QSizePolicy Class Reference
^{[QtGui module]}

Detailed Description

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

The size policy of a widget is an expression of its willingness to be resized in various ways.

Widgets that reimplement QWidget::sizePolicy() return a QSizePolicy that describes the horizontal and vertical resizing policy they prefer when being laid out.

QSizePolicy contains two independent QSizePolicy::Policy values and two stretch factors; one describes the widgets's horizontal size policy, and the other describes its vertical size policy. It also contains a flag to indicate whether the height and width of its preferred size are related.

The horizontal and vertical policies are set in the usual constructor and can be queried using horizontalPolicy() and verticalPolicy().

The hasHeightForWidth() flag indicates whether the widget's sizeHint() is width-dependent (such as a menu bar or a word-wrapping label).

See also QSize, QWidget::sizeHint(), QWidget::sizePolicy(), and QLayoutItem::sizeHint().

Member Type Documentation

enum QSizePolicy::Policy

The per-dimension sizing types used when constructing a QSizePolicy are:

See also PolicyFlag.

enum QSizePolicy::PolicyFlag

These flags are combined together to form the various Policy values:

See also Policy.

Member Function Documentation

QSizePolicy::QSizePolicy ()

Constructs a QSizePolicy with Fixed as its horizontal and vertical policies.

See also setHorizontalPolicy(), setVerticalPolicy(), setHorizontalStretch(), setVerticalStretch(), and setHeightForWidth().

QSizePolicy::QSizePolicy ( Policy horizontal, Policy vertical )

It constructs a QSizePolicy with independent horizontal and vertical policies, horizontal and vertical respectively. These policies affect how the widget is treated by the layout engine.

Use setHeightForWidth() if the preferred height of the widget is dependent on the width of the widget (for example, a QLabel with line wrapping).

See also horizontalPolicy(), verticalPolicy(), and setHeightForWidth().

Qt::Orientations QSizePolicy::expandingDirections () const

Returns whether this widget can make use of more space than sizeHint(). A value of Qt::Horizontal or Qt::Vertical means that the widget wants to grow horizontally or vertically (i.e., the horizontal or vertical policy is Expanding or MinimumExpanding), whereas Qt::Horizontal | Qt::Vertical means that it wants to grow in both dimensions.

See also horizontalPolicy() and verticalPolicy().

bool QSizePolicy::hasHeightForWidth () const

Returns true if the widget's preferred height depends on its width; otherwise returns false.

See also setHeightForWidth().

Policy QSizePolicy::horizontalPolicy () const

Returns the horizontal component of the size policy.

See also setHorizontalPolicy(), verticalPolicy(), and horizontalStretch().

int QSizePolicy::horizontalStretch () const

Returns the horizontal stretch factor of the size policy.

See also setHorizontalStretch() and verticalStretch().

void QSizePolicy::setHeightForWidth ( bool hfw )

Sets the hasHeightForWidth() flag to hfw.

See also hasHeightForWidth().

void QSizePolicy::setHorizontalPolicy ( Policy policy )

Sets the horizontal component of the size policy to policy.

See also horizontalPolicy() and setVerticalPolicy().

void QSizePolicy::setHorizontalStretch ( uchar stretch )

Sets the horizontal stretch factor of the size policy to stretch.

See also horizontalStretch() and setVerticalStretch().

void QSizePolicy::setVerticalPolicy ( Policy policy )

Sets the vertical component of the size policy to policy.

See also verticalPolicy() and setHorizontalPolicy().

void QSizePolicy::setVerticalStretch ( uchar stretch )

Sets the vertical stretch factor of the size policy to stretch.

See also verticalStretch() and setHorizontalStretch().

void QSizePolicy::transpose ()

Swaps the horizontal and vertical policies and stretches.

Policy QSizePolicy::verticalPolicy () const

Returns the vertical component of the size policy.

See also setVerticalPolicy(), horizontalPolicy(), and verticalStretch().

int QSizePolicy::verticalStretch () const

Returns the vertical stretch factor of the size policy.

See also setVerticalStretch() and horizontalStretch().

QSizePolicy::operator QVariant () const

Returns a QVariant storing this QSizePolicy.

bool QSizePolicy::operator!= ( const QSizePolicy & other ) const

Returns true if this policy is different from other; otherwise returns false.

See also operator==().

bool QSizePolicy::operator== ( const QSizePolicy & other ) const

Returns true if this policy is equal to other; otherwise returns false.

See also operator!=().