QTreeWidget Class▲
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Header: QTreeWidget
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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: QTreeView
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Group: QTreeWidget is part of model-view
Detailed Description▲
The QTreeWidget class is a convenience class that provides a standard tree widget with a classic item-based interface similar to that used by the QListView class in Qt 3. This class is based on Qt's Model/View architecture and uses a default model to hold items, each of which is a QTreeWidgetItem.
Developers who do not need the flexibility of the Model/View framework can use this class to create simple hierarchical lists very easily. A more flexible approach involves combining a QTreeView with a standard item model. This allows the storage of data to be separated from its representation.
In its simplest form, a tree widget can be constructed in the following way:
QTreeWidget *treeWidget = new QTreeWidget();
treeWidget->setColumnCount(1);
QList<QTreeWidgetItem *> items;
for (int i = 0; i < 10; ++i)
items.append(new QTreeWidgetItem(static_cast<QTreeWidget *>(nullptr), QStringList(QString("item: %1").arg(i))));
treeWidget->insertTopLevelItems(0, items);Before items can be added to the tree widget, the number of columns must be set with setColumnCount(). This allows each item to have one or more labels or other decorations. The number of columns in use can be found with the columnCount() function.
The tree can have a header that contains a section for each column in the widget. It is easiest to set up the labels for each section by supplying a list of strings with setHeaderLabels(), but a custom header can be constructed with a QTreeWidgetItem and inserted into the tree with the setHeaderItem() function.
The items in the tree can be sorted by column according to a predefined sort order. If sorting is enabled, the user can sort the items by clicking on a column header. Sorting can be enabled or disabled by calling setSortingEnabled(). The isSortingEnabled() function indicates whether sorting is enabled.
See Also▲
Property Documentation▲
columnCount : int▲
This property holds the number of columns displayed in the tree widget
By default, this property has a value of 1.
Access functions:
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int columnCount() const
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void setColumnCount(int columns)
[read-only] topLevelItemCount : const int▲
This property holds the number of top-level items
By default, this property has a value of 0.
Access functions:
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int topLevelItemCount() const
See Also▲
See also columnCount(), currentItem()
Member Function Documentation▲
[explicit] QTreeWidget::QTreeWidget(QWidget *parent = nullptr)▲
Constructs a tree widget with the given parent.
[virtual] QTreeWidget::~QTreeWidget()▲
Destroys the tree widget and all its items.
void QTreeWidget::addTopLevelItem(QTreeWidgetItem *item)▲
void QTreeWidget::addTopLevelItems(const QList<QTreeWidgetItem *> &items)▲
Appends the list of items as a top-level items in the widget.
See Also▲
See also insertTopLevelItems()
void QTreeWidget::clear()▲
Clears the tree widget by removing all of its items and selections.
Note: Since each item is removed from the tree widget before being deleted, the return value of QTreeWidgetItem::treeWidget() will be invalid when called from an item's destructor.
See Also▲
See also takeTopLevelItem(), topLevelItemCount(), columnCount()
void QTreeWidget::closePersistentEditor(QTreeWidgetItem *item, int column = 0)▲
Closes the persistent editor for the item in the given column.
This function has no effect if no persistent editor is open for this combination of item and column.
See Also▲
See also openPersistentEditor(), isPersistentEditorOpen()
void QTreeWidget::collapseItem(const QTreeWidgetItem *item)▲
Closes the item. This causes the tree containing the item's children to be collapsed.
See Also▲
See also expandItem(), currentItem(), itemAt(), topLevelItem()
int QTreeWidget::currentColumn() const▲
QTreeWidgetItem *QTreeWidget::currentItem() const▲
Returns the current item in the tree widget.
See Also▲
See also setCurrentItem(), currentItemChanged()
void QTreeWidget::currentItemChanged(QTreeWidgetItem *current, QTreeWidgetItem *previous)▲
This signal is emitted when the current item changes. The current item is specified by current, and this replaces the previous current item.
See Also▲
See also setCurrentItem()
[override virtual protected] void QTreeWidget::dropEvent(QDropEvent *event)▲
Reimplements: QAbstractItemView::dropEvent(QDropEvent *event).
[virtual protected] bool QTreeWidget::dropMimeData(QTreeWidgetItem *parent, int index, const QMimeData *data, Qt::DropAction action)▲
Handles the data supplied by a drag and drop operation that ended with the given action in the index in the given parent item.
The default implementation returns true if the drop was successfully handled by decoding the mime data and inserting it into the model; otherwise it returns false.
See Also▲
See also supportedDropActions()
void QTreeWidget::editItem(QTreeWidgetItem *item, int column = 0)▲
Starts editing the item in the given column if it is editable.
[override virtual protected] bool QTreeWidget::event(QEvent *e)▲
Reimplements: QAbstractItemView::event(QEvent *event).
void QTreeWidget::expandItem(const QTreeWidgetItem *item)▲
Expands the item. This causes the tree containing the item's children to be expanded.
