QListView Class▲
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Header: QListView
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CMake:
find_package(Qt6 REQUIRED COMPONENTS Widgets)
target_link_libraries(mytarget PRIVATE Qt6::Widgets)
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qmake: QT += widgets
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Inherits: QAbstractItemView
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Inherited By: QHelpIndexWidget, QListWidget, and QUndoView
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Group: QListView is part of model-view, advanced
Detailed Description▲
A QListView presents items stored in a model, either as a simple non-hierarchical list, or as a collection of icons. This class is used to provide lists and icon views that were previously provided by the QListBox and QIconView classes, but using the more flexible approach provided by Qt's model/view architecture.
The QListView class is one of the Model/View Classes and is part of Qt's model/view framework.
This view does not display horizontal or vertical headers; to display a list of items with a horizontal header, use QTreeView instead.
QListView implements the interfaces defined by the QAbstractItemView class to allow it to display data provided by models derived from the QAbstractItemModel class.
Items in a list view can be displayed using one of two view modes: In ListMode, the items are displayed in the form of a simple list; in IconMode, the list view takes the form of an icon view in which the items are displayed with icons like files in a file manager. By default, the list view is in ListMode. To change the view mode, use the setViewMode() function, and to determine the current view mode, use viewMode().
Items in these views are laid out in the direction specified by the flow() of the list view. The items may be fixed in place, or allowed to move, depending on the view's movement() state.
If the items in the model cannot be completely laid out in the direction of flow, they can be wrapped at the boundary of the view widget; this depends on isWrapping(). This property is useful when the items are being represented by an icon view.
The resizeMode() and layoutMode() govern how and when the items are laid out. Items are spaced according to their spacing(), and can exist within a notional grid of size specified by gridSize(). The items can be rendered as large or small icons depending on their iconSize().
Improving Performance▲
It is possible to give the view hints about the data it is handling in order to improve its performance when displaying large numbers of items. One approach that can be taken for views that are intended to display items with equal sizes is to set the uniformItemSizes property to true.
See Also▲
See also View Classes, Item Views Puzzle Example, QTreeView, QTableView, QListWidget
Member Type Documentation▲
enum QListView::Flow▲
enum QListView::LayoutMode▲
Constant |
Value |
Description |
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QListView::SinglePass |
0 |
The items are laid out all at once. |
QListView::Batched |
1 |
The items are laid out in batches of batchSize items. |
See Also▲
See also batchSize
enum QListView::Movement▲
Constant |
Value |
Description |
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QListView::Static |
0 |
The items cannot be moved by the user. |
QListView::Free |
1 |
The items can be moved freely by the user. |
QListView::Snap |
2 |
The items snap to the specified grid when moved; see setGridSize(). |
enum QListView::ResizeMode▲
enum QListView::ViewMode▲
Constant |
Value |
Description |
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QListView::ListMode |
0 |
The items are laid out using TopToBottom flow, with Small size and Static movement |
QListView::IconMode |
1 |
The items are laid out using LeftToRight flow, with Large size and Free movement |
Property Documentation▲
batchSize : int▲
This property holds the number of items laid out in each batch if layoutMode is set to Batched
The default value is 100.
Access functions:
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int batchSize() const
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void setBatchSize(int batchSize)
flow : Flow▲
This property holds which direction the items layout should flow.
If this property is LeftToRight, the items will be laid out left to right. If the isWrapping property is true, the layout will wrap when it reaches the right side of the visible area. If this property is TopToBottom, the items will be laid out from the top of the visible area, wrapping when it reaches the bottom.
Setting this property when the view is visible will cause the items to be laid out again.
By default, this property is set to TopToBottom.
Access functions:
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flow() const
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void setFlow( flow)
See Also▲
See also viewMode
gridSize : QSize▲
This property holds the size of the layout grid
This property is the size of the grid in which the items are laid out. The default is an empty size which means that there is no grid and the layout is not done in a grid. Setting this property to a non-empty size switches on the grid layout. (When a grid layout is in force the spacing property is ignored.)
Setting this property when the view is visible will cause the items to be laid out again.
Access functions:
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gridSize() const
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void setGridSize(const &size)
See Also▲
See also viewMode
isWrapping : bool▲
This property holds whether the items layout should wrap.
This property holds whether the layout should wrap when there is no more space in the visible area. The point at which the layout wraps depends on the flow property.
Setting this property when the view is visible will cause the items to be laid out again.
By default, this property is false.
Access functions:
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bool isWrapping() const
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void setWrapping(bool enable)
See Also▲
See also viewMode
[since 5.12] itemAlignment : Qt::Alignment▲
This property holds the alignment of each item in its cell
This is only supported in ListMode with TopToBottom flow and with wrapping enabled. The default alignment is 0, which means that an item fills its cell entirely.
This property was introduced in Qt 5.12.
