How to delete all QTreeWidgetItems having the same text as selected QTreeWidgetItem?

[WDR_937]

OK... So, I managed to make the widget remove items only when an item is selected. It does not remove the first tree by default if unselected. I used Resource->isSelected(). However, I am still working on how to remove the tree if the child is selected as this works only for parent. Secondly, this unselected condition works if there a trees existing in the widget. If the widget is empty, the application is crashing. Why is that happening? Here's what I did.

void Widget::on_Delete_Button_clicked()
{
    QTreeWidgetItem* Resource = ui->Usable_Resources_Tree->currentItem();

    if(Resource->isSelected())
    {
        ui->Usable_Resources_Tree->takeTopLevelItem(ui->Usable_Resources_Tree->currentIndex().row());

        ui->Unusable_Resources_Tree->addTopLevelItem(Resource);

        Resource->setExpanded(true);
    }
}

I think the currentItem() is causing the crash. How would I fix this? Please tell me this. Thank you.

EDIT: Fixed it. Thank you. It works perfectly. Although, I still have to figure out the multiple tree removal. However, most of my question has been answered. :-)

[SGaist]

Rather than checking if you have anything selected and thus having a button that might to nothing (which is never a good thing for your users) use the selectionChanged signal and enable/disable the button based on the emptiness of the selection.

For the multiple tree removal, work from your child up to the topLevelItem. I currently haven't seen any option to do it without a loop on parent until you get an item without parent but that one should work.

[WDR_937]

@SGaist

@SGaist said:

Rather than checking if you have anything selected and thus having a button that might to nothing (which is never a good thing for your users) use the selectionChanged signal and enable/disable the button based on the emptiness of the selection.

Yes, that might be the more optimal approach. Although, how would I use the selectionChanged to deselect an item when clicked on empty space?

I already figured out the multiple tree removal problem, but thanks for your solution. It's very similar to what you suggested. I used findItems to return the list of all items containing that string and iterating through that list, I'm checking if the returned item is a child or parent. If it's a parent, I'm removing it directly. If it's a child, I am removing the child's parent. It's working perfectly. However, I believe this could cause anomalies if there are multiple sub children i.e. if the child's parent is not a top level item. Since my program has parents with only one child, I guess it's fine.

Nevertheless, thank you very much for your help, SGaist. I really appreciate it.

[SGaist]

You don't, that signal just tells you that something has changed selection wise. Reaction to a click on an empty space is handled by the widget.

If you have the child deeper than the second level, then yes you would need to go back up to the top level item.

You're welcome !

[WDR_937]

@SGaist Is this the right way of doing it?

connect(ui->Usable_Resource_Tree, SIGNAL(ui->Usable_Resource_Tree->selectionModel()->selectionChanged()), this, SLOT(Disable_Button()));

void Disable_Button()
{
    ui->Delete_Button->setEnabled(false);
}

I haven't tested this. But I'm pretty sure something is definitely not right here. Please tell me whether my code is correct. Thanks.

[SGaist]

No it's not,

connect(ui->Usable_Resource_Tree->selectionModel(), SIGNAL(selectionChanged(QItemSelection,QItemSelection)), this, SLOT(updateDeleteButton(QItemSelection, QItemSelection)));

void updateDeleteButton(const QItemSelection &selected, const QItemSelection &deselected)
{
    ui->Delete_Button->setEnabled(selected.size() > 0);
}

[WDR_937]

@SGaist OK... So, I implemented what you posted here. It's working with selecting the items and is also being deselected when the item is removed. However, the clicking on empty space thing is still not implemented. How should this be implemented? Should I manually check for it or is it done automatically by the signal so that all I should do is just call it?

The deselected variable is not being used, so I set it to Q_UNUSED. Is it needed anywhere? Also, since I am calling this signal/slot, do I need to check for Item->isSelected() later on in my delete button slot? Why I ask this, is because the program crashed earlier before I even implemented Item->isSelected(). That is why I implemented it.

Finally, I am encountering two anomalous behaviors:-

1. The selectionChanged() is deselecting on removing the child items, but for parent items, it is by default selecting the next parent in the widget. How to disable this?

2. Sometimes, instead of graying out and flattening out on disabling, the delete button does not flatten out and becomes blue like it is when highlighted by the mouse. The text, however, grays out. It stays like this until it is enabled. This is only cosmetic as the button is still disabled. But it looks weird. Any way to fix this?

My apologies if I asked too many questions. I just want to solve this tree problem. Please bear with me. Thank you. :-)

[SGaist]

IIRC, you need to reimplement keyPressEvent and call clearSelection in it for that.

Q_UNUSED is the right tool, deselected is not needed in that case.

Since I don't know how you are currently performing the delete I can't comment on that one.

1. Before performing the delete, gather all informations, clear the selection, perform the deletion
2. Haven't seen that one happen

[WDR_937]

@SGaist said:

IIRC, you need to reimplement keyPressEvent and call clearSelection in it for that.

Do you mean QMouseEvent? Because I am clicking on empty space, not pressing any keys. Unless, the keyPressEvent is also used in this case, for which I don't know. Also, how would I know whether I am clicking on empty space or an item? Same selection.size > 0? Please clarify.

@SGaist said:

Since I don't know how you are currently performing the delete I can't comment on that one.

Here's what I'm doing,

QTreeWidgetItem *Resource = From_Tree->currentItem();

if(Resource != NULL)
	{
		if(Resource->isSelected())
		{
			From_Tree->takeTopLevelItem(From_Tree->indexOfTopLevelItem(Resource));
		}
	}

I remember why I implemented the isSelected(). When clicked, the button was removing the first item by default if nothing was selected. Since I am disabling the button completely when nothing is selected, I don't think I'll need this. Correct me if I'm wrong. Thanks.

[SGaist]

mousePressEvent indeed… Use itemAt to see if you have something under the mouse

You should rather user selectedItems

[WDR_937]

@SGaist said:

mousePressEvent indeed… Use itemAt to see if you have something under the mouse

Alright, thanks. I'll look into that. I'll see how it goes. If I hit any roadblock again, I'll ask here.

@SGaist said:

You should rather user selectedItems

Are you talking about the QTreeWidgetItem *Resource = From_Tree->currentItem() part of my code?

[SGaist]

No, selectedItems

[WDR_937]

@SGaist Yeah, I understood what you said. I was asking do you mean that part of my code?

[SGaist]

Ok, then yes, to replace currentItem

[WDR_937]

@SGaist Oh, OK... Then I'll implement that too and see how it goes. Thanks.