pyqt:试图了解QAbstractDataModel和QTreeView的insertrows [英] pyqt: Trying to understand insertrows for QAbstractDataModel and QTreeView
问题描述
我正在使用PyQt使用QAbstractItemModel管理树视图.到目前为止，我已经成功实现了它，以便可以加载数据，展开和折叠数据以及编辑值.
但是，我无法做的一件事就是将头缠在插入和删除行上.
我正在尝试做的简短版本:
当用户编辑特定的单元格时，我实际上需要删除对象层次结构中的基础项目，并将其替换为其他项目.我在模型的setData方法中实现了这一点.由于我不完全了解自己在做什么，因此我似乎已经对其进行了设置，以使其发生段错误.
基本上，我只需要更好地了解数据模型如何与QModelIndex交互，但是阅读和重新阅读文档似乎并没有启发我.任何帮助(或任何指向体面的教程的链接-最好但不一定是python)也将不胜感激.
以下是我正在使用的代码示例:
#---------------------------------------------------------------------------
def setData(self, index, value, role=QtCore.Qt.EditRole):
"""
Sets the data.
"""
if index.isValid() and (0 <= index.row() < self.rowCount()):
item = index.internalPointer()
value = value.toString()
if index.column() == 5:
# rip out the current object and replace it with a new one of
# the correct datatype.
#next 4 lines get info from my underlying hierarchy of objects
dataType = str(value)
parent = item.get_parent()
name = item.get_name()
row = parent.get_row_of_child(name)
#assuming everything is ok, I now am trying to manage the
#underlying objects
if row != None:
#I am calling this because I think I need to, but don't
#really know if it is called for here or not
self.beginInsertRows(self.parent(index), row, 1)
#Next 3 lines create and initialize a new underlying
#object that will be inserted.
newItem = self.root.create_template_param_obj(dataType,
name,
parent)
newItem.set_index(row)
newItem.set_default_value(item.get_default_value())
#now I remove the old object from my underlying
#hierarchy and insert the new one
parent.remove_child_at_row(row)
parent.insert_child_at_row(newItem, row)
#this is where I get lost. I *think* I need to point to
#the new underlying object (i.e. rebuild the index)
#so I am going to call the data model's index method.
#But that needs the index of the parent, so first I
#call the data model's parent method to get the index
#of the parent. But this code segfaults (I think it
#is the treeview that actually freaks out because this
#setData method completes properly before the whole thing
#crashes. Does anyone have a pointer to a decent tutorial
#that will explain how data models and mode indexes work?
self.index(row, 5, self.parent(index))
self.endInsertRows()
self.emit(QtCore.SIGNAL("dataChanged(QModelIndex,QModelIndex)"),
index, index)
return True
#Ignore any role other than the edit role
return False
#---------------------------------------------------------------------------
def index(self, row, column, parent):
"""
Connect the data model to the actual object hierarchy.
"""
if not self.hasIndex(row, column, parent):
return QtCore.QModelIndex()
if not parent.isValid():
parentItem = self.root
else:
parentItem = parent.internalPointer()
childItem = parentItem.get_child_at_row(row)
if childItem:
return self.createIndex(row, column, childItem)
else:
return QtCore.QModelIndex()
#---------------------------------------------------------------------------
def parent(self, index):
"""
Returns a QModelIndex of the parent
"""
if not index.isValid():
return QtCore.QModelIndex()
childItem = index.internalPointer()
if not childItem:
return QtCore.QModelIndex()
parentItem = childItem.get_parent()
if parentItem == self.root:
return QtCore.QModelIndex()
return self.createIndex(parentItem.get_index(), 0, parentItem)
我将尝试给您一些提示，我记得当我必须为我的应用程序实现它时，这一部分也引起了我的注意！ >
因此，据我所记得，您必须实现以下虚拟方法:
virtual bool insertRows(int Row, int Count, const QModelIndex& rParent);
virtual bool removeRows(int Row, int Count, const QModelIndex& rParent = QModelIndex());
bool SuperModel::insertRows(int Row, int Count, const QModelIndex& rParent)
{
...
// On débute l'insertion des lignes.
beginInsertRows(rParent, Row, Row + Count -1);
// ... Perform insertion here, you'll have something like
pParent->addChild(Row);
endInsertRows();
}
bool SuperModel::removeRows(int Row, int Count, const QModelIndex& rParent)
{
...
beginRemoveRows(rParent, Row, Row + Count -1);
// ... Perform removing here, you'll have something like
pParent->removeChild(Row);
endRemoveRows();
}
更多信息: http://doc.qt.io/archives/qt-4.7/qabstractitemmodel.html#insertRows
我希望它能对您有所帮助...它不在PyQt中，但希望它会给您一些提示...
