PySide6.QtWidgets.QHeaderView

class QHeaderView

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

Inheritance diagram of PySide6.QtWidgets.QHeaderView

Synopsis

Properties

Methods

Virtual methods

Slots

Signals

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description

A QHeaderView displays the headers used in item views such as the QTableView and QTreeView classes. It takes the place of Qt3’s 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 header gets the data for each section from the model using the QAbstractItemModel::headerData() function. You can set the data by using QAbstractItemModel::setHeaderData().

Each header has an orientation() and a number of sections, given by the count() function. A section refers to a part of the header - either a row or a column, depending on the orientation.

Sections can be moved and resized using moveSection() and resizeSection() ; they can also 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.

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.

Moving Header Sections

A header can be fixed in place, or made movable with setSectionsMovable() . It can be made clickable with setSectionsClickable() , and has resizing behavior in accordance with setSectionResizeMode() .

Note

Double-clicking on a header to resize a section only applies for visible rows.

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

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, but the logical index will not change.

Appearance

QTableWidget and QTableView create default headers. If you want the headers to be visible, you can use setVisible() .

Not all ItemDataRoles will have an effect on a QHeaderView . If you need to draw other roles, you can subclass QHeaderView and reimplement paintEvent() . QHeaderView respects the following item data roles, unless they are in conflict with the style (which can happen for styles that follow the desktop theme):

TextAlignmentRole, DisplayRole, FontRole, DecorationRole, ForegroundRole, and BackgroundRole.

Note

Each header renders the data for each section itself, and does not rely on a delegate. As a result, calling a header’s setItemDelegate() function will have no effect.

Special consideration for huge models

The headerview uses 8 to 16 bytes of memory per section. However, since Qt 6.9 this section memory is only used if one or more sections are resized or reordered. This means that it’s possible for a model to have millions of sections without QHeaderView consuming a proportional, and therefore huge, amount of memory, as long as there are no calls to swapSections , resizeSection , hideSection , moveSection , and stretchLastSection (enabling it). In order to avoid such calls by user actions the resize mode should be Fixed (without specifying it for any indexes, as that will do the opposite). The user should also be prevented from moving sections by keeping sectionsMovable disabled.

class ResizeMode

The resize mode specifies the behavior of the header sections. It can be set on the entire header view or on individual sections using setSectionResizeMode() .

Constant

Description

QHeaderView.ResizeMode.Interactive

The user can resize the section. The section can also be resized programmatically using resizeSection() . The section size defaults to defaultSectionSize . (See also cascadingSectionResizes .)

QHeaderView.ResizeMode.Fixed

The user cannot resize the section. The section can only be resized programmatically using resizeSection() . The section size defaults to defaultSectionSize .

QHeaderView.ResizeMode.Stretch

QHeaderView will automatically resize the section to fill the available space. The size cannot be changed by the user or programmatically.

QHeaderView.ResizeMode.ResizeToContents

QHeaderView will automatically resize the section to its optimal size based on the contents of the entire column or row. The size cannot be changed by the user or programmatically. (This value was introduced in 4.2)

The following values are obsolete:

Constant

Description

QHeaderView.ResizeMode.Custom

Use Fixed instead.

See also

setSectionResizeMode() stretchLastSection minimumSectionSize

Note

Properties can be used directly when from __feature__ import true_property is used or via accessor functions otherwise.

property cascadingSectionResizesᅟ: bool

This property holds whether interactive resizing will be cascaded to the following sections once the section being resized by the user has reached its minimum size.

This property only affects sections that have Interactive as their resize mode.

The default value is false.

Access functions:
property defaultAlignmentᅟ: Combination of Qt.AlignmentFlag

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

Access functions:
property defaultSectionSizeᅟ: int

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

This property only affects sections that have Interactive or Fixed as their resize mode.

By default, the value of this property is style dependent. Thus, when the style changes, this property updates from it. Calling setDefaultSectionSize() stops the updates, calling resetDefaultSectionSize() will restore default behavior.

Access functions:
property firstSectionMovableᅟ: bool

This property holds Whether the first column can be moved by the user.

This property controls whether the first column can be moved by the user. In a QTreeView , the first column holds the tree structure and is therefore non-movable by default, even after setSectionsMovable (true).

It can be made movable again, for instance in the case of flat lists without a tree structure, by calling this method. In such a scenario, it is recommended to call setRootIsDecorated (false) as well.

treeView->setRootIsDecorated(false);
treeView->header()->setFirstSectionMovable(true);

Setting it to true has no effect unless setSectionsMovable (true) is called as well.

Access functions:
property highlightSectionsᅟ: bool

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

By default, this property is false.

Access functions:
property maximumSectionSizeᅟ: int

This property holds the maximum size of the header sections..

