add a "responsive" widget to toolbar

user4592357

i have a toolbar widget to which i've added a couple of actions.
i also want to add some text to the toolbar. so i create a label. but i want this label to be positioned at the center of the toolbar, so:

Toolbar::Toolbar(const QString &sToolbarName, QWidget *parent /* = nullptr */) noexcept
	: QToolbar(sToolbarName, parent)
	, m_pLabel(new QLabel(this))
{
	// add actions

	auto pSpacer = new QWidget(this);
	pSpacer->setFixedWidth(width() / 2);
	addWidget(pSpacer);

	m_pLabel->setVisible(true);
	addWidget(m_pLabel);
}

however when the toolbar is resized the label remains in its old place. i want this label to respond to resizing. what should i do?

SGaist

Hi,

Why are you fixing the width of your spacer ?

user4592357

@SGaist
i wasn't sure how else to do it

qwasder85

Put the label in a layout and align it in the center (Qt::AlignHCenter, or Qt::AlignCenter). Don't forget to also align the text within the label in its center.
Assign the layout to a widget.
Set the widget's sizePolicy: setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred)
Add the widget to the toolbar

The widget should now span the entire available space and the label within it should stay centered.

Edit: Here's some test code:

    QLabel* p_label = new QLabel("Hello");
    p_label->setAlignment(Qt::AlignCenter);

    QHBoxLayout* p_tool_layout = new QHBoxLayout;
    p_tool_layout->addWidget(p_label, Qt::AlignCenter);

    QWidget* p_wid = new QWidget;
    p_wid->setContentsMargins(0, 0, 0, 0);
    p_wid->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);
    p_wid->setLayout(p_tool_layout);

    QToolButton* p_butt_1 = new QToolButton;
    QToolButton* p_butt_2 = new QToolButton;
    QToolButton* p_butt_3 = new QToolButton;

    setStyleSheet("QToolButton { border: 1px solid magenta; }"); // Just for visibility in this example

    QToolBar* p_bar = new QToolBar;
    p_bar->addWidget(p_butt_1);
    p_bar->addWidget(p_butt_2);
    p_bar->addWidget(p_wid);
    p_bar->addWidget(p_butt_3);

Result:
alt text

The layout is responsible for keeping the label centered between the tool buttons, and does so even when resizing.

user4592357

@qwasder85
thanks, this works like magic!

one problem i have is that, since i'm adding this label widget to toolbar, when the toolbar gets narrower and a drop down list is created for the other buttons, this label is not in that list.
i tried to use widget action, now the drop down list is populated with the label, but no text is visible.

class NameWidgetAction : public QWidgetAction
{
public:
	explicit NameWidgetAction(QObject *parent = nullptr);
	void setName(const QString &sName);

protected:
	QWidget *createWidget(QWidget *parent) override;

private:
	/// The name label
	QLabel *m_pNameLabel = nullptr;

}; // class NameWidgetAction

NameWidgetAction::NameWidgetAction(QObject *parent /* = nullptr */)
	: QWidgetAction(parent)
{
}

void NameWidgetAction::setName(const QString &sName)
{
	// get the list of created widgets, there should be just one
	auto lstWidgets = createdWidgets();
	if (!lstWidgets.isEmpty())
	{
		if (auto pLabel = lstWidgets[0]->findChild<QLabel *>())
			pLabel->setText(sName);
	}
}

QWidget *NameWidgetAction::createWidget(QWidget *parent)
{
	auto pWideWidget = new QWidget(parent);
	pWideWidget->setContentsMargins(0, 0, 0, 0);
	pWideWidget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Preferred);

	auto m_pDbNameLabel = new QLabel(pWideWidget);
	m_pDbNameLabel->setAlignment(Qt::AlignCenter);
	m_pDbNameLabel->setVisible(true);

	auto pLayout = new QHBoxLayout(pWideWidget);
	pLayout->addWidget(m_pDbNameLabel);

	return pWideWidget;
}

and then in my toolbar i do:

Toolbar::Toolbar(const QString &sToolbarName, QWidget *parent /* = nullptr */) noexcept
	: QToolbar(sToolbarName, parent)
{
    // ...
	addAction(new NameWidgetAction(this));
}

qwasder85

@user4592357 Just a guess, but could it be that the dropdown only displays the QAction's icons and nothing else?

user4592357

@qwasder85
i'm not sure. but i also set iconText to the name widget action and it still wasn't displayed in drop down.

user4592357

also, the buttons that actually appear in the drop-down list, become disabled in the list (but i do not explicitly disable them), and when i widen the toolbar and actions come back to the toolbar, they're enabled again.
what's the reason?