python - 将 matplotlib 的鼠标按钮事件与 pick 事件结合起来

Question

基于鼠标按钮和按键事件的组合，对散点图的点应用不同的功能。当按下鼠标左键时matplotlib的Lasso调用小部件并使用包含的点功能 1 发生。当按下 Shift+LMB 时，将绘制一个 Lasso，并使用包含的点执行功能 2。当按下 Alt+LMB 时，将绘制一个 Lasso，并使用包含的点执行功能 3。最后但并非最不重要的一点是，当我按下 RMB 时，会触发拾取事件，并给出散点图中所选点的索引。

自从我添加了 pick 事件后，上述功能就可以正常工作，直到 第一次触发 pick 事件。当它被触发时， Canvas 似乎被锁定，我无法使用任何其他功能。虽然我获得了所选点的索引，但没有收到任何错误，并且 Canvas 变得无响应。

我修改了取自 this 的代码问题，这实际上是我想做的。

代码:

import logging
import matplotlib
from matplotlib.widgets import Lasso
from matplotlib.colors import colorConverter
from matplotlib.collections import RegularPolyCollection
from matplotlib import path
import numpy as np
import matplotlib.pyplot as plt
from numpy.random import rand

logger = logging.getLogger()
logger.setLevel(logging.DEBUG)


class Datum(object):
      colorin = colorConverter.to_rgba('red')
      colorShift = colorConverter.to_rgba('cyan')
      colorCtrl = colorConverter.to_rgba('pink')
      colorout = colorConverter.to_rgba('blue')

      def __init__(self, x, y, include=False):
         self.x = x
         self.y = y
         if include:
            self.color = self.colorin
         else:
            self.color = self.colorout


class LassoManager(object):
      def __init__(self, ax, data):
         self.axes = ax
         self.canvas = ax.figure.canvas
         self.data = data

         self.Nxy = len(data)

         facecolors = [d.color for d in data]
         self.xys = [(d.x, d.y) for d in data]
         fig = ax.figure
         self.collection = RegularPolyCollection(fig.dpi, 6, sizes=(100,),facecolors=facecolors, offsets = self.xys, transOffset = ax.transData)

         ax.add_collection(self.collection)

         self.pick=self.canvas.mpl_connect('pick_event', self.onpick)
         self.cid = self.canvas.mpl_connect('button_press_event', self.onpress)
         self.keyPress = self.canvas.mpl_connect('key_press_event', self.onKeyPress)
         self.keyRelease = self.canvas.mpl_connect('key_release_event', self.onKeyRelease)
         self.lasso = None
         self.shiftKey = False
         self.ctrlKey = False

      def callback(self, verts):
          logging.debug('in LassoManager.callback(). Shift: %s, Ctrl: %s' % (self.shiftKey, self.ctrlKey))
          facecolors = self.collection.get_facecolors()
          p = path.Path(verts)
          ind = p.contains_points(self.xys)
          for i in range(len(self.xys)):
              if ind[i]:
                 if self.shiftKey:
                    facecolors[i] = Datum.colorShift
                 elif self.ctrlKey:
                    facecolors[i] = Datum.colorCtrl
                 else:
                    facecolors[i] = Datum.colorin
                    print self.xys[i]
              else:
                   facecolors[i] = Datum.colorout

          self.canvas.draw_idle()
          self.canvas.widgetlock.release(self.lasso)
          del self.lasso

      def onpress(self, event):
           if self.canvas.widgetlock.locked(): return
           if event.inaxes is None:    return
           self.lasso = Lasso(event.inaxes, (event.xdata, event.ydata), self.callback)
           # acquire a lock on the widget drawing
           self.canvas.widgetlock(self.lasso)

      def onKeyPress(self, event):
          logging.debug('in LassoManager.onKeyPress(). Event received: %s (key: %s)' % (event, event.key))
          if event.key == 'alt':
             self.ctrlKey = True
          if event.key == 'shift':
             self.shiftKey = True

      def onKeyRelease(self, event):
          logging.debug('in LassoManager.onKeyRelease(). Event received: %s (key: %s)' % (event, event.key))
          if event.key == 'alt':
             self.ctrlKey = False
          if event.key == 'shift':
             self.shiftKey = False


      def onpick(self,event):

          if event.mouseevent.button == 3:

             index = event.ind
             print('onpick scatter:', index, np.take(x, index), np.take(y, index))

      if __name__ == '__main__':

         x,y =rand(2,100)
         data = [Datum(*xy) for xy in zip(x,y)]
         fig = plt.figure()
         ax = plt.axes()

         ax.scatter(x,y,picker=True)

         lman = LassoManager(ax, data)
         plt.show()

