如何在wxPython中使用matplotlib事件处理？

Question

我正在尝试修改matplotlib文档中的"Draggable Rectangle Exercise"，以便它可以在wxPython窗口中运行。

到目前为止，我有以下内容：

import wx

import matplotlib
matplotlib.interactive(True)
matplotlib.use('WXAgg')
from matplotlib.figure import Figure
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas

import numpy as np

class DraggableRectangle:
    def __init__(self, rect):
        self.rect = rect
        self.press = None

    def connect(self):
        'connect to all the events we need'
        self.cidpress = self.rect.figure.canvas.mpl_connect(
            'button_press_event', self.on_press)
        self.cidrelease = self.rect.figure.canvas.mpl_connect(
            'button_release_event', self.on_release)
        self.cidmotion = self.rect.figure.canvas.mpl_connect(
            'motion_notify_event', self.on_motion)

    def on_press(self, event):
        'on button press we will see if the mouse is over us and store some data'
        if event.inaxes != self.rect.axes: return

        contains, attrd = self.rect.contains(event)
        if not contains: return
        print 'event contains', self.rect.xy
        x0, y0 = self.rect.xy
        self.press = x0, y0, event.xdata, event.ydata

    def on_motion(self, event):
        'on motion we will move the rect if the mouse is over us'
        if self.press is None: return
        if event.inaxes != self.rect.axes: return
        x0, y0, xpress, ypress = self.press
        dx = event.xdata - xpress
        dy = event.ydata - ypress
        #print 'x0=%f, xpress=%f, event.xdata=%f, dx=%f, x0+dx=%f'%(x0, xpress, event.xdata, dx, x0+dx)
        self.rect.set_x(x0+dx)
        self.rect.set_y(y0+dy)

        #self.rect.figure.canvas.draw()
        self.rect.figure.canvas.draw_idle()

    def on_release(self, event):
        'on release we reset the press data'
        self.press = None
        #self.rect.figure.canvas.draw()
        self.rect.figure.canvas.draw_idle()

    def disconnect(self):
        'disconnect all the stored connection ids'
        self.rect.figure.canvas.mpl_disconnect(self.cidpress)
        self.rect.figure.canvas.mpl_disconnect(self.cidrelease)
        self.rect.figure.canvas.mpl_disconnect(self.cidmotion)

class Frame(wx.Frame):
    def __init__(self, title):
        wx.Frame.__init__(self, None, title=title, pos=(150,150), size=(800,600))

        self.panel = wx.Panel(self)

        self.figure = Figure(figsize=(6, 4), dpi=100)
        self.axes = self.figure.add_subplot(111)
        self.canvas = FigureCanvas(self.panel, wx.ID_ANY, self.figure)

        rects = self.axes.bar(range(10), 20*np.random.rand(10))
        drs = []
        for rect in rects:
            dr = DraggableRectangle(rect)
            dr.connect()
            drs.append(dr)

app = wx.App(redirect=False)
top = Frame("test")
top.Show()
app.MainLoop()

不幸的是，这不像宣传的那样有效;条形图出现在图表上但它们根本不可拖动。复制并粘贴示例as-is工作正常，只有当我尝试将它与wxPython一起使用时才遇到问题。

Answer 1

不要问我为什么，但将drs更改为self.drs（第75和79行）似乎有效。好像你必须阻止drs和所有dr被垃圾收集。 （与Wx Matplotlib Event Handling相关？）

import wx

import matplotlib
matplotlib.interactive(True)
matplotlib.use('WXAgg')
from matplotlib.figure import Figure
from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas

import numpy as np

class DraggableRectangle:
    def __init__(self, rect):
        self.rect = rect
        self.press = None

    def connect(self):
        'connect to all the events we need'
        self.cidpress = self.rect.figure.canvas.mpl_connect(
            'button_press_event', self.on_press)
        self.cidrelease = self.rect.figure.canvas.mpl_connect(
            'button_release_event', self.on_release)
        self.cidmotion = self.rect.figure.canvas.mpl_connect(
            'motion_notify_event', self.on_motion)

    def on_press(self, event):
        print "on_press"
        'on button press we will see if the mouse is over us and store some data'
        if event.inaxes != self.rect.axes: return

        contains, attrd = self.rect.contains(event)
        if not contains: return
        print 'event contains', self.rect.xy
        x0, y0 = self.rect.xy
        self.press = x0, y0, event.xdata, event.ydata

    def on_motion(self, event):
        print "on_motion"
        'on motion we will move the rect if the mouse is over us'
        if self.press is None: return
        if event.inaxes != self.rect.axes: return
        x0, y0, xpress, ypress = self.press
        dx = event.xdata - xpress
        dy = event.ydata - ypress
        #print 'x0=%f, xpress=%f, event.xdata=%f, dx=%f, x0+dx=%f'%(x0, xpress, event.xdata, dx, x0+dx)
        self.rect.set_x(x0+dx)
        self.rect.set_y(y0+dy)

        #self.rect.figure.canvas.draw()
        self.rect.figure.canvas.draw_idle()

    def on_release(self, event):
        print "on_release"
        'on release we reset the press data'
        self.press = None
        #self.rect.figure.canvas.draw()
        self.rect.figure.canvas.draw_idle()

    def disconnect(self):
        'disconnect all the stored connection ids'
        self.rect.figure.canvas.mpl_disconnect(self.cidpress)
        self.rect.figure.canvas.mpl_disconnect(self.cidrelease)
        self.rect.figure.canvas.mpl_disconnect(self.cidmotion)

class Frame(wx.Frame):
    def __init__(self, title):
        wx.Frame.__init__(self, None, title=title, pos=(150,150), size=(800,600))

        self.panel = wx.Panel(self)

        self.figure = Figure(figsize=(6, 4), dpi=100)
        self.axes = self.figure.add_subplot(111)
        self.canvas = FigureCanvas(self.panel, wx.ID_ANY, self.figure)

        rects = self.axes.bar(range(10), 20*np.random.rand(10))
        self.drs = []
        for rect in rects:
            dr = DraggableRectangle(rect)
            dr.connect()
            self.drs.append(dr)

print "test"
app = wx.PySimpleApp()#redirect=False)
top = Frame("test")
top.Show()
app.MainLoop()