I'm trying to put a MySQL table into a treeView.
Each entry has three values in the database - id, text, parentId.
This treeView needs to be editable so I really like the QSqlTableModel approach, as the functionality to save back to database is already built in.
Now, the treeView is showing all entries in the same line, of course, and I need a hierarchy. What would be the best way to build this hierarchy, while maintaining the editing and saving capabilities?
(I'm using MySQL.)
mainwindow.h
private: QSqlTableModel* goalModel;
mainwindow.cpp
(this makes a flat table hierarchy. the table is filtered based on which entry is clicked in another table)
void MainWindow::on_tableViewGoals_clicked(const QModelIndex &index)
{
goalModel = new QSqlTableModel(this);
goalModel->setTable("goals");
//Gets the id from the clicked entry to use as filter
QString idGoals = index.sibling(row,0).data().toString();
goalModel->setFilter( "id_goals=" + idGoals );
goalModel->setEditStrategy(QSqlTableModel::OnRowChange);
goalModel->select();
ui->treeView->setModel(goalModel);
...
I tried this. It's wrong, but I don't really know why. (the third column contains the parentId value, if the entry has it)
for (int row = 0; row < goalModel->rowCount(); ++row)
{
//if the entry has a value over 0 in the parentId column
if (goalModel->index(row,2).data().toInt() > 0)
{
//get number in column 2
int parentId;
parentId = goalModel->index(row,2).data().toInt();
QModelIndex newChild = goalModel->index(row,0);
//find QModelIndex row with matching number in column 0
for (int row = 0; row < goalModel->rowCount(); ++row)
{
if (goalModel->index(row,0).data().toInt() == parentId )
{
//make this entry that entry's child
QModelIndex newParent = goalModel->index(row,0);
newChild = goalModel->index(0,0,newParent);
}
}
}
}
All indexes are already made, so no need to make new ones, just assign a parent to all those who have one. How best to do that?
Related
I am working with a qtableview that is filled by a model and has two columns. I can get the contents of a selected cell no problem but only want the contents of the second column even if the first column is clicked.
void MainWindow::on_tableView_clicked(const QModelIndex &index)
{
QString cellText;
if (index.isValid()) {
cellText = index.data().toString();
}
ui->lineEdit->setText(cellText);
}
the index looks like this for column 0:
QModelIndex(7,0,0x55f2e5d06b00,QStandardItemModel(0x55f2e5d09740))
And for column 1:
QModelIndex(8,1,0x55f2e5d06b00,QStandardItemModel(0x55f2e5d09740))
I tried to find a way to change the index for the cell that is clicked but I think there is no way to change it directly and I can not seem to find a way to tell my function to always use column 1 the second column.
Thanks for your time.
Code edited to reflect comment 1 below
{
QString cellText;
if (index.isValid()) {
QModelIndex idx = index;
idx = idx.sibling(idx.row(), 1);
cellText = idx.data().toString();
}
ui->lineEdit->setText(cellText);
}```
I'm not sure if the title is correct but this is the situation:
When a row is selected and contains Application Status of FULL_MEMBER,
A pushButton is enabled else it is disabled.
You have to get the text of the item (cell) in the fifth column of the selected row, each time the selection changes.
Have a slot like this in your widget:
private slots:
void tableSelectionChanged();
In the widget constructor, connect it to the table widget signal itemSelectionChanged:
connect(ui->tableWidget, SIGNAL(itemSelectionChanged()), this, SLOT(tableSelectionChanged()));
The slot definition is like this:
//retrieve a list of all selected rows
QModelIndexList list = ui->tableWidget->selectionModel()->selectedRows();
if(list.size() > 0)
{
//retrieve the index of the first (and only, maybe?) selected row
int row = list[0].row();
const int col = 4; //Application Status column id
QTableWidgetItem * item = ui->tableWidget->item(row, col); //the item we want to inspect
ui->pushButton->setEnabled( item->text() == "FULL_MEMBER" );
}
I have a QTableView with an associated model. I want to have a QComboBox in each cell of the third column.
I used a QItemDelegate as shown in this page : https://wiki.qt.io/Combo_Boxes_in_Item_Views.
