Related
I am pretty new to QT and I am using PySide2 (latest version) with Python 3.9.6.
I want to use a CustomModel via QAbstractItemModel on a QtreeView and at the same time with a QListView.
I have a CustomModel with a two-level hierarchy data.
I want to see the full data in the treeview (working).
At the beginning I show the same model in the QListView. It shows only the top level items.
So far so good.
Now I connected the setRootIndex fn from the QListView to the clicked signal of the QTreeView.
I want to be able to click on a root level item and see only the children in the QListView.
I thought the .setRootIndex should do the trick, but its weirdly offsetting the shown children.
And it's showing only ONE of the children and offsetted by the index count of the first level item.
Please see the gif:
First both views show the same model.
Then I click the first root element in the left treeView.
It updates the right ListView, but only the first children is shown.
And the second item shows its child but the second and with one gap in the listView
Here is a (almost) working example.
I really hope someone can spot the mistake or my misconception of things..
The .setRootIndex on the QListView is confusing me.
I tried approaching it differntly in the .index and .parent and .rowCount functions of the CustomModel. But like this it somehow works at least. I have the feeling I am doing something wrong somewhere or the QListView wants things differntly like the QTreeView.
Is it even possible and a good idea to use the same model in two views?
I really thought so and this is the hole point of a model/viewcontroller approach, isn't it?
# -*- coding: utf-8 -*-
from typing import *
from PySide2 import QtWidgets
from PySide2.QtCore import QAbstractItemModel, QModelIndex
from PySide2.QtGui import Qt
from PySide2.QtWidgets import QListView, QTreeView
class FirstLevelItem:
def __init__(self, name) -> None:
self.name = name
self.children = []
class SecondLevelItem:
def __init__(self, name, parent) -> None:
self.name = name
self.parent = parent
class CustomModel(QAbstractItemModel):
def __init__(self, root_items, parent=None):
super().__init__(parent)
self.root_items = root_items
def rowCount(self, itemIndex):
"""Has to return the number of children of the itemIndex.
If its not a valid index, its a root item, and we return the count of all root_items.
If its a valid one and can have children, return the number of children.
This makes the Model to ask for more indexes for each item.
Only works if parent is set properly"""
if itemIndex.isValid():
item = itemIndex.internalPointer()
if isinstance(item, FirstLevelItem):
return len(item.children)
else:
return 0
else:
return len(self.root_items)
def columnCount(self, parent=None):
return 1
def parent(self, child_index):
"""Has to return an index pointing to the parent of the current index."""
if child_index.isValid():
# get the item of this index
item = child_index.internalPointer()
# check if its one with a parent
if isinstance(item, SecondLevelItem):
# get the parent obj from the item
parent_item = item.parent
# now we have to find the parents row index to be able to create the index pointing to it
parent_row = parent_item.children.index(item)
# create an index with the parent row and column and the parent item itself
return self.createIndex(parent_row, 0, parent_item)
else:
return QModelIndex()
else:
return QModelIndex()
def data(self, index, role):
if not index.isValid():
return None
item = index.internalPointer()
if role == Qt.DisplayRole:
return item.name
return None
def index(self, row, column, parentIndex):
if parentIndex.isValid():
parent_item = parentIndex.internalPointer()
return self.createIndex(row, column, parent_item.children[row])
else:
return self.createIndex(row, column, self.root_items[row])
class ModelTestDialog(QtWidgets.QDialog):
window_instance = None
def __init__(self, parent=None):
super().__init__(parent)
self.setWindowFlags(self.windowFlags() ^ Qt.WindowContextHelpButtonHint)
# self.setMinimumSize(1024, 1024)
self.setWindowTitle("ModelTestDialog")
rootItems = []
for i in range(0, 3):
name = ["FirstLevel_A", "FirstLevel_B", "FirstLevel_C"][i]
rootItem = FirstLevelItem(name)
rootItems.append(rootItem)
for j in range(0, 3):
name = ["SecondLevel_A", "SecondLevel_B", "SecondLevel_C"][j]
childItem = SecondLevelItem(name, rootItem)
rootItem.children.append(childItem)
self.model = CustomModel(rootItems)
self.treeView = QTreeView()
self.treeView.setModel(self.model)
self.listView = QListView()
self.listView.setModel(self.model)
self.main_layout = QtWidgets.QVBoxLayout(self)
self.listViews_layout = QtWidgets.QHBoxLayout()
self.main_layout.addLayout(self.listViews_layout)
self.listViews_layout.addWidget(self.treeView)
self.listViews_layout.addWidget(self.listView)
self.treeView.clicked[QModelIndex].connect(self.listView.setRootIndex)
if __name__ == "__main__":
app = QtWidgets.QApplication()
form = ModelTestDialog()
form.show()
app.exec_()
There is absolutely nothing wrong about using the same model in multiple views.
That is the whole concept behind the model/view paradigm (which relies on the principle of separation of concerns): the same model can be shared amongs multiple views, even if they show the content of that model in different ways.
That is completely respected by Qt (as long as the model is properly implemented, obviously); this also happens for similar concepts in Qt, like the QTextDocument interface used in QTextEdit (the same document can be shown on different QTextEdit instances), or the QGraphicsScene shown in a QGraphicsView (each view can show a different portion of the same scene).
