QGraphicsAnchorLayout Class Reference
[QtGui module]

Detailed Description

The QGraphicsAnchorLayout class provides a layout where one can anchor widgets together in Graphics View.

The anchor layout allows developers to specify how widgets should be placed relative to each other, and to the layout itself. The specification is made by adding anchors to the layout by calling addAnchor(), addAnchors() or addCornerAnchors().

Existing anchors in the layout can be accessed with the anchor() function. Items that are anchored are automatically added to the layout, and if items are removed, all their anchors will be automatically removed.

Anchors are always set up between edges of an item, where the "center" is also considered to be an edge. Consider the following example:

     layout->addAnchor(b, Qt::AnchorLeft, a, Qt::AnchorRight);
     layout->addAnchor(b, Qt::AnchorTop, a, Qt::AnchorBottom);

Here, the right edge of item a is anchored to the left edge of item b and the bottom edge of item a is anchored to the top edge of item b, with the result that item b will be placed diagonally to the right and below item b.

The addCornerAnchors() function provides a simpler way of anchoring the corners of two widgets than the two individual calls to addAnchor() shown in the code above. Here, we see how a widget can be anchored to the top-left corner of the enclosing layout:

     layout->addCornerAnchors(a, Qt::TopLeftCorner, layout, Qt::TopLeftCorner);

In cases where anchors are used to match the widths or heights of widgets, it is convenient to use the addAnchors() function. As with the other functions for specifying anchors, it can also be used to anchor a widget to a layout.

     layout->addAnchor(b, Qt::AnchorLeft, c, Qt::AnchorLeft);
     layout->addAnchor(b, Qt::AnchorRight, c, Qt::AnchorRight);

     layout->addAnchors(b, c, Qt::Horizontal);

     layout->addAnchor(a, Qt::AnchorTop, layout, Qt::AnchorTop);
     layout->addAnchor(a, Qt::AnchorLeft, layout, Qt::AnchorLeft);

     layout->addCornerAnchors(a, Qt::TopLeftCorner, layout, Qt::TopLeftCorner);