QHeaderView Class Reference
^{[QtGui module]}

Detailed Description

The QHeaderView class provides a header row or header column for item views.

A QHeaderView displays the headers used in item views such as the QTableView and QTreeView classes. It takes the place of the QHeader class previously used for the same purpose, but uses the Qt's model/view architecture for consistency with the item view classes.

The QHeaderView class is one of the Model/View Classes and is part of Qt's model/view framework.

The model gets the data for each section from the model using the getHeaderData() function. You can set the data by using setHeaderData().

Each header has an orientation() and a number of sections, given by the count() function. Sections can be moved and resized using moveSection() and resizeSection(); they can be hidden and shown with hideSection() and showSection().

Each section of a header is described by a section ID, specified by its section(), and can be located at a particular visualIndex() in the header. A section can have a sort indicator set with setSortIndicator(); this indicates whether the items in the associated item view will be sorted in the order given by the section.

A header can be fixed in place, or made movable with setMovable(). It can be made clickable with setClickable(), and has resizing behavior in accordance with setResizeMode().

A header emits sectionMoved() if the user moves a section, sectionResized() if the user resizes a section, and sectionClicked() and sectionHandleDoubleClicked() in response to mouse clicks. A header also emits sectionCountChanged() and sectionAutoResize().

You can identify a section using the logicalIndex() and logicalIndexAt() functions, or by its index position, using the visualIndex() and visualIndexAt() functions. The visual index will change if a section is moved while the logical index wont change.

For a horizontal header the section is equivalent to a column in the model, and for a vertical header the section is equivalent to a row in the model.

See also Model/View Programming, QListView, QTableView, and QTreeView.

Member Type Documentation

enum QHeaderView::ResizeMode

Property Documentation

defaultAlignment : Qt::Alignment

This property holds the default alignment of the text in each header section.

This property was introduced in Qt 4.1.

Access functions:

• Qt::Alignment defaultAlignment () const
• void setDefaultAlignment ( Qt::Alignment alignment )

defaultSectionSize : int

This property holds the default size of the header sections before resizing.

Access functions:

• int defaultSectionSize () const
• void setDefaultSectionSize ( int size )

highlightSections : bool

This property holds whether the sections containing selected items are highlighted.

Access functions:

• bool highlightSections () const
• void setHighlightSections ( bool highlight )

showSortIndicator : bool

This property holds whether the sort indicator is shown.

Access functions:

• bool isSortIndicatorShown () const
• void setSortIndicatorShown ( bool show )

See also setClickable().

stretchLastSection : bool

This property holds whether the last visible section in the header takes up all the available space. The default value is false.

Access functions:

• bool stretchLastSection () const
• void setStretchLastSection ( bool stretch )

See also setResizeMode().

Member Function Documentation

QHeaderView::QHeaderView ( Qt::Orientation orientation, QWidget * parent = 0 )

Creates a new generic header with the given orientation and parent.

QHeaderView::~QHeaderView ()   [virtual]

Destroys the header.

int QHeaderView::count () const

Returns the number of sections in the header.

See also sectionCountChanged() and length().

void QHeaderView::headerDataChanged ( Qt::Orientation orientation, int logicalFirst, int logicalLast )   [slot]

Updates the changed header sections with the given orientation, from logicalFirst to logicalLast inclusive.

int QHeaderView::hiddenSectionCount () const

Returns the number of sections in the header that has been hidden.

This function was introduced in Qt 4.1.

See also setSectionHidden() and isSectionHidden().

void QHeaderView::hideSection ( int logicalIndex )

Hides the section specified by logicalIndex.

See also showSection(), isSectionHidden(), and hiddenSectionCount().

int QHeaderView::horizontalOffset () const   [virtual protected]

Returns the horizontal offset of the header. This is 0 for vertical headers.

Reimplemented from QAbstractItemView.

See also offset().

bool QHeaderView::isClickable () const

Returns true if the header is clickable; otherwise returns false. A clickable header could be set up to allow the user to change the representation of the data in the view related to the header.

See also setClickable().

bool QHeaderView::isMovable () const

Returns true if the header can be moved by the user; otherwise returns false.

See also setMovable().

bool QHeaderView::isSectionHidden ( int logicalIndex ) const

Returns true if the section specified by logicalIndex is explicitly hidden from the user; otherwise returns false.