Access functions:
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itemAlignment() const
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void setItemAlignment( alignment)
layoutMode : LayoutMode▲
determines whether the layout of items should happen immediately or be delayed.
This property holds the layout mode for the items. When the mode is SinglePass (the default), the items are laid out all in one go. When the mode is Batched, the items are laid out in batches of batchSize items, while processing events. This makes it possible to instantly view and interact with the visible items while the rest are being laid out.
Access functions:
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layoutMode() const
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void setLayoutMode( mode)
See Also▲
See also viewMode
modelColumn : int▲
This property holds the column in the model that is visible
By default, this property contains 0, indicating that the first column in the model will be shown.
Access functions:
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int modelColumn() const
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void setModelColumn(int column)
movement : Movement▲
This property holds whether the items can be moved freely, are snapped to a grid, or cannot be moved at all.
This property determines how the user can move the items in the view. Static means that the items can't be moved by the user. Free means that the user can drag and drop the items to any position in the view. Snap means that the user can drag and drop the items, but only to the positions in a notional grid signified by the gridSize property.
Setting this property when the view is visible will cause the items to be laid out again.
By default, this property is set to Static.
Access functions:
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movement() const
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void setMovement( movement)
See Also▲
See also gridSize, resizeMode, viewMode
resizeMode : ResizeMode▲
This property holds whether the items are laid out again when the view is resized.
If this property is Adjust, the items will be laid out again when the view is resized. If the value is Fixed, the items will not be laid out when the view is resized.
By default, this property is set to Fixed.
Access functions:
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resizeMode() const
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void setResizeMode( mode)
See Also▲
selectionRectVisible : bool▲
if the selection rectangle should be visible
If this property is true then the selection rectangle is visible; otherwise it will be hidden.
The selection rectangle will only be visible if the selection mode is in a mode where more than one item can be selected; i.e., it will not draw a selection rectangle if the selection mode is QAbstractItemView::SingleSelection.
By default, this property is false.
Access functions:
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bool isSelectionRectVisible() const
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void setSelectionRectVisible(bool show)
spacing : int▲
This property holds the space around the items in the layout
This property is the size of the empty space that is padded around an item in the layout.
Setting this property when the view is visible will cause the items to be laid out again.
By default, this property contains a value of 0.
Access functions:
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int spacing() const
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void setSpacing(int space)
See Also▲
See also viewMode
uniformItemSizes : bool▲
This property holds whether all items in the listview have the same size
This property should only be set to true if it is guaranteed that all items in the view have the same size. This enables the view to do some optimizations for performance purposes.
By default, this property is false.
Access functions:
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bool uniformItemSizes() const
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void setUniformItemSizes(bool enable)
viewMode : ViewMode▲
This property holds the view mode of the QListView.
This property will change the other unset properties to conform with the set view mode. QListView-specific properties that have already been set will not be changed, unless clearPropertyFlags() has been called.
Setting the view mode will enable or disable drag and drop based on the selected movement. For ListMode, the default movement is Static (drag and drop disabled); for IconMode, the default movement is Free (drag and drop enabled).
Access functions:
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viewMode() const
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void setViewMode( mode)
See Also▲
See also isWrapping, spacing, gridSize, flow, movement, resizeMode
wordWrap : bool▲
This property holds the item text word-wrapping policy
If this property is true then the item text is wrapped where necessary at word-breaks; otherwise it is not wrapped at all. This property is false by default.
Please note that even if wrapping is enabled, the cell will not be expanded to make room for the text. It will print ellipsis for text that cannot be shown, according to the view's textElideMode.
Access functions:
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bool wordWrap() const
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void setWordWrap(bool on)
Member Function Documentation▲
[explicit] QListView::QListView(QWidget *parent = nullptr)▲
[virtual] QListView::~QListView()▲
Destroys the view.
void QListView::clearPropertyFlags()▲
Clears the QListView-specific property flags. See viewMode.
Properties inherited from QAbstractItemView are not covered by the property flags. Specifically, dragEnabled and acceptsDrops are computed by QListView when calling setMovement() or setViewMode().
[override virtual protected] void QListView::currentChanged(const QModelIndex ¤t, const QModelIndex &previous)▲
Reimplements: QAbstractItemView::currentChanged(const QModelIndex ¤t, const QModelIndex &previous).
[override virtual protected] void QListView::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QList<int> &roles = QList<int>())▲
Reimplements: QAbstractItemView::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QList<int> &roles).
[override virtual protected] void QListView::dragLeaveEvent(QDragLeaveEvent *e)▲
Reimplements: QAbstractItemView::dragLeaveEvent(QDragLeaveEvent *event).
[override virtual protected] void QListView::dragMoveEvent(QDragMoveEvent *e)▲
Reimplements: QAbstractItemView::dragMoveEvent(QDragMoveEvent *event).
[override virtual protected] void QListView::dropEvent(QDropEvent *event)▲
Reimplements: QAbstractItemView::dropEvent(QDropEvent *event).
