QAbstractItemView Class

  void MyView::resizeEvent(QResizeEvent *event) {
      horizontalScrollBar()->setRange(0, realWidth - width());
      ...
  }

Member Function Documentation

QAbstractItemView::QAbstractItemView(QWidget *parent = Q_NULLPTR)

Constructs an abstract item view with the given parent.

QAbstractItemView::~QAbstractItemView()

Destroys the view.

[signal] void QAbstractItemView::activated(const QModelIndex &index)

This signal is emitted when the item specified by index is activated by the user. How to activate items depends on the platform; e.g., by single- or double-clicking the item, or by pressing the Return or Enter key when the item is current.

See also clicked(), doubleClicked(), entered(), and pressed().

[slot] void QAbstractItemView::clearSelection()

Deselects all selected items. The current index will not be changed.

See also setSelection() and selectAll().

[signal] void QAbstractItemView::clicked(const QModelIndex &index)

This signal is emitted when a mouse button is left-clicked. The item the mouse was clicked on is specified by index. The signal is only emitted when the index is valid.

See also activated(), doubleClicked(), entered(), and pressed().

[virtual protected slot] void QAbstractItemView::closeEditor(QWidget *editor, QAbstractItemDelegate::EndEditHint hint)

Closes the given editor, and releases it. The hint is used to specify how the view should respond to the end of the editing operation. For example, the hint may indicate that the next item in the view should be opened for editing.

See also edit() and commitData().

void QAbstractItemView::closePersistentEditor(const QModelIndex &index)

Closes the persistent editor for the item at the given index.

See also openPersistentEditor().

[virtual protected slot] void QAbstractItemView::commitData(QWidget *editor)

Commit the data in the editor to the model.

See also closeEditor().

[virtual protected slot] void QAbstractItemView::currentChanged(const QModelIndex &current, const QModelIndex &previous)

This slot is called when a new item becomes the current item. The previous current item is specified by the previous index, and the new item by the current index.

If you want to know about changes to items see the dataChanged() signal.

QModelIndex QAbstractItemView::currentIndex() const

Returns the model index of the current item.

See also setCurrentIndex().

[virtual protected slot] void QAbstractItemView::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles = QVector<int> ())

This slot is called when items with the given roles are changed in the model. The changed items are those from topLeft to bottomRight inclusive. If just one item is changed topLeft == bottomRight.

The roles which have been changed can either be an empty container (meaning everything has changed), or a non-empty container with the subset of roles which have changed.

[protected] QPoint QAbstractItemView::dirtyRegionOffset() const

Returns the offset of the dirty regions in the view.

If you use scrollDirtyRegion() and implement a paintEvent() in a subclass of QAbstractItemView, you should translate the area given by the paint event with the offset returned from this function.

See also scrollDirtyRegion() and setDirtyRegion().

[signal] void QAbstractItemView::doubleClicked(const QModelIndex &index)

This signal is emitted when a mouse button is double-clicked. The item the mouse was double-clicked on is specified by index. The signal is only emitted when the index is valid.

See also clicked() and activated().

[virtual protected] void QAbstractItemView::dragEnterEvent(QDragEnterEvent *event)

Reimplemented from QWidget::dragEnterEvent().

This function is called with the given event when a drag and drop operation enters the widget. If the drag is over a valid dropping place (e.g. over an item that accepts drops), the event is accepted; otherwise it is ignored.

See also dropEvent() and startDrag().

[virtual protected] void QAbstractItemView::dragLeaveEvent(QDragLeaveEvent *event)

Reimplemented from QWidget::dragLeaveEvent().

This function is called when the item being dragged leaves the view. The event describes the state of the drag and drop operation.

[virtual protected] void QAbstractItemView::dragMoveEvent(QDragMoveEvent *event)

Reimplemented from QWidget::dragMoveEvent().

This function is called continuously with the given event during a drag and drop operation over the widget. It can cause the view to scroll if, for example, the user drags a selection to view's right or bottom edge. In this case, the event will be accepted; otherwise it will be ignored.

See also dropEvent() and startDrag().