The actual issue
You're using the wrong row for the parent:
parent_row = parent_item.children.index(item)
The above returns the index (row) of the child item, but you need to use createIndex() as a reference for the parent, because parent() has to return the row/column of the parent, not that of the child.
In this simple case, just return the index within the root_items:
parent_row = self.root_items.index(parent_item)
A better approach
I would suggest a more flexible structure, where a single base class is used for all items, and it always has a parent attribute. To do this, you need to also create a "root item" which contains all top level items.
You can still create subclasses for items if you need more flexibility or specialization, but the default behavior remains unchanged, making the implementation simpler especially in the case you need further levels within the structure.
The major benefit of this approach is that you never need to care about the item type to know its level: you know that you need to access the root item when the given index is invalid, and for any other case (like index creation, parent access, etc), the implementation is much more easy and readable. This will automatically make easier to add support for other features, like moving items and drag&drop.
class TreeItem:
parent = None
def __init__(self, name='', parent=None):
self.name = name
self.children = []
if parent:
parent.appendChild(self)
def appendChild(self, item):
self.insertChild(len(self.children), item)
def insertChild(self, index, item):
self.children.insert(index, item)
item.parent = self
def row(self):
if self.parent:
return self.parent.children.index(self)
return -1
class CustomModel(QAbstractItemModel):
def __init__(self, root_items=None, parent=None):
super().__init__(parent)
self.root_item = TreeItem()
if root_items:
for item in root_items:
self.root_item.appendChild(item)
def rowCount(self, itemIndex):
if itemIndex.isValid():
return len(itemIndex.internalPointer().children)
else:
return len(self.root_item.children)
def columnCount(self, parent=None):
return 1
def parent(self, child_index):
if child_index.isValid():
item = child_index.internalPointer()
if item.parent:
return self.createIndex(item.parent.row(), 0, item.parent)
return QModelIndex()
def data(self, index, role):
if not index.isValid():
return None
item = index.internalPointer()
if role == Qt.DisplayRole:
return item.name
def index(self, row, column, parentIndex=QModelIndex()):
if parentIndex.isValid():
parent_item = parentIndex.internalPointer()
return self.createIndex(row, column, parent_item.children[row])
else:
return self.createIndex(row, column, self.root_item.children[row])
class ModelTestDialog(QDialog):
def __init__(self, parent=None):
super().__init__(parent)
self.setWindowFlags(self.windowFlags() ^ Qt.WindowContextHelpButtonHint)
self.setWindowTitle('ModelTestDialog')
rootItems = []
for i in range(0, 3):
name = 'FirstLevel {}'.format('ABC'[i])
rootItem = TreeItem(name)
rootItems.append(rootItem)
for j in range(0, 3):
name = 'SecondLevel {} (child of {})'.format('ABC'[j], 'ABC'[i])
TreeItem(name, rootItem)
# or, alternatively:
# rootItem.appendChild(TreeItem(name))
self.model = CustomModel(rootItems)
self.treeView = QTreeView()
self.treeView.setModel(self.model)
self.listView = QListView()
self.listView.setModel(self.model)
self.main_layout = QVBoxLayout(self)
self.listViews_layout = QHBoxLayout()
self.main_layout.addLayout(self.listViews_layout)
self.listViews_layout.addWidget(self.treeView)
self.listViews_layout.addWidget(self.listView)
self.treeView.clicked.connect(self.listView.setRootIndex)
As you can see, the whole model code is much simpler and cleaner: there is no need to check for item level/type, as the concept of the structure makes that automatically immediate.
Further notes:
the Qt API suggests that the parent argument of index() should be optional; while it's common to use None for that, a default (and invalid) QModelIndex() is preferable, as I did above;
python implicitly returns None if no other return value is given;
in the last few years, Qt has been in the process of removing all overloaded signals, replacing them with more verbose and unique ones; in general, it's unnecessary to specify them, especially where no overload actually exists (self.treeView.clicked);
It's OK to just show the image
# L.append([QIcon(r"favicon.ico"), "file", "absolute_path", "modifytime"])
But can't show images and text
# L.append([QTableWidgetItem(QIcon(r"favicon.ico"), "file"), "file", "absolute_path", "modifytime"])
This is my model，I am using qtableview.
I'm using the setmodel method, and I want to add data dynamically.
class FileModel(QAbstractTableModel):
def __init__(self, data, header, *args, **kwargs):
super(FileModel, self).__init__()
self.datalist = data
self.header = header
def rowCount(self, parent=None, *args, **kwargs):
return len(self.datalist)
def columnCount(self, parent=None, *args, **kwargs):
return len(self.header)
def data(self, index, role=Qt.DisplayRole):
if not index.isValid():
return None
if role == Qt.DisplayRole or role == Qt.DecorationRole:
return self.datalist[index.row()][index.column()]
else:
return None
def headerData(self, col, orientation, role=None):
if orientation == Qt.Horizontal and role == Qt.DisplayRole:
return self.header[col]
return None
def append_data(self, x):
self.datalist.append(x)
self.layoutChanged.emit()
def remove_row(self, row):
self.datalist.pop(row)
self.layoutChanged.emit()
def remove_all(self):
self.datalist.clear()
self.layoutChanged.emit()
help me，can show images and text
The problem is with how you are storing your data and accessing it in your data method. I am having a difficult time trying to describe it so instead I am just going to show examples.
