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Leviathan
24th July 2010, 14:55
Hi. How can I remove a list of selected items in the QListView in QT 4.6.?
Something like this does not work, the iterator becomes invalid:


QModelIndexList indexes = ui.listview_files->selectionModel()->selectedIndexes();
foreach(QModelIndex index, indexes)
{
model->removeRow(index.row());
}

removeRows also not suitable, it removes N-items that follows the one given.
I use QStandardItemModel to store items.

Lykurg
24th July 2010, 17:11
Something like that should work. (Idea: sort the list and begin at the end to ensure that the indices stay valid):
YOURVIEW->setUpdatesEnabled(false);
QModelIndexList indexes = ui.listview_files->selectionModel()->selectedIndexes();
indexes.sort();
for (i = indexes.count() - 1; i > -1; --i)
model->removeRow(indexes.at(i).row());
YOURVIEW->setUpdatesEnabled(true);

Leviathan
25th July 2010, 08:12
Here's the solution:

QModelIndexList indexes = ui.listview_files->selectionModel()->selectedIndexes();
while(indexes.size()) {
model->removeRow(indexes.first().row());
indexes = ui.listview_files->selectionModel()->selectedIndexes();

wysota
25th July 2010, 11:51
There is useless overhead here. Lykurg's solution is much better. And provided the list is already sorted, you can simply start removing items from the end.

saa7_go
26th July 2010, 06:02
Okay, i tried Lykurg's code. But, there is build issues informed by Qt Creator.


O:/Qt/DeleteSelectedItemInListView/form.cpp:53: error: 'class QModelIndexList' has no member named 'sort'

Then, i looked at Qt Assistant, especially in QList Class Reference. There is no sort() function.
But, i found qSort() function when searching for keyword sort.

Then, I modified Lykurg's code like following.


ui->listView->setUpdatesEnabled(false);
QModelIndexList indexes = ui->listView->selectionModel()->selectedIndexes();
qSort(indexes.begin(), indexes.end());

for(int i = indexes.count() - 1; i > -1; --i)
model->removeRow(indexes.at(i).row());

ui->listView->setUpdatesEnabled(true);

And that is work. Thanks for your sugesstion, wysota.

wysota
26th July 2010, 09:52
Check if you have to sort the list at all. As far as I remember it is already sorted and sorting a sorted list is an expensive operation.

Lykurg
26th July 2010, 10:26
Since I also wasn't sure, I've looked up and found:
QModelIndexList QItemSelectionModel::selectedIndexes () const

Returns a list of all selected model item indexes. The list contains no duplicates, and is not sorted. So you have to sort the list.

Bloody
13th September 2012, 13:10
Hello Guys,

I just had the same question, thanks for resolving!
But there is something more I'm interested in:

I want to connect the "removing"-thing with a button. How does this work?

wysota
13th September 2012, 14:18
What is the "removing-thing"?

Bloody
14th September 2012, 09:24
ui->listView->setUpdatesEnabled(false);
QModelIndexList indexes = ui->listView->selectionModel()->selectedIndexes();
qSort(indexes.begin(), indexes.end());

for(int i = indexes.count() - 1; i > -1; --i)
model->removeRow(indexes.at(i).row());

ui->listView->setUpdatesEnabled(true);

I ment the way to remove a list of selected items in the QListView.
Now I want to connect this with a button (called "Delete"). If you select the items and press delete-button, they shall be removed with that.

Thanks for beeing interested in my problem! I would be happy to read an idea, not the whole solving please. :)

wysota
14th September 2012, 09:49
So what is the problem? Make a signal-slot connection and put your code in a custom slot of yours.

Bloody
14th September 2012, 09:58
No problem, I actually did this before. :)
But I got my items from a rootpath. So I dont geht the updates "deleted-list", no he always shows me the pathlist.

wysota
14th September 2012, 11:38
But I got my items from a rootpath. So I dont geht the updates "deleted-list", no he always shows me the pathlist.
I don't understand what you mean by that.

Bloody
1st October 2012, 12:29
Sorry, that I could not answer these days. So actually I want help.. ;)

To my problem: I want a listfiew displaying files from a rootpath. 'Till here the top solution is pretty helpful. But the next step I want to go is to delete some selected files but the solution in this thread is not working as I want to.
I select items i want to delete(working well), press the "delete files" button and nothing happens. I guess the problem here is the self-updating listview. Over and above I actually want to build a "copy-program". Therefor you select some files from the listview and press "delete". Then you "save" the rest in a new folder. The system creates a new folder in any path with a copy of the left files in the listfiew.
But back to my update problem: If I press delete, nothing happens... ? And if I create new files in my path, they self-update into the listview. My idea: How to create listviewitems which are actually files able to be deleted out of the listview? How about this idea?

ZikO
2nd October 2012, 04:10
QFileSystemModel provides simple interface to operate on local file system. If you connect this with a List View I think it will sort out your problem.