See also setSectionHidden() and hiddenSectionCount().

int QHeaderView::length () const

Returns the length along the orientation of the header.

See also sizeHint(), setResizeMode(), and offset().

int QHeaderView::logicalIndex ( int visualIndex ) const

Returns the logicalIndex for the section at the given visualIndex position, or -1 otherwise.

See also visualIndex() and sectionPosition().

int QHeaderView::logicalIndexAt ( int position ) const

Returns the section that covers the given position in the viewport.

See also visualIndexAt() and isSectionHidden().

int QHeaderView::logicalIndexAt ( int x, int y ) const

This is an overloaded member function, provided for convenience.

Returns the logical index of the section at the given coordinate. If the header is horizontal x will be used, otherwise y will be used to find the logical index.

int QHeaderView::logicalIndexAt ( const QPoint & pos ) const

This is an overloaded member function, provided for convenience.

Returns the logical index of the section at the position given in pos. If the header is horizontal the x-coordinate will be used to find the logical index; otherwise the y-coordinate will be used.

See also sectionPosition().

void QHeaderView::moveSection ( int from, int to )

Moves the section at visual index from to occupy visual index to.

See also sectionsMoved().

int QHeaderView::offset () const

Returns the offset of the header: this is the header's left-most (or top-most for vertical headers) visible pixel.

See also setOffset().

Qt::Orientation QHeaderView::orientation () const

Returns the orientation of the header.

See also Qt::Orientation.

void QHeaderView::paintSection ( QPainter * painter, const QRect & rect, int logicalIndex ) const   [virtual protected]

Paints the section specified by the given logicalIndex, using the given painter and rect.

You normally would not need to use this function.

ResizeMode QHeaderView::resizeMode ( int logicalIndex ) const

Returns the resize mode that applies to the section specified by the given logicalIndex.

See also setResizeMode().

void QHeaderView::resizeSection ( int logicalIndex, int size )

Resizes the given logicalIndex to the given size.

See also sectionResized().

void QHeaderView::resizeSections ( QHeaderView::ResizeMode mode )

Resizes the sections according to the given mode, ignoring the current resize mode.

See also resizeMode() and sectionResized().

void QHeaderView::sectionAutoResize ( int logicalIndex, QHeaderView::ResizeMode mode )   [signal]

This signal is emitted when a section is automatically resized. The section's logical index is specified by logicalIndex, and the resize mode by mode.

See also setResizeMode() and stretchLastSection().

void QHeaderView::sectionClicked ( int logicalIndex )   [signal]

This signal is emitted when a section is clicked. The section's logical index is specified by logicalIndex.

Note that you will also get a sectionPressed

See also setClickable().

void QHeaderView::sectionCountChanged ( int oldCount, int newCount )   [signal]

This signal is emitted when the number of sections changes; i.e. when sections are added or deleted. The original count is specified by oldCount, and the new count by newCount.

See also count(), length(), and headerDataChanged().

void QHeaderView::sectionDoubleClicked ( int logicalIndex )   [signal]

This signal is emitted when a section is double-clicked. The section's logical index is specified by logicalIndex.

See also setClickable().

void QHeaderView::sectionHandleDoubleClicked ( int logicalIndex )   [signal]

This signal is emitted when a section is double-clicked. The section's logical index is specified by logicalIndex.

See also setClickable().

void QHeaderView::sectionMoved ( int logicalIndex, int oldVisualIndex, int newVisualIndex )   [signal]

This signal is emitted when a section is moved. The section's logical index is specified by logicalIndex, the old index by oldVisualIndex, and the new index position by newVisualIndex.

See also moveSection().

int QHeaderView::sectionPosition ( int logicalIndex ) const

Returns the section position of the given logicalIndex.

See also sectionViewportPosition().

void QHeaderView::sectionPressed ( int logicalIndex )   [signal]

This signal is emitted when a section is pressed. The section's logical index is specified by logicalIndex.

See also setClickable().

void QHeaderView::sectionResized ( int logicalIndex, int oldSize, int newSize )   [signal]

This signal is emitted when a section is resized. The section's logical number is specified by logicalIndex, the old size by oldSize, and the new size by newSize.

See also resizeSection.

int QHeaderView::sectionSize ( int logicalIndex ) const

Returns the width (or height for vertical headers) of the given logicalIndex.

See also length(), setResizeMode(), and defaultSectionSize().

