QAbstractItemView Class Reference
[QtGui module]

Detailed Description

The QAbstractItemView class provides the basic functionality for item view classes.

QAbstractItemView class is the base class for every standard view that uses a QAbstractItemModel. QAbstractItemView is an abstract class and cannot itself be instantiated. It provides a standard interface for interoperating with models through the signals and slots mechanism, enabling subclasses to be kept up-to-date with changes to their models. This class provides standard support for keyboard and mouse navigation, viewport scrolling, item editing, and selections. The keyboard navigation implements this functionality:

Note that the above table assumes that the selection mode allows the operations. For instance, you cannot select items if the selection mode is QAbstractItemView::NoSelection.

The QAbstractItemView class is one of the Model/View Classes and is part of Qt's model/view framework.

The view classes that inherit QAbstractItemView only need to implement their own view-specific functionality, such as drawing items, returning the geometry of items, finding items, etc.

QAbstractItemView provides common slots such as edit() and setCurrentIndex(). Many protected slots are also provided, including dataChanged(), rowsInserted(), rowsAboutToBeRemoved(), selectionChanged(), and currentChanged().

The root item is returned by rootIndex(), and the current item by currentIndex(). To make sure that an item is visible use scrollTo().

Some of QAbstractItemView's functions are concerned with scrolling, for example setHorizontalScrollMode() and setVerticalScrollMode(). To set the range of the scroll bars, you can, for example, reimplement the view's resizeEvent() function:

 void MyView::resizeEvent(QResizeEvent *event) {
     horizontalScrollBar()->setRange(0, realWidth - width());
     ...
 }

Note that the range is not updated until the widget is shown.

Several other functions are concerned with selection control; for example setSelectionMode(), and setSelectionBehavior(). This class provides a default selection model to work with (selectionModel()), but this can be replaced by using setSelectionModel() with an instance of QItemSelectionModel.

For complete control over the display and editing of items you can specify a delegate with setItemDelegate().

QAbstractItemView provides a lot of protected functions. Some are concerned with editing, for example, edit(), and commitData(), whilst others are keyboard and mouse event handlers.

Note: If you inherit QAbstractItemView and intend to update the contents of the viewport, you should use viewport->update() instead of update() as all painting operations take place on the viewport.

See also View Classes, Model/View Programming, QAbstractItemModel, and Chart Example.

Member Type Documentation

 setIndexWidget(index, new QLineEdit);
 ...
 setIndexWidget(index, new QTextEdit);

 QItemSelectionModel *m = view->selectionModel();
 view->setModel(new model);
 delete m;