class LassoSelection(PolygonToolBase):
def __init__(self, ax, on_move=None, on_release=None, on_enter=None,
useblit=True, line_props=None):
super(LassoSelection, self).__init__(ax, on_move=on_move,
on_release=on_release,
on_enter=on_enter,
useblit=useblit,
line_props=line_props)
self.shape = 'lasso'
self.mode = 'lasso'
self._prev_angle = 1e6
self._indicator = Rectangle((0, 0), 0, 0)
self._indicator.set_visible(False)
ax.add_patch(self._indicator)
self._artists.append(self._indicator)
def on_move(self, event):
if self.verts is None or not self._busy:
return
if self.mode == 'polygon':
self.verts[-1] = (event.xdata, event.ydata)
else:
# see if we are moving in the same direction
point2 = (event.xdata, event.ydata)
point1 = np.asarray(self.verts[-1], dtype=float)
point2 = np.asarray(point2, dtype=float)
dx, dy = point2 - point1
theta = np.arctan2(dy, dx)
if theta == self._prev_angle:
self.verts[-1] = (event.xdata, event.ydata)
else:
self.verts.append((event.xdata, event.ydata))
self._prev_angle = theta
try:
self._show_indicator()
except TypeError:
pass
self.update()
def on_mouse_release(self, event):
self.mode = 'polygon'
def on_mouse_press(self, event):
if self._indicator.get_visible() or event.dblclick:
self.verts = self.verts[:-1]
self.finalize()
return
if not self._busy:
self.start(event)
self.mode = 'lasso'
self.verts.append((event.xdata, event.ydata))
self.update()
def start(self, event):
super(LassoSelection, self).start(event)
self._prev_angle = 1e6
def finalize(self):
self.verts.append(self.verts[0])
self._indicator.set_visible(False)
super(LassoSelection, self).finalize()
def _show_indicator(self):
if not self.verts:
return
bounds = self.ax.dataLim.bounds
wid = float(bounds[2] - bounds[0])
hgt = float(bounds[3] - bounds[1])
orig = self.verts[0]
curr = self.verts[-1]
# see if we are within 2% in x and y
if (abs(curr[0] - orig[0]) / wid < 0.02 and
abs(curr[1] - orig[1]) / hgt < 0.02):
wid /= 100.
hgt /= 100.
self._indicator.set_xy((orig[0] - wid / 2.,
orig[1] - hgt / 2.))
self._indicator.set_width(wid * 2)
self._indicator.set_height(hgt * 2)
if not self._indicator.get_visible():
self._indicator.set_visible(True)
self.redraw()
elif self._indicator.get_visible():
self._indicator.set_visible(False)
self.redraw()
@property
def geometry(self):
return self.verts
@geometry.setter
def geometry(self, verts):
self.verts = verts
self.update()
