different size buttons on qlayout

user4592357

i created two buttons and a vertical layout and i want both buttons to be positioned in the center of their row. but their widths are different and that makes my work seem hard, and only the second (bottom-most) button is in the center. what's the problem with the first one?

and by the way, why don't the commented lines make a difference in the code?

#include <qapplication.h>
#include <qpushbutton.h>
#include <qlayout.h>

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

    QApplication app(argc, argv);

    QWidget window;
    window.setFixedSize(200, 100);

    QPushButton *buttonInfo = new QPushButton("Info", &window);
    //buttonInfo->setGeometry(10, 10, 80, 30);
    buttonInfo->setMaximumWidth(80);

    QPushButton *buttonQuit = new QPushButton("Quit", &window);
    //buttonQuit->setGeometry(10, 10, 110, 30);
    buttonQuit->setMinimumWidth(110);

    QObject::connect(buttonInfo, SIGNAL(clicked()), qApp, SLOT(aboutQt()));
    QObject::connect(buttonQuit, SIGNAL(clicked()), qApp, SLOT(quit()));

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(buttonInfo);
    layout->addWidget(buttonQuit);
    layout->setAlignment(Qt::AlignCenter);

    window.setLayout(layout);
    window.show();

    return app.exec();
}

denko

First you've should created a horizontal layout and added the buttonInfo widget with Qt::AlignHCenter argument, then created a vertical layout and added the horizontal layout to it and the quitButton widget. Check this code, worked as you wanted to:

#include <qapplication.h>
#include <qpushbutton.h>
#include <qlayout.h>

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

    QApplication app(argc, argv);

    QWidget window;
    window.setFixedSize(200, 100);

    QPushButton *buttonInfo = new QPushButton("Info", &window);
    //buttonInfo->setGeometry(10, 10, 80, 30);
    buttonInfo->setMaximumWidth(80);

    QPushButton *buttonQuit = new QPushButton("Quit", &window);
    //buttonQuit->setGeometry(10, 10, 110, 30);
    buttonQuit->setMinimumWidth(110);

    QObject::connect(buttonInfo, SIGNAL(clicked()), qApp, SLOT(aboutQt()));
    QObject::connect(buttonQuit, SIGNAL(clicked()), qApp, SLOT(quit()));

    QHBoxLayout *hlayout = new QHBoxLayout;
    QVBoxLayout *vlayout = new QVBoxLayout;

    hlayout->addWidget(buttonInfo, 0, Qt::AlignHCenter);

    vlayout->addLayout(hlayout);
    vlayout->addWidget(buttonQuit);
    vlayout->setAlignment(Qt::AlignCenter);

    window.setLayout(vlayout);
    window.show();

    return app.exec();
}

The commented lines doesn't work because you assigned those widgets to a layout, then the layout customizes their size for its needs.