Como arrastar e soltar de um QListWidget para outro
Existem dois QListWIdgets em uma mesma janela de diálogo. A funcionalidade DragDrop foi ativada para ambos. Se eu arrastar e soltar um arquivo em qualquer um dos dois ListWidges, o programa o reconhecerá e imprimirá a lista dos arquivos descartados. Mas, além de arrastar e soltar arquivos, eu gostaria de poder arrastar e soltar os itens do widget Lista de um para outro. Se eu arrastar o ListItems, o evento arrastar e soltar será acionado. Mas não é possível reconhecer quais itens foram descartados no widget. O código de exemplo está abaixo. O objetivo é arrastar e soltar os itens da lista de um ListWidget para outro.
import sys, os
from PyQt4 import QtCore, QtGui
class ThumbListWidget(QtGui.QListWidget):
def __init__(self, type, parent=None):
super(ThumbListWidget, self).__init__(parent)
self.setAcceptDrops(True)
self.setIconSize(QtCore.QSize(124, 124))
def dragEnterEvent(self, event):
if event.mimeData().hasUrls:
event.accept()
else:
event.ignore()
def dragMoveEvent(self, event):
if event.mimeData().hasUrls:
event.setDropAction(QtCore.Qt.CopyAction)
event.accept()
else:
event.ignore()
def dropEvent(self, event):
if event.mimeData().hasUrls:
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.ignore()
class Dialog_01(QtGui.QMainWindow):
def __init__(self):
super(QtGui.QMainWindow,self).__init__()
self.listItems={}
myQWidget = QtGui.QWidget()
myBoxLayout = QtGui.QVBoxLayout()
myQWidget.setLayout(myBoxLayout)
self.setCentralWidget(myQWidget)
self.listWidgetA = ThumbListWidget(self)
for i in range(12):
QtGui.QListWidgetItem( 'Item '+str(i), self.listWidgetA )
myBoxLayout.addWidget(self.listWidgetA)
self.listWidgetB = ThumbListWidget(self)
myBoxLayout.addWidget(self.listWidgetB)
self.listWidgetA.setDragDropMode(QtGui.QAbstractItemView.InternalMove)
self.listWidgetA.setSelectionMode(QtGui.QAbstractItemView.ExtendedSelection)
self.connect(self.listWidgetA, QtCore.SIGNAL("dropped"), self.items_dropped)
self.listWidgetA.currentItemChanged.connect(self.item_clicked)
self.listWidgetB.setDragDropMode(QtGui.QAbstractItemView.InternalMove)
self.listWidgetB.setSelectionMode(QtGui.QAbstractItemView.ExtendedSelection)
self.connect(self.listWidgetB, QtCore.SIGNAL("dropped"), self.items_dropped)
self.listWidgetB.currentItemChanged.connect(self.item_clicked)
def items_dropped(self, arg):
print arg
def item_clicked(self, arg):
print arg
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
dialog_1 = Dialog_01()
dialog_1.show()
dialog_1.resize(480,320)
sys.exit(app.exec_())
Aqui está o código que faz tudo. Mas não há como rastrear qual objeto foi descartado. Os métodos dropOnA () e dropOnB () ainda não estão funcionando.
from PyQt4 import QtGui, QtCore
import sys, os
class MyClassItem(QtGui.QListWidgetItem):
def __init__(self, parent=None):
super(QtGui.QListWidgetItem, self).__init__(parent)
class ThumbListWidget(QtGui.QListWidget):
def __init__(self, type, parent=None):
super(ThumbListWidget, self).__init__(parent)
self.setIconSize(QtCore.QSize(124, 124))
self.setDragDropMode(QtGui.QAbstractItemView.DragDrop)
self.setSelectionMode(QtGui.QAbstractItemView.ExtendedSelection)
self.setAcceptDrops(True)
def dragEnterEvent(self, event):
if event.mimeData().hasUrls():
event.accept()
else:
super(ThumbListWidget, self).dragEnterEvent(event)
def dragMoveEvent(self, event):
if event.mimeData().hasUrls():
event.setDropAction(QtCore.Qt.CopyAction)
event.accept()
else:
super(ThumbListWidget, self).dragMoveEvent(event)
def dropEvent(self, event):
print 'dropEvent', event
if event.mimeData().hasUrls():
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.MoveAction)
super(ThumbListWidget, self).dropEvent(event)
class Dialog_01(QtGui.QMainWindow):
def __init__(self):
super(QtGui.QMainWindow,self).__init__()
self.listItems={}
myQWidget = QtGui.QWidget()
myBoxLayout = QtGui.QVBoxLayout()
myQWidget.setLayout(myBoxLayout)
self.setCentralWidget(myQWidget)
self.listWidgetA = ThumbListWidget(self)
self.listWidgetB = ThumbListWidget(self)
for i in range(7):
listItemAInstance=MyClassItem()
listItemAInstance.setText('A'+'%04d'%i)
listItemAInstance.setBackgroundColor(QtCore.Qt.darkGray)
if i%2: listItemAInstance.setBackgroundColor(QtCore.Qt.gray)
self.listWidgetA.addItem(listItemAInstance)
listItemBInstance=MyClassItem()
listItemBInstance.setText('B'+'%04d'%i)
if i%2: listItemBInstance.setBackgroundColor(QtCore.Qt.lightGray)
self.listWidgetB.addItem(listItemBInstance)
myBoxLayout.addWidget(self.listWidgetA)
myBoxLayout.addWidget(self.listWidgetB)
self.connect(self.listWidgetA, QtCore.SIGNAL("dropped"), self.droppedOnA)
self.connect(self.listWidgetB, QtCore.SIGNAL("dropped"), self.droppedOnB)
def droppedOnA(self, arg):
print '\n\t droppedOnA', arg.text
def droppedOnB(self, arg):
print '\n\t droppedOnB', arg.text
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
dialog_1 = Dialog_01()
dialog_1.show()
dialog_1.resize(480,320)
sys.exit(app.exec_())
Aqui está outra tentativa, desta vez, usando o MIME para passar os objetos do Item descartado para o ListWidget. Infelizmente, o cPickle se recusa a aceitar objetos binários lançando um
TypeError: o tipo sip.wrapper não pode ser instanciado ou subclassificado
Para contornar isso, converto os nomes de cada objeto em string e o uso com o self.listItems = {} dictionary como chave para recuperar os objetos binários do item da lista. O que parece estar funcionando bem. Mas no final, quando eu quase pensei em tudo, um ListWidget sem erros visíveis não adiciona o item da lista descartada a si mesmo ... É estranho.
