Member Function Documentation
QLayoutItem::QLayoutItem ( Qt::Alignment alignment = 0 )
Constructs a layout item with an alignment. Not all subclasses support alignment.
QLayoutItem::~QLayoutItem () [virtual]
Destroys the QLayoutItem.
Qt::Alignment QLayoutItem::alignment () const
Returns the alignment of this item.
See also setAlignment().
Returns the control type(s) for the layout item. For a QWidgetItem, the control type comes from the widget's size policy; for a QLayoutItem, the control types is derived from the layout's contents.
See also QSizePolicy::controlType().
Qt::Orientations QLayoutItem::expandingDirections () const [pure virtual]
Returns whether this layout item can make use of more space than sizeHint(). A value of Qt::Vertical or Qt::Horizontal means that it wants to grow in only one dimension, whereas Qt::Vertical | Qt::Horizontal means that it wants to grow in both dimensions.
QRect QLayoutItem::geometry () const [pure virtual]
Returns the rectangle covered by this layout item.
See also setGeometry().
bool QLayoutItem::hasHeightForWidth () const [virtual]
Returns true if this layout's preferred height depends on its width; otherwise returns false. The default implementation returns false.
Reimplement this function in layout managers that support height for width.
See also heightForWidth() and QWidget::heightForWidth().
int QLayoutItem::heightForWidth ( int w ) const [virtual]
Returns the preferred height for this layout item, given the width w.
The default implementation returns -1, indicating that the preferred height is independent of the width of the item. Using the function hasHeightForWidth() will typically be much faster than calling this function and testing for -1.
Reimplement this function in layout managers that support height for width. A typical implementation will look like this:
int MyLayout::heightForWidth(int w) const
{
if (cache_dirty || cached_width != w) {
MyLayout *that = (MyLayout*)this;
int h = calculateHeightForWidth(w);
that->cached_hfw = h;
return h;
}
return cached_hfw;
}
Caching is strongly recommended; without it layout will take exponential time.
See also hasHeightForWidth().
void QLayoutItem::invalidate () [virtual]
Invalidates any cached information in this layout item.
bool QLayoutItem::isEmpty () const [pure virtual]
Implemented in subclasses to return whether this item is empty, i.e. whether it contains any widgets.
QLayout * QLayoutItem::layout () [virtual]
If this item is a QLayout, it is returned as a QLayout; otherwise 0 is returned. This function provides type-safe casting.
QSize QLayoutItem::maximumSize () const [pure virtual]
Implemented in subclasses to return the maximum size of this item.
int QLayoutItem::minimumHeightForWidth ( int w ) const [virtual]
Returns the minimum height this widget needs for the given width, w. The default implementation simply returns heightForWidth(w).
QSize QLayoutItem::minimumSize () const [pure virtual]
Implemented in subclasses to return the minimum size of this item.
void QLayoutItem::setAlignment ( Qt::Alignment alignment )
Sets the alignment of this item to alignment.
Note: Item alignment is only supported by QLayoutItem subclasses where it would have a visual effect. Except for QSpacerItem, which provides blank space for layouts, all public Qt classes that inherit QLayoutItem support item alignment.
See also alignment().
void QLayoutItem::setGeometry ( const QRect & r ) [pure virtual]
Implemented in subclasses to set this item's geometry to r.
See also geometry().
QSize QLayoutItem::sizeHint () const [pure virtual]
Implemented in subclasses to return the preferred size of this item.
QSpacerItem * QLayoutItem::spacerItem () [virtual]
If this item is a QSpacerItem, it is returned as a QSpacerItem; otherwise 0 is returned. This function provides type-safe casting.
QWidget * QLayoutItem::widget () [virtual]
If this item is a QWidget, it is returned as a QWidget; otherwise 0 is returned. This function provides type-safe casting.
