Single QTreeWidgetItem instance on multiple QTreeWidget?

Question

I'm trying to show a single QTreeWidgetItem instance on 2 QTreeWidgets, which ends up the item shown only on the 1st tree without being notified. I haven't seen its API doc talks about a limitation if any. Is there a way to workaround?

#!/usr/bin/python
import os
import sys  

from PySide.QtCore import QFile
from PySide.QtUiTools import QUiLoader
from PySide.QtGui import QApplication, QTreeWidget, QTreeWidgetItem, QWidget

class MyTreeWidgetItem(QTreeWidgetItem):
    def __init__(self, *args):  
       super(MyTreeWidgetItem, self).__init__()

class MyWidget(QWidget):
    def __init__(self, *args):  
       super(MyWidget, self).__init__()

       loader = QUiLoader()
       file = QFile('./src/prove_qtreewidget/qtree_mainwidget.ui') 
       file.open(QFile.ReadOnly)
       self.widget_ui = loader.load(file, self)
       file.close()

       item1 = MyTreeWidgetItem(self)
       item1.setText(0, 'Item 1')

       _tw1 = self.widget_ui.findChild(QTreeWidget, '_tree_widget_1')
       _tw2 = self.widget_ui.findChild(QTreeWidget, '_tree_widget_2')
       _tw1.addTopLevelItem(item1)
       _tw2.addTopLevelItem(item1)

if __name__ == '__main__':  
   print("Running in " + os.getcwd() + " .\n")    
   app = QApplication(sys.argv)      
   win = MyWidget()  
   win.show()    
   app.exec_()

.ui file above is available here.

Using Qt 4.8, Ubuntu 12.04

I haven't tried PyQt binding but I just assume shouldn't be any different w/o proof.

No. A `QTreeWidgetItem` can belong to only one `QTreeWidget`. What are you trying to do? — Avaris, Dec 19 '12 at 20:15
I appreciate if you could share a documentation if any about the limit. I'm trying to show a data that I already implemented with QTreeWidgetItem in multiple different trees for different purpose. I know QTreeView fits more for this purpose but I've already implemented non-trivial amount of code.. — IsaacS, Dec 19 '12 at 20:23
It doesn't say that explicitly (or I couldn't find it) but if you were to add it to multiple tree widgets, `item.treeWidget()` would be undefined. You're right, model/view is more appropriate if you want to share same model between views. If not, all you can do is add a copy of your item. `item_copy = QTreeWidgetItem(item)` will do that for you. If you have custom items, you can implement a `copy` method that uses this underneath. — Avaris, Dec 19 '12 at 22:48
That being said, I'd really suggest that you convert to `QTreeView`. It might be time consuming to convert your current code base, but if you are going to do anything non-trivial it would possibly be better in the long-run. — Avaris, Dec 19 '12 at 22:54

score 0 · Answer 1 · answered Dec 21 '12 at 15:02

0

What you need is a model and a QTreeView, that's for what they are for:

Model/View Programming: Widgets do not maintain internal data containers. They access external data through a standardized interface and therefore avoid data duplication.

answered Dec 21 '12 at 15:02

As in the comment area of the original question, I know Qt's MVC implementation but don't want to use it for this particular purpose. – IsaacS Dec 25 '12 at 19:40

Single QTreeWidgetItem instance on multiple QTreeWidget?

1 Answers1