Controlling a popup QWidget attached to a QToolButton

Question

I want to get a Popup Widget to be shown when clicking on a QToolbutton.

This can be done by adding an action to the button itself. The popup will contain a three buttons (update, create and cancel) and a text input field.

I have some sample code with only one button I have shared as a Github repository.

The most relevant part of the code is:

    auto button = new QToolButton(this);
    button->setText(" AA ");

    auto popup = new Popup(button, this);
    auto popupAction = new QWidgetAction(this);
    popupAction->setDefaultWidget(popup);
    button->setPopupMode(QToolButton::InstantPopup);
    button->addAction(popupAction);

The result is as follow:

I have two issues I cannot solve:

• Getting the popup widget to right align to the button.
• Getting the popup widget to close when one of the buttons inside of it are clicked.

Right align the popup

There is already a similar question: Set position (to right) of Qt QPushButton popup menu.

I can add the suggested code:

void Popup::showEvent(QShowEvent*)
{
    QPoint p = this->pos();
    QRect geo = clickedButton->geometry();

    this->move(p.x()+geo.width()-this->geometry().width(), p.y());
}

But only the content of the popup gets right aligned to the button, not the popup itself:

Closing the popup

If I click anywhere (but a widget) in the Popup it closes. I'm somehow fine with this.

But if I cannot manage to get a click on the button to close the popup.
I've tried to call the close() function but it only clears the content of the popup without closing it.

Can I get the button to trigger a signal and then close the popup?

I ask both questions as the same time, since they look very similar: both times it's the content and not the popup that is affected.

Answer 1

auto popup = new Popup(button, this);
auto popupAction = new QWidgetAction(this);
popupAction->setDefaultWidget(popup);
button->setPopupMode(QToolButton::InstantPopup);
button->addAction(popupAction);

Your Popup widget is not the actual popup, but just a widget inside the real popup. So what you're moving is the widget inside the real popup and not the popup itself.

The solution in the question you linked to uses QMenu and it works with QMenu.

In your code replace

connect(button, &QToolButton::clicked, this, &MainWindow::showPopup);

auto updateButton = new QPushButton("Update");
auto popupAction = new QWidgetAction(this);
popupAction->setDefaultWidget(updateButton);
button->setPopupMode(QToolButton::InstantPopup);
button->addAction(popupAction);

with

button->setPopupMode(QToolButton::InstantPopup);
auto menu = new Popup(button, this);
auto action = new QAction("Test");
menu->addAction(action);
button->setMenu(menu);

Change your Popup class to extend/inherit QMenu, uncomment the showEvent method and remove everything from the constructor.

EDIT

You can set a layout to the qmenu and add widgets to it.

auto menuLayout = new QGridLayout();
auto menuBtn1 = new QPushButton("Btn1");
auto menuBtn2 = new QPushButton("Btn2");
auto menuBtn3 = new QPushButton("Btn3");

menuLayout->addWidget(menuBtn1, 0, 0);
menuLayout->addWidget(menuBtn2, 0, 1);
menuLayout->addWidget(menuBtn3, 1, 0);

button->setPopupMode(QToolButton::InstantPopup);
auto menu = new Popup(button, this);
menu->setLayout(menuLayout);

Answer 2

• When you use a layout it has margins that prevent alignment.

• The QMenu of the Popup can be accessed through kinship but this must be accessed when the button is pressed as this is created when it is first shown.

popup.h

#ifndef POPUP_H
#define POPUP_H

#include <QWidget>

class QToolButton;

class Popup : public QWidget
{
    Q_OBJECT
public:
    explicit Popup(QWidget* parent=nullptr);
Q_SIGNALS:
    void clicked();
};
#endif

popup.cpp

#include "popup.h"

#include<QWidget>
#include<QVBoxLayout>
#include<QPushButton>

Popup::Popup(QWidget* parent)
    : QWidget(parent)
{
    auto layout = new QVBoxLayout(this);
    layout->setContentsMargins(0, 0, 0, 0);
    layout->addStretch();
    auto updateButton = new QPushButton("Update");
    layout->addWidget(updateButton);
    connect(updateButton, &QPushButton::clicked, this, &Popup::clicked);
}

mainwindow.h

MainWindow::MainWindow()
{
    auto widget = new QWidget;
    setCentralWidget(widget);
    auto layout = new QHBoxLayout(widget);
    layout->addStretch();

    auto button = new QToolButton;
    button->setText(" AA ");
    layout->addWidget(button);

    auto popup = new Popup;
    auto popupAction = new QWidgetAction(this);
    popupAction->setDefaultWidget(popup);
    button->setPopupMode(QToolButton::InstantPopup);
    button->addAction(popupAction);

    connect(popup, &Popup::clicked, [popup](){
        if(QWidget *p = popup->parentWidget())
            p->close();
    });
}