It works but the combo box is only shown after double clicking in the cell, the user has to click again to show the list of possible values. This is a bit inconvenient.
Is there a way to make the combo boxes always visible ?
I'm trying with openPersistentEditor method, but it does not work right now ...
there is a bit of code close to my code (ComboBoxItemDelegate is the same than the exemple linked before):
MonWidget::MonWidget() : _ui(new Ui::MonWidget())
{
// ...
// Links Model
_linksModel = new QStandardItemModel(this);
// Links Headers
QStringList linksTableViewHeader << "Name" << "Path" << "Version";
_linksModel->setHorizontalHeaderLabels(linksTableViewHeader) ;
// Create itemDelegate for linksView
_itemDelegate = new ComboBoxItemDelegate(_ui->_linksView);
// Set the links model on the links table view
_ui->_linksView->setModel(_linksModel);
_ui->_linksView->horizontalHeader()->setSectionResizeMode(QHeaderView::Interactive);
_ui->_linksView->horizontalHeader()->setStretchLastSection(true);
_ui->_linksView->horizontalHeader()->setMinimumSectionSize(100);
_ui->_linksView->setSelectionBehavior(QAbstractItemView::SelectRows);
_ui->_linksView->setItemDelegate(_itemDelegate);
}
// AddLinksInListView : method called when I add some rows ...
void MonWidget::AddLinksInListView(QList<DataItem*> listLinks)
{
int j=0;
int initialLinksNumber = _linksModel->rowCount();
// For each link, add a row with the link information
for (int row=initialLinksNumber; row<(initialLinksNumber + listLinks.size()) ; row++)
{
for (int column = 0; column < _linksModel->columnCount(); column++) {
//item used to display information for each column in the table view of links contained in the collection
QStandardItem *item=0;
switch(column)
{
case MonWidget::NAME:
{
item = new QStandardItem(listLinks.at(j)->data(MonWidget::NAME).toString());
_linksModel->setItem(row, column, item);
break;
}
case MonWidget::PATH:
{
item = new QStandardItem(listLinks.at(j)->data(MonWidget::PATH).toString());
_linksModel->setItem(row, column, item);
break;
}
case MonWidget::VERSION:
{
item = new QStandardItem(listLinks.at(j)->data(MonWidget::PATH).toString());
_linksModel->setItem(row, column, item);
_ui->_linksView->openPersistentEditor(_linksModel->index(row, column));
break;
}
}
}
j++;
}
}
Yes, there is a way, using openPersistentEditor. Assuming your model is named myModel:
YourDelegate* comboDelegate = new YourDelegate(this);
setItemDelegateForColumn(2, comboDelegate); // delegate set for the third column
...
// when adding a new line, use this.
// The combo box will be always visible
openPersistentEditor(myModel->index(iRow, 1));
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 don't know why I have trouble removing all rows and sub rows from qtreeview
I'm using QStandardItemModel as the model. Now here is my code that doesn't work.
What could be the problem?
QModelIndex FirstQModelIndex;
QModelIndex parentQModelIndex;
int iMdlChidCound = m_model->hasChildren();
if(iMdlChidCound > 0)
{
// only if there at list 1 row in the view
FirstQModelIndex = m_model->item(0,0)->index();
QStandardItem* feedItem = m_model->itemFromIndex(FirstQModelIndex);
// get the parent of the first row its the header row
QStandardItem* parentItem = feedItem->parent();
// here im getting exception
int parent_rows= parentItem->hasChildren();
parentQModelIndex = m_model->indexFromItem(parentItem);
// now i like to delete all the rows under the header , and its dosnt work
if(parent_rows>0)
{
bool b = feedItem->model()->removeRows(0,y,parentQModelIndex);
}
}
It seems like a lot of what you're doing is superfluous. If your only goal is to remove all the rows from the model, you could probably just use QStandardItemModel::clear
In your code you're jumping between the model and the items in a way you don't have to.
if(m_model->hasChildren()) {
m_model->removeRows(0, m_model->rowCount());
}
That should do what you're seeking.
QStandardItemModel::clear()
Which clears all the items including the header rows.