[virtual protected] void QAbstractItemView::dropEvent(QDropEvent *event)

Reimplemented from QWidget::dropEvent().

This function is called with the given event when a drop event occurs over the widget. If the model accepts the even position the drop event is accepted; otherwise it is ignored.

See also startDrag().

[protected] DropIndicatorPosition QAbstractItemView::dropIndicatorPosition() const

Returns the position of the drop indicator in relation to the closest item.

This function was introduced in Qt 4.1.

[slot] void QAbstractItemView::edit(const QModelIndex &index)

Starts editing the item corresponding to the given index if it is editable.

Note that this function does not change the current index. Since the current index defines the next and previous items to edit, users may find that keyboard navigation does not work as expected. To provide consistent navigation behavior, call setCurrentIndex() before this function with the same model index.

See also QModelIndex::flags().

[virtual protected] bool QAbstractItemView::edit(const QModelIndex &index, EditTrigger trigger, QEvent *event)

Starts editing the item at index, creating an editor if necessary, and returns true if the view's State is now EditingState; otherwise returns false.

The action that caused the editing process is described by trigger, and the associated event is specified by event.

Editing can be forced by specifying the trigger to be QAbstractItemView::AllEditTriggers.

See also closeEditor().

[virtual protected slot] void QAbstractItemView::editorDestroyed(QObject *editor)

This function is called when the given editor has been destroyed.

See also closeEditor().

[signal] void QAbstractItemView::entered(const QModelIndex &index)

This signal is emitted when the mouse cursor enters the item specified by index. Mouse tracking needs to be enabled for this feature to work.

See also viewportEntered(), activated(), clicked(), doubleClicked(), and pressed().

[virtual protected] bool QAbstractItemView::event(QEvent *event)

Reimplemented from QObject::event().

[protected] void QAbstractItemView::executeDelayedItemsLayout()

Executes the scheduled layouts without waiting for the event processing to begin.

See also scheduleDelayedItemsLayout().

[virtual protected] void QAbstractItemView::focusInEvent(QFocusEvent *event)

Reimplemented from QWidget::focusInEvent().

This function is called with the given event when the widget obtains the focus. By default, the event is ignored.

See also setFocus() and focusOutEvent().

[virtual protected] bool QAbstractItemView::focusNextPrevChild(bool next)

Reimplemented from QWidget::focusNextPrevChild().

[virtual protected] void QAbstractItemView::focusOutEvent(QFocusEvent *event)

Reimplemented from QWidget::focusOutEvent().

This function is called with the given event when the widget looses the focus. By default, the event is ignored.

See also clearFocus() and focusInEvent().

[pure virtual protected] int QAbstractItemView::horizontalOffset() const

Returns the horizontal offset of the view.

In the base class this is a pure virtual function.

See also verticalOffset().

[pure virtual] QModelIndex QAbstractItemView::indexAt(const QPoint &point) const

Returns the model index of the item at the viewport coordinates point.

In the base class this is a pure virtual function.

See also visualRect().

QWidget *QAbstractItemView::indexWidget(const QModelIndex &index) const

Returns the widget for the item at the given index.

This function was introduced in Qt 4.1.

See also setIndexWidget().

[virtual protected] void QAbstractItemView::inputMethodEvent(QInputMethodEvent *event)

Reimplemented from QWidget::inputMethodEvent().

[virtual] QVariant QAbstractItemView::inputMethodQuery(Qt::InputMethodQuery query) const

Reimplemented from QWidget::inputMethodQuery().

[pure virtual protected] bool QAbstractItemView::isIndexHidden(const QModelIndex &index) const

Returns true if the item referred to by the given index is hidden in the view, otherwise returns false.

Hiding is a view specific feature. For example in TableView a column can be marked as hidden or a row in the TreeView.

In the base class this is a pure virtual function.

QAbstractItemDelegate *QAbstractItemView::itemDelegate() const

Returns the item delegate used by this view and model. This is either one set with setItemDelegate(), or the default one.

See also setItemDelegate().

QAbstractItemDelegate *QAbstractItemView::itemDelegate(const QModelIndex &index) const

Returns the item delegate used by this view and model for the given index.

