動的に作成されたQMDiareAsubWindow内のMatpLoTLIB Pick Artistイベントを処理する方法（与えられた例 - 部分的に働く！）

Question

PythonとMatplotLibを使用してQT4アプリケーションを作成しようとしていますが、私は行動に立ち往生しています。

このアプリケーションには、ID個別サブウィンドウに動的に作成されたグラフを保持するQMDIAREAがあります。データのプロット中に以前に定義されているアーティストピッキングイベントを作成しているが、すべてがうまくいっているようです。MainWindowクラス内にQMDiaReasubWindowインスタンスを作成するときは、明らかに "Pick_Event" MPL_Connectionが除外されます。

MainWinddowアプリケーションの外で同じコードが実行されている場合は不思議なことに。

私は行動を再現するために私のコードの単純化されたバージョンを書きました、そして、誰かが私に間違っていることの手がかりを私に与えることができるかもしれません。

歓声！

#!/usr/bin/python
import sys
from PyQt4.QtGui import QWidget, QPushButton, QMainWindow, QMdiArea, QVBoxLayout, QApplication
from PyQt4.QtCore import Qt

from pylab import *
from matplotlib.backends.backend_qt4agg import (
    FigureCanvasQTAgg as FigureCanvas,
    NavigationToolbar2QTAgg as NavigationToolbar)
from matplotlib.backend_bases import key_press_handler


class MyMainWindow(QMainWindow):
    """ Defines a simple MainWindow with a QPushButton that plots a Random Wave Fucntion
    which must be shown in a Window within a QMdiArea Widget.
    """

    def __init__(self, parent=None):
        """
        """

        super(MyMainWindow,self).__init__(parent)
        self.setWidgets()

    def setWidgets(self, ):
        """ Createsthe QPushButton and QMdiArea Widgets, organising them in 
        QVBoxLayout as a central Widget of the MainWindow
        """

        vBox = QVBoxLayout()
        mainFrame = QWidget()

        self._plotGraphButton = QPushButton("Plot Graph")
        self._plotGraphButton.clicked.connect(self.plotRandom)

        self._mdiArea = QMdiArea()
        vBox.addWidget(self._plotGraphButton)
        vBox.addWidget(self._mdiArea)

        mainFrame.setLayout(vBox)
        self.setCentralWidget(mainFrame)


    # This is the function called when the Plot Graph Button is pressed
    #and where the Picking event does not work.
    # When the button is pressed a new window with the plot is shown, but
    #it is not possible to drag the rectangle patch with the mouse.
    def plotRandom(self, ):
        """ Generates and Plots a random wave function (+noise) embedding into a 
        QMdiAreaSubWindow.
        """
        print "Plotting!!"
        x = linspace(0,10,1000)
        w = rand(1)*10
        y = 100*rand(1)*sin(2*pi*w*x)+rand(1000)

        p = PlotGraph(x,y)
        child = self._mdiArea.addSubWindow(p.plotQtCanvas())
        child.show()



class PlotGraph(object):
    """
    """

    def __init__(self, x,y):
        """ This class plots the data and encapsulates the figure instance in a FigureCanvasQt4Agg,
        which can be used to create a QMdiArea SubWindow.
         A rectangle patch is added to the plot and linked to the methods that
        can drag it horizontally in the graph.

        Arguments:
        - `x`: Data
        - `y`: Data
        """
        self._x = x
        self._dx = x[1]-x[0]
        self._y = y


    def _createPlotWidget(self, ):
        """ Creates a figure and a NavigationBar organising them vertically into a QWidget,
        which can be used by a QMdiArea.addSubWindow method.
        """
        self._mainFrame = QWidget()

        self._fig = figure(facecolor="white")
        self._canvas = FigureCanvas(self._fig)
        self._canvas.setParent(self._mainFrame)
        self._canvas.setFocusPolicy(Qt.StrongFocus)

        # Standard NavigationBar and button press management
        self._mplToolbar = NavigationToolbar(self._canvas, self._mainFrame)
        self._canvas.mpl_connect('key_press_event', self.on_key_press)

