Adding event to the context menu in QPlainTextEdit

c++, contextmenu, qplaintextedit, qt

Solution

Method 1: `QPlainTextEdit::contextMenuEvent`

You should override the `QPlainTextEdit::contextMenuEvent` as mentioned in the Qt documentation:

void MyQPlainTextEdit::contextMenuEvent(QContextMenuEvent *event)
{
    QMenu *menu = createStandardContextMenu();
    menu->addAction(tr("My Menu Item"));
    //...
    menu->exec(event->globalPos());
    delete menu;
}

You can connect the `QAction::triggered` signal to your method (slot) to load the data or you can use one of the `QMenu::addAction` overloads, which allows you to specify a slot directly.

If you do not want to subclass `QPlainTextEdit` (to override `contextMenuEvent`), you can use event filtering in Qt.

Note that `contextMenuEvent()` is only called when `contextMenuPolicy` is not set (or set to its default value `Qt::DefaultContextMenu`)

Method 2: `QWidget::customContextMenuRequested`

As an alternative, you can use Qt's signal and slot mechanism to create the context menu when requested by the user.

The `contextMenuPolicy` property should be set to `Qt::CustomContextMenu`, in which case the `QWidget::customContextMenuRequested` signal is invoked whenever a context menu is requested by the user. This signal should be connected to your own slot, which should create the context menu as shown in the code above (Method 1).

Using `MyQPlainTextEdit` in Qt Designer

To use your `MyQPlainTextEdit` in a `.ui` file, you should implement it as a promoted `QPlainTextEdit` and use it in your `.ui` file instead of a regular `QPlainTextEdit`. See the Qt documentation for more information.

To be able to use your class in the Qt Designer, you should not forget to implement a constructor accepting a parent `QWidget` as is done in the `AnalogClock` example. Note that implementing such a constructor is always a good idea, because Qt typically manages ownership through a child-parent relationship.

Problem

Original source