Hierarchial QTreeView mapping with QStackedWidget - c++

Question

I am creating a UI with QTreeView representing list of items(which may or may not have children) and displaying corresponding widget on right side using QStackedWidget. Previously the behaviour of my data or the list of items mentioned above was flat, hence I was using QListView but when the data had to have children I replaced the QListView with QTreeView so I can add children as well. I have achieved the above in the following manner:
for(std::vector<AWidget* >::iterator it=widgets.begin(); it!=widgets.end(); ++it)
{
AWidget* w = *it;
QStandardItem *parent = new QStandardItem(w->Name());
model->setItem(i, 0, parent);
QWidget *PageWidget = w->getWidget();
QScrollArea * pScrollArea = new QScrollArea();
pScrollArea->setWidget(PageWidget);
m_ui.AStackedWidget->addWidget(pScrollArea);
if(!w->hasChildren())
{
std::vector<AWidget*> children = w->getChildren();
for(std::vector<AWidget*>::iterator iChild=children.begin(); iChild!=children.end(); ++iChild)
{
AWidget* childWidget = *iChild;
QStandardItem *child = new QStandardItem(childWidget->Name());
parent->appendRow(child);
QWidget *childPageWidget = childWidget->getWidget();
QScrollArea * pChildScrollArea = new QScrollArea();
pChildScrollArea->setWidget(childPageWidget);
pChildScrollArea->setWidgetResizable(true);
m_ui.AStackedWidget->addWidget(pChildScrollArea);
}
}
i++;
}
m_ui.ATreeView->setEditTriggers(QAbstractItemView::NoEditTriggers);
m_ui.ATreeView->setTabKeyNavigation(true);
m_ui.ATreeView->setModel(model);
QModelIndex index = m_ui.ATreeView->model()->index(0,0);
QItemSelectionModel * selModel = m_ui.ATreeView->selectionModel();
if(selModel)
{
connect(selModel, SIGNAL( currentChanged(const QModelIndex &, const QModelIndex &) ), this , SLOT(slotOptionSelectedForChangeUI(const QModelIndex & )) );
selModel->select(index,QItemSelectionModel::Select);
}
slotOptionSelectedForChangeUI(index);
Definition of slotOptionSelectedForChangeUI() is as follows:
void slotOptionSelectedForChangeUI(const QModelIndex & indx)
{
int rowNum = indx.row();
if(m_ui.AStackedWidget)
m_ui.AStackedWidget->setCurrentIndex(rowNum);
}
For eg: following is the view:
-A -> widget1
-B -> widget2
-C -> widget3
-D -> widget4
-E -> widget5
-E1 -> widget6
-E2 -> widget7
-E3 -> widget8
-E4 -> widget9
-E5 -> widget10
-E6 -> widget11
- E7 -> widget12
A,B,C,D,E show correct corresponding widgets on the right side in the QStackedWidget. However E1, E2, E3, E4,E5,E6,E7 show widgets widget1,2,3,4,5,6,7 respectively. This means index of E1 starts again from 0 and stacked widget shows widget0 for index 0 and so on. How should E1-E7 be mapped with widget6-12 so that proper widgets are displayed on the right side stacked widget?

Answer 1

The proper way of doing this is by not using a QStackedWidget, but only displaying one. To do this, all you have to do is:
Add the widget to the item using QStandardItem::setData
In the ui, instead of a QStackedWidget, just use a simple QWidget (with a horizontal/vertical layout without margins)
Connect the selection model index changed signal to a slot that removes all children from the simple widget, and adds the one stored with the item. You can retrieve it by using the QStandardItem::data function (or the models data function)
Here a minimal example of those steps:
#define MyRole Qt::UserRole + 42
//...
//adding the item
AWidget* w = *it;
QStandardItem *parent = new QStandardItem(w->Name());
parent->setData(QVariant::fromValue(w), MyRole);
model->setItem(i, 0, parent);
//...
//the index changed slot
void slotOptionSelectedForChangeUI(const QModelIndex & indx)
{
AWidget *w = model->data(index, MyRole).value<AWidget*>();//will internally call QStandardItem::data
//remove old children
QList<QWidget*> children = m_ui.containerWidget->findChildren<QWidget*>(QString(), Qt::FindDirectChildrenOnly);
foreach(QWidget *child, children)
child->deleteLater();
//add the new one
QWidget *PageWidget = w->getWidget();
ScrollArea * pScrollArea = new QScrollArea(m_ui.containerWidget);
pScrollArea->setWidget(PageWidget);
m_ui.containerWidget->layout()->addWidget(pScrollArea);
}