If you want a cell to contain both a icon and text then you need to return the icon when the role is the decoration role and the text when it is the display roll.
For example:
def data(self, index, role=Qt.DisplayRole):
if index.isValid():
row = index.row()
if role == Qt.DisplayRole:
return 'some text here'
elif role == Qt.DecorationRole:
return QIcon('path/to/icon')
return None
Since it appears that you are storing your data in a 2dim list this is a problem because you want every index to store the data for it's own cell.
So one possible solution is to store tuples at each index. So your dataList would have to look like this:
[(text, QIcon()), (text, QIcon), (text,)]
In which case your data method would do:
...
if role == Qt.DecorationRole:
return self.dataList[index.row()][index.column()][1]
elif role == Qt.DisplayRole:
return self.dataList[index.row()][index.column()][0]
...
or you could create your own item class that would work like the QTableWidgetItem.
class TableItem:
def __init__(self, text, icon=None):
self.icon = icon
self.text = text
...
then your data method would look like this:
...
item = self.dataList[index.row()][index.column()]
if role == Qt.DecorationRole:
return item.icon
elif role == Qt.DisplayRole:
return item.text
...
and you would need to construct the dataList like this:
dataList.append([TableItem('text', QIcon('/patth')), TableItem('text'), TableItem('Text')])
Hopefully those examples will help make up for my terrible explanation.
musicmante cleverly suggested using a dictionary where the keys are the different data roles in the comments.
For example:
Your data list rows would look like:
[{Qt.DisplayRole: 'text', Qt.DecorationRole: QIcon('/path')},
{Qt.DisplayRole: 'other text', Qt.DecorationRole: None},
{Qt.DisplayRole: 'more text', 'Qt.DecorationRole': None},....]
and the data method would do something like this.
...
item = self.dataList[index.row()][index.column()]
if role in [Qt.DisplayRole, Qt.DecorationRole]:
return item[role]
...
I am trying to update listview model in QML quick controls with python. Every item in this model contains address and status property. Right now my code is this:
ListModel:
class ServersModel(QAbstractListModel):
def __init__(self, parent=None):
super(ServersModel, self).__init__(parent)
self.list = []
for address, status in (
("server 1", "green"),
("server 2", "green"),
("server 3", "red")):
self.list.append(server(address, status))
def rowCount(self, parent=QModelIndex()):
return len(self.list)
def data(self, index, role=None):
if role == Qt.DisplayRole: #show just the name
person = self.list[index.row()]
return QVariant(person.name)
elif role == Qt.UserRole: #return the whole python object
person = self.list[index.row()]
return person
return QVariant()
def removeRow(self, position):
self.list = self.list[:position] + self.list[position+1:]
self.reset()
ServerObject:
class server(object):
'''
a custom data structure, for example purposes
'''
def __init__(self, address, status):
self.address = address
self.status = status
def __repr__(self):
return "%s\n%s"% (self.address, self.status)
Python connection handler:
class ServersListViewHandler(QObject):
def __init__(self):
QObject.__init__(self)
listLoaded = pyqtSignal(QAbstractListModel, arguments=['model'])
data_changed = pyqtSignal(QModelIndex, QModelIndex)
# Slot for detecting clicks in listView
#pyqtSlot(str)
def listViewItemClicked(self, name):
self.listLoaded.emit(ServersModel())
And this is my connectin at qml:
Connections {
target: serversListViewHandler
onListLoaded: {
serversListView.model = model
}
}
Address property should go to text as value and status is color of circle. This works fine if I implement model directly to QML but I want to update it dynamically and load it form python. Any ideas on how to accomplish this? I am probably doing it totally wrong but there are almost none tutorial or references about pyqt 5
I'm working on a similar experiment at the moment. I succeeded doing this by using dedicated role names for columns (in my case in the list view).
For your example this would kinda look like this:
class ServersModel(QAbstractListModel):
AddressRole = Qt.UserRole + 1
StatusRole = Qt.UserRole + 2
_roles = {AddressRole: b"address", StatusRole: b"status"}
...
def roleNames(self):
return self._roles
def data(self, index, role=None):
if role == AddressRole: #show just the name
person = self.list[index.row()]
return QVariant(person.name)
elif role == StatusRole: #return the whole python object
person = self.list[index.row()]
return person
return QVariant()
Though this may only target the displaying part, not the complete update procedure. Would be interesting to see the QML where you access the model.
Also I'm not really sure if there is some kind of best practice for this kind of thing.
I am trying to make a simple property editor, where the property list is a nested dict and the data is displayed and edited in a QTreeView. (Before I get to my question -- if anyone already has a working implementation of this in Python 3 I'd love to be pointed at it).
Anyway, after much work I have my QAbstractItemModel and I can open a QTreeView with this model and it shows the data. If I click on a label in the first column (the key) then it opens up an editor, either a text editor or a spinbox etc depending on the datatype. When I finish editing it calls my "model.setData" where I reject it because I don't want to allow editable keys. I can disable the editing of this by using flags and that works fine. I just wanted to check that everything works the way that I'd expect it to.
Here is what doesn't happen: if I click on a cell in the second column (the value that I actually want to edit) then it bypasses the loading of an editor and simply calls model.setData with the current value. I am baffled. I've tried changing the tree selectionBehavior and selectionMode but no dice. I'm returning Qt.ItemIsEnabled | Qt.ItemIsSelectable | Qt.ItemIsEditable in flags. It seems to display fine. It just won't open up an editor.
