How to make widgets automatically stretch to the parent widget's size in Qt Designer

Question

I need to add a TabWidget control to the MainWindow and place TableWidget in every tab it has. The problem is that I need to make them automatically stretch to the parent widget's size ( TabWidget to the window's size, TableWidget 's to the TabWidget 's size).

What is the easiest way to achieve it via Qt Designer?

Answer 1

You should use Qt layouts.

In designer you have to select the widget you want to have its children laid out properly, then choose Form -> Lay Out Vertically/Horizontally/... shortcuts: Ctrl+1...6

Answer 2

Below is an example program that will create a view as you needed. Logic is Mainwindow-> Central Widget-> Add Vertical Layout-> Add Tab Widget
->Add Tab 1->Add V Box Layout -> Add Table 1 (5 X 5)
->Add Tab 2->Add V Box Layout -> Add Table 1 (5 X 5)

Code comment will explain in detail.

void MainWindow::fnInit()
{
    //Layout to the MainWindow
    QVBoxLayout *vLayoutMain;
    QTabWidget *Tab;
    QWidget *Widget1;
    //Layout to the Tab1
    QVBoxLayout *vLayoutTab1;
    QTableWidget *Table1;
    QWidget *Widget2;
    //Layout to the Tab2
    QVBoxLayout *vLayoutTab2;
    QTableWidget *Table2;

    //Set Vertical Box Layout to the main Window (central widget)
    vLayoutMain = new QVBoxLayout(this->centralWidget());
    Tab = new QTabWidget(this->centralWidget());

    Widget1 = new QWidget();
    //Set the Vertical Box Layout to the Widget 1 (holds the tab1)
    vLayoutTab1 = new QVBoxLayout(Widget1);
    Table1 = new QTableWidget(5,5,Widget1);
    vLayoutTab1->addWidget(Table1);
    Tab->addTab(Widget1, QString("Tab 1"));

    Widget2 = new QWidget();
    //Set the Vertical Box Layout to the Widget 2 (holds the tab2)
    vLayoutTab2 = new QVBoxLayout(Widget2);
    Table2 = new QTableWidget(5,5,Widget2);
    vLayoutTab2->addWidget(Table2);

    Tab->addTab(Widget2, QString("Tab 2"));

    //Adding the Tab widget to the main layout
    vLayoutMain->addWidget(Tab);
    Tab->setCurrentIndex(0);
}