QAbstractItemDelegate *QAbstractItemView::itemDelegateForColumn(int column) const

Returns the item delegate used by this view and model for the given column. You can call itemDelegate() to get a pointer to the current delegate for a given index.

This function was introduced in Qt 4.2.

See also setItemDelegateForColumn(), itemDelegateForRow(), and itemDelegate().

QAbstractItemDelegate *QAbstractItemView::itemDelegateForRow(int row) const

Returns the item delegate used by this view and model for the given row, or 0 if no delegate has been assigned. You can call itemDelegate() to get a pointer to the current delegate for a given index.

This function was introduced in Qt 4.2.

See also setItemDelegateForRow(), itemDelegateForColumn(), and setItemDelegate().

[virtual protected] void QAbstractItemView::keyPressEvent(QKeyEvent *event)

Reimplemented from QWidget::keyPressEvent().

This function is called with the given event when a key event is sent to the widget. The default implementation handles basic cursor movement, e.g. Up, Down, Left, Right, Home, PageUp, and PageDown; the activated() signal is emitted if the current index is valid and the activation key is pressed (e.g. Enter or Return, depending on the platform). This function is where editing is initiated by key press, e.g. if F2 is pressed.

See also edit(), moveCursor(), keyboardSearch(), and tabKeyNavigation.

[virtual] void QAbstractItemView::keyboardSearch(const QString &search)

Moves to and selects the item best matching the string search. If no item is found nothing happens.

In the default implementation, the search is reset if search is empty, or the time interval since the last search has exceeded QApplication::keyboardInputInterval().

QAbstractItemModel *QAbstractItemView::model() const

Returns the model that this view is presenting.

See also setModel().

[virtual protected] void QAbstractItemView::mouseDoubleClickEvent(QMouseEvent *event)

Reimplemented from QWidget::mouseDoubleClickEvent().

This function is called with the given event when a mouse button is double clicked inside the widget. If the double-click is on a valid item it emits the doubleClicked() signal and calls edit() on the item.

[virtual protected] void QAbstractItemView::mouseMoveEvent(QMouseEvent *event)

Reimplemented from QWidget::mouseMoveEvent().

This function is called with the given event when a mouse move event is sent to the widget. If a selection is in progress and new items are moved over the selection is extended; if a drag is in progress it is continued.

[virtual protected] void QAbstractItemView::mousePressEvent(QMouseEvent *event)

Reimplemented from QWidget::mousePressEvent().

This function is called with the given event when a mouse button is pressed while the cursor is inside the widget. If a valid item is pressed on it is made into the current item. This function emits the pressed() signal.

[virtual protected] void QAbstractItemView::mouseReleaseEvent(QMouseEvent *event)

Reimplemented from QWidget::mouseReleaseEvent().

This function is called with the given event when a mouse button is released, after a mouse press event on the widget. If a user presses the mouse inside your widget and then drags the mouse to another location before releasing the mouse button, your widget receives the release event. The function will emit the clicked() signal if an item was being pressed.

[pure virtual protected] QModelIndex QAbstractItemView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifiers modifiers)

Returns a QModelIndex object pointing to the next object in the view, based on the given cursorAction and keyboard modifiers specified by modifiers.

In the base class this is a pure virtual function.

void QAbstractItemView::openPersistentEditor(const QModelIndex &index)

Opens a persistent editor on the item at the given index. If no editor exists, the delegate will create a new editor.

See also closePersistentEditor().

[signal] void QAbstractItemView::pressed(const QModelIndex &index)

This signal is emitted when a mouse button is pressed. The item the mouse was pressed on is specified by index. The signal is only emitted when the index is valid.

Use the QApplication::mouseButtons() function to get the state of the mouse buttons.

See also activated(), clicked(), doubleClicked(), and entered().

[virtual slot] void QAbstractItemView::reset()

Reset the internal state of the view.

Warning: This function will reset open editors, scroll bar positions, selections, etc. Existing changes will not be committed. If you would like to save your changes when resetting the view, you can reimplement this function, commit your changes, and then call the superclass' implementation.

