以編程方式更改Qt4中的matplotlib工具欄模式

Question

我正在使用matplotlib版本1.2.1，Qt4.7，python 2.7構建應用程序。

我想修改matplotlib工具欄添加另一個可選按鈕，它設置了一個模式來選擇響應pick事件的數據點。除了在選擇縮放或平移導航按鈕時不會發送選擇事件外，它幾乎都可以工作。

我在尋找的是一種以編程方式關閉平移和縮放模式的方法。我認爲我可以通過將工具欄平移和縮放按鈕的選中狀態設置爲False來完成此操作。這似乎工作（例如，如果選中縮放按鈕，設置爲false使其看起來未被選中）。但它不會改變畫布的模式 - 光標仍然是縮放光標，並且選取事件不會觸發。

下面的代碼演示了這一點：

import sys, os, math 
from PyQt4.QtCore import * 
from PyQt4.QtGui import * 

import matplotlib 
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg 
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QTAgg 
from matplotlib.figure import Figure 

class NavigationToolbar(NavigationToolbar2QTAgg): 

    picked=pyqtSignal(int,name='picked') 

    def __init__(self, canvas, parent): 
     NavigationToolbar2QTAgg.__init__(self,canvas,parent) 
     self.clearButtons=[] 
     # Search through existing buttons 
     # next use for placement of custom button 
     next=None 
     for c in self.findChildren(QToolButton): 
      if next is None: 
       next=c 
      # Don't want to see subplots and customize 
      if str(c.text()) in ('Subplots','Customize'): 
       c.defaultAction().setVisible(False) 
       continue 
      # Need to keep track of pan and zoom buttons 
      # Also grab toggled event to clear checked status of picker button 
      if str(c.text()) in ('Pan','Zoom'): 
       c.toggled.connect(self.clearPicker) 
       self.clearButtons.append(c) 
       next=None 

     # create custom button 
     pm=QPixmap(32,32) 
     pm.fill(QApplication.palette().color(QPalette.Normal,QPalette.Button)) 
     painter=QPainter(pm) 
     painter.fillRect(6,6,20,20,Qt.red) 
     painter.fillRect(15,3,3,26,Qt.blue) 
     painter.fillRect(3,15,26,3,Qt.blue) 
     painter.end() 
     icon=QIcon(pm) 
     picker=QAction("Pick",self) 
     picker.setIcon(icon) 
     picker.setCheckable(True) 
     picker.setToolTip("Pick data point") 
     self.picker = picker 
     button=QToolButton(self) 
     button.setDefaultAction(self.picker) 

     # Add it to the toolbar, and connect up event 
     self.insertWidget(next.defaultAction(),button) 
     picker.toggled.connect(self.pickerToggled) 

     # Grab the picked event from the canvas 
     canvas.mpl_connect('pick_event',self.canvasPicked) 

    def clearPicker(self, checked): 
     if checked: 
      self.picker.setChecked(False) 

    def pickerToggled(self, checked): 
     if checked: 
      for c in self.clearButtons: 
       c.defaultAction().setChecked(False) 
      self.set_message('Reject/use observation') 

    def canvasPicked(self, event): 
     if self.picker.isChecked(): 
      self.picked.emit(event.ind) 

class MainWindow(QMainWindow): 
    def __init__(self, parent=None): 
     QMainWindow.__init__(self, parent) 
     self.x=[i*0.1 for i in range(30)] 
     self.y=[math.sin(x) for x in self.x] 
     self.picked=[] 
     self.setWindowTitle('Custom toolbar') 

     self.frame = QWidget() 

     self.fig = Figure((4.0, 4.0)) 
     self.canvas = FigureCanvasQTAgg(self.fig) 
     self.canvas.setParent(self.frame) 

     self.axes = self.fig.add_subplot(111) 

     # Create the navigation toolbar, tied to the canvas 
     # and link the clicked event 
     self.toolbar = NavigationToolbar(self.canvas, self.frame) 
     self.toolbar.picked.connect(self.addPoint) 

     vbox = QVBoxLayout() 
     vbox.addWidget(self.canvas) 
     vbox.addWidget(self.toolbar) 
     self.frame.setLayout(vbox) 
     self.setCentralWidget(self.frame) 
     self.draw() 

    def draw(self): 
     while self.axes.lines: 
      self.axes.lines[0].remove() 
     self.axes.plot(self.x,self.y,'b+',picker=5) 
     xp=[self.x[i] for i in self.picked] 
     yp=[self.y[i] for i in self.picked] 
     self.axes.plot(xp,yp,'rs') 
     self.canvas.draw() 

    def addPoint(self,index): 
     if index in self.picked: 
      self.picked.remove(index) 
     else: 
      self.picked.append(index) 
     self.draw() 

if __name__ == "__main__": 
    app = QApplication(sys.argv) 
    form = MainWindow() 
    form.show() 
    app.exec_() 

Answer 1

如果你讀的NavigationToolbar2QT的源代碼，你可以發現：

1. _active是平移和縮放的當前狀態。
2. 調用pan(),zoom()方法將切換狀態。

所以，這裏是代碼，禁用泛&變焦：

def pickerToggled(self, checked): 
    if checked:    
     if self._active == "PAN": 
      self.pan() 
     elif self._active == "ZOOM": 
      self.zoom() 
     self.set_message('Reject/use observation')