get_text() # Save value before overwriting it.
widthtext = text[:self.cursor_index]
self.text_disp.set_text(widthtext or ",")
bb = self.text_disp.get_window_extent()
if not widthtext: # Use the comma for the height, but keep width to 0.
bb.x1 = bb.x0
self.cursor.set(
segments=[[(bb.x1, bb.y0), (bb.x1, bb.y1)]], visible=True)
self.text_disp.set_text(text)
self.ax.figure.canvas.draw()
def _notify_submit_observers(self):
if self.eventson:
for cid, func in self.submit_observers.items():
func(self.text)
def _release(self, event):
if self.ignore(event):
return
if event.canvas.mouse_grabber != self.ax:
return
event.canvas.release_mouse(self.ax)
def _keypress(self, event):
if self.ignore(event):
return
if self.capturekeystrokes:
key = event.key
text = self.text
if len(key) == 1:
text = (text[:self.cursor_index] + key +
text[self.cursor_index:])
self.cursor_index += 1
elif key == "right":
if self.cursor_index != len(text):
self.cursor_index += 1
elif key == "left":
if self.cursor_index != 0:
self.cursor_index -= 1
elif key == "home":
self.cursor_index = 0
elif key == "end":
self.cursor_index = len(text)
elif key == "backspace":
if self.cursor_index != 0:
text = (text[:self.cursor_index - 1] +
text[self.cursor_index:])
self.cursor_index -= 1
elif key == "delete":
if self.cursor_index != len(self.text):
text = (text[:self.cursor_index] +
text[self.cursor_index + 1:])
self.text_disp.set_text(text)
self._rendercursor()
self._notify_change_observers()
if key == "enter":
self._notify_submit_observers()
[docs] def set_val(self, val):
newval = str(val)
if self.text == newval:
return
self.text_disp.set_text(newval)
self._rendercursor()
self._notify_change_observers()
self._notify_submit_observers()
def _notify_change_observers(self):
if self.eventson:
for cid, func in self.change_observers.items():
func(self.text)
[docs] def begin_typing(self, x):
self.capturekeystrokes = True
# Disable keypress shortcuts, which may otherwise cause the figure to
# be saved, closed, etc., until the user stops typing. The way to
# achieve this depends on whether toolmanager is in use.
stack = ExitStack() # Register cleanup actions when user stops typing.
self._on_stop_typing = stack.close
toolmanager = getattr(
self.ax.figure.canvas.manager, "toolmanager", None)
if toolmanager is not None:
# If using toolmanager, lock keypresses, and plan to release the
# lock when typing stops.
toolmanager.keypresslock(self)
stack.push(toolmanager.keypresslock.release, self)
else:
# If not using toolmanager, disable all keypress-related rcParams.
# Avoid spurious warnings if keymaps are getting deprecated.
with cbook._suppress_matplotlib_deprecation_warning():
stack.enter_context(mpl.rc_context(
{k: [] for k in mpl.rcParams if k.startswith("keymap.")}))
[docs] def stop_typing(self):
if self.capturekeystrokes:
self._on_stop_typing()
self._on_stop_typing = None
notifysubmit = True
else:
notifysubmit = False
self.capturekeystrokes = False
self.cursor.set_visible(False)
self.ax.figure.canvas.draw()
if notifysubmit:
# Because _notify_submit_observers might throw an error in the
# user's code, only call it once we've already done our cleanup.
self._notify_submit_observers()
[docs] def position_cursor(self, x):
# now, we have to figure out where the cursor goes.
# approximate it based on assuming all characters the same length
if len(self.text) == 0:
self.cursor_index = 0
else:
bb = self.text_disp.get_window_extent()
ratio = np.clip((x - bb.x0) / bb.width, 0, 1)
self.cursor_index = int(len(self.text) * ratio)
self._rendercursor()
def _click(self, event):
if self.ignore(event):
return
if event.inaxes != self.ax:
self.stop_typing()
return
if not self.eventson:
return
if event.canvas.mouse_grabber != self.ax:
event.canvas.grab_mouse(self.ax)
if not self.capturekeystrokes:
self.begin_typing(event.x)
self.position_cursor(event.x)
def _resize(self, event):
self.stop_typing()
def _motion(self, event):
if self.ignore(event):
return
c = self.hovercolor if event.inaxes == self.ax else self.color
if not colors.same_color(c, self.ax.get_facecolor()):
self.ax.set_facecolor(c)
if self.drawon:
self.ax.figure.canvas.draw()
[docs] def on_text_change(self, func):
"""
When the text changes, call this *func* with event.
A connection id is returned which can be used to disconnect.
"""
cid = self.cnt
self.change_observers[cid] = func
self.cnt += 1
return cid
[docs] def on_submit(self, func):
"""
When the user hits enter or leaves the submission box, call this
*func* with event.
A connection id is returned which can be used to disconnect.
"""
cid = self.cnt
self.submit_observers[cid] = func
self.cnt += 1
return cid
[docs] def disconnect(self, cid):
"""Remove the observer with connection id *cid*."""
for reg in [self.change_observers, self.submit_observers]:
try:
del reg[cid]
except KeyError:
pass
[docs]class Cursor(AxesWidget):
"""
A crosshair cursor that spans the axes and moves with mouse cursor.
For the cursor to remain responsive you must keep a reference to it.
Parameters
----------
ax : `matplotlib.axes.Axes`
The `~.axes.Axes` to attach the cursor to.
horizOn : bool, default: True
Whether to draw the horizontal line.
vertOn : bool, default: True
Whether to draw the vertical line.
useblit : bool, default: False
Use blitting for faster drawing if supported by the backend.
Other Parameters
----------------
**lineprops
`.Line2D` properties that control the appearance of the lines.
See also `~.Axes.axhline`.
Examples
--------
See :doc:`/gallery/widgets/cursor`.