The maximum section size is the largest section size allowed. The default value for this property is 1048575, which is also the largest possible size for a section. Setting maximum to -1 will reset the value to the largest section size.

With exception of stretch this property is honored by all resize modes

Access functions:
property minimumSectionSizeᅟ: int

This property holds the minimum size of the header sections..

The minimum section size is the smallest section size allowed. If the minimum section size is set to -1, QHeaderView will use the font metrics size.

This property is honored by all resize modes .

Access functions:
property sectionsClickableᅟ: bool

Holds true if the header is clickable; otherwise 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.

Access functions:
property sectionsMovableᅟ: bool

If sectionsMovable is true, the header sections may be moved by the user; otherwise they are fixed in place.

When used in combination with QTreeView , the first column is not movable (since it contains the tree structure), by default. You can make it movable with setFirstSectionMovable (true).

Access functions:
property showSortIndicatorᅟ: bool

This property holds whether the sort indicator is shown.

By default, this property is false.

Access functions:
property sortIndicatorClearableᅟ: bool

This property holds Whether the sort indicator can be cleared by clicking on a section multiple times.

This property controls whether the user is able to remove the sorting indicator on a given section by clicking on the section multiple times. Normally, clicking on a section will simply change the sorting order for that section. By setting this property to true, the sorting indicator will be cleared after alternating to ascending and descending; this will typically restore the original sorting of a model.

Setting this property to true has no effect unless sectionsClickable() is also true (which is the default for certain views, for instance QTableView , or is automatically set when making a view sortable, for instance by calling setSortingEnabled ).

Access functions:
property stretchLastSectionᅟ: bool

This property holds whether the last visible section in the header takes up all the available space.

The default value is false.

Note

The horizontal headers provided by QTreeView are configured with this property set to true, ensuring that the view does not waste any of the space assigned to it for its header. If this value is set to true, this property will override the resize mode set on the last section in the header.

See also

setSectionResizeMode()

Access functions:
__init__(orientation[, parent=None])
Parameters:

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

cascadingSectionResizes()
Return type:

bool

See also

setCascadingSectionResizes()

Getter of property cascadingSectionResizesᅟ .

count()
Return type:

int

Returns the number of sections in the header.

defaultAlignment()
Return type:

Combination of AlignmentFlag

See also

setDefaultAlignment()

Getter of property defaultAlignmentᅟ .

defaultSectionSize()
Return type:

int

See also

setDefaultSectionSize()

Getter of property defaultSectionSizeᅟ .

geometriesChanged()

This signal is emitted when the header’s geometries have changed.

headerDataChanged(orientation, logicalFirst, logicalLast)
Parameters:

  • orientation – Orientation

  • logicalFirst – int

  • logicalLast – int

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

hiddenSectionCount()
Return type:

int

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

hideSection(logicalIndex)
Parameters:

logicalIndex – int

Hides the section specified by logicalIndex.

highlightSections()
Return type:

bool

See also

setHighlightSections()

Getter of property highlightSectionsᅟ .

initStyleOption(option)
Parameters:

option – QStyleOptionHeader

Initialize option with the values from this QHeaderView . This method is useful for subclasses when they need a QStyleOptionHeader , but do not want to fill in all the information themselves.

initStyleOptionForIndex(option, logicalIndex)
Parameters:

Initializes the style option from the specified logicalIndex. This function is called by the default implementation of paintSection after initStyleOption has been called.

initialize()
initializeSections()
initializeSections(start, end)
Parameters:

  • start – int

  • end – int

isFirstSectionMovable()
Return type:

bool

Getter of property firstSectionMovableᅟ .

isSectionHidden(logicalIndex)
Parameters:

logicalIndex – int

Return type:

bool

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

isSortIndicatorClearable()
Return type:

bool

Getter of property sortIndicatorClearableᅟ .

isSortIndicatorShown()
Return type:

bool

Getter of property showSortIndicatorᅟ .

length()
Return type:

int

Returns the length along the orientation of the header.

See also

sizeHint() setSectionResizeMode() offset()

logicalIndex(visualIndex)
Parameters:

visualIndex – int

Return type:

int

Returns the logicalIndex for the section at the given visualIndex position, or -1 if visualIndex < 0 or visualIndex >= count() .

Note that the visualIndex is not affected by hidden sections.

logicalIndexAt(pos)
Parameters:

pos – QPoint

Return type:

int

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

logicalIndexAt(position)
Parameters:

position – int

Return type:

int

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

logicalIndexAt(x, y)
Parameters:

  • x – int

  • y – int

Return type:

int

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.

maximumSectionSize()
Return type:

int

See also

setMaximumSectionSize()

Getter of property maximumSectionSizeᅟ .

minimumSectionSize()
Return type:

int

See also

setMinimumSectionSize()

Getter of property minimumSectionSizeᅟ .

moveSection(from, to)
Parameters:

  • from – int

  • to – int

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

See also

sectionsMoved()

offset()
Return type:

int

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

See also

setOffset()

orientation()
Return type:

Orientation

Returns the orientation of the header.