self.listWidgetB.addItem (dropItemInstance)
.
from PyQt4 import QtGui, QtCore
import sys, os
import cPickle
class MyClassItem(QtGui.QListWidgetItem):
def __init__(self, parent=None):
super(QtGui.QListWidgetItem, self).__init__(parent)
class ThumbListWidget(QtGui.QListWidget):
def __init__(self, type, parent=None):
super(ThumbListWidget, self).__init__(parent)
self.setIconSize(QtCore.QSize(124, 124))
self.setDragDropMode(QtGui.QAbstractItemView.DragDrop)
self.setSelectionMode(QtGui.QAbstractItemView.ExtendedSelection)
self.setAcceptDrops(True)
def dragEnterEvent(self, event):
if event.mimeData().hasUrls():
event.accept()
else:
super(ThumbListWidget, self).dragEnterEvent(event)
def dragMoveEvent(self, event):
if event.mimeData().hasUrls():
event.setDropAction(QtCore.Qt.CopyAction)
event.accept()
else:
super(ThumbListWidget, self).dragMoveEvent(event)
def dropEvent(self, event):
if event.mimeData().hasUrls():
event.setDropAction(QtCore.Qt.CopyAction)
event.accept()
links = []
for url in event.mimeData().urls():
links.append(str(url.toLocalFile()))
else:
event.setDropAction(QtCore.Qt.MoveAction)
super(ThumbListWidget, self).dropEvent(event)
def mimeTypes(self):
return ['bstream', 'text/xml']
def mimeData(self, droppedItems):
mimedata = QtCore.QMimeData()
droppedItemsAsStrings=[]
for each in droppedItems:
droppedItemsAsStrings.append( str(each) )
bstream = cPickle.dumps(droppedItemsAsStrings)
mimedata.setData('bstream', bstream)
return mimedata
def dropMimeData(self, action, mimedata, row):
if action == QtCore.Qt.IgnoreAction: return True
dropped=cPickle.loads(str(mimedata.data('bstream')))
self.emit(QtCore.SIGNAL("dropped"), dropped)
return True
class Dialog_01(QtGui.QMainWindow):
def __init__(self):
super(QtGui.QMainWindow,self).__init__()
self.listItems={}
myQWidget = QtGui.QWidget()
myBoxLayout = QtGui.QVBoxLayout()
myQWidget.setLayout(myBoxLayout)
self.setCentralWidget(myQWidget)
self.listWidgetA = ThumbListWidget(self)
self.listWidgetB = ThumbListWidget(self)
for i in range(7):
listItemAInstance=MyClassItem()
listItemAInstance.setText('A'+'%04d'%i)
listItemAInstance.setBackgroundColor(QtCore.Qt.darkGray)
if i%2: listItemAInstance.setBackgroundColor(QtCore.Qt.gray)
self.listWidgetA.addItem(listItemAInstance)
listItemBInstance=MyClassItem()
listItemBInstance.setText('B'+'%04d'%i)
if i%2: listItemBInstance.setBackgroundColor(QtCore.Qt.lightGray)
self.listWidgetB.addItem(listItemBInstance)
self.listItems[str(listItemAInstance)]=listItemAInstance
self.listItems[str(listItemBInstance)]=listItemBInstance
myBoxLayout.addWidget(self.listWidgetA)
myBoxLayout.addWidget(self.listWidgetB)
self.connect(self.listWidgetA, QtCore.SIGNAL("dropped"), self.droppedOnA)
self.connect(self.listWidgetB, QtCore.SIGNAL("dropped"), self.droppedOnB)
def droppedOnA(self, droppedItemsAsStrings):
print '\n\t droppedOnA()'
for each in droppedItemsAsStrings:
if each in self.listItems.keys():
droppedItemInstance = self.listItems[each]
print 'adding', droppedItemInstance.text()
self.listWidgetA.addItem(droppedItemInstance)
def droppedOnB(self, droppedItemsAsStrings):
print '\n\t droppedOnB()'
for each in droppedItemsAsStrings:
if each in self.listItems.keys():
droppedItemInstance = self.listItems[each]
self.listWidgetB.addItem(droppedItemInstance)
print 'adding', droppedItemInstance.text()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
dialog_1 = Dialog_01()
dialog_1.show()
dialog_1.resize(480,320)
sys.exit(app.exec_())