I am currently adding rows to my QTableView as such
QStandardItem* itm;
QStandardItemModel* model = new QStandardItemModel(this);
model->setColumnCount(2);
model->appendRow(new QStandardItem("Some Text in Column1");
How do I add items to column 2 dynamically by appending?
In the above example column 2 is empty. How do I add item to column 2?
Calling appendRow(QStandardItem *) only adds a single item to the first column. You would need to pass in a QList to appendRow() to add items to each column, e.g.:
QList<QStandardItem *> items;
items.append(new QStandardItem("Column 1 Text"));
items.append(new QStandardItem("Column 2 Text"));
QStandardItemModel* model = new QStandardItemModel(this);
model->setColumnCount(2);
model->appendRow(items);
See http://doc.qt.io/qt-5/qstandarditemmodel.html#appendRow for more detail.
Related
How can I implement this code I have for a qTreeWidget for a qTreeView?
for (const auto & i : names) {
QTreeWidgetItem * item = new QTreeWidgetItem(ui->treeWidget);
item->setText(0, QString::fromStdString(i));
ui->treeWidget->addTopLevelItem(item);
const std::unordered_map<std::string, double> map = m_reader.getMapFromEntry(i);
for (const auto & j : map) {
QTreeWidgetItem * item2 = new QTreeWidgetItem();
item2->setText(0,QString::fromStdString(j.first));
item2->setText(1,QString::number(j.second));
item->addChild(item2);
}
}
I have a model and a treeView, like this:
m_model = new QStandardItemModel(m_reader.getAllNames().size(),2,this);
ui->treeView->setModel(m_model);
I tried this, but that only shows one column:
QStandardItem * parentItem = m_model->invisibleRootItem();
for (const auto & i : names) {
QStandardItem * item = new QStandardItem(QString::fromStdString(i));
parentItem->appendRow(item);
const std::unordered_map<std::string, double> map = m_reader.getMapFromEntry(i);
for (const auto & j : map) {
QList<QStandardItem *> rowItems;
rowItems << new QStandardItem(QString::fromStdString(j.first));
rowItems << new QStandardItem(QString::number(j.second));
item->appendRow(rowItems);
}
}
With the treeWidget, I had so set the columnCount, like this:
ui->treeWidget->setColumnCount(2);
But treeView does not have a method like this.
So, to summarize: How can I implement a TreeView with more than one column?
EDIT:
To clarify, I want something like this:
|-A
| |-B-C
| |-D-E
where A is the parent and B,C,D,E the children, with B,D being in column 0 and C,E in column 1.
Hope this helps!
To support multiple columns, the model must contain data for multiple columns.
So in some sense, columns are a property of the model, not the view. Views then can decide to hide or rearrange certain columns (For example, a QListView always only shows the first column, while one can hide or reorder columns in a QTableView).
As you use QStandardItemModel, its documentation should give a few hints how to create multiple columns.
E.g., look at this example from the documentation:
QStandardItemModel model(4, 4);
for (int row = 0; row < 4; ++row) {
for (int column = 0; column < 4; ++column) {
QStandardItem *item = new QStandardItem(QString("row %0, column %1").arg(row).arg(column));
model.setItem(row, column, item);
}
}
It creates a model with 4 initial rows and columns each, and then fills it with items via setItem().
Alternatively, you can pass a list of items to QStandardItemModel::appendRow(), with an item for each column:
QList<QStandardItem*> items;
items.append(new QStandardItem(tr("One"));
items.append(new QStandardItem(tr("Two"));
model->appendRow(items);
This adds a new row with "One' in the first column and "Two" in the second. For even more ways to deal with multiple columns, see the QStandardItemModel docs.
Note: QTreeView expects the same number of columns on all levels of the hierarchy, so one should fill rows with empty items for the unused columns if need be.
Just an addition to answer by Frank Osterfeld:
QTreeView displays all columns of subtables inserted into top level QStandardItems. You just have to "force" it to show additional columns by inserting dummy QStandardItems into top-level table. Example:
QStandardItemModel *objectTreeModel = new QStandardItemModel(NULL);
QStandardItem *mainItem = new QStandardItem(tr("Main Item"));
QStandardItem *subItem1 = new QStandardItem(tr("Sub-Item 1"));
QStandardItem *subItem2 = new QStandardItem(tr("Sub-Item 2"));
mainItem->appendRow(QList<QStandardItem *>() << subItem1 << subItem2);
QStandardItem *dummyItem = new QStandardItem();
objectTreeModel->appendRow(QList<QStandardItem *>() << mainItem << dummyItem );
Now you will be able to see 2 columns and if you expand mainItem, both subitems will be visible.