Any thoughts about what stupid mistake I must be making? I'll include the code below, with some print statements that I'm using to try to debug the thing.
Thanks
PS One thing that hung me up for a long time was that my QModelIndex members would just disappear, so the indices that I got back were garbage. I found that by keeping a reference to them (throwing them in a list) that they worked. This seems to be a problem that springs up a lot in Qt work (I had the same problem with menus disappearing -- I guess that means that I should think about it sooner). Is there a "best practices" way of dealing with this?
# -*- coding: utf-8 -*-
from collections import OrderedDict
from PyQt4.QtCore import QAbstractItemModel, QModelIndex, Qt
from PyQt4.QtGui import QAbstractItemView
class PropertyList(OrderedDict):
def __init__(self, *args, **kwargs):
OrderedDict.__init__(self, *args, **kwargs)
self.myModel = PropertyListModel(self)
def __getitem__(self,index):
if issubclass(type(index), list):
item = self
for key in index:
item = item[key]
return item
else:
return OrderedDict.__getitem__(self, index)
class PropertyListModel(QAbstractItemModel):
def __init__(self, propList, *args, **kwargs):
QAbstractItemModel.__init__(self, *args, **kwargs)
self.propertyList = propList
self.myIndexes = [] # Needed to stop garbage collection
def index(self, row, column, parent):
"""Returns QModelIndex to row, column in parent (QModelIndex)"""
if not self.hasIndex(row, column, parent):
return QModelIndex()
if parent.isValid():
indexPtr = parent.internalPointer()
parentDict = self.propertyList[indexPtr]
else:
parentDict = self.propertyList
indexPtr = []
rowKey = list(parentDict.keys())[row]
childPtr = indexPtr+[rowKey]
newIndex = self.createIndex(row, column, childPtr)
self.myIndexes.append(childPtr)
return newIndex
def get_row(self, key):
"""Returns the row of the given key (list of keys) in its parent"""
if key:
parent = key[:-1]
return list(self.propertyList[parent].keys()).index(key[-1])
else:
return 0
def parent(self, index):
"""
Returns the parent (QModelIndex) of the given item (QModelIndex)
Top level returns QModelIndex()
"""
if not index.isValid():
return QModelIndex()
childKeylist = index.internalPointer()
if childKeylist:
parentKeylist = childKeylist[:-1]
self.myIndexes.append(parentKeylist)
return self.createIndex(self.get_row(parentKeylist), 0,
parentKeylist)
else:
return QModelIndex()
def rowCount(self, parent):
"""Returns number of rows in parent (QModelIndex)"""
if parent.column() > 0:
return 0 # only keys have children, not values
if parent.isValid():
indexPtr = parent.internalPointer()
try:
parentValue = self.propertyList[indexPtr]
except:
return 0
if issubclass(type(parentValue), dict):
return len(self.propertyList[indexPtr])
else:
return 0
else:
return len(self.propertyList)
def columnCount(self, parent):
return 2 # Key & value
def data(self, index, role):
"""Returns data for given role for given index (QModelIndex)"""
# print('Looking for data in role {}'.format(role))
if not index.isValid():
return None
if role in (Qt.DisplayRole, Qt.EditRole):
indexPtr = index.internalPointer()
if index.column() == 1: # Column 1, send the value
return self.propertyList[indexPtr]
else: # Column 0, send the key
if indexPtr:
return indexPtr[-1]
else:
return ""
else: # Not display or Edit
return None
def setData(self, index, value, role):
"""Sets the value of index in a given role"""
print('In SetData')
if not index.isValid():
return False
print('Trying to set {} to {}'.format(index,value))
print('That is column {}'.format(index.column()))
if not index.column(): # Only change column 1
return False
try:
ptr = index.internalPointer()
self.propertyList[ptr[:-1]][ptr[-1]] = value
self.emit(self.dataChanged(index, index))
return True
except:
return False
def flags(self, index):
"""Indicates what can be done with the data"""
if not index.isValid():
return Qt.NoItemFlags
if index.column(): # only enable editing of values, not keys
return Qt.ItemIsEnabled | Qt.ItemIsSelectable | Qt.ItemIsEditable
else:
return Qt.ItemIsEnabled | Qt.ItemIsSelectable | Qt.ItemIsEditable #Qt.NoItemFlags
if __name__ == '__main__':
p = PropertyList({'k1':'v1','k2':{'k3':'v3','k4':4}})
import sys
from PyQt4 import QtGui
qApp = QtGui.QApplication(sys.argv)
treeView = QtGui.QTreeView()
# I've played with all the settings on these to no avail
treeView.setHeaderHidden(False)
treeView.setAllColumnsShowFocus(True)
treeView.setUniformRowHeights(True)
treeView.setSelectionBehavior(QAbstractItemView.SelectRows)
treeView.setSelectionMode(QAbstractItemView.SingleSelection)
treeView.setAlternatingRowColors(True)
treeView.setEditTriggers(QAbstractItemView.DoubleClicked |
QAbstractItemView.SelectedClicked |
QAbstractItemView.EditKeyPressed |
QAbstractItemView.AnyKeyPressed)
treeView.setTabKeyNavigation(True)
treeView.setModel(p.myModel)
treeView.show()
sys.exit(qApp.exec_())
#strubbly was real close but forgot to unpack the tuple in his index method.