[virtual protected] void QAbstractItemView::resizeEvent(QResizeEvent *event)

Reimplemented from QWidget::resizeEvent().

This function is called with the given event when a resize event is sent to the widget.

See also QWidget::resizeEvent().

QModelIndex QAbstractItemView::rootIndex() const

Returns the model index of the model's root item. The root item is the parent item to the view's toplevel items. The root can be invalid.

See also setRootIndex().

[virtual protected slot] void QAbstractItemView::rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end)

This slot is called when rows are about to be removed. The deleted rows are those under the given parent from start to end inclusive.

See also rowsInserted().

[virtual protected slot] void QAbstractItemView::rowsInserted(const QModelIndex &parent, int start, int end)

This slot is called when rows are inserted. The new rows are those under the given parent from start to end inclusive. The base class implementation calls fetchMore() on the model to check for more data.

See also rowsAboutToBeRemoved().

[protected] void QAbstractItemView::scheduleDelayedItemsLayout()

Schedules a layout of the items in the view to be executed when the event processing starts.

Even if scheduleDelayedItemsLayout() is called multiple times before events are processed, the view will only do the layout once.

See also executeDelayedItemsLayout().

[protected] void QAbstractItemView::scrollDirtyRegion(int dx, int dy)

Prepares the view for scrolling by (dx,dy) pixels by moving the dirty regions in the opposite direction. You only need to call this function if you are implementing a scrolling viewport in your view subclass.

If you implement scrollContentsBy() in a subclass of QAbstractItemView, call this function before you call QWidget::scroll() on the viewport. Alternatively, just call update().

See also scrollContentsBy(), dirtyRegionOffset(), and setDirtyRegion().

[pure virtual] void QAbstractItemView::scrollTo(const QModelIndex &index, ScrollHint hint = EnsureVisible)

Scrolls the view if necessary to ensure that the item at index is visible. The view will try to position the item according to the given hint.

In the base class this is a pure virtual function.

[slot] void QAbstractItemView::scrollToBottom()

Scrolls the view to the bottom.

This function was introduced in Qt 4.1.

See also scrollTo() and scrollToTop().

[slot] void QAbstractItemView::scrollToTop()

Scrolls the view to the top.

This function was introduced in Qt 4.1.

See also scrollTo() and scrollToBottom().

[virtual slot] void QAbstractItemView::selectAll()

Selects all items in the view. This function will use the selection behavior set on the view when selecting.

See also setSelection(), selectedIndexes(), and clearSelection().

[virtual protected] QModelIndexList QAbstractItemView::selectedIndexes() const

This convenience function returns a list of all selected and non-hidden item indexes in the view. The list contains no duplicates, and is not sorted.

See also QItemSelectionModel::selectedIndexes().

[virtual protected slot] void QAbstractItemView::selectionChanged(const QItemSelection &selected, const QItemSelection &deselected)

This slot is called when the selection is changed. The previous selection (which may be empty), is specified by deselected, and the new selection by selected.

See also setSelection().

[virtual protected] QItemSelectionModel::SelectionFlags QAbstractItemView::selectionCommand(const QModelIndex &index, const QEvent *event = Q_NULLPTR) const

Returns the SelectionFlags to be used when updating a selection with to include the index specified. The event is a user input event, such as a mouse or keyboard event.

Reimplement this function to define your own selection behavior.

See also setSelection().

QItemSelectionModel *QAbstractItemView::selectionModel() const

Returns the current selection model.

See also setSelectionModel() and selectedIndexes().

[slot] void QAbstractItemView::setCurrentIndex(const QModelIndex &index)

Sets the current item to be the item at index.

Unless the current selection mode is NoSelection, the item is also selected. Note that this function also updates the starting position for any new selections the user performs.

To set an item as the current item without selecting it, call

selectionModel()->setCurrentIndex(index, QItemSelectionModel::NoUpdate);

See also currentIndex(), currentChanged(), and selectionMode.

[protected] void QAbstractItemView::setDirtyRegion(const QRegion &region)

Marks the given region as dirty and schedules it to be updated. You only need to call this function if you are implementing your own view subclass.

This function was introduced in Qt 4.1.

