可编辑的可重排序（通过拖放）Qt5 QTreeView示例
[英]Editable reorderable (by drag and drop) Qt5 QTreeView example
问题描述
在找不到适合Qt5的QTreeView的通用分层可重排序示例之后，我尝试相应地转换可编辑树模型示例代码。
在PyQt中有拖放支持的QTreeView记录了一个相关的问题，但是虽然它是PyQt4，但这本身不是问题（无论如何我都会将其转换为PyQt；）），treeview +抽象模型不会工作不正常。 至少，它不会在这里重新排序任何项目。
此示例代码无法正常运行：它允许移动项目，但是将其删除会导致空白行，但条目不会移动。
diff -up editabletreemodel.orig/mainwindow.cpp editabletreemodel/mainwindow.cpp
--- editabletreemodel.orig/mainwindow.cpp 2016-06-10 08:48:56.000000000 +0200
+++ editabletreemodel/mainwindow.cpp 2016-10-25 23:20:09.909671875 +0200
@@ -67,6 +67,7 @@ MainWindow::MainWindow(QWidget *parent)
file.close();
view->setModel(model);
+ view->setDragDropMode(QAbstractItemView::InternalMove);
for (int column = 0; column < model->columnCount(); ++column)
view->resizeColumnToContents(column);
diff -up editabletreemodel.orig/treemodel.cpp editabletreemodel/treemodel.cpp
--- editabletreemodel.orig/treemodel.cpp 2016-06-10 08:48:56.000000000 +0200
+++ editabletreemodel/treemodel.cpp 2016-10-25 23:23:47.408024344 +0200
@@ -96,10 +96,12 @@ QVariant TreeModel::data(const QModelInd
//! [3]
Qt::ItemFlags TreeModel::flags(const QModelIndex &index) const
{
- if (!index.isValid())
- return 0;
+ Qt::ItemFlags defaultFlags = Qt::ItemIsEditable | QAbstractItemModel::flags(index);
- return Qt::ItemIsEditable | QAbstractItemModel::flags(index);
+ if (index.isValid())
+ return Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled | defaultFlags;
+ else
+ return Qt::ItemIsDropEnabled | defaultFlags;
}
//! [3]
@@ -295,3 +297,8 @@ void TreeModel::setupModelData(const QSt
++number;
}
}
+
+Qt::DropActions TreeModel::supportedDropActions() const
+{
+ return Qt::MoveAction;
+}
diff -up editabletreemodel.orig/treemodel.h editabletreemodel/treemodel.h
--- editabletreemodel.orig/treemodel.h 2016-06-10 08:48:56.000000000 +0200
+++ editabletreemodel/treemodel.h 2016-10-25 23:19:18.884870266 +0200
@@ -95,6 +95,7 @@ public:
const QModelIndex &parent = QModelIndex()) Q_DECL_OVERRIDE;
bool removeRows(int position, int rows,
const QModelIndex &parent = QModelIndex()) Q_DECL_OVERRIDE;
+ Qt::DropActions supportedDropActions() const Q_DECL_OVERRIDE;
private:
void setupModelData(const QStringList &lines, TreeItem *parent);
从理论上讲，这就是所有需要重新排序物品的条件。
这是PyQt5版本：--- editabletreemodel.py.orig 2015-07-17 13：39：33.000000000 +0200 +++ editabletreemodel.py 2016-10-26 00：24：51.857176297 +0200 @@ -44,7 + 44,7 @@
from PyQt5.QtCore import (QAbstractItemModel, QFile, QIODevice,
QItemSelectionModel, QModelIndex, Qt)
-from PyQt5.QtWidgets import QApplication, QMainWindow
+from PyQt5.QtWidgets import QApplication, QMainWindow, QAbstractItemView
import editabletreemodel_rc
from ui_mainwindow import Ui_MainWindow
@@ -151,10 +151,12 @@ class TreeModel(QAbstractItemModel):
return item.data(index.column())
def flags(self, index):
- if not index.isValid():
- return 0
+ defaultFlags = Qt.ItemIsEditable | super(TreeModel, self).flags(index)
- return Qt.ItemIsEditable | Qt.ItemIsEnabled | Qt.ItemIsSelectable
+ if index.isValid():
+ return defaultFlags | Qt.ItemIsDragEnabled | Qt.ItemIsDropEnabled
+ else:
+ return defaultFlags | Qt.ItemIsDropEnabled
def getItem(self, index):
if index.isValid():
@@ -296,6 +298,9 @@ class TreeModel(QAbstractItemModel):
number += 1
+ def supportedDropActions(self):
+ return Qt.MoveAction
+
class MainWindow(QMainWindow, Ui_MainWindow):
def __init__(self, parent=None):
@@ -311,6 +316,7 @@ class MainWindow(QMainWindow, Ui_MainWin
file.close()
self.view.setModel(model)
+ self.view.setDragDropMode(QAbstractItemView.InternalMove)
for column in range(model.columnCount()):
self.view.resizeColumnToContents(column)
1 个解决方案
解决方案1
1 2016-11-04 11:21:21
我设法扩展了所引用问题的答案 ，以使模型项可以通过拖放进行重新排序。 但是，我必须指出，引用的示例和我的答案实际上都处理的是类似于列表模型而不是树的模型，因为拖放不影响模型项之间的父子关系。放置处理实现为始终执行项目重新排序。
只要drag-n-drop需要序列化一些与要重新定位的商品有关的数据，就可以通过以下方式实现通过drag-n-drop进行的重新排序：
- 在拖动时，我们序列化有关拖动项目的一些信息
- 在下降时，我们：
- 反序列化此信息
- 使用此信息在模型中找到每个拖动项目的原始位置
- 从模型中删除定位的项目，从而导致其余项目移动其位置； 如果模型正确实现
removeRows方法，Qt会为我们做到这一点。 - 将删除的项目重新插入模型中，但这一次是将其放置在放置项目之前或之后的位置 。 前一个选项可用于放置第一个项目，后一个选项可用于其他情况。