Here's the working code for Qt5. There are probably a couple of imports and stuff that would need to be fixed. Only cost me a couple weeks of my life :)
import sys
from collections import OrderedDict
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtCore import Qt
class TupleKeyedOrderedDict(OrderedDict):
def __init__(self, *args, **kwargs):
super().__init__(sorted(kwargs.items()))
def __getitem__(self, key):
if isinstance(key, tuple):
item = self
for k in key:
if item != ():
item = item[k]
return item
else:
return super().__getitem__(key)
def __setitem__(self, key, value):
if isinstance(key, tuple):
item = self
previous_item = None
for k in key:
if item != ():
previous_item = item
item = item[k]
previous_item[key[-1]] = value
else:
return super().__setitem__(key, value)
class SettingsModel(QtCore.QAbstractItemModel):
def __init__(self, data, parent=None):
super().__init__(parent)
self.root = data
self.my_index = {} # Needed to stop garbage collection
def index(self, row, column, parent):
if not self.hasIndex(row, column, parent):
return QtCore.QModelIndex()
if parent.isValid():
index_pointer = parent.internalPointer()
parent_dict = self.root[index_pointer]
else:
parent_dict = self.root
index_pointer = ()
row_key = list(parent_dict.keys())[row]
child_pointer = (*index_pointer, row_key)
try:
child_pointer = self.my_index[child_pointer]
except KeyError:
self.my_index[child_pointer] = child_pointer
index = self.createIndex(row, column, child_pointer)
return index
def get_row(self, key):
if key:
parent = key[:-1]
if not parent:
return 0
return list(self.root[parent].keys()).index(key[-1])
else:
return 0
def parent(self, index):
if not index.isValid():
return QtCore.QModelIndex()
child_key_list = index.internalPointer()
if child_key_list:
parent_key_list = child_key_list[:-1]
try:
parent_key_list = self.my_index[parent_key_list]
except KeyError:
self.my_index[parent_key_list] = parent_key_list
return self.createIndex(self.get_row(parent_key_list), 0,
parent_key_list)
else:
return QtCore.QModelIndex()
def rowCount(self, parent):
if parent.column() > 0:
return 0 # only keys have children, not values
if parent.isValid():
indexPtr = parent.internalPointer()
parentValue = self.root[indexPtr]
if isinstance(parentValue, OrderedDict):
return len(self.root[indexPtr])
else:
return 0
else:
return len(self.root)
def columnCount(self, parent):
return 2 # Key & value
def data(self, index, role):
if not index.isValid():
return None
if role in (QtCore.Qt.DisplayRole, QtCore.Qt.EditRole):
indexPtr = index.internalPointer()
if index.column() == 1: # Column 1, send the value
return self.root[indexPtr]
else: # Column 0, send the key
if indexPtr:
return indexPtr[-1]
else:
return None
else: # Not display or Edit
return None
def setData(self, index, value, role):
pointer = self.my_index[index.internalPointer()]
self.root[pointer] = value
self.dataChanged.emit(index, index)
return True
def flags(self, index):
if not index.isValid():
return 0
return Qt.ItemIsEnabled | Qt.ItemIsSelectable | Qt.ItemIsEditable
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
data = TupleKeyedOrderedDict(**{'1': OrderedDict({'sub': 'b'}), '2': OrderedDict({'subsub': '3'})})
model = SettingsModel(data)
tree_view = QtWidgets.QTreeView()
tree_view.setModel(model)
tree_view.show()
sys.exit(app.exec_())
You keep a list of indexes to prevent them being garbage collected. This is needed because, as the documentation explains, the Python object referenced by the internalPointer of a QModelIndex is not protected from garbage collection by that reference. However, your list is added to every time your Model is asked for an index so a new internalPointer is created even for the same Item in the Model. Whereas Qt expects the index and therefore the internalPointer to be the same. This is also problematic since it means the indexes list just keeps growing (as you can see if you add a debug print printing out the contents of self.myIndexes).
This is not trivial to fix in your case. In most models, the internalPointer just stores a pointer to the parent item which is therefore never duplicated. But that won't work in your case because items in the PropertyList don't know their parent. The easiest solution might be to change that, but the PropertyList shouldn't really be affected by its use in the Qt model.
Instead, I have built a dict which is used to find an "original" key list for any key list you build. This looks a bit odd but it works and fixes your code with the fewest changes. I have mentioned some alternative approaches at the bottom.