See also scrollDirtyRegion() and dirtyRegionOffset().

void QAbstractItemView::setIndexWidget(const QModelIndex &index, QWidget *widget)

Sets the given widget on the item at the given index, passing the ownership of the widget to the viewport.

If index is invalid (e.g., if you pass the root index), this function will do nothing.

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 item at the given index.

If index widget A is replaced with index widget B, index widget A will be deleted. For example, in the code snippet below, the QLineEdit object will be deleted.

  setIndexWidget(index, new QLineEdit);
  ...
  setIndexWidget(index, new QTextEdit);

This function should only be used to display static content within the visible area corresponding to an item of data. If you want to display custom dynamic content or implement a custom editor widget, subclass QItemDelegate instead.

This function was introduced in Qt 4.1.

See also indexWidget() and Delegate Classes.

void QAbstractItemView::setItemDelegate(QAbstractItemDelegate *delegate)

Sets the item delegate for this view and its model to delegate. This is useful if you want complete control over the editing and display of items.

Any existing delegate will be removed, but not deleted. QAbstractItemView does not take ownership of delegate.

Warning: You should not share the same instance of a delegate between views. Doing so can cause incorrect or unintuitive editing behavior since each view connected to a given delegate may receive the closeEditor() signal, and attempt to access, modify or close an editor that has already been closed.

See also itemDelegate().

void QAbstractItemView::setItemDelegateForColumn(int column, QAbstractItemDelegate *delegate)

Sets the given item delegate used by this view and model for the given column. All items on column will be drawn and managed by delegate instead of using the default delegate (i.e., itemDelegate()).

Any existing column delegate for column will be removed, but not deleted. QAbstractItemView does not take ownership of delegate.

Note: If a delegate has been assigned to both a row and a column, the row delegate will take precedence and manage the intersecting cell index.

Warning: You should not share the same instance of a delegate between views. Doing so can cause incorrect or unintuitive editing behavior since each view connected to a given delegate may receive the closeEditor() signal, and attempt to access, modify or close an editor that has already been closed.

This function was introduced in Qt 4.2.

See also itemDelegateForColumn(), setItemDelegateForRow(), and itemDelegate().

void QAbstractItemView::setItemDelegateForRow(int row, QAbstractItemDelegate *delegate)

Sets the given item delegate used by this view and model for the given row. All items on row will be drawn and managed by delegate instead of using the default delegate (i.e., itemDelegate()).

Any existing row delegate for row will be removed, but not deleted. QAbstractItemView does not take ownership of delegate.

Note: If a delegate has been assigned to both a row and a column, the row delegate (i.e., this delegate) will take precedence and manage the intersecting cell index.

Warning: You should not share the same instance of a delegate between views. Doing so can cause incorrect or unintuitive editing behavior since each view connected to a given delegate may receive the closeEditor() signal, and attempt to access, modify or close an editor that has already been closed.

This function was introduced in Qt 4.2.

See also itemDelegateForRow(), setItemDelegateForColumn(), and itemDelegate().

[virtual] void QAbstractItemView::setModel(QAbstractItemModel *model)

Sets the model for the view to present.

This function will create and set a new selection model, replacing any model that was previously set with setSelectionModel(). However, the old selection model will not be deleted as it may be shared between several views. We recommend that you delete the old selection model if it is no longer required. This is done with the following code:

  QItemSelectionModel *m = view->selectionModel();
  view->setModel(new model);
  delete m;

If both the old model and the old selection model do not have parents, or if their parents are long-lived objects, it may be preferable to call their deleteLater() functions to explicitly delete them.

The view does not take ownership of the model unless it is the model's parent object because the model may be shared between many different views.

See also model(), selectionModel(), and setSelectionModel().

[virtual slot] void QAbstractItemView::setRootIndex(const QModelIndex &index)

Sets the root item to the item at the given index.

See also rootIndex().

[pure virtual protected] void QAbstractItemView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags flags)

Applies the selection flags to the items in or touched by the rectangle, rect.

When implementing your own itemview setSelection should call selectionModel()->select(selection, flags) where selection is either an empty QModelIndex or a QItemSelection that contains all items that are contained in rect.

