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The abstract items which a QLayout manipulates. More...
#include <qabstractlayout.h>
Inherited by QLayout, QSpacerItem and QWidgetItem.
For custom layouts.
See also QLayout.
Constructs a layout item with an alignment that is a bitwise OR of Qt::AlignmentFlags. Alignment may not be supported by all subclasses.
[virtual]Destructs the QLayoutItem.
Returns the alignment of this item.
[virtual]Implemented in subclasses to return whether this item "wants" to expand.
Reimplemented in QSpacerItem, QWidgetItem, QBoxLayout, QGridLayout and QLayout.
[virtual]Returns the rectangle covered by this layout item.
Reimplemented in QWidgetItem, QLayout and QSpacerItem.
[virtual]Returns TRUE if this layout's preferred height depends on its width. The default implementation returns FALSE;
Reimplement this function in layout managers that support height for width.
See also heightForWidth() and QWidget::heightForWidth().
Reimplemented in QBoxLayout, QGridLayout and QWidgetItem.
[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 ) {
//Not all C++ compilers support "mutable" yet:
MyLayout * mthis = (MyLayout*)this;
int h = calculateHeightForWidth( w );
mthis->cached_hfw = h;
return h;
}
return cached_hfw;
}
Caching is strongly recommended, without it layout will take exponential time.
See also hasHeightForWidth().
Reimplemented in QGridLayout, QWidgetItem and QBoxLayout.
[virtual]Invalidates any cached information in this layout item.
Reimplemented in QBoxLayout, QLayout and QGridLayout.
[virtual]Implemented in subclasses to return whether this item is empty, i.e. whether it contains any widgets.
Reimplemented in QLayout, QWidgetItem and QSpacerItem.
[virtual]Returns an iterator over this item's QLayoutItem children. The default implementation returns an empty iterator.
Reimplement this function in subclasses that can have children.
Reimplemented in QGridLayout, QLayout and QBoxLayout.
[virtual]If this item is a QLayout, return it as a QLayout, otherwise return 0. This function provides type-safe casting.
Reimplemented in QLayout.
[virtual]Implemented in subclasses to return the maximum size of this item.
Reimplemented in QLayout, QSpacerItem, QGridLayout, QWidgetItem and QBoxLayout.
[virtual]Implemented in subclasses to return the minimum size of this item.
Reimplemented in QSpacerItem, QGridLayout, QBoxLayout, QLayout and QWidgetItem.
[virtual]Sets the alignment of this item to a, which is a bitwise OR of Qt::AlignmentFlags.
[virtual]Implemented in subclasses to set this item's geometry to r.
Reimplemented in QWidgetItem, QBoxLayout, QGridLayout, QLayout and QSpacerItem.
[virtual]Implemented in subclasses to return the preferred size of this item.
Reimplemented in QWidgetItem, QBoxLayout, QSpacerItem and QGridLayout.
[virtual]If this item is a QSpacerItem, return it as a QSpacerItem, otherwise return 0. This function provides type-safe casting.
Reimplemented in QSpacerItem.
[virtual]If this item is a QWidgetItem, the managed widget is returned. The default implementation returns 0;.
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