Simpliest way for creating contextMenu for QTableWidget cells

Engelard

In QTableWidget so many SLOTs, but only one for right click, and even that won't help with info about on which cell user rightclicked... Would be great to have same SLOT, but which would simply tell in params row&column.

Like SLOT cellClicked(int, int) should be also cellRightClicked(int, int). Why there is no such thing exist yet?

SGaist

Hi,

What about customContextMenuRequested ?

You can get the model index using indexAt.

Engelard

@SGaist That's what i'm talking about. I've tried to read this stuff, i rly can't get it, how it should work and how i'll get info about cell was rightclicked....

Engelard

@SGaist said in Simpliest way for creating contextMenu for QTbaleWidget cells:

Hi,

You can get the model index using indexAt.

How can i use this function? I can't use it directly because it's not static. Create variable of this QAbstractItemView i also can't because alot of errors and in google it seems like a pretty complicated stuff(advanced Qt).

SGaist

Why would you need it as static ?

You have QTableWidget instance (e.g. _myTableWidget), then connect its customContextMenuRequested signal to some slots and in that slot call indexAt.

Something along the lines:

MainWindow(QWidget *parent)
    QWidget(parent)
{
    _myTableWidget = new QTableWidget;
    // layout stuff etc.
    connect(_myTableWidget, &QTableWidget::customContextMenuRequested, this, &handleContextMenu);
}

void MainWindow::handleContextMenu(const QPoint& pos)
{
    QTableWidgetItem *item = _myTableWidget->itemAt(pos);
    if (item) {
        // do what you want with the item.
    }
}

Christian Ehrlicher

@SGaist said in Simpliest way for creating contextMenu for QTableWidget cells:

QTableWidgetItem *item = _myTableWidget->itemAt(pos);

Imo there is a small mapping needed:
The exception to this rule is QAbstractScrollArea and its subclasses that map the context menu event to coordinates of the viewport().

Engelard

@SGaist Ah now i get it. You misswrite in first post. Not indexAt but itemAt.

P.S. there is no need to making connect, i just use all stuff inside customContextMenuRequested SLOT.

P.P.S. everything seems to be well, compiles well, but not working i rly can't understand why:

void MWindow::on_tableWidMemory_customContextMenuRequested(const QPoint &pos)
{
    QTableWidgetItem *tempItem = ui->tableWidMemory->itemAt(pos);

    ui->tableWidMemory->item(tempItem->row(), tempItem->column())->setBackgroundColor(Qt::green);
}

Also tried:

ui->tableWidMemory->itemAt(pos.x(), pos.y())->setBackgroundColor(Qt::green);

Still nothing....

jsulm

@Engelard I don't have a solution, but want to say that you're writing dangerous code: you're not checking whether tempItem is a valid pointer! If it is not your app will crash.
Also, shouldn't it be http://doc.qt.io/qt-5/qtablewidgetitem.html#setBackground?

VRonin

You just need to set the menu policy: http://doc.qt.io/qt-5/qwidget.html#contextMenuPolicy-prop

In MWindow constructor call setContextMenuPolicy(Qt::CustomContextMenu);

Also note what @Christian-Ehrlicher said.
Instead of ui->tableWidMemory->itemAt(pos); you'll probably need ui->tableWidMemory->itemAt(ui->tableWidMemory->mapFromGlobal(mapToGlobal(pos)));

Engelard

@jsulm said in Simpliest way for creating contextMenu for QTableWidget cells:

Also, shouldn't it be http://doc.qt.io/qt-5/qtablewidgetitem.html#setBackground?

Nope. setBackgroundColor is wroked well with leftClick slot.

Engelard

@VRonin nothing changed, still not working..

VRonin

@Engelard said in Simpliest way for creating contextMenu for QTableWidget cells:

nothing changed, still not working

~~Does on_tableWidMemory_customContextMenuRequested get executed at all?~~

Actually realised my mistake. You are asking the context menu only for the table widget so instead of setContextMenuPolicy(Qt::CustomContextMenu); you should have ui->tableWidMemory->setContextMenuPolicy(Qt::CustomContextMenu); and forget about the mapFromGlobal/mapToGlobal part

Engelard

@VRonin said in Simpliest way for creating contextMenu for QTableWidget cells:

@Engelard said in Simpliest way for creating contextMenu for QTableWidget cells:

nothing changed, still not working

~~Does on_tableWidMemory_customContextMenuRequested get executed at all?~~

Lol, no it does'nt. But after your:

Actually realised my mistake. You are asking the context menu only for the table widget so instead of setContextMenuPolicy(Qt::CustomContextMenu); you should have ui->tableWidMemory->setContextMenuPolicy(Qt::CustomContextMenu); and forget about the mapFromGlobal/mapToGlobal part

It called, but whole app crashes)

Engelard

Now it's woring, i removed whole that stuff

QTableWidgetItem *tempItem = ui->tableWidMemory->itemAt(pos);

The only thing is left now:

ui->tableWidMemory->itemAt(pos)->setBackgroundColor(Qt::green);

And

ui->tableWidMemory->setContextMenuPolicy(Qt::CustomContextMenu);

in constructor.

Tnx VRonin for help. Still can't get why no slot for rightclick for QTableWidget cells, would be way efficient and simplier for newcomers. But anyway, at least it working with two extra-lines of code.

jsulm

@Engelard said in Simpliest way for creating contextMenu for QTableWidget cells:

It called, but whole app crashes)

Where do you execute this code? It should be after ui->setupUI

Engelard

P.S. Ah. Now i get it, that new object

QTableWidgetItem *tempItem = ui->tableWidMemory->itemAt(pos);

needed for checking if user rightclick to anything in TableWidget but cells, it would crash without it.

jsulm

@Engelard I told you :-)