"""
def __init__(self, ax, horizOn=True, vertOn=True, useblit=False,
**lineprops):
AxesWidget.__init__(self, ax)
self.connect_event('motion_notify_event', self.onmove)
self.connect_event('draw_event', self.clear)
self.visible = True
self.horizOn = horizOn
self.vertOn = vertOn
self.useblit = useblit and self.canvas.supports_blit
if self.useblit:
lineprops['animated'] = True
self.lineh = ax.axhline(ax.get_ybound()[0], visible=False, **lineprops)
self.linev = ax.axvline(ax.get_xbound()[0], visible=False, **lineprops)
self.background = None
self.needclear = False
[docs] def clear(self, event):
"""Internal event handler to clear the cursor."""
if self.ignore(event):
return
if self.useblit:
self.background = self.canvas.copy_from_bbox(self.ax.bbox)
self.linev.set_visible(False)
self.lineh.set_visible(False)
[docs] def onmove(self, event):
"""Internal event handler to draw the cursor when the mouse moves."""
if self.ignore(event):
return
if not self.canvas.widgetlock.available(self):
return
if event.inaxes != self.ax:
self.linev.set_visible(False)
self.lineh.set_visible(False)
if self.needclear:
self.canvas.draw()
self.needclear = False
return
self.needclear = True
if not self.visible:
return
self.linev.set_xdata((event.xdata, event.xdata))
self.lineh.set_ydata((event.ydata, event.ydata))
self.linev.set_visible(self.visible and self.vertOn)
self.lineh.set_visible(self.visible and self.horizOn)
self._update()
def _update(self):
if self.useblit:
if self.background is not None:
self.canvas.restore_region(self.background)
self.ax.draw_artist(self.linev)
self.ax.draw_artist(self.lineh)
self.canvas.blit(self.ax.bbox)
else:
self.canvas.draw_idle()
return False
[docs]class MultiCursor(Widget):
"""
Provide a vertical (default) and/or horizontal line cursor shared between
multiple axes.
For the cursor to remain responsive you must keep a reference to it.
Example usage::
from matplotlib.widgets import MultiCursor
import matplotlib.pyplot as plt
import numpy as np
fig, (ax1, ax2) = plt.subplots(nrows=2, sharex=True)
t = np.arange(0.0, 2.0, 0.01)
ax1.plot(t, np.sin(2*np.pi*t))
ax2.plot(t, np.sin(4*np.pi*t))
multi = MultiCursor(fig.canvas, (ax1, ax2), color='r', lw=1,
horizOn=False, vertOn=True)
plt.show()
"""
def __init__(self, canvas, axes, useblit=True, horizOn=False, vertOn=True,
**lineprops):
self.canvas = canvas
self.axes = axes
self.horizOn = horizOn
self.vertOn = vertOn
xmin, xmax = axes[-1].get_xlim()
ymin, ymax = axes[-1].get_ylim()
xmid = 0.5 * (xmin + xmax)
ymid = 0.5 * (ymin + ymax)
self.visible = True
self.useblit = useblit and self.canvas.supports_blit
self.background = None
self.needclear = False
if self.useblit:
lineprops['animated'] = True
if vertOn:
self.vlines = [ax.axvline(xmid, visible=False, **lineprops)
for ax in axes]
else:
self.vlines = []
if horizOn:
self.hlines = [ax.axhline(ymid, visible=False, **lineprops)
for ax in axes]
else:
self.hlines = []
self.connect()
[docs] def connect(self):
"""Connect events."""
self._cidmotion = self.canvas.mpl_connect('motion_notify_event',
self.onmove)
self._ciddraw = self.canvas.mpl_connect('draw_event', self.clear)
[docs] def disconnect(self):
"""Disconnect events."""
self.canvas.mpl_disconnect(self._cidmotion)
self.canvas.mpl_disconnect(self._ciddraw)
[docs] def clear(self, event):
"""Clear the cursor."""
if self.ignore(event):
return
if self.useblit:
self.background = (
self.canvas.copy_from_bbox(self.canvas.figure.bbox))
for line in self.vlines + self.hlines:
line.set_visible(False)
[docs] def onmove(self, event):
if self.ignore(event):
return
if event.inaxes is None:
return
if not self.canvas.widgetlock.available(self):
return
self.needclear = True
if not self.visible:
return
if self.vertOn:
for line in self.vlines:
line.set_xdata((event.xdata, event.xdata))
line.set_visible(self.visible)
if self.horizOn:
for line in self.hlines:
line.set_ydata((event.ydata, event.ydata))
line.set_visible(self.visible)
self._update()
def _update(self):
if self.useblit:
if self.background is not None:
self.canvas.restore_region(self.background)
if self.vertOn:
for ax, line in zip(self.axes, self.vlines):
ax.draw_artist(line)
if self.horizOn:
for ax, line in zip(self.axes, self.hlines):
ax.draw_artist(line)
self.canvas.blit()
else:
self.canvas.draw_idle()
class _SelectorWidget(AxesWidget):
def __init__(self, ax, onselect, useblit=False, button=None,
state_modifier_keys=None):
AxesWidget.__init__(self, ax)
self.visible = True
self.onselect = onselect
self.useblit = useblit and self.canvas.supports_blit
self.connect_default_events()
self.state_modifier_keys = dict(move=' ', clear='escape',
square='shift', center='control')
self.state_modifier_keys.update(state_modifier_keys or {})
self.background = None
self.artists = []
if isinstance(button, Integral):
self.validButtons = [button]
else:
self.validButtons = button
# will save the data (position at mouseclick)
self.eventpress = None
# will save the data (pos. at mouserelease)
self.eventrelease = None
self._prev_event = None
self.state = set()
def set_active(self, active):
AxesWidget.set_active(self, active)
if active:
self.update_background(None)
def update_background(self, event):
"""Force an update of the background."""
