layout->addWidget() creating problems with full screen

[Rahem027]

I have a dock widget with a bunch of line edits and radio buttons. This is my create dock function which creates and shows the dock:

//initialize main layout of dock
    layout = new QVBoxLayout;

    //initialize dock
    QDockWidget *dock = new QDockWidget("Filters", this);
    dock->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
    dock->setFeatures(QDockWidget::DockWidgetFloatable | QDockWidget::DockWidgetMovable);

    //make group boxes
    QWidget *filters = new QWidget(this);

    //only show book which are not returned yet
    notReturnedOnly = new QCheckBox("Only Show books which are not returned");
    connect(notReturnedOnly, &QCheckBox::clicked, this, &LogWindow::onNotReturnedClicked);
    layout->addWidget(notReturnedOnly);

    createHistory();
    createIssuedBy();
    createBookIssued();
    createClassGroup();
    createRack();
    createPublisher();

    //resetFilters
    resetFilters = new QPushButton("Reset Filters");
    connect(resetFilters, &QPushButton::clicked, this, &LogWindow::reset);
    layout->addWidget(resetFilters, 0, Qt::AlignCenter);

    filters->setLayout(layout);
    dock->setWidget(filters);

    this->addDockWidget(Qt::RightDockWidgetArea, dock);
    dock->show();

This is my createRack() function definition:

QGroupBox *rackFilter = new QGroupBox("Rack Number");
    rack = new QLineEdit;
    QHBoxLayout *rackLayout = new QHBoxLayout;
    rackLayout->addWidget(rack);
    rackFilter->setLayout(rackLayout);

    //layout->addLayout(tempLayout);

    connect(rack, &QLineEdit::editingFinished, this, &LogWindow::onRackNumberEntered);

    completeRack = new QCompleter(rackModel);
    completeRack->setCaseSensitivity(Qt::CaseInsensitive);
    completeRack->setCompletionColumn(0);
    rack->setCompleter(completeRack);

The window is shown using `this->showMaximized() .

If I uncomment the line:
layout->addWidget()

The window shows up like this: 0_1529479971612_screenshot.png .

Interestingly, If I remove any one widget from the dock, the program runs perfectly fine.

[Prince_0912]

Hi @Rahem027 ,
In some cases, it is relevant when a layout is added to a widget. When you set the widget of a QDockWidget or a QScrollArea (with QDockWidget::setWidget() and QScrollArea::setWidget()), the layout must already have been set on the widget. If not, the widget will not be visible.
This might helpful to you.
layout->addStretch(1);

[Rahem027]

@Prince_0912 I didnt get you

[Prince_0912]

@Rahem027 You have to set layout size policy before adding widgets to layout.

[Rahem027]

@Prince_0912 No. Which one should I use?

[Prince_0912]

@Rahem027 I had same problem as your but i solve this in different manner.
I take one button and one groupbox.

in loading form i hide by,
ui->groupBox_mrr->hide();

in button click event i put,
ui->groupBox_mrr->setVisible(!ui->groupBox_mrr->isVisible());

See the property window in this photo.

[Rahem027]

From what I interpreted, I set the size policy of my dockWidget: horizontal is now fixed and vertical, i set to expanding. But the window remains the same.

PS: forgive me if I didn't understand what you said.

[Prince_0912]

@Rahem027 ,
In my case initially my GroupBox is hide by setting
ui->groupBox_mrr->hide();

After that when i click on Mirror Button then GroupBox is appear on display. for that on click function i put,
ui->groupBox_mrr->setVisible(!ui->groupBox_mrr->isVisible());

if you click again in button then GroupBox is hide.

last for the sizepolicy i send you last one photo see ,
parameter of SizePolicy , minimumSize , MaximumSize what i set there.

[Rahem027]

Cant everything be shown at once? It is important