[override virtual protected] bool QListView::event(QEvent *e)▲
Reimplements: QAbstractItemView::event(QEvent *event).
[override virtual protected] int QListView::horizontalOffset() const▲
Reimplements: QAbstractItemView::horizontalOffset() const.
[override virtual] QModelIndex QListView::indexAt(const QPoint &p) const▲
Reimplements: QAbstractItemView::indexAt(const QPoint &point) const.
void QListView::indexesMoved(const QModelIndexList &indexes)▲
This signal is emitted when the specified indexes are moved in the view.
[override virtual protected] void QListView::initViewItemOption(QStyleOptionViewItem *option) const▲
[override virtual protected] bool QListView::isIndexHidden(const QModelIndex &index) const▲
bool QListView::isRowHidden(int row) const▲
Returns true if the row is hidden; otherwise returns false.
[override virtual protected] void QListView::mouseMoveEvent(QMouseEvent *e)▲
Reimplements: QAbstractItemView::mouseMoveEvent(QMouseEvent *event).
[override virtual protected] void QListView::mouseReleaseEvent(QMouseEvent *e)▲
Reimplements: QAbstractItemView::mouseReleaseEvent(QMouseEvent *event).
[override virtual protected] QModelIndex QListView::moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers modifiers)▲
Reimplements: QAbstractItemView::moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers modifiers).
[override virtual protected] void QListView::paintEvent(QPaintEvent *e)▲
Reimplements: QAbstractScrollArea::paintEvent(QPaintEvent *event).
[protected] QRect QListView::rectForIndex(const QModelIndex &index) const▲
Returns the rectangle of the item at position index in the model. The rectangle is in contents coordinates.
See Also▲
See also visualRect()
[override virtual protected] void QListView::resizeEvent(QResizeEvent *e)▲
Reimplements: QAbstractItemView::resizeEvent(QResizeEvent *event).
[override virtual protected] void QListView::rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end)▲
Reimplements: QAbstractItemView::rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end).
[override virtual protected] void QListView::rowsInserted(const QModelIndex &parent, int start, int end)▲
[override virtual protected] void QListView::scrollContentsBy(int dx, int dy)▲
Reimplements: QAbstractScrollArea::scrollContentsBy(int dx, int dy).
Scroll the view contents by dx and dy.
[override virtual] void QListView::scrollTo(const QModelIndex &index, QAbstractItemView::ScrollHint hint = EnsureVisible)▲
Reimplements: QAbstractItemView::scrollTo(const QModelIndex &index, QAbstractItemView::ScrollHint hint).
[override virtual protected] QModelIndexList QListView::selectedIndexes() const▲
Reimplements: QAbstractItemView::selectedIndexes() const.
[override virtual protected] void QListView::selectionChanged(const QItemSelection &selected, const QItemSelection &deselected)▲
Reimplements: QAbstractItemView::selectionChanged(const QItemSelection &selected, const QItemSelection &deselected).
[protected] void QListView::setPositionForIndex(const QPoint &position, const QModelIndex &index)▲
Sets the contents position of the item at index in the model to the given position. If the list view's movement mode is Static or its view mode is ListView, this function will have no effect.
[override virtual] void QListView::setRootIndex(const QModelIndex &index)▲
Reimplements: QAbstractItemView::setRootIndex(const QModelIndex &index).
void QListView::setRowHidden(int row, bool hide)▲
If hide is true, the given row will be hidden; otherwise the row will be shown.
See Also▲
See also isRowHidden()
[override virtual protected] void QListView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)▲
Reimplements: QAbstractItemView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags flags).
[override virtual protected] void QListView::startDrag(Qt::DropActions supportedActions)▲
[override virtual protected] void QListView::timerEvent(QTimerEvent *e)▲
Reimplements: QAbstractItemView::timerEvent(QTimerEvent *event).
[override virtual protected] void QListView::updateGeometries()▲
Reimplements: QAbstractItemView::updateGeometries().
[override virtual protected] int QListView::verticalOffset() const▲
Reimplements: QAbstractItemView::verticalOffset() const.
[override virtual protected, since 5.2] QSize QListView::viewportSizeHint() const▲
Reimplements: QAbstractItemView::viewportSizeHint() const.
This function was introduced in Qt 5.2.
[override virtual] QRect QListView::visualRect(const QModelIndex &index) const▲
[override virtual protected] QRegion QListView::visualRegionForSelection(const QItemSelection &selection) const▲
Reimplements: QAbstractItemView::visualRegionForSelection(const QItemSelection &selection) const.
Since 4.7, the returned region only contains rectangles intersecting (or included in) the viewport.
[override virtual protected] void QListView::wheelEvent(QWheelEvent *e)▲
Reimplements: QAbstractScrollArea::wheelEvent(QWheelEvent *e).