I want to add Qdate to my table say QTableview.The problem is if i convert it into string i can add and retrieve the data.But i want to store as date only in my model.
void MainWindow::setUpTabel()
{
QDateTime myDate;
myDate.setDate(QDate::currentDate());
//myModel
QStandardItemModel model = new QStandardItemModel(this);
QStandardItem *item = new QStandardItem;
item.setData(myDate,Qt::UserRole);
//Myview is also created and set the model to it
m_tableView->setModel(model);
}
The problem is i'm not able to see the date in my table.
As the documentation says, you must set the item into the model specifying the row and columng where you are going to set the item.
http://qt-project.org/doc/qt-4.8/qstandarditemmodel.html
Modifying your code:
void MainWindow::setUpTabel()
{
int row = 0, column = 0; // here you decide where is the item
QDateTime myDate;
myDate.setDate(QDate::currentDate());
QStandardItemModel model = new QStandardItemModel(this);
QStandardItem *item = new QStandardItem(myDate);
model.setItem(row, column, item);
m_tableView->setModel(model);
}
Is there any way to assign a unique key to an entry in a QStandardItemModel so that we can check for the presence of that key. If it is present we get the relevant QstandardItem ?
Update:
Here is what I am trying to do. I have 3 column in my table so so i have 3 QStandardItem.
This is the code I am using:
QStandardItem* item0 = new QStandardItem("Column1");
QStandardItem* item1 = new QStandardItem("Column2");
QStandardItem* item2 = new QStandardItem("Column3");
Now my model is called model and I am attaching these to my model as such
moddel->setItem(0,0,item0);
moddel->setItem(0,1,item1);
moddel->setItem(0,2,item2);
I need to assign a row some unique key so that I could check the model for that key and the model would return the row number. Any suggestions.
You could use the setData function of QStandardItem in order to set a custom key for a user defined role, eg
#define MyRole Qt::UserRole + 2
myItem->setData(Qvariant(key), MyRole)
You can get the data of any index in your model by using the data call.
QVariant d = mymodel->data(anindex, MyRole)
Writing a function that checks if a key exists should be straight forward.
The answer by pnezis addresses the storing of a key but not the accessing of a QStandardItem from the model. I addressed the storing of data with a QStandardItem by sub classing QStandardItem as I needed to store a lot of complex data.
To obtain the QStandardItem from the model you need to create a QModelIndex instance with the row/column and then call itemFromIndex(index)
on the model.
My example is taken from a selection callback.
QModelIndex& selectedItem = itemsSelected.front();
QStandardItemModel* model = reinterpret_cast<QStandardItemModel*>(tableView->model());
if (nullptr == model)
return;
QStandardItem *item = model->itemFromIndex(selectedItem);
if (nullptr == item)
return ;
i like to make my QStandardItemModel that populates items in qtreeview
to append rows on top the allready defined items in the view .
something like the twitter view , new items first.
all i see in the QStandardItemModel is the appendRow/s that appends then to button.
this is what im using now.
SWidget *widget = new SWidget;
QStandardItem *newItem = new QStandardItem;
newItem->setSizeHint( widget->size() );
appendRow( newItem );
view->setIndexWidget( newItem->index(), widget );
void QStandardItemModel::insertRow ( int row, QStandardItem * item ) inserts a row at row containing item. So instead of calling appendRow(newItem); call insertRow(0, newItem);
After reading some examples I am still missing here something.
I have Qtreeview for view and QStandardItemModel for the data interface, also using QSortFilterProxyModel subclass but I don't know if its relevant.
This is my logic:
First I create the model with the QWidget as the parent:
QStandardItemModel m_model = new QStandardItemModel(0,4,parent);
then setSourceModel(m_model) for the widget
Set the treeview with QSortFilterProxyModel. something like this:
GroupProxyModel = new GroupSortFilterProxyModel;
GroupProxyModel->setDynamicSortFilter(true);
setSourceModel(createSubjectModel(parent));
ui.treeView_mainwindow->setModel(GroupProxyModel);
ui.treeView_mainwindow->setSortingEnabled(true);
Then later I fill the first row like this:
QList<QStandardItem *> items;
items.insert(0,new QStandardItem("Test 0"));
items.at(0)->setEditable(false);
m_model->insertRow(0,items);
Until now every thing working fine and I see the row with the data. But when I like to
add child to the row like this:
QModelIndex parentQModelIndex = m_model->item(0,0)->index();
m_model->insertRows(0,1,parentQModelIndex);
m_model->insertColumns(0,1,parentQModelIndex);
QModelIndex indexB = m_model->index(0, 0, parentQModelIndex);
m_model->setData(indexB,"Child test",Qt::DisplayRole);
But I don't see the child, why?
That's not how QStandardItemModel works - to add a child, call appendRow(s)/insertRow(s) on the parent QStandardItem:
QStandardItem* child = new QStandardItem( tr("Child test") );
...
QStandardItem* parentItem = m_model->item( 0, 0 );
parentItem->appendRow( child );