QComboBox and QTreeView

[Carlsberg]

I'm trying to use a QTreeView as a view for a QComboBox.

I've done something like this:

TreeView m_view = new TreeView(this);
 
QComboBox* m_combo = new QComboBox(this);
m_combo->setModel(m_view->getModel());
m_combo->setView(m_view);
 
QStandardItem* item1 = new QStandardItem("One");
QStandardItem* item2 = new QStandardItem("Two");
QStandardItem* item3 = new QStandardItem("Three);
QStandardItem* item4 = new QStandardItem("Four");
 
m_view->getModel()->appendRow(item1);
item1->appendRow(item2);
m_view->getModel()->appendRow(item3);
m_view->getModel()->appendRow(item4);

TreeView m_view = new TreeView(this);

QComboBox* m_combo = new QComboBox(this);
m_combo->setModel(m_view->getModel());
m_combo->setView(m_view);

QStandardItem* item1 = new QStandardItem("One");
QStandardItem* item2 = new QStandardItem("Two");
QStandardItem* item3 = new QStandardItem("Three);
QStandardItem* item4 = new QStandardItem("Four");

m_view->getModel()->appendRow(item1);
item1->appendRow(item2);
m_view->getModel()->appendRow(item3);
m_view->getModel()->appendRow(item4);

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My questions are:

1) Am I doing the right thing there?

2) How can I select an item from the list?

3) How can I know when an item has been selected?

For 2) and 3) I tried several things but failed

For example if the QTreeView is not set as a view for the combo box, I can use the signal clicked(), but this is not working with the view set on the combo box. If I use the combo's currentIndexChanged() signal, selecting item 2 will return index 0, because item 2 is a child of item 1 at index 0. I'm really confused about this model/view thing

[nish]

first set a model to treeview
treeview->setModel(new QStandardItemModel()).

secondly i dont know wether tree view is a good choice (or even work) for comboboxes...

[Carlsberg]

Thanks for the answer. I did set the model for tree view, my class TreeView is an extension of QTreeView

What I'm trying to achieve is a combo box like the one in the Windows Explorer file dialog, like:

Image - Desktop
	Image - My Documents
	Image - My Computer
		Image - C:
		Image - D:
			Image - Folder

Image - Desktop
	Image - My Documents
	Image - My Computer
		Image - C:
		Image - D:
			Image - Folder

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[nikhilqt]

If i have understood your question right, then why cannot you use QDirView to show like windows explorer.

[Carlsberg]

If you mean QDirModel, that is because i want to include those Windows "special folders", like "Desktop" and also I want to put in the volume names, because only C, D, E, F, G, H, I, J, M, R etc look weird and not so clear

It's really not important what is in the tree, it's just I don't really manage to get it work

[faldzip]

If you mean QDirModel, that is because i want to include those Windows "special folders", like "Desktop" and also I want to put in the volume names, because only C, D, E, F, G, H, I, J, M, R etc look weird and not so clear

I'm not sure but QFileSystemModel can be better in your case.

It's really not important what is in the tree, it's just I don't really manage to get it work

Here it is (screenshot attached):

//prepare model
	QStandardItemModel *model = new QStandardItemModel(ui->comboBox);
	QStandardItem *item = new QStandardItem("item1");
	model->appendRow(item);
	item->appendRow(new QStandardItem("item2"));
	item = new QStandardItem("item3");
	model->appendRow(item);
	item->appendRow(new QStandardItem("item4"));
	item = item->child(0,0);
	item->appendRow(new QStandardItem("item5"));
 
	// or
	QFileSystemModel *fsmodel = new QFileSystemModel(this);
	fsmodel->setRootPath("/");
 
	// set view
	QTreeView *tv = new QTreeView(ui->comboBox);
	ui->comboBox->setView(tv);
 
 
	// set model
//	ui->comboBox->setModel(model);
	ui->comboBox->setModel(fsmodel);

//prepare model
	QStandardItemModel *model = new QStandardItemModel(ui->comboBox);
	QStandardItem *item = new QStandardItem("item1");
	model->appendRow(item);
	item->appendRow(new QStandardItem("item2"));
	item = new QStandardItem("item3");
	model->appendRow(item);
	item->appendRow(new QStandardItem("item4"));
	item = item->child(0,0);
	item->appendRow(new QStandardItem("item5"));

	// or
	QFileSystemModel *fsmodel = new QFileSystemModel(this);
	fsmodel->setRootPath("/");

	// set view
	QTreeView *tv = new QTreeView(ui->comboBox);
	ui->comboBox->setView(tv);


	// set model
//	ui->comboBox->setModel(model);
	ui->comboBox->setModel(fsmodel);

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The only problem is that expanding treeview closes the popup.

For example if the QTreeView is not set as a view for the combo box, I can use the signal clicked(), but this is not working with the view set on the combo box. If I use the combo's currentIndexChanged() signal, selecting item 2 will return index 0, because item 2 is a child of item 1 at index 0. I'm really confused about this model/view thing

You can use QComboBox::currentText() to get currently selected text or maybe use QItemSelectionModel::currentChanged() from:

comboBox->view()->selectionModel()

comboBox->view()->selectionModel()

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(didn't try this).

[Carlsberg]

Could't make it work, now I'm doing something else with a QTreeWidget

I have a question regarding the cursor appearance. How can I make it span only the text width (like in the picture above), not the whole line width?

[Batox]

I just spent two days trying to find a simple way to get a tree into the combobox popup, and here's the solution I finally came up with. I'm putting these few lines of code here so they may help others

#include <QtGui>
 
int main(int argc, char *argv[]) {
  QApplication app(argc, argv);
  QComboBox combo;
 
  combo.setView(new QTreeView(&combo));
  combo.setModel(new QStandardItemModel(&combo));
 
  // when adding children use a QStandardItem pointer to the parent
  QStandardItem *item = new QStandardItem("Toplevel1");
  item->setSelectable(false);  // make partents of subtrees not selectable
  ((QStandardItemModel*)combo.model())->appendRow(item);
  item->appendRow(new QStandardItem("Child1"));
  item->appendRow(new QStandardItem("Child2"));
 
  // with no children the standard QComboBox method can be used
  combo.addItem("Toplevel2");
  combo.show();
 
  return app.exec();
}

#include <QtGui>

int main(int argc, char *argv[]) {
  QApplication app(argc, argv);
  QComboBox combo;

  combo.setView(new QTreeView(&combo));
  combo.setModel(new QStandardItemModel(&combo));

  // when adding children use a QStandardItem pointer to the parent
  QStandardItem *item = new QStandardItem("Toplevel1");
  item->setSelectable(false);  // make partents of subtrees not selectable
  ((QStandardItemModel*)combo.model())->appendRow(item);
  item->appendRow(new QStandardItem("Child1"));
  item->appendRow(new QStandardItem("Child2"));

  // with no children the standard QComboBox method can be used
  combo.addItem("Toplevel2");
  combo.show();

  return app.exec();
}

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