# If you add a call to `ignore` here, you'll want to check edge case:
# `release` can call a draw event even when `ignore` is True.
if self.useblit:
self.background = self.canvas.copy_from_bbox(self.ax.bbox)
def connect_default_events(self):
"""Connect the major canvas events to methods."""
self.connect_event('motion_notify_event', self.onmove)
self.connect_event('button_press_event', self.press)
self.connect_event('button_release_event', self.release)
self.connect_event('draw_event', self.update_background)
self.connect_event('key_press_event', self.on_key_press)
self.connect_event('key_release_event', self.on_key_release)
self.connect_event('scroll_event', self.on_scroll)
def ignore(self, event):
# docstring inherited
if not self.active or not self.ax.get_visible():
return True
# If canvas was locked
if not self.canvas.widgetlock.available(self):
return True
if not hasattr(event, 'button'):
event.button = None
# Only do rectangle selection if event was triggered
# with a desired button
if (self.validButtons is not None
and event.button not in self.validButtons):
return True
# If no button was pressed yet ignore the event if it was out
# of the axes
if self.eventpress is None:
return event.inaxes != self.ax
# If a button was pressed, check if the release-button is the same.
if event.button == self.eventpress.button:
return False
# If a button was pressed, check if the release-button is the same.
return (event.inaxes != self.ax or
event.button != self.eventpress.button)
def update(self):
"""Draw using blit() or draw_idle(), depending on ``self.useblit``."""
if not self.ax.get_visible():
return False
if self.useblit:
if self.background is not None:
self.canvas.restore_region(self.background)
for artist in self.artists:
self.ax.draw_artist(artist)
self.canvas.blit(self.ax.bbox)
else:
self.canvas.draw_idle()
return False
def _get_data(self, event):
"""Get the xdata and ydata for event, with limits."""
if event.xdata is None:
return None, None
xdata = np.clip(event.xdata, *self.ax.get_xbound())
ydata = np.clip(event.ydata, *self.ax.get_ybound())
return xdata, ydata
def _clean_event(self, event):
"""
Preprocess an event:
- Replace *event* by the previous event if *event* has no ``xdata``.
- Clip ``xdata`` and ``ydata`` to the axes limits.
- Update the previous event.
"""
if event.xdata is None:
event = self._prev_event
else:
event = copy.copy(event)
event.xdata, event.ydata = self._get_data(event)
self._prev_event = event
return event
def press(self, event):
"""Button press handler and validator."""
if not self.ignore(event):
event = self._clean_event(event)
self.eventpress = event
self._prev_event = event
key = event.key or ''
key = key.replace('ctrl', 'control')
# move state is locked in on a button press
if key == self.state_modifier_keys['move']:
self.state.add('move')
self._press(event)
return True
return False
def _press(self, event):
"""Button press handler."""
def release(self, event):
"""Button release event handler and validator."""
if not self.ignore(event) and self.eventpress:
event = self._clean_event(event)
self.eventrelease = event
self._release(event)
self.eventpress = None
self.eventrelease = None
self.state.discard('move')
return True
return False
def _release(self, event):
"""Button release event handler."""
def onmove(self, event):
"""Cursor move event handler and validator."""
if not self.ignore(event) and self.eventpress:
event = self._clean_event(event)
self._onmove(event)
return True
return False
def _onmove(self, event):
"""Cursor move event handler."""
def on_scroll(self, event):
"""Mouse scroll event handler and validator."""
if not self.ignore(event):
self._on_scroll(event)
def _on_scroll(self, event):
"""Mouse scroll event handler."""
def on_key_press(self, event):
"""Key press event handler and validator for all selection widgets."""
if self.active:
key = event.key or ''
key = key.replace('ctrl', 'control')
if key == self.state_modifier_keys['clear']:
for artist in self.artists:
artist.set_visible(False)
self.update()
return
for (state, modifier) in self.state_modifier_keys.items():
if modifier in key:
self.state.add(state)
self._on_key_press(event)
def _on_key_press(self, event):
"""Key press event handler - for widget-specific key press actions."""
def on_key_release(self, event):
"""Key release event handler and validator."""
if self.active:
key = event.key or ''
for (state, modifier) in self.state_modifier_keys.items():
if modifier in key:
self.state.discard(state)
self._on_key_release(event)
def _on_key_release(self, event):
"""Key release event handler."""
def set_visible(self, visible):
"""Set the visibility of our artists."""
self.visible = visible
for artist in self.artists:
artist.set_visible(visible)
[docs]class SpanSelector(_SelectorWidget):
"""
Visually select a min/max range on a single axis and call a function with
those values.
To guarantee that the selector remains responsive, keep a reference to it.
In order to turn off the SpanSelector, set ``span_selector.active`` to
False. To turn it back on, set it to True.
Parameters
----------
ax : `matplotlib.axes.Axes`
onselect : func(min, max), min/max are floats
direction : {"horizontal", "vertical"}
The direction along which to draw the span selector.
minspan : float, default: None
If selection is less than *minspan*, do not call *onselect*.
useblit : bool, default: False
If True, use the backend-dependent blitting features for faster
canvas updates.
rectprops : dict, default: None
Dictionary of `matplotlib.patches.Patch` properties.
onmove_callback : func(min, max), min/max are floats, default: None
Called on mouse move while the span is being selected.
span_stays : bool, default: False
If True, the span stays visible after the mouse is released.
button : `.MouseButton` or list of `.MouseButton`
The mouse buttons which activate the span selector.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> import matplotlib.widgets as mwidgets
>>> fig, ax = plt.subplots()
>>> ax.plot([1, 2, 3], [10, 50, 100])
>>> def onselect(vmin, vmax):
... print(vmin, vmax)
>>> rectprops = dict(facecolor='blue', alpha=0.5)
>>> span = mwidgets.SpanSelector(ax, onselect, 'horizontal',
... rectprops=rectprops)
>>> fig.show()
See also: :doc:`/gallery/widgets/span_selector`
"""
def __init__(self, ax, onselect, direction, minspan=None, useblit=False,
rectprops=None, onmove_callback=None, span_stays=False,
button=None):
_SelectorWidget.__init__(self, ax, onselect, useblit=useblit,
button=button)
if rectprops is None:
rectprops = dict(facecolor='red', alpha=0.5)
rectprops['animated'] = self.useblit
cbook._check_in_list(['horizontal', 'vertical'], direction=direction)
self.direction = direction
self.rect = None
self.pressv = None
self.rectprops = rectprops
self.onmove_callback = onmove_callback
self.minspan = minspan
self.span_stays = span_stays
# Needed when dragging out of axes
self.prev = (0, 0)
# Reset canvas so that `new_axes` connects events.
self.canvas = None
self.new_axes(ax)
[docs] def new_axes(self, ax):
"""Set SpanSelector to operate on a new Axes."""
