如何在左侧显示QMenu

Question

QMenu显示在QLineEdit右键单击。 问题：如何修改此代码以显示左键单击菜单？

from PyQt4.QtCore import * 
from PyQt4.QtGui import * 
import sys 

class MyWindow(QWidget): 
    def __init__(self, *args): 
     QWidget.__init__(self, *args) 

    def actionFunct(self, argBool): 
     print 'actionFunct()', argBool 

    def buildGUI(self): 
     self.line=QLineEdit(self) 
     self.line.setText('My Line Edit')  

     self.menu=QMenu(self.line) 

     self.line.installEventFilter(self) 
     self.menu.installEventFilter(self) 

     for i in range(3): 
      actn=QAction('Action 0%s'%i, self.menu, checkable=True) 
      actn.triggered.connect(self.actionFunct) 
      self.menu.addAction(actn) 

     self.line.setContextMenuPolicy(Qt.CustomContextMenu) 
     self.line.connect(self.line, SIGNAL("customContextMenuRequested(QPoint)"), self.lineClicked) 

     layout=QVBoxLayout(self) 
     layout.addWidget(self.line) 
     self.setLayout(layout) 

    def lineClicked(self, QPos): 
     print 'lineClicked', QPos 
     parentPosition = self.line.mapToGlobal(QPoint(0, 0))   
     menuPosition = parentPosition + QPos 

     self.menu.move(menuPosition) 
     self.menu.show() 

if __name__ == "__main__": 
    app = QApplication(sys.argv) 
    w = MyWindow() 
    w.buildGUI() 
    w.show() 
    sys.exit(app.exec_()) 

Answer 1

你需要在你的窗口类来过滤/处理该事件定义eventFilter方法。

def eventFilter(self, obj, event): 
    if obj == self.line and isinstance(event, QMouseEvent) and event.buttons() & Qt.LeftButton: 
     self.lineClicked(event.pos()) 
     return True 
    return False 

Answer 2

解决方案＃1（感谢Brendan Abel）。

使用installEventFilter()方法路由通过易于被定制eventFilter()方法的所有lineedit事件：

self.line.installEventFilter(self) 

现在所有的事件self.line触发器要经过eventFilter。使用有收到event对象，我们查询现在的位置使用：

event.pos() 

我们发送给leftClicked()方法作为参数（同样的方法被称为上lineeidit的右键）。 从PyQt4.QtCore进口* 从PyQt4.QtGui进口* 进口SYS

class MyWindow(QWidget): 
    def __init__(self, *args): 
     QWidget.__init__(self, *args) 

    def actionFunct(self, argBool): 
     print 'actionFunct()', argBool 

    def buildGUI(self): 
     self.line=QLineEdit(self) 
     self.line.setText('My Line Edit')  
     self.line.installEventFilter(self) 

     self.menu=QMenu(self.line) 

     for i in range(3): 
      actn=QAction('Action 0%s'%i, self.menu, checkable=True) 
      actn.triggered.connect(self.actionFunct) 
      self.menu.addAction(actn) 

     self.line.setContextMenuPolicy(Qt.CustomContextMenu) 
     self.line.connect(self.line, SIGNAL("customContextMenuRequested(QPoint)"), self.leftClicked) 

     self.line.cursorPositionChanged.connect(self.leftClicked) 

     layout=QVBoxLayout(self) 
     layout.addWidget(self.line) 
     self.setLayout(layout) 


    def eventFilter(self, widget, event): 
     print 'eventFilter', widget, event 
     if widget == self.line and isinstance(event, QMouseEvent) and event.buttons() & Qt.LeftButton: 
      self.leftClicked(event.pos()) 
      return True 
     return False 

    def leftClicked(self, QPos): 
     print 'leftClicked', QPos 
     parentPosition = self.line.mapToGlobal(QPoint(0, 0))   
     menuPosition = parentPosition + QPos 

     self.menu.move(menuPosition) 
     self.menu.show() 

if __name__ == "__main__": 
    app = QApplication(sys.argv) 
    w = MyWindow() 
    w.buildGUI() 
    w.show() 
    sys.exit(app.exec_()) 

溶液＃2

首先QLineEdit的最易于触发cursorPositionChanged信号连接到的方法。 当在左击调用此方法查询与Qt的QCursor.pos()当前鼠标光标位置：返回类似

current_mouse_cursor=QCursor.pos() 

：

QtCore.QPoint(852, 595) 

最后菜单移至查询鼠标光标位置并显示：

self.menu.move(current_mouse_cursor) 
    self.menu.show() 

工作代码如下：

from PyQt4.QtCore import * 
from PyQt4.QtGui import * 
import sys 

class MyWindow(QWidget): 
    def __init__(self, *args): 
     QWidget.__init__(self, *args) 

    def actionFunct(self, argBool): 
     print 'actionFunct()', argBool 

    def buildGUI(self): 
     self.line=QLineEdit(self) 
     self.line.setText('My Line Edit')  

     self.menu=QMenu(self.line) 

     for i in range(3): 

      actn=QAction('Action 0%s'%i, self.menu, checkable=True) 
      actn.triggered.connect(self.actionFunct) 
      self.menu.addAction(actn) 

     self.line.setContextMenuPolicy(Qt.CustomContextMenu) 
     self.line.connect(self.line, SIGNAL("customContextMenuRequested(QPoint)"), self.rightClicked) 

     self.line.cursorPositionChanged.connect(self.leftClicked) 

     layout=QVBoxLayout(self) 
     layout.addWidget(self.line) 
     self.setLayout(layout) 


    def leftClicked(self, arg): 
     print 'leftClicked', arg, QCursor.pos() 
     self.menu.move(QCursor.pos()) 
     self.menu.show() 

    def rightClicked(self, QPos): 
     print 'rightClicked', QPos 
     parentPosition = self.line.mapToGlobal(QPoint(0, 0))   
     menuPosition = parentPosition + QPos 

     self.menu.move(menuPosition) 
     self.menu.show() 

if __name__ == "__main__": 
    app = QApplication(sys.argv) 
    w = MyWindow() 
    w.buildGUI() 
    w.show() 
    sys.exit(app.exec_())