Custom context menu on disabeld widget... ?

[Dariusz]

Hey

Is there a way to enable custom context menu on a widget that is disabled? I'd like to still be able to right click on it.

TIA.

[spobit]

Hi.

You can use the functions, but I do not test its valid range:

void QObject::installEventFilter(QObject *filterObj);
virtual bool QObject::eventFilter(QObject *watched, QEvent *event);

bool QApplicationPrivate::notify_helper(QObject *receiver, QEvent * e)
{
    ...

    // send to all receiver event filters
    if (sendThroughObjectEventFilters(receiver, e)) {
        filtered = true;
        return filtered;
    }

    // deliver the event
    consumed = receiver->event(e);

    QCoreApplicationPrivate::setEventSpontaneous(e, false);
    return consumed;
}

The differentiation is at:

bool QAbstractButton::event(QEvent *e)
{
    // as opposed to other widgets, disabled buttons accept mouse
    // events. This avoids surprising click-through scenarios
    if (!isEnabled()) {
        switch(e->type()) {
        case QEvent::TabletPress:
        case QEvent::TabletRelease:
        case QEvent::TabletMove:
        case QEvent::MouseButtonPress:
        case QEvent::MouseButtonRelease:
        case QEvent::MouseButtonDblClick:
        case QEvent::MouseMove:
        case QEvent::HoverMove:
        case QEvent::HoverEnter:
        case QEvent::HoverLeave:
        case QEvent::ContextMenu:
#if QT_CONFIG(wheelevent)
        case QEvent::Wheel:
#endif
            return true;
        default:
            break;
        }
    }

#ifndef QT_NO_SHORTCUT
    if (e->type() == QEvent::Shortcut) {
        Q_D(QAbstractButton);
        QShortcutEvent *se = static_cast<QShortcutEvent *>(e);
        if (d->shortcutId != se->shortcutId())
            return false;
        if (!se->isAmbiguous()) {
            if (!d->animateTimer.isActive())
                animateClick();
        } else {
            if (focusPolicy() != Qt::NoFocus)
                setFocus(Qt::ShortcutFocusReason);
            window()->setAttribute(Qt::WA_KeyboardFocusChange);
        }
        return true;
    }
#endif
    return QWidget::event(e);
}

This is my test:

#include "mainwindow.h"
#include "pushbutton.h"
#include "ui_mainwindow.h"

#include <QContextMenuEvent>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    b1_ = new PushButton("b1", this);
    b1_->move(100, 100);
    b1_->setDisabled(true);
    b2_ = new PushButton("b2", this);
    b2_->move(200, 200);

    setObjectName("mainwindow");
    b1_->setObjectName("b1");
    b2_->setObjectName("b2");

    b1_->installEventFilter(this);
    b2_->installEventFilter(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::contextMenuEvent(QContextMenuEvent *event)
{
    QMenu* menu = new QMenu(this);
    menu->addAction("a1");
    menu->addAction("a2");
    menu->addAction("a3");
    menu->exec(event->globalPos());

    QWidget::contextMenuEvent(event);
}

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
    if (event->type() == QEvent::MouseButtonRelease)
    {
        QMouseEvent* e = static_cast<QMouseEvent*>(event);

        if (obj == b1_ && (e->button() == Qt::RightButton) )
        {
            // Do what you want
            QMenu* menu = new QMenu(this);
            menu->addAction("c1");
            menu->addAction("c2");
            menu->addAction("c3");
            menu->exec(e->globalPos());
            return true;
        }
    }

    return QObject::eventFilter(obj, event);
}

[spobit]

event() is a vfun, so you also can do that:

bool PushButton::event(QEvent *event)
{
    if (event->type() == QEvent::MouseButtonRelease)
    {
        QMouseEvent* e = static_cast<QMouseEvent*>(event);

        if (e->button() == Qt::RightButton)
        {
            // Do what you want
            QMenu* menu = new QMenu(this);
            menu->addAction("d1");
            menu->addAction("d2");
            menu->addAction("d3");
            menu->exec(e->globalPos());
            return true;
        }
    }

    return QPushButton::event(event);
}