self.ax = ax
if self.canvas is not ax.figure.canvas:
if self.canvas is not None:
self.disconnect_events()
self.canvas = ax.figure.canvas
self.connect_default_events()
if self.direction == 'horizontal':
trans = blended_transform_factory(self.ax.transData,
self.ax.transAxes)
w, h = 0, 1
else:
trans = blended_transform_factory(self.ax.transAxes,
self.ax.transData)
w, h = 1, 0
self.rect = Rectangle((0, 0), w, h,
transform=trans,
visible=False,
**self.rectprops)
if self.span_stays:
self.stay_rect = Rectangle((0, 0), w, h,
transform=trans,
visible=False,
**self.rectprops)
self.stay_rect.set_animated(False)
self.ax.add_patch(self.stay_rect)
self.ax.add_patch(self.rect)
self.artists = [self.rect]
[docs] def ignore(self, event):
# docstring inherited
return _SelectorWidget.ignore(self, event) or not self.visible
def _press(self, event):
"""on button press event"""
self.rect.set_visible(self.visible)
if self.span_stays:
self.stay_rect.set_visible(False)
# really force a draw so that the stay rect is not in
# the blit background
if self.useblit:
self.canvas.draw()
xdata, ydata = self._get_data(event)
if self.direction == 'horizontal':
self.pressv = xdata
else:
self.pressv = ydata
self._set_span_xy(event)
return False
def _release(self, event):
"""on button release event"""
if self.pressv is None:
return
self.rect.set_visible(False)
if self.span_stays:
self.stay_rect.set_x(self.rect.get_x())
self.stay_rect.set_y(self.rect.get_y())
self.stay_rect.set_width(self.rect.get_width())
self.stay_rect.set_height(self.rect.get_height())
self.stay_rect.set_visible(True)
self.canvas.draw_idle()
vmin = self.pressv
xdata, ydata = self._get_data(event)
if self.direction == 'horizontal':
vmax = xdata or self.prev[0]
else:
vmax = ydata or self.prev[1]
if vmin > vmax:
vmin, vmax = vmax, vmin
span = vmax - vmin
if self.minspan is not None and span < self.minspan:
return
self.onselect(vmin, vmax)
self.pressv = None
return False
def _onmove(self, event):
"""on motion notify event"""
if self.pressv is None:
return
self._set_span_xy(event)
if self.onmove_callback is not None:
vmin = self.pressv
xdata, ydata = self._get_data(event)
if self.direction == 'horizontal':
vmax = xdata or self.prev[0]
else:
vmax = ydata or self.prev[1]
if vmin > vmax:
vmin, vmax = vmax, vmin
self.onmove_callback(vmin, vmax)
self.update()
return False
def _set_span_xy(self, event):
"""Set the span coordinates."""
x, y = self._get_data(event)
if x is None:
return
self.prev = x, y
if self.direction == 'horizontal':
v = x
else:
v = y
minv, maxv = v, self.pressv
if minv > maxv:
minv, maxv = maxv, minv
if self.direction == 'horizontal':
self.rect.set_x(minv)
self.rect.set_width(maxv - minv)
else:
self.rect.set_y(minv)
self.rect.set_height(maxv - minv)
[docs]class RectangleSelector(_SelectorWidget):
"""
Select a rectangular region of an axes.
For the cursor to remain responsive you must keep a reference to it.
Examples
--------
:doc:`/gallery/widgets/rectangle_selector`
"""
_shape_klass = Rectangle
def __init__(self, ax, onselect, drawtype='box',
minspanx=0, minspany=0, useblit=False,
lineprops=None, rectprops=None, spancoords='data',
button=None, maxdist=10, marker_props=None,
interactive=False, state_modifier_keys=None):
r"""
Parameters
----------
ax : `~matplotlib.axes.Axes`
The parent axes for the widget.
onselect : function
A callback function that is called after a selection is completed.
It must have the signature::
def onselect(eclick: MouseEvent, erelease: MouseEvent)
where *eclick* and *erelease* are the mouse click and release
`.MouseEvent`\s that start and complete the selection.
drawtype : {"box", "line", "none"}, default: "box"
Whether to draw the full rectangle box, the diagonal line of the
rectangle, or nothing at all.
minspanx : float, default: 0
Selections with an x-span less than *minspanx* are ignored.
minspany : float, default: 0
Selections with an y-span less than *minspany* are ignored.
useblit : bool, default: False
Whether to use blitting for faster drawing (if supported by the
backend).
lineprops : dict, optional
Properties with which the line is drawn, if ``drawtype == "line"``.
Default::
dict(color="black", linestyle="-", linewidth=2, alpha=0.5)
rectprops : dict, optional
Properties with which the rectangle is drawn, if ``drawtype ==
"box"``. Default::
dict(facecolor="red", edgecolor="black", alpha=0.2, fill=True)
spancoords : {"data", "pixels"}, default: "data"
Whether to interpret *minspanx* and *minspany* in data or in pixel
coordinates.
button : `.MouseButton`, list of `.MouseButton`, default: all buttons
Button(s) that trigger rectangle selection.
maxdist : float, default: 10
Distance in pixels within which the interactive tool handles can be
activated.
marker_props : dict
Properties with which the interactive handles are drawn. Currently
not implemented and ignored.
interactive : bool, default: False
Whether to draw a set of handles that allow interaction with the
widget after it is drawn.
state_modifier_keys : dict, optional
Keyboard modifiers which affect the widget's behavior. Values
amend the defaults.