See also

Orientation

paintSection(painter, rect, logicalIndex)
Parameters:

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

Normally, you do not have to call this function.

resetDefaultSectionSize()

Reset function of property defaultSectionSizeᅟ .

resizeContentsPrecision()
Return type:

int

Returns how precise QHeaderView will calculate on ResizeToContents .

resizeSection(logicalIndex, size)
Parameters:

  • logicalIndex – int

  • size – int

Resizes the section specified by logicalIndex to size measured in pixels. The size parameter must be a value larger or equal to zero. A size equal to zero is however not recommended. In that situation hideSection should be used instead.

resizeSections()

Resizes the sections according to their size hints. Normally, you do not have to call this function.

resizeSections(mode)
Parameters:

mode – ResizeMode

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

See also

sectionResized()

restoreState(state)
Parameters:

state – QByteArray

Return type:

bool

Restores the state of this header view. This function returns true if the state was restored; otherwise returns false.

See also

saveState()

saveState()
Return type:

QByteArray

Saves the current state of this header view.

To restore the saved state, pass the return value to restoreState() .

See also

restoreState()

sectionClicked(logicalIndex)
Parameters:

logicalIndex – int

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

Note that the sectionPressed signal will also be emitted.

sectionCountChanged(oldCount, newCount)
Parameters:

  • oldCount – int

  • newCount – int

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.

sectionDoubleClicked(logicalIndex)
Parameters:

logicalIndex – int

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

sectionEntered(logicalIndex)
Parameters:

logicalIndex – int

This signal is emitted when the cursor moves over the section and the left mouse button is pressed. The section’s logical index is specified by logicalIndex.

sectionHandleDoubleClicked(logicalIndex)
Parameters:

logicalIndex – int

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

sectionMoved(logicalIndex, oldVisualIndex, newVisualIndex)
Parameters:

  • logicalIndex – int

  • oldVisualIndex – int

  • newVisualIndex – int

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()

sectionPosition(logicalIndex)
Parameters:

logicalIndex – int

Return type:

int

Returns the section position of the given logicalIndex, or -1 if the section is hidden. The position is measured in pixels from the first visible item’s top-left corner to the top-left corner of the item with logicalIndex. The measurement is along the x-axis for horizontal headers and along the y-axis for vertical headers.

sectionPressed(logicalIndex)
Parameters:

logicalIndex – int

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

sectionResizeMode(logicalIndex)
Parameters:

logicalIndex – int

Return type:

ResizeMode

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

sectionResized(logicalIndex, oldSize, newSize)
Parameters:

  • logicalIndex – int

  • oldSize – int

  • newSize – int

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()

sectionSize(logicalIndex)
Parameters:

logicalIndex – int

Return type:

int

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

sectionSizeFromContents(logicalIndex)
Parameters:

logicalIndex – int

Return type:

QSize

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

sectionSizeHint(logicalIndex)
Parameters:

logicalIndex – int

Return type:

int

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

Qt::SizeHintRole

sectionViewportPosition(logicalIndex)
Parameters:

logicalIndex – int

Return type:

int

Returns the section viewport position of the given logicalIndex.

If the section is hidden, the return value is undefined.

sectionsAboutToBeRemoved(parent, logicalFirst, logicalLast)
Parameters:

  • parent – QModelIndex

  • logicalFirst – int

  • logicalLast – int

This slot is called when sections are removed from the parent. logicalFirst and logicalLast signify where the sections were removed.

If only one section is removed, logicalFirst and logicalLast will be the same.

sectionsClickable()
Return type:

bool

Returns sectionsClickable.

Getter of property sectionsClickableᅟ .

sectionsHidden()
Return type:

bool

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

sectionsInserted(parent, logicalFirst, logicalLast)
Parameters:

  • parent – QModelIndex

  • logicalFirst – int

  • logicalLast – int

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

If only one section is inserted, logicalFirst and logicalLast will be the same.

sectionsMovable()
Return type:

bool

Returns sectionsMovable.

