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Menus and toolbars in Qt5

last modified October 18, 2023

In this part of the Qt5 C++ programming tutorial, we talk about menus and toolbars in Qt5 applications.

A menubar is a common part of a GUI application. It is a group of commands located in various places called menus. Menus group commands that we can use in an application. Toolbars provide a quick access to the most frequently used commands.

Qt5 simple menu

The first example shows a simple menu.

simple_menu.h
#pragma once

#include <QMainWindow>
#include <QApplication>

class SimpleMenu : public QMainWindow {

  public:
    SimpleMenu(QWidget *parent = nullptr);
};

This is a header file for our code example.

simple_menu.cpp
#include <QMenu>
#include <QMenuBar>
#include "simple_menu.h"

SimpleMenu::SimpleMenu(QWidget *parent)
    : QMainWindow(parent) {

  auto *quit = new QAction("&Quit", this);

  QMenu *file = menuBar()->addMenu("&File");
  file->addAction(quit);

  connect(quit, &QAction::triggered, qApp, QApplication::quit);
}

We have a menubar, a menu and an action. In order to work with menus, we must inherit from a QMainWindow widget.

auto *quit = new QAction("&Quit", this);

This code line creates a QAction. Each QMenu has one or more action objects.

QMenu *file;
file = menuBar()->addMenu("&File");

We create a QMenu object.

file->addAction(quit);

We put an action inside the menu using the addAction method.

connect(quit, &QAction::triggered, qApp, QApplication::quit);

When we select this option from the menu, the application quits.

main.cpp
#include "simple_menu.h"

int main(int argc, char *argv[]) {

  QApplication app(argc, argv);

  SimpleMenu window;

  window.resize(350, 250);
  window.setWindowTitle("Simple menu");
  window.show();

  return app.exec();
}

The main file.

Simple menu
Figure: Simple menu

Qt5 icons, shortcuts, and separators

In the following example, we further enhance our previous application. We add icons to the menus, use shortcuts and a separator.

another_menu.h
#pragma once

#include <QMainWindow>
#include <QApplication>

class AnotherMenu : public QMainWindow {

  public:
    AnotherMenu(QWidget *parent = nullptr);
};

The header file for the example.

another_menu.cpp
#include <QMenu>
#include <QMenuBar>
#include "another_menu.h"

AnotherMenu::AnotherMenu(QWidget *parent)
    : QMainWindow(parent) {

  QPixmap newpix("new.png");
  QPixmap openpix("open.png");
  QPixmap quitpix("quit.png");

  auto *newa = new QAction(newpix, "&New", this);
  auto *open = new QAction(openpix, "&Open", this);
  auto *quit = new QAction(quitpix, "&Quit", this);
  quit->setShortcut(tr("CTRL+Q"));

  QMenu *file = menuBar()->addMenu("&File");
  file->addAction(newa);
  file->addAction(open);
  file->addSeparator();
  file->addAction(quit);

  qApp->setAttribute(Qt::AA_DontShowIconsInMenus, false);

  connect(quit, &QAction::triggered, qApp, &QApplication::quit);
}

In our example, we have one menu with three actions. Only the quit action will actually do something if we select it. We also create a separator and a CTRL+Q shortcut, which terminates the application.

QPixmap newpix("new.png");
QPixmap openpix("open.png");
QPixmap quitpix("quit.png");

These are images that we use in menus. Note that some desktop environments might not display images in the menus.

auto *newa = new QAction(newpix, "&New", this);
auto *open = new QAction(openpix, "&Open", this);
auto *quit = new QAction(quitpix, "&Quit", this);

In this code we use the QAction constructor with a pixmap as the first argument.

quit->setShortcut(tr("CTRL+Q"));

Here we create a keyboard shortcut. By pressing this shortcut, we run the quit action which will quit the application.

file->addSeparator();

We create a separator. The separator is a horizontal line which enables us to group menu actions into some logical groups.

qApp->setAttribute(Qt::AA_DontShowIconsInMenus, false);

In some environments, the menu icons are not shown by default. In this case we can disable the Qt::AA_DontShowIconsInMenus attribute.

main.cpp
#include "another_menu.h"

int main(int argc, char *argv[]) {

  QApplication app(argc, argv);

  AnotherMenu window;

  window.resize(350, 250);
  window.setWindowTitle("Another menu");
  window.show();

  return app.exec();
}

This is the main file.

