python - 如何判断一个项目在 qlistview 中的位置？

Question

我有一个自定义 QListView:

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

from Diagnostics import Trace2 #writes to log file
import traceback

class ListOrderView(QListView):

    itemMoved = pyqtSignal(int, int, QStandardItem) # Old index, new index, item 

    def __init__(self, parent=None):
        try:
            super(ListOrderView, self).__init__(parent)

            self.setAcceptDrops(True)
            self.setDragEnabled(True)
            self.setDragDropMode(QAbstractItemView.InternalMove)
            self.setDefaultDropAction(Qt.MoveAction)

            self.setEditTriggers(QAbstractItemView.NoEditTriggers)
            self.setSelectionBehavior(QAbstractItemView.SelectRows)
            self.setSelectionMode(QAbstractItemView.SingleSelection)

            self.dragItem = None
            self.dragRow = None

            self.indexesMoved.connect(self.onIndexesMoved)
            #self.installEventFilter(self)
        except:
            Trace2.WriteLine(str(traceback.format_exc()))

    def onIndexesMoved(self, indexes):
        Trace2.WriteLine("indexes were moved")

    def dropEvent(self, event): 
        try:
            super(ListOrderView, self).dropEvent(event) 

            self.selectionModel().setCurrentIndex(self.model().indexFromItem(self.dragItem), QItemSelectionModel.SelectCurrent)
            Trace2.WriteLine("[LISTVIEW] item dropped")
            Trace2.WriteLine("[LISTVIEW] current index is %d" %self.selectionModel().currentIndex().row())
            Trace2.WriteLine("[LISTVIEW] current selection is %d" %self.selectionModel().selection().indexes()[0].row())

            self.itemMoved.emit(self.dragRow, self.row(self.dragItem), self.dragItem)
            self.dragItem = None
        except:
            Trace2.WriteLine(str(traceback.format_exc()))

    def startDrag(self, supportedActions): 
        try:
            self.dragItem = self.currentItem() 
            self.dragRow = self.row(self.dragItem) 
            super(ListOrderView, self).startDrag(Qt.MoveAction)
        except:
            Trace2.WriteLine(str(traceback.format_exc()))

    def currentItem(self):
        index = self.currentIndex()
        item = self.model().itemFromIndex(index)
        #Trace2.WriteLine("[LISTVIEW] currentItem = %s" % item.data(Qt.DisplayRole).toString())
        return item

    def row(self, item):
        #index = self.model().indexFromItem(item)
        index = self.selectedIndexes()[0]
        row = index.row()

        #Trace2.WriteLine("[LISTVIEW] row = %d" %row)
        return row

而且我真的需要知道在拖放操作后项目被放置在哪里，以便其他东西可以正确更新(我试图将拖放放入从未为它设计的东西，大应用程序，而不是我的设计)。选择模型的当前索引和选择不遵循丢弃的项目，它们会有效地选择新项目并把事情搞砸。有没有办法让它们随着掉落的物品移动？信号 indexMoved 看起来和我想要的完全一样，但它永远不会触发。我用错了吗？有不同/更好的方法吗？

Answer 1

我认为您可能需要让模型告诉您某些东西被丢弃的位置，因为它最终会处理移动:

class Model(QStandardItemModel):

    rowDropped = pyqtSignal(int)

    def dropMimeData(self, *args):
        success =  super(Model, self).dropMimeData(*args)
        if success:
            self.rowDropped.emit(args[2])
        return success

这将从模型中发出发生下降的行号。您的 View 已经知道从其自己的事件中拖放了哪个项目。

我确信还有其他方法可以跟踪对象，然后在放置完成后再次查询它。