Qwt User's Guide
QwtDynGridLayout Class Reference

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

#include <qwt_dyngrid_layout.h>

Public Member Functions

 QwtDynGridLayout (QWidget *, int margin=0, int space=-1)
 QwtDynGridLayout (int space=-1)
virtual ~QwtDynGridLayout ()
 Destructor.
virtual void invalidate ()
 Invalidate all internal caches.
void setMaxColumns (uint maxCols)
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 numCols) 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 numCols, QVector< int > &rowHeight, QVector< int > &colWidth) const
void stretchGrid (const QRect &rect, uint numCols, 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:
parentParent widget
marginMargin
spacingSpacing
QwtDynGridLayout::QwtDynGridLayout ( int  spacing = -1) [explicit]
Parameters:
spacingSpacing

Member Function Documentation

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

Add an item to the next free position.

Parameters:
itemLayout 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:
widthAvailable 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:
indexIndex
Returns:
Item at a specific index
See also:
takeAt()
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:
numColumnsNumber of columns.
rowHeightArray where to fill in the calculated row heights.
colWidthArray 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:
rectRect where to place the items
numColumnsNumber of columns
Returns:
item geometries

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
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:
expandingOr'd orientations
See also:
expandingDirections()
void QwtDynGridLayout::setGeometry ( const QRect &  rect) [virtual]

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

Parameters:
rectLayout geometry
void QwtDynGridLayout::setMaxColumns ( uint  maxColumns)

Limit the number of columns.

Parameters:
maxColumnsupper 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:
rectBounding rectangle
numColumnsNumber of columns
rowHeightArray to be filled with the calculated row heights
colWidthArray 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:
indexIndex
Returns:
Layout item, removed from the layout
See also:
itemAt()

List of all members.

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