如何从一个列表中使用拖放进行复制，但使用移动进行内部拖放

Question

我需要能够将一个项目从一个listWidget复制到另一个listWidget。这很容易做到，但我似乎无法根据被拖动的项是否源于被拖放到的列表中来区分拖放操作，而不需要用我自己的方法覆盖几乎所有的拖放函数。当我把一个项目从一个列表拖到另一个列表时，我想复制它，但是当我拖动同一个列表中的项目时，我想移动它。在

我一直在研究如何设置mimetype，但后来我不得不编写自己的mouseMoveEvent，以此来判断拖动项的来源，但到目前为止，尝试这样做会破坏一切。在不重写mouseMoveEvent的情况下，是否不可能为项目设置mime类型？在

因为我拖动的项目是自定义的，所以当它被移动或复制到第二个列表时，我必须编写自己的定义来重建它。在默认的拖动功能下，这一切都可以很好地与内部移动。但是到目前为止，我还没有弄清楚如何在拖动是内部移动时使用默认的拖放函数，然后在拖放来自不同列表时切换到我的自定义函数来复制项目。在

import sys
from PyQt4 import QtGui , QtCore


def main():

    app = QtGui.QApplication(sys.argv)

    w = QtGui.QWidget()
    w.resize(250, 150)
    w.move(300, 300)
    w.setWindowTitle('Simple')
    layout=QtGui.QHBoxLayout(w)
    dragList=DragDropListWidget()
    layout.addWidget(dragList)
    dragList.setDragDropMode(QtGui.QAbstractItemView.InternalMove)
    dragList.name='dragList'
    dragList.populate(['one','two','three'])
    dragList2=DragDropListWidget()
    dragList2.setDragDropMode(QtGui.QAbstractItemView.DragDrop)
    dragList2.name='dragList'


    layout.addWidget(dragList2)
    w.show()

    sys.exit(app.exec_())

class scriptsWidget(QtGui.QWidget):


    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self)

        self.name=''

        self.widget_QHBoxLayout = QtGui.QHBoxLayout(self)
        self.widget_QHBoxLayout.setSpacing(0)
        self.widget_QHBoxLayout.setContentsMargins(0, 0, 0, 0)

        self.name_QLabel = QtGui.QLabel(self)
        self.widget_QHBoxLayout.addWidget(self.name_QLabel)

        self.user_QLabel = QtGui.QLabel(self)
        self.widget_QHBoxLayout.addWidget(self.user_QLabel)

        self.widget_QHBoxLayout.setSpacing(0)
        self.widget_QHBoxLayout.setContentsMargins(0, 0, 0, 0)



    def setName(self,name):
        self.name_QLabel.setText(name)
        self.name=name

    def setUser(self,user):
        self.user_QLabel.setText(user)

class customQListWidgetItem(QtGui.QListWidgetItem):


    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self)
        self.name=''

    def setName(self,name):
        self.name=name   




class DragDropListWidget(QtGui.QListWidget):
    _drag_info = []
    def __init__(self, parent = None):

        super(DragDropListWidget, self).__init__(parent)


        self.name=''


    def dragMoveEvent(self, event):
        if event.mimeData().hasUrls():
            event.setDropAction(QtCore.Qt.CopyAction)
            event.accept()

        else:
            super(DragDropListWidget, self).dragMoveEvent(event)


    def dropEvent(self, event):
        if event.mimeData().hasText():
            event.setDropAction(QtCore.Qt.CopyAction)
            event.accept()
            links = []
            for url in event.mimeData().urls():
                links.append(str(url.toLocalFile()))
            self.emit(QtCore.SIGNAL("dropped"), links)

        else:
            event.setDropAction(QtCore.Qt.CopyAction)
            items = []
            for index in xrange(self.count()):
                items.append(self.item(index))

            super(DragDropListWidget, self).dropEvent(event)

            for index in xrange(self.count()):
                if self.item(index) not in items:
                    self.populateDrop(self.item(index), index, [self.item(index).data(QtCore.Qt.UserRole).toPyObject()])

    def populateDrop(self,item,row,items=[]):
        for i in items:
            widget = scriptsWidget()
            widget.setName(i)
            widget.setUser('x')
            self.takeItem(row)
            item = customQListWidgetItem()
            item.setName(i)
            item.setWhatsThis(i)
            data = (i)
            item.setData(QtCore.Qt.UserRole, data)
            self.insertItem (row, item)
            self.setItemWidget(item,widget)



    def populate(self,items=[]):
        self.clear()
        for i in items:
            print(i)
            widget = scriptsWidget()
            widget.setName(i)
            widget.setUser('x')
            item = customQListWidgetItem()
            item.setName(i)
            data = (i)
            item.setData(QtCore.Qt.UserRole, data)
            self.addItem(item)
            self.setItemWidget(item,widget)



if __name__ == '__main__':
    main()

