Fixed-size widget in a layout



  • Hi, I need to have a fixed-size widget in a layout and it isn't working that well. The simplified example would be:

    @#include <QApplication>
    #include <QMainWindow>
    #include <QHBoxLayout>
    #include <QTextEdit>
    #include <QPushButton>

    int main(int argc, char * * argv)
    {
    QApplication application(argc, argv);

    QMainWindow mainWindow;
    
    QWidget * const widget = new QWidget;
    mainWindow.setCentralWidget(widget);
    
    QHBoxLayout * const layout = new QHBoxLayout;
    layout->setMargin(0);
    layout->setSpacing(0);
    widget->setLayout(layout);
    
    QTextEdit * const textEdit = new QTextEdit;
    layout->addWidget(textEdit);
    
    QPushButton * const pushButton = new QPushButton("A");
    pushButton->setFixedSize(25, 25);
    layout->addWidget(pushButton);
    
    mainWindow.show();
    
    return application.exec&#40;&#41;;
    

    }@

    Which gives me some unexpected results:

    !http://i.imgur.com/OzpG6M0.png!

    Am I not supposed to put fixed-size widgets in layouts? Should I create my own class for every fixed-size widget I need and override sizeHint() method?

    I'd be grateful if someone could clarify that for me.


  • Qt Champions 2017

    You can do it. In general use the sizePolicy of Layout. This will help you to do the required thing. Set the sizePolicy of QPushButton to setSizePolicy(QSizePolicy::Fixed,QSizePolicy::Fixed). This should work. You don't have to sub-class.



  • I have a similar problem, only difference is I am using qtcreator 2.8.1;

    I have 3 panels within the MainWindow, I want to set the relative size of the panels, the panel with start/quit button small, the status log button also small and the main instructions panel relatively large.

    How do I do that?


  • Qt Champions 2017

    As guidline, you can use the stretch factor while adding the widgets to layout and use the sizepolicy to handle your case.

    If you can give your code snippet it would help. I can make it work and share you the piece of sample for you.



  • Unfortunately sizePolicy didn't do it. I added

    @pushButton->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);@

    to the previous code and the result is exactly the same.

    As I understand it, sizePolicy relates to sizeHint, so for it to work I would have to subclass the widget and override the sizeHint() method like I said before. Am I wrong?



  • I had a similar issue with the QDial; I simply set the min/max sizes to be the same in QtCreator 2.8.1;



  • Hi,
    Try this one:
    @
    minimumSizeHint : const QSize
    @
    QWidget docs -> also set sizepolicy to something else then ignore. That should do the trick ;-)


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