Getter of property sectionsMovableᅟ .

sectionsMoved()
Return type:

bool

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

See also

moveSection()

setCascadingSectionResizes(enable)
Parameters:

enable – bool

See also

cascadingSectionResizes()

Setter of property cascadingSectionResizesᅟ .

setDefaultAlignment(alignment)
Parameters:

alignment – Combination of AlignmentFlag

See also

defaultAlignment()

Setter of property defaultAlignmentᅟ .

setDefaultSectionSize(size)
Parameters:

size – int

See also

defaultSectionSize()

Setter of property defaultSectionSizeᅟ .

setFirstSectionMovable(movable)
Parameters:

movable – bool

See also

isFirstSectionMovable()

Setter of property firstSectionMovableᅟ .

setHighlightSections(highlight)
Parameters:

highlight – bool

See also

highlightSections()

Setter of property highlightSectionsᅟ .

setMaximumSectionSize(size)
Parameters:

size – int

See also

maximumSectionSize()

Setter of property maximumSectionSizeᅟ .

setMinimumSectionSize(size)
Parameters:

size – int

See also

minimumSectionSize()

Setter of property minimumSectionSizeᅟ .

setOffset(offset)
Parameters:

offset – int

Sets the header’s offset to offset.

See also

offset() length()

setOffsetToLastSection()

Sets the offset to make the last section visible.

setOffsetToSectionPosition(visualIndex)
Parameters:

visualIndex – int

Sets the offset to the start of the section at the given visualSectionNumber. visualSectionNumber is the actual visible section when hiddenSections are not considered. That is not always the same as visualIndex() .

setResizeContentsPrecision(precision)
Parameters:

precision – int

Sets how precise QHeaderView should calculate the size when ResizeToContents is used. A low value will provide a less accurate but fast auto resize while a higher value will provide a more accurate resize that however can be slow.

The number precision specifies how many sections that should be consider when calculating the preferred size.

The default value is 1000 meaning that a horizontal column with auto-resize will look at maximum 1000 rows on calculating when doing an auto resize.

Special value 0 means that it will look at only the visible area. Special value -1 will imply looking at all elements.

This value is used in sizeHintForColumn() , sizeHintForRow() and sizeHintForColumn() . Reimplementing these functions can make this function not having an effect.

See also

resizeContentsPrecision() setSectionResizeMode() resizeSections() sizeHintForColumn() sizeHintForRow() sizeHintForColumn()

setSectionHidden(logicalIndex, hide)
Parameters:

  • logicalIndex – int

  • hide – bool

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

setSectionResizeMode(mode)
Parameters:

mode – ResizeMode

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

setSectionResizeMode(logicalIndex, mode)
Parameters:

Sets the constraints on how the section specified by logicalIndex in the header can be resized to those described by the given mode. The logical index should exist at the time this function is called.

Note

This setting will be ignored for the last section if the stretchLastSection property is set to true. This is the default for the horizontal headers provided by QTreeView .

See also

setStretchLastSection() resizeContentsPrecision()

setSectionsClickable(clickable)
Parameters:

clickable – bool

Set sectionsClickable to clickable.

Setter of property sectionsClickableᅟ .

setSectionsMovable(movable)
Parameters:

movable – bool

Sets sectionsMovable to movable.

Setter of property sectionsMovableᅟ .

setSortIndicator(logicalIndex, order)
Parameters:

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.

logicalIndex may be -1, in which case no sort indicator will be shown and the model will return to its natural, unsorted order. Note that not all models support this and may even crash in this case.

setSortIndicatorClearable(clearable)
Parameters:

clearable – bool

See also

isSortIndicatorClearable()

Setter of property sortIndicatorClearableᅟ .

setSortIndicatorShown(show)
Parameters:

show – bool

See also

isSortIndicatorShown()

Setter of property showSortIndicatorᅟ .

setStretchLastSection(stretch)
Parameters:

stretch – bool

See also

stretchLastSection()

Setter of property stretchLastSectionᅟ .

showSection(logicalIndex)
Parameters:

logicalIndex – int

Shows the section specified by logicalIndex.

sortIndicatorChanged(logicalIndex, order)
Parameters:

This signal is emitted when the section containing the sort indicator or the order indicated is changed. The section’s logical index is specified by logicalIndex and the sort order is specified by order.

sortIndicatorClearableChanged(clearable)
Parameters:

clearable – bool

Notification signal of property sortIndicatorClearableᅟ .

sortIndicatorOrder()
Return type:

SortOrder

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

sortIndicatorSection()
Return type:

int

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

stretchLastSection()
Return type:

bool

See also

setStretchLastSection()

Getter of property stretchLastSectionᅟ .

stretchSectionCount()
Return type:

int

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’s geometry changes.

swapSections(first, second)
Parameters:

  • first – int

  • second – int

Swaps the section at visual index first with the section at visual index second.

See also

moveSection()

updateSection(logicalIndex)
Parameters:

logicalIndex – int

visualIndex(logicalIndex)
Parameters:

logicalIndex – int

Return type:

int

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()

visualIndexAt(position)
Parameters:

position – int

Return type:

int

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

See also

logicalIndexAt()