How to anchor pushButton to the widget ??

Question

Hi, I'm QT beginner.

I've created very simple window with one button on it. My button id 10 pixels from right edge of the window and 10 from the bottom. I'd like to keep this position even when the window will get resized. That means, still 10 from the right and 10 from the bottom.

How to do this ??

Thanks

zalkap

Answer 1

Install a QGridLayout on the widget with 2 columns and 2 rows, add the button on the bottom-right cell, then set the first row and the first column to stretch.

QWidget *widget = new QWidget(); // The main window
QGridLayout *layout = new QGridLayout(widget); // The layout
QPushButton *button = new QPushButton(QString("Button"), widget); // The button

layout->setContentsMargin(10,10,10,10); // To have 10 pixels margins all around the widget
layout->addWidget(button, 1, 1);
layout->setRowStretch(0, 1);
layout->setColumnStretch(0, 1);

Answer 2

In general, use a layout. It's the easiest and most robust solution, and it works best with unpredictable widget sizes (and they are unpredictable in most cases, due to different platforms, font sizes, translated strings etc.). If you really need to position something manually (doesn't happen often), you can reimplement resizeEvent() in the parent and move the children yourself. E.g.

void MyParentWidget::resizeEvent( QResizeEvent* ) {
    m_child->move( width() - m_child->width() - 10, height() - m_child->height() - 10 ); 
}

This moves the child to the bottom-right corner.