So these are my changes (really just the lines changing self.myIndexes but also changing the key list to be a tuple rather than a list so it can be hashed):
def __init__(self, propList, *args, **kwargs):
QAbstractItemModel.__init__(self, *args, **kwargs)
self.propertyList = propList
self.myIndexes = {} # Needed to stop garbage collection
def index(self, row, column, parent):
"""Returns QModelIndex to row, column in parent (QModelIndex)"""
if not self.hasIndex(row, column, parent):
return QModelIndex()
if parent.isValid():
indexPtr = parent.internalPointer()
parentDict = self.propertyList[indexPtr]
else:
parentDict = self.propertyList
indexPtr = ()
rowKey = list(parentDict.keys())[row]
childPtr = indexPtr+(rowKey,)
try:
childPtr = self.myIndexes[childPtr]
except KeyError:
self.myIndexes[childPtr] = childPtr
newIndex = self.createIndex(row, column, childPtr)
return newIndex
def parent(self, index):
"""
Returns the parent (QModelIndex) of the given item (QModelIndex)
Top level returns QModelIndex()
"""
if not index.isValid():
return QModelIndex()
childKeylist = index.internalPointer()
if childKeylist:
parentKeylist = childKeylist[:-1]
try:
parentKeylist = self.myIndexes[parentKeylist]
except KeyError:
self.myIndexes[parentKeylist] = parentKeylist
return self.createIndex(self.get_row(parentKeylist), 0,
parentKeylist)
else:
return QModelIndex()
This seems to work, though I've not done too much testing.
Alternatively you could use the internalPointer to store the parent model item (dictionary) and keep a mapping from model item to key list. Or a mapping from model item to parent item. Both of these need a little fiddling (not least because dictionaries are not immediately hashable) but both are possible.
Here is a code I ended up after two days of TreeView/Model madness. The subject appeared to be much more broad than I thought. I barely can spend so much time creating a singe widget. Anyway. The drag-and-drop functionality of TreeView items has been enabled. But other than few interesting printout there is not much there. The double click on an item allows the user to enter a new item name which won't be picked up.
EDITED A DAY LATER WITH A REVISED CODE.
It is now by 90% functional tool.
The user can manipulate the TreeView items by drag and dropping, creating/duplicating/deleting and renaming. The TreeView items are representing the directories or folders in hierarchical fashion before they are created on a drive by hitting 'Print' button (instead of os.makedirs() the tool still simply prints each directory as a string.
I would say I am pretty happy with the result. Thanks to hackyday and to everyone who responded and helped with my questions.
A few last wishes...
A wish number 01:
I wish the PrintOut() method would use a more elegant smarter function to loop through the TreeView items to build a dictionary that is being passed to make_dirs_from_dict() method.
A wish number 02:
I wish deleting the items would be more stable. By some unknown reason a tool crashes on third/fourth Delete button clicks. So far, I was unable to trace the problem down.
A wish number 03:
3. I wish everyone the best and thanks for your help :
import sys, os
from PyQt4 import QtGui, QtCore
from PyQt4.QtGui import *
from PyQt4.QtCore import *
from copy import deepcopy
import cPickle
class TreeItem(object):
def __init__(self, name, parent=None):
self.name = QtCore.QString(name)
self.parent = parent
self.children = []
self.setParent(parent)
def setParent(self, parent):
if parent != None:
self.parent = parent
self.parent.appendChild(self)
else: self.parent = None
def appendChild(self, child):
self.children.append(child)
def childAtRow(self, row):
if len(self.children)>row:
return self.children[row]
def rowOfChild(self, child):
for i, item in enumerate(self.children):
if item == child: return i
return -1
def removeChild(self, row):
value = self.children[row]
self.children.remove(value)
return True
def __len__(self):
return len(self.children)
class TreeModel(QtCore.QAbstractItemModel):
def __init__(self):
QtCore.QAbstractItemModel.__init__(self)
self.columns = 1
self.clickedItem=None
self.root = TreeItem('root', None)
levelA = TreeItem('levelA', self.root)
levelB = TreeItem('levelB', levelA)
levelC1 = TreeItem('levelC1', levelB)
levelC2 = TreeItem('levelC2', levelB)
levelC3 = TreeItem('levelC3', levelB)
levelD = TreeItem('levelD', levelC3)
levelE = TreeItem('levelE', levelD)
levelF = TreeItem('levelF', levelE)
def nodeFromIndex(self, index):
return index.internalPointer() if index.isValid() else self.root
def index(self, row, column, parent):
node = self.nodeFromIndex(parent)
return self.createIndex(row, column, node.childAtRow(row))
def parent(self, child):
# print '\n parent(child)', child # PyQt4.QtCore.QModelIndex
if not child.isValid(): return QModelIndex()
node = self.nodeFromIndex(child)
if node is None: return QModelIndex()
parent = node.parent
if parent is None: return QModelIndex()
grandparent = parent.parent
if grandparent==None: return QModelIndex()
row = grandparent.rowOfChild(parent)
assert row != - 1
return self.createIndex(row, 0, parent)
def rowCount(self, parent):
node = self.nodeFromIndex(parent)
if node is None: return 0
return len(node)
def columnCount(self, parent):
return self.columns
def data(self, index, role):