Another menu example
Figure: Another menu example

Qt5 checkable menu

In the next example, we create a checkable menu. This will be an action with a check box. The option toggles the visibility of a statusbar.

checkable.h
#pragma once

#include <QMainWindow>
#include <QApplication>

class Checkable : public QMainWindow {

  Q_OBJECT

  public:
    Checkable(QWidget *parent = nullptr);

  private slots:
    void toggleStatusbar();

  private:
    QAction *viewst;
};

The header file for the example.

checkable.cpp
#include <QMenu>
#include <QMenuBar>
#include <QStatusBar>
#include "checkable.h"

Checkable::Checkable(QWidget *parent)
    : QMainWindow(parent) {

  viewst = new QAction("&View statusbar", this);
  viewst->setCheckable(true);
  viewst->setChecked(true);

  QMenu *file = menuBar()->addMenu("&File");
  file->addAction(viewst);

  statusBar();

  connect(viewst, &QAction::triggered, this, &Checkable::toggleStatusbar);
}

void Checkable::toggleStatusbar() {

  if (viewst->isChecked()) {

      statusBar()->show();
  } else {

      statusBar()->hide();
  }
}

A checkable menu item toggles the visibility of the statusbar.

viewst = new QAction("&View statusbar", this);
viewst->setCheckable(true);
viewst->setChecked(true);

We create an action and make it checkable with the setCheckable method. The setChecked method makes it checked.

if (viewst->isChecked()) {

    statusBar()->show();
} else {

    statusBar()->hide();
}

Inside the toggleStatusbar method, we determine if the menu item is checked and hide or show the statusbar accordingly.

main.cpp
#include "checkable.h"

int main(int argc, char *argv[]) {

  QApplication app(argc, argv);

  Checkable window;

  window.resize(350, 250);
  window.setWindowTitle("Checkable menu");
  window.show();

  return app.exec();
}

This is the main file.

Checkable menu
Figure: Checkable menu

Qt5 QToolBar

The QToolBar class provides a movable panel that contains a set of controls which provide a quick access to the application actions.

toolbar.h
#pragma once

#include <QMainWindow>
#include <QApplication>

class Toolbar : public QMainWindow {

  Q_OBJECT

  public:
    Toolbar(QWidget *parent = nullptr);
};

The header file for the example.

toolbar.cpp
#include <QToolBar>
#include <QIcon>
#include <QAction>
#include "toolbar.h"

Toolbar::Toolbar(QWidget *parent)
    : QMainWindow(parent) {

  QPixmap newpix("new.png");
  QPixmap openpix("open.png");
  QPixmap quitpix("quit.png");

  QToolBar *toolbar = addToolBar("main toolbar");
  toolbar->addAction(QIcon(newpix), "New File");
  toolbar->addAction(QIcon(openpix), "Open File");
  toolbar->addSeparator();

  QAction *quit = toolbar->addAction(QIcon(quitpix),
      "Quit Application");

  connect(quit, &QAction::triggered, qApp, &QApplication::quit);
}

To create a toolbar, we inherit from the QMainWindow widget.

QToolBar *toolbar = addToolBar("main toolbar");

The addToolBar method creates a toolbar and returns a pointer to it.

toolbar->addAction(QIcon(newpix), "New File");
toolbar->addAction(QIcon(openpix), "Open File");
toolbar->addSeparator();

Here we add two actions and a separator to the toolbar.

main.cpp
#include "toolbar.h"

int main(int argc, char *argv[]) {

  QApplication app(argc, argv);

  Toolbar window;

  window.resize(350, 250);
  window.setWindowTitle("QToolBar");
  window.show();

  return app.exec();
}

This is the main file.

QToolBar
Figure: QToolBar

Qt5 aplication skeleton

In the end of this part of the C++ Qt5 tutorial, we create an application skeleton. The example is based mainly on the QMainWindow widget.

skeleton.h
#pragma once

#include <QMainWindow>
#include <QApplication>

class Skeleton : public QMainWindow {

  Q_OBJECT

  public:
    Skeleton(QWidget *parent = nullptr);
};

The header file for the example.

skeleton.cpp
#include <QToolBar>
#include <QIcon>
#include <QAction>
#include <QMenu>
#include <QMenuBar>
#include <QStatusBar>
#include <QTextEdit>
#include "skeleton.h"

Skeleton::Skeleton(QWidget *parent)
    : QMainWindow(parent) {

  QPixmap newpix("new.png");
  QPixmap openpix("open.png");
  QPixmap quitpix("quit.png");

  auto *quit = new QAction("&Quit", this);

  QMenu *file = menuBar()->addMenu("&File");
  file->addAction(quit);

  connect(quit, &QAction::triggered, qApp, &QApplication::quit);

  QToolBar *toolbar = addToolBar("main toolbar");
  toolbar->addAction(QIcon(newpix), "New File");
  toolbar->addAction(QIcon(openpix), "Open File");
  toolbar->addSeparator();

  QAction *quit2 = toolbar->addAction(QIcon(quitpix),
      "Quit Application");
  connect(quit2, &QAction::triggered, qApp, &QApplication::quit);

  auto *edit = new QTextEdit(this);

  setCentralWidget(edit);

  statusBar()->showMessage("Ready");
}

Here we create a menu a toolbar and a statusbar.

auto *edit = new QTextEdit(this);

setCentralWidget(edit);

We create a QTextEdit widget and place it into the central part of the QMainWindow widget.

main.cpp
#include "skeleton.h"

int main(int argc, char *argv[]) {

  QApplication app(argc, argv);

  Skeleton window;

  window.resize(450, 350);
  window.setWindowTitle("Application skeleton");
  window.show();

  return app.exec();
}

This is the main file.

Application skeleton
Figure: Application skeleton

In this part of the Qt5 tutorial, we have covered menus and toolbars.