- "move": Move the existing shape, default: no modifier.
- "clear": Clear the current shape, default: "escape".
- "square": Makes the shape square, default: "shift".
- "center": Make the initial point the center of the shape,
default: "ctrl".
"square" and "center" can be combined.
"""
_SelectorWidget.__init__(self, ax, onselect, useblit=useblit,
button=button,
state_modifier_keys=state_modifier_keys)
self.to_draw = None
self.visible = True
self.interactive = interactive
if drawtype == 'none': # draw a line but make it invisible
drawtype = 'line'
self.visible = False
if drawtype == 'box':
if rectprops is None:
rectprops = dict(facecolor='red', edgecolor='black',
alpha=0.2, fill=True)
rectprops['animated'] = self.useblit
self.rectprops = rectprops
self.to_draw = self._shape_klass((0, 0), 0, 1, visible=False,
**self.rectprops)
self.ax.add_patch(self.to_draw)
if drawtype == 'line':
if lineprops is None:
lineprops = dict(color='black', linestyle='-',
linewidth=2, alpha=0.5)
lineprops['animated'] = self.useblit
self.lineprops = lineprops
self.to_draw = Line2D([0, 0], [0, 0], visible=False,
**self.lineprops)
self.ax.add_line(self.to_draw)
self.minspanx = minspanx
self.minspany = minspany
cbook._check_in_list(['data', 'pixels'], spancoords=spancoords)
self.spancoords = spancoords
self.drawtype = drawtype
self.maxdist = maxdist
if rectprops is None:
props = dict(mec='r')
else:
props = dict(mec=rectprops.get('edgecolor', 'r'))
self._corner_order = ['NW', 'NE', 'SE', 'SW']
xc, yc = self.corners
self._corner_handles = ToolHandles(self.ax, xc, yc, marker_props=props,
useblit=self.useblit)
self._edge_order = ['W', 'N', 'E', 'S']
xe, ye = self.edge_centers
self._edge_handles = ToolHandles(self.ax, xe, ye, marker='s',
marker_props=props,
useblit=self.useblit)
xc, yc = self.center
self._center_handle = ToolHandles(self.ax, [xc], [yc], marker='s',
marker_props=props,
useblit=self.useblit)
self.active_handle = None
self.artists = [self.to_draw, self._center_handle.artist,
self._corner_handles.artist,
self._edge_handles.artist]
if not self.interactive:
self.artists = [self.to_draw]
self._extents_on_press = None
def _press(self, event):
"""on button press event"""
# make the drawn box/line visible get the click-coordinates,
# button, ...
if self.interactive and self.to_draw.get_visible():
self._set_active_handle(event)
else:
self.active_handle = None
if self.active_handle is None or not self.interactive:
# Clear previous rectangle before drawing new rectangle.
self.update()
if not self.interactive:
x = event.xdata
y = event.ydata
self.extents = x, x, y, y
self.set_visible(self.visible)
def _release(self, event):
"""on button release event"""
if not self.interactive:
self.to_draw.set_visible(False)
# update the eventpress and eventrelease with the resulting extents
x1, x2, y1, y2 = self.extents
self.eventpress.xdata = x1
self.eventpress.ydata = y1
xy1 = self.ax.transData.transform([x1, y1])
self.eventpress.x, self.eventpress.y = xy1
self.eventrelease.xdata = x2
self.eventrelease.ydata = y2
xy2 = self.ax.transData.transform([x2, y2])
self.eventrelease.x, self.eventrelease.y = xy2
# calculate dimensions of box or line
if self.spancoords == 'data':
spanx = abs(self.eventpress.xdata - self.eventrelease.xdata)
spany = abs(self.eventpress.ydata - self.eventrelease.ydata)
elif self.spancoords == 'pixels':
spanx = abs(self.eventpress.x - self.eventrelease.x)
spany = abs(self.eventpress.y - self.eventrelease.y)
else:
cbook._check_in_list(['data', 'pixels'],
spancoords=self.spancoords)
# check if drawn distance (if it exists) is not too small in
# either x or y-direction
if (self.drawtype != 'none'
and (self.minspanx is not None and spanx < self.minspanx
or self.minspany is not None and spany < self.minspany)):
for artist in self.artists:
artist.set_visible(False)
self.update()
return
# call desired function
self.onselect(self.eventpress, self.eventrelease)
self.update()
return False
def _onmove(self, event):
"""on motion notify event if box/line is wanted"""
# resize an existing shape
if self.active_handle and self.active_handle != 'C':
x1, x2, y1, y2 = self._extents_on_press
if self.active_handle in ['E', 'W'] + self._corner_order:
x2 = event.xdata
if self.active_handle in ['N', 'S'] + self._corner_order:
y2 = event.ydata
# move existing shape
elif (('move' in self.state or self.active_handle == 'C')
and self._extents_on_press is not None):
x1, x2, y1, y2 = self._extents_on_press
dx = event.xdata - self.eventpress.xdata
dy = event.ydata - self.eventpress.ydata
x1 += dx
x2 += dx
y1 += dy
y2 += dy
# new shape
else:
center = [self.eventpress.xdata, self.eventpress.ydata]
center_pix = [self.eventpress.x, self.eventpress.y]
dx = (event.xdata - center[0]) / 2.
dy = (event.ydata - center[1]) / 2.