if role == Qt.DecorationRole:
return QVariant()
if role == Qt.TextAlignmentRole:
return QVariant(int(Qt.AlignTop | Qt.AlignLeft))
if role != Qt.DisplayRole:
return QVariant()
node = self.nodeFromIndex(index)
if index.column() == 0:
return QVariant(node.name)
elif index.column() == 1:
return QVariant(node.state)
elif index.column() == 2:
return QVariant(node.description)
else: return QVariant()
def supportedDropActions(self):
return Qt.CopyAction | Qt.MoveAction
def flags(self, index):
defaultFlags = QAbstractItemModel.flags(self, index)
if index.isValid(): return Qt.ItemIsEditable | Qt.ItemIsDragEnabled | Qt.ItemIsDropEnabled | defaultFlags
else: return Qt.ItemIsDropEnabled | defaultFlags
def setData(self, index, value, role):
if role == Qt.EditRole:
if value.toString() and len(value.toString())>0:
self.nodeFromIndex(index).name = value.toString()
self.dataChanged.emit(index, index)
return True
def mimeTypes(self):
return ['bstream', 'text/xml']
def mimeData(self, indexes):
mimedata = QtCore.QMimeData()
bstream = cPickle.dumps(self.nodeFromIndex(indexes[0]))
mimedata.setData('bstream', bstream)
return mimedata
def dropMimeData(self, mimedata, action, row, column, parentIndex):
if action == Qt.IgnoreAction: return True
droppedNode=cPickle.loads(str(mimedata.data('bstream')))
droppedIndex = self.createIndex(row, column, droppedNode)
parentNode = self.nodeFromIndex(parentIndex)
newNode = deepcopy(droppedNode)
newNode.setParent(parentNode)
self.insertRow(len(parentNode)-1, parentIndex)
self.emit(SIGNAL("dataChanged(QModelIndex,QModelIndex)"), parentIndex, parentIndex)
return True
def insertRow(self, row, parent):
return self.insertRows(row, 1, parent)
def insertRows(self, row, count, parent):
self.beginInsertRows(parent, row, (row + (count - 1)))
self.endInsertRows()
return True
def removeRow(self, row, parentIndex):
return self.removeRows(row, 1, parentIndex)
def removeRows(self, row, count, parentIndex):
self.beginRemoveRows(parentIndex, row, row)
node = self.nodeFromIndex(parentIndex)
node.removeChild(row)
self.endRemoveRows()
return True
class GUI(QtGui.QDialog):
def build(self, myWindow):
myWindow.resize(600, 400)
self.myWidget = QWidget(myWindow)
self.boxLayout = QtGui.QVBoxLayout(self.myWidget)
self.treeView = QtGui.QTreeView()
self.treeModel = TreeModel()
self.treeView.setModel(self.treeModel)
self.treeView.expandAll()
self.treeView.setDragDropMode(QtGui.QAbstractItemView.InternalMove)
self.treeView.connect(self.treeView.model(), SIGNAL("dataChanged(QModelIndex,QModelIndex)"), self.onDataChanged)
QtCore.QObject.connect(self.treeView, QtCore.SIGNAL("clicked (QModelIndex)"), self.treeItemClicked)
self.boxLayout.addWidget(self.treeView)
self.PrintButton= QtGui.QPushButton("Print")
self.PrintButton.clicked.connect(self.PrintOut)
self.boxLayout.addWidget(self.PrintButton)
self.DeleteButton= QtGui.QPushButton("Delete")
self.DeleteButton.clicked.connect(self.DeleteLevel)
self.boxLayout.addWidget(self.DeleteButton)
self.insertButton= QtGui.QPushButton("Insert")
self.insertButton.clicked.connect(self.insertLevel)
self.boxLayout.addWidget(self.insertButton)
self.duplicateButton= QtGui.QPushButton("Duplicate")
self.duplicateButton.clicked.connect(self.duplicateLevel)
self.boxLayout.addWidget(self.duplicateButton)
myWindow.setCentralWidget(self.myWidget)
def make_dirs_from_dict(self, dirDict, current_dir='/'):
for key, val in dirDict.items():
#os.mkdir(os.path.join(current_dir, key))
print "\t\t Creating directory: ", os.path.join(current_dir, key)
if type(val) == dict:
self.make_dirs_from_dict(val, os.path.join(current_dir, key))
def PrintOut(self):
result_dict = {}
for a1 in self.treeView.model().root.children:
result_dict[str(a1.name)]={}
for a2 in a1.children:
result_dict[str(a1.name)][str(a2.name)]={}
for a3 in a2.children:
result_dict[str(a1.name)][str(a2.name)][str(a3.name)]={}
for a4 in a3.children:
result_dict[ str(a1.name)][str(a2.name)][str(a3.name)][str(a4.name)]={}
for a5 in a4.children:
result_dict[ str(a1.name)][str(a2.name)][str(a3.name)][str(a4.name)][str(a5.name)]={}
for a6 in a5.children:
result_dict[str(a1.name)][str(a2.name)][str(a3.name)][str(a4.name)][str(a5.name)][str(a6.name)]={}
for a7 in a6.children:
result_dict[str(a1.name)][str(a2.name)][str(a3.name)][str(a4.name)][str(a5.name)][str(a6.name)][str(a7.name)]={}
self.make_dirs_from_dict(result_dict)
def DeleteLevel(self):
if len(self.treeView.selectedIndexes())==0: return
currentIndex = self.treeView.selectedIndexes()[0]
currentRow=currentIndex.row()
currentColumn=currentIndex.column()
currentNode = currentIndex.internalPointer()
parentNode = currentNode.parent
parentIndex = self.treeView.model().createIndex(currentRow, currentColumn, parentNode)
print '\n\t\t\t CurrentNode:', currentNode.name, ', ParentNode:', currentNode.parent.name, ', currentColumn:', currentColumn, ', currentRow:', currentRow
# self.treeView.model().removeRow(len(parentNode)-1, parentIndex)
self.treeView.model().removeRows(currentRow, 1, parentIndex )
#self.treeView.model().removeRow(len(parentNode), parentIndex)
#self.treeView.model().emit(SIGNAL("dataChanged(QModelIndex,QModelIndex)"), parentIndex, parentIndex)
def insertLevel(self):
if len(self.treeView.selectedIndexes())==0: return
currentIndex = self.treeView.selectedIndexes()[0]
currentNode = currentIndex.internalPointer()