I am using PyQt to manage a tree view using a QAbstractItemModel. So far I have successfully implemented it such that I can load the data, expand and collapse it, and edit values.
One thing I am not able to do, however, is wrap my head around inserting and removing rows.
Short version of what I am trying to do:
When the user edits a particular cell, I need to actually delete the underlying item in my object hierarchy and replace it with a different one. I implement this in the setData method of my model. Since I don't completely understand what I am doing I seem to have set it up so that it segfaults.
Basically, I just need to get a better understanding of how the data model interacts with QModelIndex, but reading and re-reading the docs does not seem to enlighten me. Any help (or any links to a decent tutorial - preferably, though not necessarily, in python - would also be greatly appreciated).
Here is a sample of the code I am using:
#---------------------------------------------------------------------------
def setData(self, index, value, role=QtCore.Qt.EditRole):
"""
Sets the data.
"""
if index.isValid() and (0 <= index.row() < self.rowCount()):
item = index.internalPointer()
value = value.toString()
if index.column() == 5:
# rip out the current object and replace it with a new one of
# the correct datatype.
#next 4 lines get info from my underlying hierarchy of objects
dataType = str(value)
parent = item.get_parent()
name = item.get_name()
row = parent.get_row_of_child(name)
#assuming everything is ok, I now am trying to manage the
#underlying objects
if row != None:
#I am calling this because I think I need to, but don't
#really know if it is called for here or not
self.beginInsertRows(self.parent(index), row, 1)
#Next 3 lines create and initialize a new underlying
#object that will be inserted.
newItem = self.root.create_template_param_obj(dataType,
name,
parent)
newItem.set_index(row)
newItem.set_default_value(item.get_default_value())
#now I remove the old object from my underlying
#hierarchy and insert the new one
parent.remove_child_at_row(row)
parent.insert_child_at_row(newItem, row)
#this is where I get lost. I *think* I need to point to
#the new underlying object (i.e. rebuild the index)
#so I am going to call the data model's index method.
#But that needs the index of the parent, so first I
#call the data model's parent method to get the index
#of the parent. But this code segfaults (I think it
#is the treeview that actually freaks out because this
#setData method completes properly before the whole thing
#crashes. Does anyone have a pointer to a decent tutorial
#that will explain how data models and mode indexes work?
self.index(row, 5, self.parent(index))
self.endInsertRows()
self.emit(QtCore.SIGNAL("dataChanged(QModelIndex,QModelIndex)"),
index, index)
return True
#Ignore any role other than the edit role
return False
#---------------------------------------------------------------------------
def index(self, row, column, parent):
"""
Connect the data model to the actual object hierarchy.
"""
if not self.hasIndex(row, column, parent):
return QtCore.QModelIndex()
if not parent.isValid():
parentItem = self.root
else:
parentItem = parent.internalPointer()
childItem = parentItem.get_child_at_row(row)
if childItem:
return self.createIndex(row, column, childItem)
else:
return QtCore.QModelIndex()
#---------------------------------------------------------------------------
def parent(self, index):
"""
Returns a QModelIndex of the parent
"""
if not index.isValid():
return QtCore.QModelIndex()
childItem = index.internalPointer()
if not childItem:
return QtCore.QModelIndex()
parentItem = childItem.get_parent()
if parentItem == self.root:
return QtCore.QModelIndex()
return self.createIndex(parentItem.get_index(), 0, parentItem)
I'll try and give you some tips, I remember that this part did my head in as well when I had to implement it for my application !
So, from what I remember, you have to implement the following virtual methods :
virtual bool insertRows(int Row, int Count, const QModelIndex& rParent);
virtual bool removeRows(int Row, int Count, const QModelIndex& rParent = QModelIndex());
bool SuperModel::insertRows(int Row, int Count, const QModelIndex& rParent)
{
...
// On débute l'insertion des lignes.
beginInsertRows(rParent, Row, Row + Count -1);
// ... Perform insertion here, you'll have something like
pParent->addChild(Row);
endInsertRows();
}
bool SuperModel::removeRows(int Row, int Count, const QModelIndex& rParent)
{
...
beginRemoveRows(rParent, Row, Row + Count -1);
// ... Perform removing here, you'll have something like
pParent->removeChild(Row);
endRemoveRows();
}
Some more informations : http://doc.qt.io/archives/qt-4.7/qabstractitemmodel.html#insertRows
I hope it will help you a bit... it's not in PyQt but hopefully it will give you some tips...
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