Centering a QToolButton in a QVBoxLayout?

drwho

It appears that QVBoxLayout's setAlignment(Qt::AlignHCenter) only sudo centres the widgets (or only the widest one). The smaller QToolButton is left aligned with the left edge of widest widget.

Is this a bug in QVBoxLayout or am I doing somehing wrong? QGridLayout (below) works fine. Code that made above image....

test.pro

QT+= core gui widgets
TARGET = test
TEMPLATE = app
SOURCES+= main.cpp

main.cpp

#include <QWidget>
#include <QVBoxLayout>
#include <QToolButton>
#include <QApplication>
#include <QStyle>

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

	QWidget *window = new QWidget();
	QVBoxLayout *layout = new QVBoxLayout();
	QToolButton *button;

	layout->setAlignment(Qt::AlignHCenter);

	layout->addStretch();

	button = new QToolButton();
	button->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
	button->setIcon(window->style()->standardIcon(QStyle::SP_BrowserReload));
	button->setIconSize(QSize(25,25));
	button->setText("Short");
	//button->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Maximum);
	layout->addWidget(button);

	layout->addStretch();

	button = new QToolButton();
	button->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
	button->setIcon(window->style()->standardIcon(QStyle::SP_BrowserReload));
	button->setIconSize(QSize(25,25));
	button->setText("Long Long Long Long Long");
	//button->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Maximum);
	layout->addWidget(button);

	layout->addStretch();

	window->setLayout(layout);
	window->show();

	return a.exec();
}

QGridLayout works fine....

Code that made this below....

#include <QWidget>
#include <QGridLayout>
#include <QToolButton>
#include <QApplication>
#include <QStyle>

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

	QWidget *window = new QWidget();
	QGridLayout *layout = new QGridLayout();
	QToolButton *button;

	//layout->setAlignment(Qt::AlignHCenter);  // does nothing

	layout->setRowStretch(0, 1);
	layout->setRowStretch(2, 1);
	layout->setRowStretch(4, 1);
	layout->setColumnStretch(0, 1);
	layout->setColumnStretch(2, 1);

	button = new QToolButton();
	button->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
	button->setIcon(window->style()->standardIcon(QStyle::SP_BrowserReload));
	button->setIconSize(QSize(25,25));
	button->setText("Short");
	layout->addWidget(button, 1, 1, Qt::AlignHCenter);

	button = new QToolButton();
	button->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
	button->setIcon(window->style()->standardIcon(QStyle::SP_BrowserReload));
	button->setIconSize(QSize(25,25));
	button->setText("Long Long Long Long Long");
	layout->addWidget(button, 3, 1, Qt::AlignHCenter);

	window->setLayout(layout);
	window->show();

	return a.exec();
}

mostefa

Hi @drwho

The problem is with this line :

layout->setAlignment(Qt::AlignHCenter);

You are calling this function before the addWidget function, and i think that with vertialLayout to use AlignHCenter , you need to tell which item you need to center,

-just put setAlignement after the addWidget, and use setAlignement(button, Qt::AlignHCenter) instead of setAlgnement(Qt::AlignHCenter);

You code should look to something like this:

QWidget *window = new QWidget();
    QVBoxLayout *layout = new QVBoxLayout();
    QToolButton *button;

    layout->addStretch();

    button = new QToolButton();
    button->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    button->setIcon(window->style()->standardIcon(QStyle::SP_BrowserReload));
    button->setIconSize(QSize(25,25));
    button->setText("Short");
    //button->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Maximum);
    layout->addWidget(button);
    layout->setAlignment(button, Qt::AlignHCenter);// Call setAlignement(button, Qt::AlignHCenter) after addWidget
    layout->addStretch();

    button = new QToolButton();
    button->setToolButtonStyle(Qt::ToolButtonTextUnderIcon);
    button->setIcon(window->style()->standardIcon(QStyle::SP_BrowserReload));
    button->setIconSize(QSize(25,25));
    button->setText("Long Long Long Long Long");
    //button->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Maximum);
    layout->addWidget(button);
    layout->setAlignment(button, Qt::AlignHCenter);// Call setAlignement(button, Qt::AlignHCenter) after addWidget
    layout->addStretch();

    window->setLayout(layout);
    window->show();

I hope this can help you !

drwho

Yes, setAlignment(button, Qt::AlignHCenter) does the trick. Thanks! It is too bad the alignment parameter in QVBoxLayout's addWidget() doesn't do this like QGridLayout's addWidget() does.