newItem = TreeItem('Brand New', currentNode)
self.treeView.model().insertRow(len(currentNode)-1, currentIndex)
self.treeView.model().emit(SIGNAL("dataChanged(QModelIndex,QModelIndex)"), currentIndex, currentIndex)
def duplicateLevel(self):
if len(self.treeView.selectedIndexes())==0: return
currentIndex = self.treeView.selectedIndexes()[0]
currentRow=currentIndex.row()
currentColumn=currentIndex.column()
currentNode=currentIndex.internalPointer()
parentNode=currentNode.parent
parentIndex=self.treeView.model().createIndex(currentRow, currentColumn, parentNode)
parentRow=parentIndex.row()
parentColumn=parentIndex.column()
newNode = deepcopy(currentNode)
newNode.setParent(parentNode)
self.treeView.model().insertRow(len(parentNode)-1, parentIndex)
self.treeView.model().emit(SIGNAL("dataChanged(QModelIndex,QModelIndex)"), parentIndex, parentIndex)
print '\n\t\t\t CurrentNode:', currentNode.name, ', ParentNode:', parentNode.name, ', currentColumn:', currentColumn, ', currentRow:', currentRow, ', parentColumn:', parentColumn, ', parentRow:', parentRow
self.treeView.update()
self.treeView.expandAll()
def treeItemClicked(self, index):
print "\n clicked item ----------->", index.internalPointer().name
def onDataChanged(self, indexA, indexB):
print "\n onDataChanged NEVER TRIGGERED! ####################### \n ", index.internalPointer().name
self.treeView.update(indexA)
self.treeView.expandAll()
self.treeView.expanded()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
myWindow = QMainWindow()
myGui = GUI()
myGui.build(myWindow)
myWindow.show()
sys.exit(app.exec_())
I am not totally sure what you are trying to achieve, but it sounds like you want to retrieve the dragged item in the drop operation, and have double click save a new node name.
Firstly, you need to save the dragged item into the mimeData. Currently, you are only saving the string 'mimeData', which doesn't tell you much. The mimeType string that it is saved as (here I used 'bstream') can actually be anything. As long as it matches what you use to retrieve the data, and is in the list returned by the mimeTypes method of the model. To pass the object itself, you must first serialize it (you can convert your object to xml alternatively, if that was something you are planning on doing), since it is not a standard type for mime data.
In order for the data you enter to be saved you must re-implement the setData method of the model and define behaviour for EditRole.
The relevant methods:
def setData(self, index, value, role):
if role == Qt.EditRole:
self.nodeFromIndex(index).name = value
self.dataChanged.emit(index, index)
return True
def mimeTypes(self):
return ['bstream', 'text/xml']
def mimeData(self, indexes):
mimedata = QtCore.QMimeData()
# assuming single dragged item ...
# only pass the node name
# mimedata.setData('text/xml', str(self.nodeFromIndex(indexes[0]).name))
# pass the entire object
bstream = cPickle.dumps(self.nodeFromIndex(indexes[0]))
mimedata.setData('bstream', bstream)
return mimedata
def dropMimeData(self, mimedata, action, row, column, parentIndex):
if action == Qt.IgnoreAction: return True
parentNode = self.nodeFromIndex(parentIndex)
# data = mimedata.data('text/xml')
data = cPickle.loads(str(mimedata.data('bstream')))
print '\n\t incoming row number:', row, ', incoming column:', column, \
', action:', action, ' mimedata: ', data.name
print "\n\t Item's name on which drop occurred: ", parentNode.name, \
', number of its childred:', len(parentNode.children)
if len(parentNode.children)>0: print '\n\t zero indexed child:', parentNode.children[0].name
return True
EDIT:
That is a lot of code you updated, but I will oblige on the points you highlighted. Avoid calling createIndex outside of the model class. This is a protected method in Qt; Python doesn't enforce private/protected variables or methods, but when using a library from another language that does, I try to respect the intended organization of the classes, and access to them.
The purpose of the model is to provide an interface to your data. You should access it using the index, data, parent etc. public functions of the model. To get the parent of a given index, use that index's (or the model's) parent function, which will also return a QModelIndex. This way, you don't have to go through (or indeed know about) the internal structure of the data. This is what I did in the deleteLevel method.
From the qt docs:
To ensure that the representation of the data is kept separate from the way it is accessed, the concept of a model index is introduced. Each piece of information that can be obtained via a model is represented by a model index... only the model needs to know how to obtain data, and the type of data managed by the model can be defined fairly generally.
Also, you can use recursion to simplify the print method.
def printOut(self):
result_dict = dictify(self.treeView.model().root)
self.make_dirs_from_dict(result_dict)
def deleteLevel(self):
if len(self.treeView.selectedIndexes()) == 0:
return
currentIndex = self.treeView.selectedIndexes()[0]
self.treeView.model().removeRow(currentIndex.row(), currentIndex.parent())
I had this separate from class
def dictify(node):
kids = {}
for child in node.children:
kids.update(dictify(child))
return {str(node.name): kids}