QGraphicsGridLayout Class

Detailed Description

The most common way to use QGraphicsGridLayout is to construct an object on the heap with no parent, add widgets and layouts by calling addItem(), and finally assign the layout to a widget by calling QGraphicsWidget::setLayout(). QGraphicsGridLayout automatically computes the dimensions of the grid as you add items.

 QGraphicsScene scene;
 QGraphicsWidget *textEdit = scene.addWidget(new QTextEdit);
 QGraphicsWidget *pushButton = scene.addWidget(new QPushButton);

 QGraphicsGridLayout *layout = new QGraphicsGridLayout;
 layout->addItem(textEdit, 0, 0);
 layout->addItem(pushButton, 0, 1);

 QGraphicsWidget *form = new QGraphicsWidget;
 form->setLayout(layout);
 scene.addItem(form);

The layout takes ownership of the items. In some cases when the layout item also inherits from QGraphicsItem (such as QGraphicsWidget) there will be a ambiguity in ownership because the layout item belongs to two ownership hierarchies. See the documentation of QGraphicsLayoutItem::setOwnedByLayout() how to handle this. You can access each item in the layout by calling count() and itemAt(). Calling removeAt() will remove an item from the layout, without destroying it.

Size Hints and Size Policies in QGraphicsGridLayout

QGraphicsGridLayout respects each item's size hints and size policies, and when a cell in the grid has more space than the items can fill, each item is arranged according to the layout's alignment for that item. You can set an alignment for each item by calling setAlignment(), and check the alignment for any item by calling alignment(). You can also set the alignment for an entire row or column by calling setRowAlignment() and setColumnAlignment() respectively. By default, items are aligned to the top left.