QSize QHeaderView::sectionSizeFromContents ( int logicalIndex ) const   [virtual protected]

Returns the size of the contents of the section specified by the give logicalIndex.

See also defaultSectionSize().

int QHeaderView::sectionSizeHint ( int logicalIndex ) const

Returns a suitable size hint for the section specified by logicalIndex.

See also sizeHint() and defaultSectionSize().

int QHeaderView::sectionViewportPosition ( int logicalIndex ) const

Returns the section viewport position of the given logicalIndex. If the section is hidden the function returns -1.

See also sectionPosition().

void QHeaderView::sectionsAboutToBeRemoved ( const QModelIndex & parent, int logicalFirst, int logicalLast )   [protected slot]

This slot is called when sections are removed from the parent, logicalFirst and logicalLast signify where the sections are removed from. (logicalFirst and logicalLast will be the same if just one section is removed.)

bool QHeaderView::sectionsHidden () const

Returns true if sections in the header has been hidden; otherwise returns false;

This function was introduced in Qt 4.1.

See also setSectionHidden().

void QHeaderView::sectionsInserted ( const QModelIndex & parent, int logicalFirst, int logicalLast )   [protected slot]

This slot is called when sections are inserted into the parent, logicalFirst and logicalLast indexes signify where the new sections are inserted.

logicalFirst and logicalLast will be the same if just one section is inserted.

bool QHeaderView::sectionsMoved () const

Returns true if sections in the header has been moved; otherwise returns false;

See also moveSection().

void QHeaderView::setClickable ( bool clickable )

If clickable is true, the header will respond to single clicks.

See also isClickable(), sectionClicked(), sectionPressed(), and setSortIndicatorShown().

void QHeaderView::setMovable ( bool movable )

If movable is true, the header may be moved by the user; otherwise it is fixed in place.

See also isMovable() and sectionMoved().

void QHeaderView::setOffset ( int offset )   [slot]

Sets the header's offset to offset.

See also offset() and length().

void QHeaderView::setResizeMode ( ResizeMode mode )

Sets the constraints on how the header can be resized to those described by the given mode.

See also resizeMode(), length(), sectionResized(), and sectionAutoResize().

void QHeaderView::setResizeMode ( int logicalIndex, ResizeMode mode )

This is an overloaded member function, provided for convenience.

Sets the constraints on how the section specified by logicalIndex in the header can be resized to those described by the given mode.

void QHeaderView::setSectionHidden ( int logicalIndex, bool hide )

If hide is true the section specified by logicalIndex is hidden, otherwise the section is shown.

See also isSectionHidden() and hiddenSectionCount().

void QHeaderView::setSortIndicator ( int logicalIndex, Qt::SortOrder order )

Sets the sort indicator for the section specified by the given logicalIndex in the direction specified by order, and removes the sort indicator from any other section that was showing it.

See also sortIndicatorSection() and sortIndicatorOrder().

void QHeaderView::showSection ( int logicalIndex )

Shows the section specified by logicalIndex.

See also hideSection() and isSectionHidden().

QSize QHeaderView::sizeHint () const   [virtual]

Returns a suitable size hint for this header.

Reimplemented from QWidget.

See also sectionSizeHint().

Qt::SortOrder QHeaderView::sortIndicatorOrder () const

Returns the order for the sort indicator. If no section has a sort indicator the return value of this function is undefined.

See also setSortIndicator() and sortIndicatorSection().

int QHeaderView::sortIndicatorSection () const

Returns the logical index of the section that has a sort indicator. By default this is section 0.

See also setSortIndicator(), sortIndicatorOrder(), and setSortIndicatorShown().

int QHeaderView::stretchSectionCount () const

Returns the number of sections that are set to resize mode stretch. In views this can be used to see if the headerview needs to resize the sections when the view geometry changes.

This function was introduced in Qt 4.1.

See also stretchLastSection and resizeMode().

int QHeaderView::verticalOffset () const   [virtual protected]

Returns the vertical offset of the header. This is 0 for horizontal headers.

Reimplemented from QAbstractItemView.

See also offset().

int QHeaderView::visualIndex ( int logicalIndex ) const

Returns the visual index position of the section specified by the given logicalIndex, or -1 otherwise. Hidden sections still have valid visual indexes.

See also logicalIndex().

int QHeaderView::visualIndexAt ( int position ) const

Returns the visual index of the section that covers the given position in the viewport.

See also logicalIndexAt().