Change QAction icon on QAction Trigger

codeaway

Hi,

I have a MainWindow with a toolbar. The toolbar has 2 actions on it.

actionConnect (Connect)
actionCheck (Check Status)

MainWindow::MainWindow(QWidget *parent)
	: QMainWindow(parent)
	, ui(new Ui::MainWindow)
{
	ui->setupUi(this);
	m_Connect = 0;
}

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


void MainWindow::on_actionConnect_triggered()
{
	qDebug() << "Connect triggered";
	m_Connect = 1;
}

void MainWindow::on_actionCheck_triggered()
{
	qDebug() << "Check Status, triggered";
	if (m_Connect) {
		qDebug() << "Connected, Can check Status now.";
	}
}

actionCheck can be done only after a successful connection;
in the ActionEditor, I've set Disabled Off for the icon, so that it appears disabled.

After a successful connection, I would like to change the icon, so that it looks enabled now.

But, that said, I wonder how to change the icon associated with actionCheck within ui->toolBar

Any thoughts, on how to do this ?

Thanks,

Christian Ehrlicher

QAction has an icon property. Apart from this - when an action is disabled, Qt automatically shows the icon greyed out.

codeaway

@Christian-Ehrlicher said in Change QAction icon on QAction Trigger:

QAction has an icon property. Apart from this - when an action is disabled, Qt automatically shows the icon greyed out.

Thanks for the reponse.

I see that QAction has the setIcon() property with which you can set change the icon.

Maybe it is a stupid question. How to set setIcon() ?
I can access toolBar from ui->toolBar, but how to access the QAction members in toolBar ?

Thanks,

Christian Ehrlicher

The signal actionTriggered() has the triggered action as first parameter.

codeaway

@Christian-Ehrlicher said in Change QAction icon on QAction Trigger:

The signal actionTriggered() has the triggered action as first parameter.

I didnt think of that; But, that said, Action Editor was used from QT designer to create those actions. As a result, I do feel blind how to get access to QAction.

I am no QT expert by any chance, hence all the dumb questions probably.

void MainWindow::on_actionConnect_triggered()
{
	qDebug() << "Connect triggered";
	m_Connect = 1;
}

void MainWindow::on_actionCheck_triggered()
{
	qDebug() << "Check Status, triggered";
	if (m_Connect) {
		qDebug() << "Connected, Can check Status now.";
	}
}

Thanks,

Christian Ehrlicher

Please read about signals and slots and change your slot to get QAction* as parameter.

codeaway

@Christian-Ehrlicher said in Change QAction icon on QAction Trigger:

Please read about signals and slots and change your slot to get QAction* as parameter.

I did the following:

MainWindow::MainWindow(QWidget *parent)
	: QMainWindow(parent)
	, ui(new Ui::MainWindow)
{
	ui->setupUi(this);
	m_Connect = 0;

	QPixmap pix_Conn = QPixmap(":/connect.png");
	QPixmap pix_Status = QPixmap(":/check_disabled.png");
	QToolBar *toolbar = ui->toolBar;
	QAction *conn = new QAction(QIcon(pix_Conn), "Connect");
	toolbar->addAction(conn);

	QAction *check = new QAction(QIcon(pix_Status), "Status");
	toolbar->addAction(check);

	connect(conn, SIGNAL(triggered()), this, SLOT(on_actionConnect_triggered(conn)));
	connect(check, SIGNAL(triggered()), this, SLOT(on_actionCheck_triggered(check)));
}

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

void MainWindow::on_actionConnect_triggered(QAction *action)
{
	(void) action;
	qDebug() << "Connect triggered";
	m_Connect = 1;
}

void MainWindow::on_actionCheck_triggered(QAction *action)
{
	QPixmap pix_Status = QPixmap(":/check.png");

	qDebug() << "Check Status, triggered";
	if (m_Connect) {
		qDebug() << "Connected, Can check Status now.";
		action->setIcon(pix_Status);
	}
}

Likely, I am doing something incorrect ..

Somehow, that does not seem to work, as

it gives out a runtime error.

QMetaObject::connectSlotsByName: No matching signal for on_actionConnect_triggered(QAction*)
QMetaObject::connectSlotsByName: No matching signal for on_actionCheck_triggered(QAction*)
QObject::connect: No such slot MainWindow::on_actionConnect_triggered(conn) in ..\QActionTest\mainwindow.cpp:28
QObject::connect:  (receiver name: 'MainWindow')
QObject::connect: No such slot MainWindow::on_actionCheck_triggered(check) in ..\QActionTest\mainwindow.cpp:29
QObject::connect:  (receiver name: 'MainWindow')

Adding QAction programatically brings another TextLabel to the ToolBar.

I am slightly lost in here ...

JonB

@codeaway said in Change QAction icon on QAction Trigger:

it gives out a runtime error.

Exactly the same advice as I just put in another thread, https://forum.qt.io/topic/119502/emit-signal-from-a-static-method-and-connect-it-to-a-setvalue-slot-on-a-progress-bar/3, and others. Really suggest you act on that....

codeaway

@JonB said in Change QAction icon on QAction Trigger:

@codeaway said in Change QAction icon on QAction Trigger:

it gives out a runtime error.

Exactly the same advice as I just put in another thread, https://forum.qt.io/topic/119502/emit-signal-from-a-static-method-and-connect-it-to-a-setvalue-slot-on-a-progress-bar/3, and others. Really suggest you act on that....

Did change to the new SIGNAL/SLOT methods. I guess, this is correct ..

class MainWindow : public QMainWindow
{
	Q_OBJECT

public:
	MainWindow(QWidget *parent = nullptr);
	~MainWindow();

private slots:
	void on_actionConnect_triggered();

	void on_actionCheck_triggered();

private:
	Ui::MainWindow *ui;

	QAction *conn;
	QAction *check;

	bool m_Connect;
};
#endif // MAINWINDOW_H



MainWindow::MainWindow(QWidget *parent)
	: QMainWindow(parent)
	, ui(new Ui::MainWindow)
{
	ui->setupUi(this);
	m_Connect = 0;

	QPixmap pix_Conn = QPixmap(":/icons/connect.png");
	QPixmap pix_Status = QPixmap(":/icons/check_disabled.png");
	QToolBar *toolbar = ui->toolBar;

	conn = new QAction(QIcon(pix_Conn), "Connect");
	toolbar->addAction(conn);

	check = new QAction(QIcon(pix_Status), "Status");
	toolbar->addAction(check);

	connect(conn, &QAction::triggered, this, &MainWindow::on_actionConnect_triggered);
	connect(check, &QAction::triggered, this, &MainWindow::on_actionCheck_triggered);
}

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

void MainWindow::on_actionConnect_triggered()
{
	qDebug() << "Connect triggered";
	m_Connect = 1;
}

void MainWindow::on_actionCheck_triggered()
{
	QPixmap pix_Status = QPixmap(":/icons/check.png");

	qDebug() << "Check Status, triggered";
	if (m_Connect) {
		qDebug() << "Connected, Can check Status now.";
		conn->setIcon(pix_Status);
	}
}

There are no runtime errors... Phew..
The same issue does exist, what I wrote previously.

The signals/slots do work.. :-)

I can see the triggers being called..

I guess there exists 4 QAction methods in toolbar ?
(2 of them added, using action editor .. ?)

The icons do not seem to change .. Sigh!