Qt 4.2: QGridLayout Class Reference

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# QGridLayout Class Reference
[QtGui module]

The QGridLayout class lays out widgets in a grid. More...

     #include <QGridLayout>

Inherits QLayout.

- List of all members, including inherited members
- Qt 3 support members

### Public Functions

- QGridLayout ( QWidget * parent )
- QGridLayout ()
- ~QGridLayout ()
- void addItem ( QLayoutItem * item, int row, int column, int rowSpan = 1, int columnSpan = 1, Qt::Alignment alignment = 0 )
- void addLayout ( QLayout * layout, int row, int column, Qt::Alignment alignment = 0 )
- void addLayout ( QLayout * layout, int row, int column, int rowSpan, int columnSpan, Qt::Alignment alignment = 0 )
- void addWidget ( QWidget * widget, int row, int column, Qt::Alignment alignment = 0 )
- void addWidget ( QWidget * widget, int fromRow, int fromColumn, int rowSpan, int columnSpan, Qt::Alignment alignment = 0 )
- QRect cellRect ( int row, int column ) const
- int columnCount () const
- int columnMinimumWidth ( int column ) const
- int columnStretch ( int column ) const
- void getItemPosition ( int index, int * row, int * column, int * rowSpan, int * columnSpan )
- Qt::Corner originCorner () const
- int rowCount () const
- int rowMinimumHeight ( int row ) const
- int rowStretch ( int row ) const
- void setColumnMinimumWidth ( int column, int minSize )
- void setColumnStretch ( int column, int stretch )
- void setOriginCorner ( Qt::Corner corner )
- void setRowMinimumHeight ( int row, int minSize )
- void setRowStretch ( int row, int stretch )

- 26 public functions inherited from QLayout
- 29 public functions inherited from QObject
- 16 public functions inherited from QLayoutItem

### Additional Inherited Members

- 3 properties inherited from QLayout
- 1 property inherited from QObject
- 1 public slot inherited from QObject
- 1 signal inherited from QObject
- 1 static public member inherited from QLayout
- 5 static public members inherited from QObject
- 3 protected functions inherited from QLayout
- 7 protected functions inherited from QObject

## Detailed Description

The QGridLayout class lays out widgets in a grid.

QGridLayout takes the space made available to it (by its parent layout or by the parentWidget()), divides it up into rows and columns, and puts each widget it manages into the correct cell.

Columns and rows behave identically; we will discuss columns, but there are equivalent functions for rows.

Each column has a minimum width and a stretch factor. The minimum width is the greatest of that set using setColumnMinimumWidth() and the minimum width of each widget in that column. The stretch factor is set using setColumnStretch() and determines how much of the available space the column will get over and above its necessary minimum.

Normally, each managed widget or layout is put into a cell of its own using addWidget(). It is also possible for a widget to occupy multiple cells using the row and column spanning overloads of addItem() and addWidget(). If you do this, QGridLayout will guess how to distribute the size over the columns/rows (based on the stretch factors).

To remove a widget from a layout, call remove(). Calling QWidget::hide() on a widget also effectively removes the widget from the layout until QWidget::show() is called.

This illustration shows a fragment of a dialog with a five-column, three-row grid (the grid is shown overlaid in magenta):

Columns 0, 2 and 4 in this dialog fragment are made up of a QLabel, a QLineEdit, and a QListBox. Columns 1 and 3 are placeholders made with setColumnMinimumWidth(). Row 0 consists of three QLabel objects, row 1 of three QLineEdit objects and row 2 of three QListBox objects. We used placeholder columns (1 and 3) to get the right amount of space between the columns.

Note that the columns and rows are not equally wide or tall. If you want two columns to have the same width, you must set their minimum widths and stretch factors to be the same yourself. You do this using setColumnMinimumWidth() and setColumnStretch().

If the QGridLayout is not the top-level layout (i.e. does not manage all of the widget's area and children), you must add it to its parent layout when you create it, but before you do anything with it. The normal way to add a layout is by calling addLayout() on the parent layout.

Once you have added your layout you can start putting widgets and other layouts into the cells of your grid layout using addWidget(), addItem(), and addLayout().

QGridLayout also includes two margin widths: the margin and the spacing. The margin is the width of the reserved space along each of the QGridLayout's four sides. The spacing is the width of the automatically allocated spacing between neighboring boxes.

The default margin and spacing values are provided by the style. The default margin Qt styles specify is 9 for child widgets and 11 for windows. The spacing defaults to the same as the margin width for a top-level layout, or to the same as the parent layout.

See also QBoxLayout, QStackedLayout, Layout Classes, and Basic Layouts Example.

## Member Function Documentation

### QGridLayout::QGridLayout ( QWidget * parent )

Constructs a new QGridLayout with parent widget, parent. The layout has one row and one column initially, and will expand when new items are inserted.

