QSizePolicy Class Reference

A layout attribute describing horizontal and vertical resizing. More...

#include <qsizepolicy.h>

List of all member functions.

Public Members

• enum SizeType { Fixed = 0, Minimum = MayGrow, Maximum = MayShrink, Preferred = MayGrow|MayShrink, MinimumExpanding = Minimum|ExpMask, Expanding = MinimumExpanding|MayShrink }
• enum ExpandData { NoDirection = 0, Horizontal = 1, Vertical = 2, BothDirections = Horizontal | Vertical }
• QSizePolicy () 
• QSizePolicy ( SizeType hor, SizeType ver, bool hfw = FALSE ) 
• SizeType horData () const
• SizeType verData () const
• bool mayShrinkHorizontally () const
• bool mayShrinkVertically () const
• bool mayGrowHorizontally () const
• bool mayGrowVertically () const
• ExpandData expanding () const
• void setHorData ( SizeType d ) 
• void setVerData ( SizeType d ) 
• void setHeightForWidth ( bool b ) 
• bool hasHeightForWidth () const

Detailed Description

Widgets which override QWidget::sizePolicy() return a QSizePolicy describing the horizontal and vertical resizing policy best used when laying out the widget.

Only the constructor is of interest in most applications.

Member Type Documentation

QSizePolicy::SizeType

• Fixed - the sizeHint() is the only acceptable alternative, so never grow or shrink (eg. the vertical direction of a pushbutton)
• Minimum - the sizeHint() is minimal, and sufficient. The widget can be expanded, but there is no advantage to it being larger. (eg. the horizontal direction of a pushbutton)
• Maximum - the sizeHint() is a maximum, the widget can be shrunk any amount without detriment if other widgets need the space (eg. a separator line)
• Preferred - the sizeHint() is best, but the widget can be shrunk below that and still be useful. The widget can be expanded, but there is no advantage to it being larger than sizeHint() (the default QWidget policy)
• MinimumExpanding - the sizeHint() is a minimum, the widget can make use of extra space, so it should get as much space as possible. (not currently used by any standard Qt widgets)
• Expanding - the sizeHint() is a sensible size, but the widget can be shrunk below that and still be useful. The widget can make use of extra space, so it should get as much space as possible. (eg. the horizontal direction of a slider)

Member Function Documentation

QSizePolicy::QSizePolicy ()

Default constructor, produces a minimally initialized QSizePolicy.

QSizePolicy::QSizePolicy ( SizeType hor, SizeType ver, bool hfw = FALSE )

This is the constructor normally used to return a value in the overridden sizeHint() function of a QWidget subclass.

It constructs a QSizePolicy with independent horizontal and vertical sizing types, hor and ver respectively. These sizing types affect how the widget is treated by the link QLayout layout engine\endlink.

If hfw is TRUE, the preferred height of the widget is dependent on the width of the widget (for example, a QLabel with automatic word-breaking).

bool QSizePolicy::hasHeightForWidth () const

Returns TRUE if the widget's preferred height depends on its width.

QSizePolicy::SizeType QSizePolicy::horData() const

Returns the horizontal component of the size policy.

bool QSizePolicy::mayGrowHorizontally () const

Returns TRUE if the widget can sensibly be wider than its sizeHint().

bool QSizePolicy::mayGrowVertically () const

Returns TRUE if the widget can sensibly be taller than its sizeHint().

bool QSizePolicy::mayShrinkHorizontally () const

Returns TRUE if the widget can sensibly be narrower than its sizeHint().

bool QSizePolicy::mayShrinkVertically () const

Returns TRUE if the widget can sensibly be lower than its sizeHint().

void QSizePolicy::setHeightForWidth ( bool b )

Sets the hasHeightForWidth() flag to b.

void QSizePolicy::setHorData ( SizeType d )

Sets the horizontal component of the size policy to d.

void QSizePolicy::setVerData ( SizeType d )

Sets the vertical component of the size policy to d.

QSizePolicy::SizeType QSizePolicy::verData() const

Returns the vertical component of the size policy.

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