ZetCode PyQt4 tutorial Drag and Drop

#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
ZetCode PyQt4 tutorial

This is a simple drag and
drop example. 

author: Jan Bodnar
website: zetcode.com
last edited: January 2015
"""

import sys
from PyQt4 import QtGui

# In order to drop text on the QtGui.QPushButton widget, we must reimplement some methods. Therefore, we create our own Button class which inherits from the QtGui.QPushButton class.
class Button(QtGui.QPushButton):
  
    def __init__(self, title, parent):
        super(Button, self).__init__(title, parent)
        
        # We enable drop events for the widget.
        self.setAcceptDrops(True)

    # First, we reimplement the dragEnterEvent() method. We inform about the data type that we accept. In our case it is plain text.
    def dragEnterEvent(self, e):
      
        if e.mimeData().hasFormat('text/plain'):
            e.accept()
        else:
            e.ignore() 

    # By reimplementing the dropEvent() method we define what we will do upon the drop event. Here we change the text of the button widget.
    def dropEvent(self, e):
        self.setText(e.mimeData().text()) 


class Example(QtGui.QWidget):
  
    def __init__(self):
        super(Example, self).__init__()
        
        self.initUI()
        
    def initUI(self):

        edit = QtGui.QLineEdit('', self)
        # The QtGui.QLineEdit widget has a built-in support for drag operations. All we need to do is to call setDragEnabled() method to activate it.
        edit.setDragEnabled(True)
        edit.move(30, 65)

        button = Button("Button", self)
        button.move(190, 65)
        
        self.setWindowTitle('Simple drag & drop')
        self.setGeometry(300, 300, 300, 150)


def main():
  
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    ex.show()
    app.exec_()  
  

if __name__ == '__main__':
    main()   

--------------------------------------------------------------------------------

#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
ZetCode PyQt4 tutorial

In this program, we can press on a button 
with a left mouse click or drag and drop the 
button with  the right mouse click. 

author: Jan Bodnar
website: zetcode.com
last edited: October 2013
"""

import sys
from PyQt4 import QtCore, QtGui


# We create a Button class which will derive from the QtGui.QPushButton. We also reimplement two methods of the QtGui.QPushButton: the mouseMoveEvent() and the mousePressEvent(). The mouseMoveEvent() method is the place where the drag & drop operation begins.
class Button(QtGui.QPushButton):
  
    def __init__(self, title, parent):
        super(Button, self).__init__(title, parent)

    def mouseMoveEvent(self, e):

        # Here we decide that we can perform drag & drop only with a right mouse button. The left mouse button is reserved for clicking on the button.
        if e.buttons() != QtCore.Qt.RightButton:
            return

        # The QDrag object is created. The class provides support for MIME-based drag and drop data transfer.
        mimeData = QtCore.QMimeData()

        drag = QtGui.QDrag(self)
        drag.setMimeData(mimeData)
        drag.setHotSpot(e.pos() - self.rect().topLeft())

        # The start() method of the drag object starts the drag & drop operation.
        dropAction = drag.start(QtCore.Qt.MoveAction)

    # We print 'press' to the console if we left click on the button with the mouse. Notice that we call mousePressEvent() method on the parent as well. Otherwise, we would not see the button being pushed.
    def mousePressEvent(self, e):
      
        super(Button, self).mousePressEvent(e)
        
        if e.button() == QtCore.Qt.LeftButton:
            print 'press'


class Example(QtGui.QWidget):
  
    def __init__(self):
        super(Example, self).__init__()

        self.initUI()
        
    def initUI(self):

        self.setAcceptDrops(True)

        self.button = Button('Button', self)
        self.button.move(100, 65)

        self.setWindowTitle('Click or Move')
        self.setGeometry(300, 300, 280, 150)
        self.show()

    def dragEnterEvent(self, e):
      
        e.accept()

    def dropEvent(self, e):

        # In the dropEvent() method we code what happens after we release the mouse button and finish the drop operation. We find out the current mouse pointer position and move the button accordingly.
        position = e.pos()        
        self.button.move(position)

        # We specify the type of the drop action. In our case it is a move action.
        e.setDropAction(QtCore.Qt.MoveAction)
        e.accept()
        

def main():
  
    app = QtGui.QApplication([])
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

 

转载于:https://www.cnblogs.com/zengjfgit/p/4851876.html

评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值