# square shape
if 'square' in self.state:
dx_pix = abs(event.x - center_pix[0])
dy_pix = abs(event.y - center_pix[1])
if not dx_pix:
return
maxd = max(abs(dx_pix), abs(dy_pix))
if abs(dx_pix) < maxd:
dx *= maxd / (abs(dx_pix) + 1e-6)
if abs(dy_pix) < maxd:
dy *= maxd / (abs(dy_pix) + 1e-6)
# from center
if 'center' in self.state:
dx *= 2
dy *= 2
# from corner
else:
center[0] += dx
center[1] += dy
x1, x2, y1, y2 = (center[0] - dx, center[0] + dx,
center[1] - dy, center[1] + dy)
self.extents = x1, x2, y1, y2
@property
def _rect_bbox(self):
if self.drawtype == 'box':
x0 = self.to_draw.get_x()
y0 = self.to_draw.get_y()
width = self.to_draw.get_width()
height = self.to_draw.get_height()
return x0, y0, width, height
else:
x, y = self.to_draw.get_data()
x0, x1 = min(x), max(x)
y0, y1 = min(y), max(y)
return x0, y0, x1 - x0, y1 - y0
@property
def corners(self):
"""Corners of rectangle from lower left, moving clockwise."""
x0, y0, width, height = self._rect_bbox
xc = x0, x0 + width, x0 + width, x0
yc = y0, y0, y0 + height, y0 + height
return xc, yc
@property
def edge_centers(self):
"""Midpoint of rectangle edges from left, moving clockwise."""
x0, y0, width, height = self._rect_bbox
w = width / 2.
h = height / 2.
xe = x0, x0 + w, x0 + width, x0 + w
ye = y0 + h, y0, y0 + h, y0 + height
return xe, ye
@property
def center(self):
"""Center of rectangle"""
x0, y0, width, height = self._rect_bbox
return x0 + width / 2., y0 + height / 2.
@property
def extents(self):
"""Return (xmin, xmax, ymin, ymax)."""
x0, y0, width, height = self._rect_bbox
xmin, xmax = sorted([x0, x0 + width])
ymin, ymax = sorted([y0, y0 + height])
return xmin, xmax, ymin, ymax
@extents.setter
def extents(self, extents):
# Update displayed shape
self.draw_shape(extents)
# Update displayed handles
self._corner_handles.set_data(*self.corners)
self._edge_handles.set_data(*self.edge_centers)
self._center_handle.set_data(*self.center)
self.set_visible(self.visible)
self.update()
[docs] def draw_shape(self, extents):
x0, x1, y0, y1 = extents
xmin, xmax = sorted([x0, x1])
ymin, ymax = sorted([y0, y1])
xlim = sorted(self.ax.get_xlim())
ylim = sorted(self.ax.get_ylim())
xmin = max(xlim[0], xmin)
ymin = max(ylim[0], ymin)
xmax = min(xmax, xlim[1])
ymax = min(ymax, ylim[1])
if self.drawtype == 'box':
self.to_draw.set_x(xmin)
self.to_draw.set_y(ymin)
self.to_draw.set_width(xmax - xmin)
self.to_draw.set_height(ymax - ymin)
elif self.drawtype == 'line':
self.to_draw.set_data([xmin, xmax], [ymin, ymax])
def _set_active_handle(self, event):
"""Set active handle based on the location of the mouse event"""
# Note: event.xdata/ydata in data coordinates, event.x/y in pixels
c_idx, c_dist = self._corner_handles.closest(event.x, event.y)
e_idx, e_dist = self._edge_handles.closest(event.x, event.y)
m_idx, m_dist = self._center_handle.closest(event.x, event.y)
if 'move' in self.state:
self.active_handle = 'C'
self._extents_on_press = self.extents
# Set active handle as closest handle, if mouse click is close enough.
elif m_dist < self.maxdist * 2:
self.active_handle = 'C'
elif c_dist > self.maxdist and e_dist > self.maxdist:
self.active_handle = None
return
elif c_dist < e_dist:
self.active_handle = self._corner_order[c_idx]
else:
self.active_handle = self._edge_order[e_idx]
# Save coordinates of rectangle at the start of handle movement.
x1, x2, y1, y2 = self.extents
# Switch variables so that only x2 and/or y2 are updated on move.
if self.active_handle in ['W', 'SW', 'NW']:
x1, x2 = x2, event.xdata
if self.active_handle in ['N', 'NW', 'NE']:
y1, y2 = y2, event.ydata
self._extents_on_press = x1, x2, y1, y2
@property
def geometry(self):
"""
Return an array of shape (2, 5) containing the
x (``RectangleSelector.geometry[1, :]``) and
y (``RectangleSelector.geometry[0, :]``) coordinates
of the four corners of the rectangle starting and ending
in the top left corner.
"""
if hasattr(self.to_draw, 'get_verts'):
xfm = self.ax.transData.inverted()
y, x = xfm.transform(self.to_draw.get_verts()).T
return np.array([x, y])
else:
return np.array(self.to_draw.get_data())
[docs]class EllipseSelector(RectangleSelector):
"""
Select an elliptical region of an axes.
For the cursor to remain responsive you must keep a reference to it.
Example usage::
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import EllipseSelector
def onselect(eclick, erelease):
"eclick and erelease are matplotlib events at press and release."
print('startposition: (%f, %f)' % (eclick.xdata, eclick.ydata))
print('endposition : (%f, %f)' % (erelease.xdata, erelease.ydata))
print('used button : ', eclick.button)
def toggle_selector(event):
print(' Key pressed.')
if event.key in ['Q', 'q'] and toggle_selector.ES.active:
print('EllipseSelector deactivated.')
toggle_selector.RS.set_active(False)
if event.key in ['A', 'a'] and not toggle_selector.ES.active:
print('EllipseSelector activated.')
toggle_selector.ES.set_active(True)
x = np.arange(100.) / 99
y = np.sin(x)
fig, ax = plt.subplots()
ax.plot(x, y)
toggle_selector.ES = EllipseSelector(ax, onselect, drawtype='line')
fig.canvas.mpl_connect('key_press_event', toggle_selector)
plt.show()
"""
_shape_klass = Ellipse
[docs] def draw_shape(self, extents):
x1, x2, y1, y2 = extents
xmin, xmax = sorted([x1, x2])
ymin, ymax = sorted([y1, y2])
center = [x1 + (x2 - x1) / 2., y1 + (y2 - y1) / 2.]
a = (xmax - xmin) / 2.
b = (ymax - ymin) / 2.
if self.drawtype == 'box':
self.to_draw.center = center
self.to_draw.width = 2 * a
self.to_draw.height = 2 * b
else:
rad = np.deg2rad(np.arange(31) * 12)
x = a * np.cos(rad) + center[0]
y = b * np.sin(rad) + center[1]
self.to_draw.set_data(x, y)
@property
def _rect_bbox(self):
if self.drawtype == 'box':
x, y = self.to_draw.center
width = self.to_draw.width
height = self.to_draw.height
return x - width / 2., y - height / 2., width, height
else:
x, y = self.to_draw.get_data()
x0, x1 = min(x), max(x)
y0, y1 = min(y), max(y)
return x0, y0, x1 - x0, y1 - y0
[docs]class LassoSelector(_SelectorWidget):
"""
Selection curve of an arbitrary shape.