Answer 1

这就是我想到的。我正在设置一个类数据变量，当项目被单击时，我可以知道它来自何处。我尝试在DragDropListWidget中使用一个类变量，但由于某些原因，它只存储当前列表的本地名称。。奇怪的。全局变量也起作用，但并不可取。在

import sys
from PyQt4 import QtGui , QtCore

def main():

    app = QtGui.QApplication(sys.argv)

    w = QtGui.QWidget()
    w.resize(250, 150)
    w.move(300, 300)
    w.setWindowTitle('Simple')
    layout=QtGui.QHBoxLayout(w)
    dragList=DragDropListWidget()
    layout.addWidget(dragList)
    d=data()
    dragList.setDragDropMode(QtGui.QAbstractItemView.InternalMove)
    dragList.name='dragList'
    dragList.populate(['one','two','three'])
    dragList.data=d
    dragList2=DragDropListWidget()
    dragList2.setDragDropMode(QtGui.QAbstractItemView.DragDrop)
    dragList2.name='dragList2'
    dragList2.external='dragList2'
    dragList2.data=d


    layout.addWidget(dragList2)
    w.show()

    sys.exit(app.exec_())

class data(object):
    def __init__(self, parent=None):
        self.origin='new'




class scriptsWidget(QtGui.QWidget):


    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self)

        self.name=''

        self.widget_QHBoxLayout = QtGui.QHBoxLayout(self)
        self.widget_QHBoxLayout.setSpacing(0)
        self.widget_QHBoxLayout.setContentsMargins(0, 0, 0, 0)

        self.name_QLabel = QtGui.QLabel(self)
        self.widget_QHBoxLayout.addWidget(self.name_QLabel)

        self.user_QLabel = QtGui.QLabel(self)
        self.widget_QHBoxLayout.addWidget(self.user_QLabel)

        self.widget_QHBoxLayout.setSpacing(0)
        self.widget_QHBoxLayout.setContentsMargins(0, 0, 0, 0)



    def setName(self,name):
        self.name_QLabel.setText(name)
        self.name=name

    def setUser(self,user):
        self.user_QLabel.setText(user)

class customQListWidgetItem(QtGui.QListWidgetItem):


    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self)
        self.name=''
        self.list=''

    def setName(self,name):
        self.name=name   




class DragDropListWidget(QtGui.QListWidget):

    def __init__(self, parent = None):

        super(DragDropListWidget, self).__init__(parent)
        self._dropping = False
        self.itemPressed.connect(self.clicked)

        self.data=''

        self.name=''
        self.external=''
        self.internal=False

    def clicked(self):
        global origin 
        self.data.origin=self.name


    def dragMoveEvent(self, event):

        if event.mimeData().hasUrls():
            event.setDropAction(QtCore.Qt.CopyAction)
            event.accept()

        else:

            super(DragDropListWidget, self).dragMoveEvent(event)


    def dropEvent(self, event):

        if event.mimeData().hasText():
            event.setDropAction(QtCore.Qt.CopyAction)
            event.accept()
            links = []
            for url in event.mimeData().urls():
                links.append(str(url.toLocalFile()))
            self.emit(QtCore.SIGNAL("dropped"), links)

        else:
            if self.external is self.name and self.data.origin is not self.name:
                print('external')
                event.setDropAction(QtCore.Qt.CopyAction)
                items = []
                for index in xrange(self.count()):
                    items.append(self.item(index))
                print items

                super(DragDropListWidget, self).dropEvent(event)

                for index in xrange(self.count()):
                    if self.item(index) not in items:
                        print(index)
                        self.populateDrop(self.item(index), index, [self.item(index).data(QtCore.Qt.UserRole).toPyObject()])

            else:
                print('internal')
                event.setDropAction(QtCore.Qt.MoveAction)

                super(DragDropListWidget, self).dropEvent(event)

        self.data.origin = None       

    def populateDrop(self,item,row,items=[]):
        for i in items:
            widget = scriptsWidget()
            widget.setName(i)
            widget.setUser('x')
            self.takeItem(row)
            item = customQListWidgetItem()
            item.setName(i)
            item.setWhatsThis(i)
            item.list=self.name
            data = (i)
            item.setData(QtCore.Qt.UserRole, data)
            self.insertItem (row, item)
            self.setItemWidget(item,widget)



    def populate(self,items=[]):
        self.clear()
        for i in items:
            print(i)
            widget = scriptsWidget()
            widget.setName(i)
            widget.setUser('x')

            item = customQListWidgetItem()
            item.setName(i)
            item.list=self.name
            data = (i)
            item.setData(QtCore.Qt.UserRole, data)
            self.addItem(item)
            self.setItemWidget(item,widget)



if __name__ == '__main__':
    main()