QSizePolicy Class

The QSizePolicy class is a layout attribute describing horizontal and vertical resizing policy. More…

Header	`#include <QSizePolicy>`
CMake	`target_link_libraries(app PRIVATE Nt::Widgets)`
Module	Nt Widgets C++ Classes

List of all members, including inherited members

Public Types

enum	PolicyFlag
enum	Policy

Public Functions

	QSizePolicy()
	QSizePolicy(Policy horizontal, Policy vertical)
Policy	horizontalPolicy() const
Policy	verticalPolicy() const
void	setHorizontalPolicy(Policy policy)
void	setVerticalPolicy(Policy policy)
int	horizontalStretch() const
int	verticalStretch() const
void	setHorizontalStretch(int stretch)
void	setVerticalStretch(int stretch)
Qt::Orientations	expandingDirections() const

Detailed Description

A widget's size policy tells layouts how it may be resized. Each direction has a policy: whether the widget can grow beyond its size hint, shrink below it, and whether it wants to take extra space.

label->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);

See also QWidget::setSizePolicy() and QLayout.

Differences from Qt

There is no height-for-width support, retainSizeWhenHidden(), ControlType or transposed(). The policy is a plain value with the stretch factors, which the box layouts of Nt do not use: use QBoxLayout::addWidget()'s stretch argument.

Member Type Documentation

enum QSizePolicy::Policy

This enum describes how a widget can be resized in one direction.

Constant	Description
`QSizePolicy::Fixed`	The size hint is the only size that the widget can have.
`QSizePolicy::Minimum`	The size hint is the smallest size; the widget can grow.
`QSizePolicy::Maximum`	The size hint is the largest size; the widget can shrink.
`QSizePolicy::Preferred`	The size hint is best, but the widget can grow and shrink.
`QSizePolicy::MinimumExpanding`	The size hint is the smallest size; the widget can grow and wants to.
`QSizePolicy::Expanding`	The size hint is a sensible size; the widget can grow and shrink and wants to grow.
`QSizePolicy::Ignored`	The size hint is ignored; the widget gets as much space as it can.

enum QSizePolicy::PolicyFlag

These flags make up the policies. A policy is a combination of them.

Constant	Description
`QSizePolicy::GrowFlag`	The widget can grow beyond its size hint if necessary.
`QSizePolicy::ExpandFlag`	The widget wants to get as much space as possible.
`QSizePolicy::ShrinkFlag`	The widget can shrink below its size hint if necessary.
`QSizePolicy::IgnoreFlag`	The size hint is ignored; the widget gets as much space as it can.