### QGridLayout::QGridLayout ()

Constructs a new grid layout.

You must insert this grid into another layout. You can insert widgets and layouts into this layout at any time, but laying out will not be performed before this is inserted into another layout.

### QGridLayout::~QGridLayout ()

Destroys the grid layout. Geometry management is terminated if this is a top-level grid.

The layout's widgets aren't destroyed.

### void QGridLayout::addItem ( QLayoutItem * item, int row, int column, int rowSpan = 1, int columnSpan = 1, Qt::Alignment alignment = 0 )

Adds item at position row, column, spanning rowSpan rows and columnSpan columns, and aligns it according to alignment. If rowSpan and/or columnSpan is -1, then the item will extend to the bottom and/or right edge, respectively. The layout takes ownership of the item.

Warning: Do not use this function to add child layouts or child widget items. Use addLayout() or addWidget() instead.

### void QGridLayout::addLayout ( QLayout * layout, int row, int column, Qt::Alignment alignment = 0 )

Places the layout at position (row, column) in the grid. The top-left position is (0, 0).

The alignment is specified by alignment. The default alignment is 0, which means that the widget fills the entire cell.

A non-zero alignment indicates that the layout should not grow to fill the available space but should be sized according to sizeHint().

layout becomes a child of the grid layout.

### void QGridLayout::addLayout ( QLayout * layout, int row, int column, int rowSpan, int columnSpan, Qt::Alignment alignment = 0 )

This is an overloaded member function, provided for convenience.

This version adds the layout layout to the cell grid, spanning multiple rows/columns. The cell will start at row, column spanning rowSpan rows and columnSpan columns.

If rowSpan and/or columnSpan is -1, then the layout will extend to the bottom and/or right edge, respectively.

### void QGridLayout::addWidget ( QWidget * widget, int row, int column, Qt::Alignment alignment = 0 )

Adds the given widget to the cell grid at row, column. The top-left position is (0, 0) by default.

The alignment is specified by alignment. The default alignment is 0, which means that the widget fills the entire cell.

### void QGridLayout::addWidget ( QWidget * widget, int fromRow, int fromColumn, int rowSpan, int columnSpan, Qt::Alignment alignment = 0 )

This is an overloaded member function, provided for convenience.

This version adds the given widget to the cell grid, spanning multiple rows/columns. The cell will start at fromRow, fromColumn spanning rowSpan rows and columnSpan columns. The grid will have the given alignment.

If rowSpan and/or columnSpan is -1, then the widget will extend to the bottom and/or right edge, respectively.

### QRect QGridLayout::cellRect ( int row, int column ) const

Returns the geometry of the cell with row row and column column in the grid. Returns an invalid rectangle if row or column is outside the grid.

Warning: in the current version of Qt this function does not return valid results until setGeometry() has been called, i.e. after the parentWidget() is visible.

### int QGridLayout::columnCount () const

Returns the number of columns in this grid.

### int QGridLayout::columnMinimumWidth ( int column ) const

Returns the column spacing for column column.

See also setColumnMinimumWidth().

### int QGridLayout::columnStretch ( int column ) const

Returns the stretch factor for column column.

See also setColumnStretch().

### void QGridLayout::getItemPosition ( int index, int * row, int * column, int * rowSpan, int * columnSpan )

Returns the position information of the item with the given index.

The variables passed as row and column are updated with the position of the item in the layout, and the rowSpan and columnSpan variables are updated with the vertical and horizontal spans of the item.

### Qt::Corner QGridLayout::originCorner () const

Returns the corner that's used for the grid's origin, i.e. for position (0, 0).

See also setOriginCorner().

### int QGridLayout::rowCount () const

Returns the number of rows in this grid.

### int QGridLayout::rowMinimumHeight ( int row ) const

Returns the minimum width set for row row.

See also setRowMinimumHeight().

### int QGridLayout::rowStretch ( int row ) const

Returns the stretch factor for row row.

See also setRowStretch().

### void QGridLayout::setColumnMinimumWidth ( int column, int minSize )

Sets the minimum width of column column to minSize pixels.

See also columnMinimumWidth() and setRowMinimumHeight().

### void QGridLayout::setColumnStretch ( int column, int stretch )

Sets the stretch factor of column column to stretch. The first column is number 0.

The stretch factor is relative to the other columns in this grid. Columns with a higher stretch factor take more of the available space.

The default stretch factor is 0. If the stretch factor is 0 and no other column in this table can grow at all, the column may still grow.

An alternative approach is to add spacing using addItem() with a QSpacerItem.

See also columnStretch() and setRowStretch().

### void QGridLayout::setOriginCorner ( Qt::Corner corner )

Sets the grid's origin corner, i.e. position (0, 0), to corner.