See also selectionCommand() and selectedIndexes().

[virtual] void QAbstractItemView::setSelectionModel(QItemSelectionModel *selectionModel)

Sets the current selection model to the given selectionModel.

Note that, if you call setModel() after this function, the given selectionModel will be replaced by one created by the view.

Note: It is up to the application to delete the old selection model if it is no longer needed; i.e., if it is not being used by other views. This will happen automatically when its parent object is deleted. However, if it does not have a parent, or if the parent is a long-lived object, it may be preferable to call its deleteLater() function to explicitly delete it.

See also selectionModel(), setModel(), and clearSelection().

[protected] void QAbstractItemView::setState(State state)

Sets the item view's state to the given state.

See also state().

[virtual] int QAbstractItemView::sizeHintForColumn(int column) const

Returns the width size hint for the specified column or -1 if there is no model.

This function is used in views with a horizontal header to find the size hint for a header section based on the contents of the given column.

See also sizeHintForRow().

QSize QAbstractItemView::sizeHintForIndex(const QModelIndex &index) const

Returns the size hint for the item with the specified index or an invalid size for invalid indexes.

See also sizeHintForRow() and sizeHintForColumn().

[virtual] int QAbstractItemView::sizeHintForRow(int row) const

Returns the height size hint for the specified row or -1 if there is no model.

The returned height is calculated using the size hints of the given row's items, i.e. the returned value is the maximum height among the items. Note that to control the height of a row, you must reimplement the QAbstractItemDelegate::sizeHint() function.

This function is used in views with a vertical header to find the size hint for a header section based on the contents of the given row.

See also sizeHintForColumn().

[virtual protected] void QAbstractItemView::startDrag(Qt::DropActions supportedActions)

Starts a drag by calling drag->exec() using the given supportedActions.

[protected] State QAbstractItemView::state() const

Returns the item view's state.

See also setState().

[virtual protected] void QAbstractItemView::timerEvent(QTimerEvent *event)

Reimplemented from QObject::timerEvent().

This function is called with the given event when a timer event is sent to the widget.

See also QObject::timerEvent().

[slot] void QAbstractItemView::update(const QModelIndex &index)

Updates the area occupied by the given index.

This function was introduced in Qt 4.3.

[virtual protected slot] void QAbstractItemView::updateGeometries()

Updates the geometry of the child widgets of the view.

This function was introduced in Qt 4.4.

[pure virtual protected] int QAbstractItemView::verticalOffset() const

Returns the vertical offset of the view.

In the base class this is a pure virtual function.

See also horizontalOffset().

[virtual protected] QStyleOptionViewItem QAbstractItemView::viewOptions() const

Returns a QStyleOptionViewItem structure populated with the view's palette, font, state, alignments etc.

[signal] void QAbstractItemView::viewportEntered()

This signal is emitted when the mouse cursor enters the viewport. Mouse tracking needs to be enabled for this feature to work.

See also entered().

[virtual protected] bool QAbstractItemView::viewportEvent(QEvent *event)

Reimplemented from QAbstractScrollArea::viewportEvent().

This function is used to handle tool tips, and What's This? mode, if the given event is a QEvent::ToolTip,or a QEvent::WhatsThis. It passes all other events on to its base class viewportEvent() handler.

[virtual protected] QSize QAbstractItemView::viewportSizeHint() const

Reimplemented from QAbstractScrollArea::viewportSizeHint().

This function was introduced in Qt 5.2.

[pure virtual] QRect QAbstractItemView::visualRect(const QModelIndex &index) const

Returns the rectangle on the viewport occupied by the item at index.

If your item is displayed in several areas then visualRect should return the primary area that contains index and not the complete area that index might encompasses, touch or cause drawing.

In the base class this is a pure virtual function.

See also indexAt() and visualRegionForSelection().

[pure virtual protected] QRegion QAbstractItemView::visualRegionForSelection(const QItemSelection &selection) const

Returns the region from the viewport of the items in the given selection.

In the base class this is a pure virtual function.

See also visualRect() and selectedIndexes().