For the selector to remain responsive you must keep a reference to it.
The selected path can be used in conjunction with `~.Path.contains_point`
to select data points from an image.
In contrast to `Lasso`, `LassoSelector` is written with an interface
similar to `RectangleSelector` and `SpanSelector`, and will continue to
interact with the axes until disconnected.
Example usage::
ax = subplot(111)
ax.plot(x, y)
def onselect(verts):
print(verts)
lasso = LassoSelector(ax, onselect)
Parameters
----------
ax : `~matplotlib.axes.Axes`
The parent axes for the widget.
onselect : function
Whenever the lasso is released, the *onselect* function is called and
passed the vertices of the selected path.
button : `.MouseButton` or list of `.MouseButton`, optional
The mouse buttons used for rectangle selection. Default is ``None``,
which corresponds to all buttons.
"""
def __init__(self, ax, onselect=None, useblit=True, lineprops=None,
button=None):
_SelectorWidget.__init__(self, ax, onselect, useblit=useblit,
button=button)
self.verts = None
if lineprops is None:
lineprops = dict()
# self.useblit may be != useblit, if the canvas doesn't support blit.
lineprops.update(animated=self.useblit, visible=False)
self.line = Line2D([], [], **lineprops)
self.ax.add_line(self.line)
self.artists = [self.line]
[docs] def onpress(self, event):
self.press(event)
def _press(self, event):
self.verts = [self._get_data(event)]
self.line.set_visible(True)
[docs] def onrelease(self, event):
self.release(event)
def _release(self, event):
if self.verts is not None:
self.verts.append(self._get_data(event))
self.onselect(self.verts)
self.line.set_data([[], []])
self.line.set_visible(False)
self.verts = None
def _onmove(self, event):
if self.verts is None:
return
self.verts.append(self._get_data(event))
self.line.set_data(list(zip(*self.verts)))
self.update()
[docs]class PolygonSelector(_SelectorWidget):
"""
Select a polygon region of an axes.
Place vertices with each mouse click, and make the selection by completing
the polygon (clicking on the first vertex). Hold the *ctrl* key and click
and drag a vertex to reposition it (the *ctrl* key is not necessary if the
polygon has already been completed). Hold the *shift* key and click and
drag anywhere in the axes to move all vertices. Press the *esc* key to
start a new polygon.
For the selector to remain responsive you must keep a reference to it.
Parameters
----------
ax : `~matplotlib.axes.Axes`
The parent axes for the widget.
onselect : function
When a polygon is completed or modified after completion,
the *onselect* function is called and passed a list of the vertices as
``(xdata, ydata)`` tuples.
useblit : bool, default: False
lineprops : dict, default: \
``dict(color='k', linestyle='-', linewidth=2, alpha=0.5)``.
Artist properties for the line representing the edges of the polygon.
markerprops : dict, default: \
``dict(marker='o', markersize=7, mec='k', mfc='k', alpha=0.5)``.
Artist properties for the markers drawn at the vertices of the polygon.
vertex_select_radius : float, default: 15px
A vertex is selected (to complete the polygon or to move a vertex) if
the mouse click is within *vertex_select_radius* pixels of the vertex.
Examples
--------
:doc:`/gallery/widgets/polygon_selector_demo`
"""
def __init__(self, ax, onselect, useblit=False,
lineprops=None, markerprops=None, vertex_select_radius=15):
# The state modifiers 'move', 'square', and 'center' are expected by
# _SelectorWidget but are not supported by PolygonSelector
# Note: could not use the existing 'move' state modifier in-place of
# 'move_all' because _SelectorWidget automatically discards 'move'
# from the state on button release.
state_modifier_keys = dict(clear='escape', move_vertex='control',
move_all='shift', move='not-applicable',
square='not-applicable',
center='not-applicable')
_SelectorWidget.__init__(self, ax, onselect, useblit=useblit,
state_modifier_keys=state_modifier_keys)
self._xs, self._ys = [0], [0]
self._polygon_completed = False
if lineprops is None:
lineprops = dict(color='k', linestyle='-', linewidth=2, alpha=0.5)
lineprops['animated'] = self.useblit
self.line = Line2D(self._xs, self._ys, **lineprops)
self.ax.add_line(self.line)
if markerprops is None:
markerprops = dict(mec='k', mfc=lineprops.get('color', 'k'))
self._polygon_handles = ToolHandles(self.ax, self._xs, self._ys,
useblit=self.useblit,
marker_props=markerprops)
self._active_handle_idx = -1
self.vertex_select_radius = vertex_select_radius
self.artists = [self.line, self._polygon_handles.artist]
self.set_visible(True)
def _press(self, event):
"""Button press event handler"""
# Check for selection of a tool handle.
if ((self._polygon_completed or 'move_vertex' in self.state)
and len(self._xs) > 0):
h_idx, h_dist = self._polygon_handles.closest(event.x, event.y)
if h_dist < self.vertex_select_radius:
self._active_handle_idx = h_idx
# Save the vertex positions at the time of the press event (needed to
# support the 'move_all' state modifier).
self._xs_at_press, self._ys_at_press = self._xs.copy(), self._ys.copy()
def _release(self, event):
"""Button release event handler"""
# Release active tool handle.
if self._active_handle_idx >= 0:
self._active_handle_idx = -1
# Complete the polygon.
elif (len(self._xs) > 3
and self._xs[-1] == self._xs[0]
and self._ys[-1] == self._ys[0]):
self._polygon_completed = True
# Place new vertex.
elif (not self._polygon_completed
and 'move_all' not in self.state
and 'move_vertex' not in self.state):
self._xs.insert(-1, event.xdata)
self._ys.insert(-1, event.ydata)
if self._polygon_completed:
self.onselect(self.verts)
[docs] def onmove(self, event):
"""Cursor move event handler and validator"""