See Also▲
See also collapseItem(), currentItem(), itemAt(), topLevelItem(), itemExpanded()
QList<QTreeWidgetItem *> QTreeWidget::findItems(const QString &text, Qt::MatchFlags flags, int column = 0) const▲
Returns a list of items that match the given text, using the given flags, in the given column.
QTreeWidgetItem *QTreeWidget::headerItem() const▲
QModelIndex QTreeWidget::indexFromItem(const QTreeWidgetItem *item, int column = 0) const▲
Returns the QModelIndex associated with the given item in the given column.
In Qt versions prior to 5.7, this function took a non-const item.
See Also▲
See also itemFromIndex(), topLevelItem()
int QTreeWidget::indexOfTopLevelItem(QTreeWidgetItem *item) const▲
Returns the index of the given top-level item, or -1 if the item cannot be found.
See Also▲
See also sortItems(), topLevelItemCount()
void QTreeWidget::insertTopLevelItem(int index, QTreeWidgetItem *item)▲
Inserts the item at index in the top level in the view.
If the item has already been inserted somewhere else it won't be inserted.
See Also▲
See also addTopLevelItem(), columnCount()
void QTreeWidget::insertTopLevelItems(int index, const QList<QTreeWidgetItem *> &items)▲
Inserts the list of items at index in the top level in the view.
Items that have already been inserted somewhere else won't be inserted.
See Also▲
See also addTopLevelItems()
QTreeWidgetItem *QTreeWidget::invisibleRootItem() const▲
Returns the tree widget's invisible root item.
The invisible root item provides access to the tree widget's top-level items through the QTreeWidgetItem API, making it possible to write functions that can treat top-level items and their children in a uniform way; for example, recursive functions.
[since 5.10] bool QTreeWidget::isPersistentEditorOpen(QTreeWidgetItem *item, int column = 0) const▲
Returns whether a persistent editor is open for item item in column column.
This function was introduced in Qt 5.10.
See Also▲
See also openPersistentEditor(), closePersistentEditor()
QTreeWidgetItem *QTreeWidget::itemAbove(const QTreeWidgetItem *item) const▲
Returns the item above the given item.
void QTreeWidget::itemActivated(QTreeWidgetItem *item, int column)▲
This signal is emitted when the user activates an item by single- or double-clicking (depending on the platform, i.e. on the QStyle::SH_ItemView_ActivateItemOnSingleClick style hint) or pressing a special key (e.g., Enter).
The specified item is the item that was clicked, or nullptr if no item was clicked. The column is the item's column that was clicked, or -1 if no item was clicked.
QTreeWidgetItem *QTreeWidget::itemAt(const QPoint &p) const▲
Returns a pointer to the item at the coordinates p. The coordinates are relative to the tree widget's viewport().
See Also▲
See also visualItemRect()
QTreeWidgetItem *QTreeWidget::itemAt(int x, int y) const▲
This is an overloaded function.
Returns a pointer to the item at the coordinates (x, y). The coordinates are relative to the tree widget's viewport().
QTreeWidgetItem *QTreeWidget::itemBelow(const QTreeWidgetItem *item) const▲
Returns the item visually below the given item.
void QTreeWidget::itemChanged(QTreeWidgetItem *item, int column)▲
This signal is emitted when the contents of the column in the specified item changes.
void QTreeWidget::itemClicked(QTreeWidgetItem *item, int column)▲
This signal is emitted when the user clicks inside the widget.
The specified item is the item that was clicked. The column is the item's column that was clicked. If no item was clicked, no signal will be emitted.
void QTreeWidget::itemCollapsed(QTreeWidgetItem *item)▲
This signal is emitted when the specified item is collapsed so that none of its children are displayed.
This signal will not be emitted if an item changes its state when collapseAll() is invoked.
See Also▲
See also QTreeWidgetItem::isExpanded(), itemExpanded(), collapseItem()
void QTreeWidget::itemDoubleClicked(QTreeWidgetItem *item, int column)▲
This signal is emitted when the user double clicks inside the widget.
The specified item is the item that was clicked, or nullptr if no item was clicked. The column is the item's column that was clicked. If no item was double clicked, no signal will be emitted.
void QTreeWidget::itemEntered(QTreeWidgetItem *item, int column)▲
This signal is emitted when the mouse cursor enters an item over the specified column. QTreeWidget mouse tracking needs to be enabled for this feature to work.
void QTreeWidget::itemExpanded(QTreeWidgetItem *item)▲
This signal is emitted when the specified item is expanded so that all of its children are displayed.
See Also▲
See also QTreeWidgetItem::isExpanded(), itemCollapsed(), expandItem()
QTreeWidgetItem *QTreeWidget::itemFromIndex(const QModelIndex &index) const▲
Returns a pointer to the QTreeWidgetItem associated with the given index.