See also originCorner().

### void QGridLayout::setRowMinimumHeight ( int row, int minSize )

Sets the minimum height of row row to minSize pixels.

See also rowMinimumHeight() and setColumnMinimumWidth().

### void QGridLayout::setRowStretch ( int row, int stretch )

Sets the stretch factor of row row to stretch. The first row is number 0.

The stretch factor is relative to the other rows in this grid. Rows with a higher stretch factor take more of the available space.

The default stretch factor is 0. If the stretch factor is 0 and no other row in this table can grow at all, the row may still grow.

See also rowStretch(), setRowMinimumHeight(), and setColumnStretch().

## Member Function Documentation

### QGridLayout::QGridLayout ( QWidget * parent, int nRows, int nCols = 1, int margin = 0, int space = -1, const char * name = 0 )

Constructs a new QGridLayout with nRows rows, nCols columns and parent widget, parent. parent may not be 0. The grid layout is called name.

margin is the number of pixels between the edge of the widget and its managed children. space is the default number of pixels between cells. If space is -1, the value of margin is used.

### QGridLayout::QGridLayout ( int nRows, int nCols = 1, int spacing = -1, const char * name = 0 )

Constructs a new grid with nRows rows and nCols columns. If spacing is -1, this QGridLayout inherits its parent's spacing(); otherwise spacing is used. The grid layout is called name.

You must insert this grid into another layout. You can insert widgets and layouts into this layout at any time, but laying out will not be performed before this is inserted into another layout.

### QGridLayout::QGridLayout ( QLayout * parentLayout, int nRows = 1, int nCols = 1, int spacing = -1, const char * name = 0 )

Constructs a new grid with nRows rows and nCols columns. If spacing is -1, this QGridLayout inherits its parent's spacing(); otherwise spacing is used. The grid layout is called name.

You must insert this grid into another layout. You can insert widgets and layouts into this layout at any time, but laying out will not be performed before this is inserted into another layout.

### void QGridLayout::addColSpacing ( int col, int minsize )

Use addItem(new QSpacerItem(minsize, 0), 0, col) instead.

### void QGridLayout::addMultiCell ( QLayoutItem * l, int fromRow, int toRow, int fromCol, int toCol, Qt::Alignment align = 0 )

Use an addItem() overload that allows you to specify row and column spans instead.

### void QGridLayout::addMultiCellLayout ( QLayout * layout, int fromRow, int toRow, int fromCol, int toCol, Qt::Alignment align = 0 )

Use an addLayout() overload that allows you to specify row and column spans instead.

### void QGridLayout::addMultiCellWidget ( QWidget * widget, int fromRow, int toRow, int fromCol, int toCol, Qt::Alignment align = 0 )

Use an addWidget() overload that allows you to specify row and column spans instead.

### void QGridLayout::addRowSpacing ( int row, int minsize )

Use addItem(new QSpacerItem(0, minsize), row, 0) instead.

### QRect QGridLayout::cellGeometry ( int row, int column ) const

Use cellRect(row, column) instead.

### int QGridLayout::colSpacing ( int col ) const

Use columnSpacing() instead.

See also setColSpacing().

### int QGridLayout::colStretch ( int col ) const

Use columnStretch() instead.

See also setColStretch().

### void QGridLayout::expand ( int nRows, int nCols )

Expands this grid so that it will have nRows rows and nCols columns. Will not shrink the grid. You should not need to call this function because QGridLayout expands automatically as new items are inserted.

### bool QGridLayout::findWidget ( QWidget * w, int * row, int * column ) `[protected]`

Searches for widget w in this layout (not including child layouts). If w is found, it sets `*`row and `*`column to the row and column that the widget occupies and returns true; otherwise returns false.

If the widget spans multiple rows/columns, the top-left cell is returned.

Use indexOf() and getItemPosition() instead.

### int QGridLayout::numCols () const

Use columnCount() instead.

### int QGridLayout::numRows () const

Use rowCount() instead.

### Qt::Corner QGridLayout::origin () const

Use originCorner() instead.

See also setOrigin().

### int QGridLayout::rowSpacing ( int row ) const

Use rowMinimumHeight(row) instead.

See also setRowSpacing().

### void QGridLayout::setColSpacing ( int col, int minSize )

Use setColumnMinimumWidth() instead.

See also colSpacing().

### void QGridLayout::setColStretch ( int col, int stretch )

Use setColumnStretch() instead.

See also colStretch().

### void QGridLayout::setOrigin ( Qt::Corner corner )

Use setOriginCorner(corner) instead.

See also origin().

### void QGridLayout::setRowSpacing ( int row, int minSize )

Use setRowMinimumHeight(row, minSize) instead.

See also rowSpacing().