        # Layouting
        vbox = QVBoxLayout()
        vbox.addWidget(self._canvas)  # the matplotlib canvas
        vbox.addWidget(self._mplToolbar)
        self._mainFrame.setLayout(vbox)

    def plotQtCanvas(self, ):
        """ Plots data using matplotlib, adds a draggable Rectangle and connects the dragging
        methods to the mouse events
        """
        self._createPlotWidget()
        ax = self._fig.add_subplot(111)
        ax.plot(self._x,self._y)
        ax.set_xlim(self._x[0],self._x[-1])
        ax.set_ylim(-max(self._y)*1.1,max(self._y)*1.1)

        xlim = ax.get_xlim()
        ylim = ax.get_ylim()

        wd = (xlim[1]-xlim[0])*0.1
        ht = (ylim[1]-ylim[0])

        rect = Rectangle((xlim[0],ylim[0]),wd,ht,alpha=0.3,color="g",picker=True)
        ax.add_patch(rect)


        # Connecting Events to Rectangle dragging methods
        self._canvas.mpl_connect("pick_event",self.on_pick)
        self._canvas.mpl_connect("button_release_event",self.on_release)

        return self._mainFrame

    def on_pick(self,event):
        """ Manages the Artist Picking event. This method register which 
        Artist was picked and connects the rectOnMove method to the mouse
        motion_notify_event SIGNAL.

        Arguments:
        - `event`:
        """
        if isinstance(event.artist, Rectangle):

            rectWd = event.artist.get_width()
            if event.mouseevent.button == 1:
                self._dragged = event.artist
                self._id = self._canvas.mpl_connect("motion_notify_event",self.rectOnMove)


    def rectOnMove(self, event):
        """ After being picked, updates the new position of the Artist.

        Arguments:
        - `event`:
        """
        rectWd = self._dragged.get_width()
        if event.xdata:
            i = event.xdata
            n2 = rectWd/2.0
            if i>=n2 and i<(self._x[-1]-n2):
                self._dragged.set_x(i-n2)
                self._canvas.draw()

    def on_release(self,event):
        """ When the mouse button is released, simply disconnect the
        SIGNAL motion_notify_event and the rectOnMove method.

        Arguments:
        - `event`:
        """
        self._canvas.mpl_disconnect(self._id)


    def on_key_press(self, event):
        # implement the default mpl key press events described at
        # http://matplotlib.org/users/navigation_toolbar.html#navigation-keyboard-shortcuts
        key_press_handler(event, self._canvas, self._mplToolbar)



if __name__ == '__main__':
    qApp = QApplication(sys.argv)
    MainWindow = MyMainWindow()

    # By calling the piece of code bellow everything works fine and the
    # the rectangle patch can be dragged, as expected.

    # This piece of code "theoretically" does the same thing as the 
    # method plotRandom() defined in the class MyMainWindow.
    print "Plotting!!"
    x = linspace(0,10,1000)
    w = rand(1)*10
    y = 100*rand(1)*sin(2*pi*w*x)
    ####################################################################

    p = PlotGraph(x,y)
    child = MainWindow._mdiArea.addSubWindow(p.plotQtCanvas())
    child.show()

    MainWindow.show()
    sys.exit(qApp.exec_())

.

Answer 1

これは機能しません：

p = PlotGraph(x,y)
child = MainWindow._mdiArea.addSubWindow(p.plotQtCanvas())
child.show()
p = PlotGraph(x,y)
child = MainWindow._mdiArea.addSubWindow(p.plotQtCanvas())
child.show()

.

これは機能します：

p = PlotGraph(x,y)
child = MainWindow._mdiArea.addSubWindow(p.plotQtCanvas())
child.show()
p2 = PlotGraph(x,y)
child2 = MainWindow._mdiArea.addSubWindow(p2.plotQtCanvas())
child2.show()

.

編集：解決策：

setwidgets

でこれを行う

self.plotlist= []

とこれはplotRandom

self.plotlist.append（p）

そしてこれは私が遭遇したもう一つの問題を解決します：

on_release関数

でこれを追加

すべてのMouseClickがピッカーイベントを引き起こすわけではないので、発砲しなかった場合は切断することはできません。

try:
    self._canvas.mpl_disconnect(self._id)
except AttributeError:
    pass

.