See Also▲
See also indexFromItem()
void QTreeWidget::itemPressed(QTreeWidgetItem *item, int column)▲
This signal is emitted when the user presses a mouse button inside the widget.
The specified item is the item that was clicked, or nullptr if no item was clicked. The column is the item's column that was clicked, or -1 if no item was clicked.
void QTreeWidget::itemSelectionChanged()▲
This signal is emitted when the selection changes in the tree widget. The current selection can be found with selectedItems().
QWidget *QTreeWidget::itemWidget(QTreeWidgetItem *item, int column) const▲
Returns the widget displayed in the cell specified by item and the given column.
See Also▲
See also setItemWidget()
[virtual protected] QMimeData *QTreeWidget::mimeData(const QList<QTreeWidgetItem *> &items) const▲
Returns an object that contains a serialized description of the specified items. The format used to describe the items is obtained from the mimeTypes() function.
If the list of items is empty, nullptr is returned rather than a serialized empty list.
[virtual protected] QStringList QTreeWidget::mimeTypes() const▲
Returns a list of MIME types that can be used to describe a list of treewidget items.
See Also▲
See also mimeData()
void QTreeWidget::openPersistentEditor(QTreeWidgetItem *item, int column = 0)▲
Opens a persistent editor for the item in the given column.
See Also▲
See also closePersistentEditor(), isPersistentEditorOpen()
void QTreeWidget::removeItemWidget(QTreeWidgetItem *item, int column)▲
Removes the widget set in the given item in the given column.
void QTreeWidget::scrollToItem(const QTreeWidgetItem *item, QAbstractItemView::ScrollHint hint = EnsureVisible)▲
Ensures that the item is visible, scrolling the view if necessary using the specified hint.
See Also▲
See also currentItem(), itemAt(), topLevelItem()
QList<QTreeWidgetItem *> QTreeWidget::selectedItems() const▲
void QTreeWidget::setCurrentItem(QTreeWidgetItem *item)▲
Sets the current item in the tree widget.
Unless the selection mode is NoSelection, the item is also selected.
See Also▲
See also currentItem(), currentItemChanged()
void QTreeWidget::setCurrentItem(QTreeWidgetItem *item, int column)▲
Sets the current item in the tree widget and the current column to column.
See Also▲
See also currentItem()
void QTreeWidget::setCurrentItem(QTreeWidgetItem *item, int column, QItemSelectionModel::SelectionFlags command)▲
Sets the current item in the tree widget and the current column to column, using the given command.
See Also▲
See also currentItem()
void QTreeWidget::setHeaderItem(QTreeWidgetItem *item)▲
Sets the header item for the tree widget. The label for each column in the header is supplied by the corresponding label in the item.
The tree widget takes ownership of the item.
See Also▲
See also headerItem(), setHeaderLabels()
void QTreeWidget::setHeaderLabel(const QString &label)▲
Same as setHeaderLabels(QStringList(label)).
void QTreeWidget::setHeaderLabels(const QStringList &labels)▲
Adds a column in the header for each item in the labels list, and sets the label for each column.
Note that setHeaderLabels() won't remove existing columns.
See Also▲
See also setHeaderItem(), setHeaderLabel()
void QTreeWidget::setItemWidget(QTreeWidgetItem *item, int column, QWidget *widget)▲
Sets the given widget to be displayed in the cell specified by the given item and column.
The given widget's autoFillBackground property must be set to true, otherwise the widget's background will be transparent, showing both the model data and the tree widget item.
This function should only be used to display static content in the place of a tree widget item. If you want to display custom dynamic content or implement a custom editor widget, use QTreeView and subclass QStyledItemDelegate instead.
This function cannot be called before the item hierarchy has been set up, i.e., the QTreeWidgetItem that will hold widget must have been added to the view before widget is set.
The tree takes ownership of the widget.
See Also▲
See also itemWidget(), Delegate Classes
[override virtual] void QTreeWidget::setSelectionModel(QItemSelectionModel *selectionModel)▲
int QTreeWidget::sortColumn() const▲
void QTreeWidget::sortItems(int column, Qt::SortOrder order)▲
Sorts the items in the widget in the specified order by the values in the given column.
See Also▲
See also sortColumn()
[virtual protected] Qt::DropActions QTreeWidget::supportedDropActions() const▲
QTreeWidgetItem *QTreeWidget::takeTopLevelItem(int index)▲
Removes the top-level item at the given index in the tree and returns it, otherwise returns nullptr;
See Also▲
See also insertTopLevelItem(), topLevelItem(), topLevelItemCount()
QTreeWidgetItem *QTreeWidget::topLevelItem(int index) const▲
Returns the top level item at the given index, or nullptr if the item does not exist.
See Also▲
See also topLevelItemCount(), insertTopLevelItem()