QwtDynGridLayout - Man Page

The QwtDynGridLayout class lays out widgets in a grid, adjusting the number of columns and rows to the current size.

Synopsis

#include <qwt_dyngrid_layout.h>

Inherits QLayout.

Public Member Functions

QwtDynGridLayout (QWidget *, int margin=0, int spacing=-1)
QwtDynGridLayout (int spacing=-1)
virtual ~QwtDynGridLayout ()
Destructor.
virtual void invalidate ()
Invalidate all internal caches.
void setMaxColumns (uint maxColumns)
uint maxColumns () const
Return the upper limit for the number of columns.
uint numRows () const
uint numColumns () const
virtual void addItem (QLayoutItem *)
Add an item to the next free position.
virtual QLayoutItem * itemAt (int index) const
virtual QLayoutItem * takeAt (int index)
virtual int count () const
void setExpandingDirections (Qt::Orientations)
virtual Qt::Orientations expandingDirections () const
Returns whether this layout can make use of more space than sizeHint().
QList< QRect > layoutItems (const QRect &, uint numColumns) const
virtual int maxItemWidth () const
virtual void setGeometry (const QRect &rect)
virtual bool hasHeightForWidth () const
virtual int heightForWidth (int) const
virtual QSize sizeHint () const
virtual bool isEmpty () const
uint itemCount () const
virtual uint columnsForWidth (int width) const
Calculate the number of columns for a given width.

Protected Member Functions

void layoutGrid (uint numColumns, QVector< int > &rowHeight, QVector< int > &colWidth) const
void stretchGrid (const QRect &rect, uint numColumns, QVector< int > &rowHeight, QVector< int > &colWidth) const

Detailed Description

The QwtDynGridLayout class lays out widgets in a grid, adjusting the number of columns and rows to the current size.

QwtDynGridLayout takes the space it gets, divides it up into rows and columns, and puts each of the widgets it manages into the correct cell(s). It lays out as many number of columns as possible (limited by maxColumns()).

Constructor & Destructor Documentation

QwtDynGridLayout::QwtDynGridLayout (QWidget * parent, int margin = 0, int spacing = -1) [explicit]

Parameters

parent Parent widget
margin Margin
spacing Spacing

QwtDynGridLayout::QwtDynGridLayout (int spacing = -1) [explicit]

Parameters

spacing Spacing

Member Function Documentation

void QwtDynGridLayout::addItem (QLayoutItem * item) [virtual]

Add an item to the next free position.

Parameters

item Layout item

uint QwtDynGridLayout::columnsForWidth (int width) const [virtual]

Calculate the number of columns for a given width. The calculation tries to use as many columns as possible ( limited by maxColumns() )

Parameters

width Available width for all columns

Returns

Number of columns for a given width

See also

maxColumns(), setMaxColumns()

int QwtDynGridLayout::count () const [virtual]

Returns

Number of items in the layout

Qt::Orientations QwtDynGridLayout::expandingDirections () const [virtual]

Returns whether this layout 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, while Qt::Vertical | Qt::Horizontal means that it wants to grow in both dimensions.

Returns

Orientations, where the layout expands

See also

setExpandingDirections()

bool QwtDynGridLayout::hasHeightForWidth () const [virtual]

Returns

true: QwtDynGridLayout implements heightForWidth().

See also

heightForWidth()

int QwtDynGridLayout::heightForWidth (int width) const [virtual]

Returns

The preferred height for this layout, given a width.

See also

hasHeightForWidth()

bool QwtDynGridLayout::isEmpty () const [virtual]

Returns

true if this layout is empty.

QLayoutItem * QwtDynGridLayout::itemAt (int index) const [virtual]

Find the item at a specific index

Parameters

index Index

Returns

Item at a specific index

See also

takeAt()

uint QwtDynGridLayout::itemCount () const

Returns

number of layout items

void QwtDynGridLayout::layoutGrid (uint numColumns, QVector< int > & rowHeight, QVector< int > & colWidth) const [protected]

Calculate the dimensions for the columns and rows for a grid of numColumns columns.

Parameters

numColumns Number of columns.
rowHeight Array where to fill in the calculated row heights.
colWidth Array where to fill in the calculated column widths.

QList< QRect > QwtDynGridLayout::layoutItems (const QRect & rect, uint numColumns) const

Calculate the geometries of the layout items for a layout with numColumns columns and a given rectangle.

Parameters

rect Rect where to place the items
numColumns Number of columns

Returns

item geometries

uint QwtDynGridLayout::maxColumns () const

Return the upper limit for the number of columns. 0 means unlimited, what is the default.

Returns

Upper limit for the number of columns

See also

setMaxColumns()

int QwtDynGridLayout::maxItemWidth () const [virtual]

Returns

the maximum width of all layout items

uint QwtDynGridLayout::numColumns () const

Returns

Number of columns of the current layout.

See also

numRows()

Warning

The number of columns might change whenever the geometry changes

uint QwtDynGridLayout::numRows () const

Returns

Number of rows of the current layout.

See also

numColumns()

Warning

The number of rows might change whenever the geometry changes

void QwtDynGridLayout::setExpandingDirections (Qt::Orientations expanding)

Set whether this layout 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, while Qt::Vertical | Qt::Horizontal means that it wants to grow in both dimensions. The default value is 0.

Parameters

expanding Or'd orientations

See also

expandingDirections()

void QwtDynGridLayout::setGeometry (const QRect & rect) [virtual]

Reorganizes columns and rows and resizes managed items within a rectangle.

Parameters

rect Layout geometry

void QwtDynGridLayout::setMaxColumns (uint maxColumns)

Limit the number of columns.

Parameters

maxColumns upper limit, 0 means unlimited

See also

maxColumns()

QSize QwtDynGridLayout::sizeHint () const [virtual]

Return the size hint. If maxColumns() > 0 it is the size for a grid with maxColumns() columns, otherwise it is the size for a grid with only one row.

Returns

Size hint

See also

maxColumns(), setMaxColumns()

void QwtDynGridLayout::stretchGrid (const QRect & rect, uint numColumns, QVector< int > & rowHeight, QVector< int > & colWidth) const [protected]

Stretch columns in case of expanding() & QSizePolicy::Horizontal and rows in case of expanding() & QSizePolicy::Vertical to fill the entire rect. Rows and columns are stretched with the same factor.

Parameters

rect Bounding rectangle
numColumns Number of columns
rowHeight Array to be filled with the calculated row heights
colWidth Array to be filled with the calculated column widths

See also

setExpanding(), expanding()

QLayoutItem * QwtDynGridLayout::takeAt (int index) [virtual]

Find the item at a specific index and remove it from the layout

Parameters

index Index

Returns

Layout item, removed from the layout

See also

itemAt()

Author

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Info

Mon Jun 1 2020 Version 6.1.5 Qwt User's Guide