这是PyQt4解决方案的完整代码：
import sys
from PyQt4 import QtGui, QtCore
class TreeModel(QtCore.QAbstractItemModel):
def __init__(self):
QtCore.QAbstractItemModel.__init__(self)
self.nodes = ['node0', 'node1', 'node2', 'node3', 'node4', 'node5']
def index(self, row, column, parent):
if row < 0 or row >= len(self.nodes):
return QtCore.QModelIndex()
return self.createIndex(row, column, self.nodes[row])
def parent(self, index):
return QtCore.QModelIndex()
def rowCount(self, index):
if index.isValid():
return 0
if index.internalPointer() in self.nodes:
return 0
return len(self.nodes)
def columnCount(self, index):
if index.isValid():
return 0
return 1
def data(self, index, role):
if not index.isValid():
return None
if role == 0:
return index.internalPointer()
else:
return None
def supportedDropActions(self):
return QtCore.Qt.CopyAction | QtCore.Qt.MoveAction
def flags(self, index):
if not index.isValid():
return QtCore.Qt.ItemIsEnabled
return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable | \
QtCore.Qt.ItemIsDragEnabled | QtCore.Qt.ItemIsDropEnabled
def insertRows(self, row, count, index):
if index.isValid():
return False
if count <= 0:
return False
# inserting 'count' empty rows starting at 'row'
self.beginInsertRows(QtCore.QModelIndex(), row, row + count - 1)
for i in range(0, count):
self.nodes.insert(row + i, '')
self.endInsertRows()
return True
def removeRows(self, row, count, index):
if index.isValid():
return False
if count <= 0:
return False
num_rows = self.rowCount(QtCore.QModelIndex())
self.beginRemoveRows(QtCore.QModelIndex(), row, row + count - 1)
for i in range(count, 0, -1):
self.nodes.pop(row - i + 1)
self.endRemoveRows()
return True
def setData(self, index, value, role):
if not index.isValid():
return False
if index.row() < 0 or index.row() > len(self.nodes):
return False
self.nodes[index.row()] = str(value)
self.dataChanged.emit(index, index)
def mimeTypes(self):
return ['application/vnd.treeviewdragdrop.list']
def mimeData(self, indexes):
mimedata = QtCore.QMimeData()
encoded_data = QtCore.QByteArray()
stream = QtCore.QDataStream(encoded_data, QtCore.QIODevice.WriteOnly)
for index in indexes:
if index.isValid():
text = self.data(index, 0)
stream << QtCore.QString(text)
mimedata.setData('application/vnd.treeviewdragdrop.list', encoded_data)
return mimedata
def dropMimeData(self, data, action, row, column, parent):
if action == QtCore.Qt.IgnoreAction:
return True
if not data.hasFormat('application/vnd.treeviewdragdrop.list'):
return False
if column > 0:
return False
num_rows = self.rowCount(QtCore.QModelIndex())
begin_row = 0
if row != -1:
begin_row = row
elif parent.isValid():
begin_row = parent.row()
else:
begin_row = num_rows
if begin_row != num_rows and begin_row != 0:
begin_row += 1
encoded_data = data.data('application/vnd.treeviewdragdrop.list')
stream = QtCore.QDataStream(encoded_data, QtCore.QIODevice.ReadOnly)
new_items = []
rows = 0
while not stream.atEnd():
text = QtCore.QString()
stream >> text
new_items.append(text)
rows += 1
# insert the new rows for the dropped items and set the data to these items appropriately
self.insertRows(begin_row, rows, QtCore.QModelIndex())
for text in new_items:
idx = self.index(begin_row, 0, QtCore.QModelIndex())
self.setData(idx, text, 0)
self.dataChanged.emit(idx, idx)
begin_row += 1
return True
class MainForm(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MainForm, self).__init__(parent)
self.treeModel = TreeModel()
self.view = QtGui.QTreeView()
self.view.setModel(self.treeModel)
self.view.setDragDropMode(QtGui.QAbstractItemView.InternalMove)
self.setCentralWidget(self.view)
def main():
app = QtGui.QApplication(sys.argv)
form = MainForm()
form.show()
app.exec_()
if __name__ == '__main__':
main()
更新。 ：以防万一，如果有人感兴趣，我已扩展了此演示文稿，以在拖放后正确处理选择， 此处可以找到PyQt5和Python 3的代码。
Qt：尝试将拖放添加到可编辑树 Model 示例不起作用
[英]Qt: Attempt to add Drag and Drop to Editable Tree Model example not working
在QTreeView中拖放隐藏的QStandardItemModel列
[英]Drag & Drop of hidden QStandardItemModel columns in QTreeView
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