对于可能导致此故障的原因有什么建议吗？提前致谢。

Answer 1

这次您遇到的问题是，当您单击艺术家时，会同时生成 PickEvent 和 MouseEvent。 MouseEvent 会锁定 Canvas 并阻止您随后执行任何其他操作。

最好的解决方案是防止在 PickEvent 之后触发 MouseEvent，但我不知道是否有办法做到这一点。相反，我添加了一个测试来检查是否在 onpick() 之后调用 onpress() 以禁用锁定机制。

import logging
import matplotlib
from matplotlib.widgets import Lasso
from matplotlib.colors import colorConverter
from matplotlib.collections import RegularPolyCollection
from matplotlib import path
import numpy as np
import matplotlib.pyplot as plt
from numpy.random import rand

logger = logging.getLogger()
logger.setLevel(logging.DEBUG)


class Datum(object):
      colorin = colorConverter.to_rgba('red')
      colorShift = colorConverter.to_rgba('cyan')
      colorCtrl = colorConverter.to_rgba('pink')
      colorout = colorConverter.to_rgba('blue')

      def __init__(self, x, y, include=False):
         self.x = x
         self.y = y
         if include:
            self.color = self.colorin
         else:
            self.color = self.colorout


class LassoManager(object):
      def __init__(self, ax, data):
         self.axes = ax
         self.canvas = ax.figure.canvas
         self.data = data

         self.Nxy = len(data)

         facecolors = [d.color for d in data]
         self.xys = [(d.x, d.y) for d in data]
         fig = ax.figure
         self.collection = RegularPolyCollection(fig.dpi, 6, sizes=(100,),facecolors=facecolors, offsets = self.xys, transOffset = ax.transData)

         ax.add_collection(self.collection)

         self.cid = self.canvas.mpl_connect('button_press_event', self.onpress)
         self.keyPress = self.canvas.mpl_connect('key_press_event', self.onKeyPress)
         self.keyRelease = self.canvas.mpl_connect('key_release_event', self.onKeyRelease)
         self.pick=self.canvas.mpl_connect('pick_event', self.onpick)
         self.lasso = None
         self.shiftKey = False
         self.ctrlKey = False
         self.pickEvent = False

      def callback(self, verts):
          logging.debug('in LassoManager.callback(). Shift: %s, Ctrl: %s' % (self.shiftKey, self.ctrlKey))
          facecolors = self.collection.get_facecolors()
          p = path.Path(verts)
          ind = p.contains_points(self.xys)
          for i in range(len(self.xys)):
              if ind[i]:
                 if self.shiftKey:
                    facecolors[i] = Datum.colorShift
                 elif self.ctrlKey:
                    facecolors[i] = Datum.colorCtrl
                 else:
                    facecolors[i] = Datum.colorin
                    print self.xys[i]
              else:
                   facecolors[i] = Datum.colorout

          self.canvas.draw_idle()
          self.canvas.widgetlock.release(self.lasso)
          del self.lasso

      def onpress(self, event):
            logging.debug('in LassoManager.onpress(). Event received: %s' % event)
            if self.pickEvent:
                self.pickEvent = False
                return
            if self.canvas.widgetlock.locked(): return
            if event.inaxes is None: return
            self.lasso = Lasso(event.inaxes, (event.xdata, event.ydata), self.callback)
            # acquire a lock on the widget drawing
            self.canvas.widgetlock(self.lasso)

      def onKeyPress(self, event):
          logging.debug('in LassoManager.onKeyPress(). Event received: %s (key: %s)' % (event, event.key))
          if event.key == 'alt':
             self.ctrlKey = True
          if event.key == 'shift':
             self.shiftKey = True

      def onKeyRelease(self, event):
          logging.debug('in LassoManager.onKeyRelease(). Event received: %s (key: %s)' % (event, event.key))
          if event.key == 'alt':
             self.ctrlKey = False
          if event.key == 'shift':
             self.shiftKey = False

      def onpick(self, event):
          logging.debug('in LassoManager.onpick(). Event received: %s' % event)
          self.pickEvent = True
          if event.mouseevent.button == 3:
             index = event.ind
             print 'onpick scatter: ', index, np.take(x, index), np.take(y, index)


if __name__ == '__main__':
    x,y =rand(2,100)
    data = [Datum(*xy) for xy in zip(x,y)]
    fig = plt.figure()
    ax = plt.axes()

    ax.scatter(x,y,picker=True)

    lman = LassoManager(ax, data)
    plt.show()