QWidget over and outside parent QMainwindow

jacobP

I have a mainWindow and a widget that will be a child of that main window. Below is a code example created with QTCreator.

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    //create test widget
        QWidget* blue_widget = new QWidget(); //no parent
        blue_widget->setFixedSize(100,100);
        blue_widget->setStyleSheet("background-color:blue;");
        blue_widget->setWindowFlags(Qt::FramelessWindowHint | Qt::Tool );
        blue_widget->setVisible(true);
        //create test widget END

        blue_widget->setParent(this);
        blue_widget->move(-50,-10);

        show();
}

MainWindow::~MainWindow()
{
    delete ui;
}

Right now I can only see the part of the blue_widget that is inside the boundaries of the main window. I would like to be able to have the totality of the blue_widget shown. How can I prevent the main window cutting the blue_widget like that ? I really need to have the blue_widget to be a child of the main window.

Thanks for the help.

SGaist

Hi,

Why not set it as central widget ? Or put it in a QDockWidget ?

Jeroentjehome

Hi,
You should set the blue_widget as the central widget of the MainWindow, or fill the MainWindow with a QWidget in designer and set your blueWidget to that one. In designer you should set MainWindow to be e.g. a GridLayout, or any other layout. Leaving the MAinWindow without a layout will not force you Blue Widget to resize according the MainWindow size.

mrjj

Hi
As long as the widget is a child of the mainwindow, it will be clipped to it.
To have a floating window that is not clipped to parent, you can use QDialogs or
simply do not set the parent. ( you must manually delete it then)

Its by design that widgets are clipped. So you must make it a true window type ( as Dialog is) ( or using Qt::Window flag)
or dont give it parent.

http://doc.qt.io/qt-5/application-windows.html