# Method overrides _SelectorWidget.onmove because the polygon selector
# needs to process the move callback even if there is no button press.
# _SelectorWidget.onmove include logic to ignore move event if
# eventpress is None.
if not self.ignore(event):
event = self._clean_event(event)
self._onmove(event)
return True
return False
def _onmove(self, event):
"""Cursor move event handler"""
# Move the active vertex (ToolHandle).
if self._active_handle_idx >= 0:
idx = self._active_handle_idx
self._xs[idx], self._ys[idx] = event.xdata, event.ydata
# Also update the end of the polygon line if the first vertex is
# the active handle and the polygon is completed.
if idx == 0 and self._polygon_completed:
self._xs[-1], self._ys[-1] = event.xdata, event.ydata
# Move all vertices.
elif 'move_all' in self.state and self.eventpress:
dx = event.xdata - self.eventpress.xdata
dy = event.ydata - self.eventpress.ydata
for k in range(len(self._xs)):
self._xs[k] = self._xs_at_press[k] + dx
self._ys[k] = self._ys_at_press[k] + dy
# Do nothing if completed or waiting for a move.
elif (self._polygon_completed
or 'move_vertex' in self.state or 'move_all' in self.state):
return
# Position pending vertex.
else:
# Calculate distance to the start vertex.
x0, y0 = self.line.get_transform().transform((self._xs[0],
self._ys[0]))
v0_dist = np.hypot(x0 - event.x, y0 - event.y)
# Lock on to the start vertex if near it and ready to complete.
if len(self._xs) > 3 and v0_dist < self.vertex_select_radius:
self._xs[-1], self._ys[-1] = self._xs[0], self._ys[0]
else:
self._xs[-1], self._ys[-1] = event.xdata, event.ydata
self._draw_polygon()
def _on_key_press(self, event):
"""Key press event handler"""
# Remove the pending vertex if entering the 'move_vertex' or
# 'move_all' mode
if (not self._polygon_completed
and ('move_vertex' in self.state or 'move_all' in self.state)):
self._xs, self._ys = self._xs[:-1], self._ys[:-1]
self._draw_polygon()
def _on_key_release(self, event):
"""Key release event handler"""
# Add back the pending vertex if leaving the 'move_vertex' or
# 'move_all' mode (by checking the released key)
if (not self._polygon_completed
and
(event.key == self.state_modifier_keys.get('move_vertex')
or event.key == self.state_modifier_keys.get('move_all'))):
self._xs.append(event.xdata)
self._ys.append(event.ydata)
self._draw_polygon()
# Reset the polygon if the released key is the 'clear' key.
elif event.key == self.state_modifier_keys.get('clear'):
event = self._clean_event(event)
self._xs, self._ys = [event.xdata], [event.ydata]
self._polygon_completed = False
self.set_visible(True)
def _draw_polygon(self):
"""Redraw the polygon based on the new vertex positions."""
self.line.set_data(self._xs, self._ys)
# Only show one tool handle at the start and end vertex of the polygon
# if the polygon is completed or the user is locked on to the start
# vertex.
if (self._polygon_completed
or (len(self._xs) > 3
and self._xs[-1] == self._xs[0]
and self._ys[-1] == self._ys[0])):
self._polygon_handles.set_data(self._xs[:-1], self._ys[:-1])
else:
self._polygon_handles.set_data(self._xs, self._ys)
self.update()
@property
def verts(self):
"""The polygon vertices, as a list of ``(x, y)`` pairs."""
return list(zip(self._xs[:-1], self._ys[:-1]))
[docs]class Lasso(AxesWidget):
"""
Selection curve of an arbitrary shape.
The selected path can be used in conjunction with
`~matplotlib.path.Path.contains_point` to select data points from an image.
Unlike `LassoSelector`, this must be initialized with a starting
point *xy*, and the `Lasso` events are destroyed upon release.
Parameters
----------
ax : `~matplotlib.axes.Axes`
The parent axes for the widget.
xy : (float, float)
Coordinates of the start of the lasso.
callback : callable
Whenever the lasso is released, the *callback* function is called and
passed the vertices of the selected path.
"""
def __init__(self, ax, xy, callback=None, useblit=True):
AxesWidget.__init__(self, ax)
self.useblit = useblit and self.canvas.supports_blit
if self.useblit:
self.background = self.canvas.copy_from_bbox(self.ax.bbox)
x, y = xy
self.verts = [(x, y)]
self.line = Line2D([x], [y], linestyle='-', color='black', lw=2)
self.ax.add_line(self.line)
self.callback = callback
self.connect_event('button_release_event', self.onrelease)
self.connect_event('motion_notify_event', self.onmove)
[docs] def onrelease(self, event):
if self.ignore(event):
return
if self.verts is not None:
self.verts.append((event.xdata, event.ydata))
if len(self.verts) > 2:
self.callback(self.verts)
self.ax.lines.remove(self.line)
self.verts = None
self.disconnect_events()
[docs] def onmove(self, event):
if self.ignore(event):
return
if self.verts is None:
return
if event.inaxes != self.ax:
return
if event.button != 1:
return
self.verts.append((event.xdata, event.ydata))
self.line.set_data(list(zip(*self.verts)))
if self.useblit:
self.canvas.restore_region(self.background)
self.ax.draw_artist(self.line)
self.canvas.blit(self.ax.bbox)
else:
self.canvas.draw_idle()
