QAbstractItemView Class Reference

The QAbstractItemView class provides the basic functionality for item view classes. More...

 #include <QAbstractItemView>

Inherits: QAbstractScrollArea.

Inherited by: QColumnView, QHeaderView, QListView, QTableView, and QTreeView.

Public Types

enum DragDropMode { NoDragDrop, DragOnly, DropOnly, DragDrop, InternalMove }
enum EditTrigger { NoEditTriggers, CurrentChanged, DoubleClicked, SelectedClicked, ..., AllEditTriggers }
flags EditTriggers
enum ScrollHint { EnsureVisible, PositionAtTop, PositionAtBottom, PositionAtCenter }
enum ScrollMode { ScrollPerItem, ScrollPerPixel }
enum SelectionBehavior { SelectItems, SelectRows, SelectColumns }
enum SelectionMode { SingleSelection, ContiguousSelection, ExtendedSelection, MultiSelection, NoSelection }

Properties

Public Functions

QAbstractItemView ( QWidget * parent = 0 )
~QAbstractItemView ()
bool alternatingRowColors () const
int autoScrollMargin () const
void closePersistentEditor ( const QModelIndex & index )
QModelIndex currentIndex () const
Qt::DropAction defaultDropAction () const
DragDropMode dragDropMode () const
bool dragDropOverwriteMode () const
bool dragEnabled () const
EditTriggers editTriggers () const
bool hasAutoScroll () const
ScrollMode horizontalScrollMode () const
QSize iconSize () const
virtual QModelIndex indexAt ( const QPoint & point ) const = 0
QWidget * indexWidget ( const QModelIndex & index ) const
QAbstractItemDelegate * itemDelegate () const
QAbstractItemDelegate * itemDelegate ( const QModelIndex & index ) const
QAbstractItemDelegate * itemDelegateForColumn ( int column ) const
QAbstractItemDelegate * itemDelegateForRow ( int row ) const
virtual void keyboardSearch ( const QString & search )
QAbstractItemModel * model () const
void openPersistentEditor ( const QModelIndex & index )
QModelIndex rootIndex () const
virtual void scrollTo ( const QModelIndex & index, ScrollHint hint = EnsureVisible ) = 0
QAbstractItemView::SelectionBehavior selectionBehavior () const
QAbstractItemView::SelectionMode selectionMode () const
QItemSelectionModel * selectionModel () const
void setAlternatingRowColors ( bool enable )
void setAutoScroll ( bool enable )
void setAutoScrollMargin ( int margin )
void setDefaultDropAction ( Qt::DropAction dropAction )
void setDragDropMode ( DragDropMode behavior )
void setDragDropOverwriteMode ( bool overwrite )
void setDragEnabled ( bool enable )
void setDropIndicatorShown ( bool enable )
void setEditTriggers ( EditTriggers triggers )
void setHorizontalScrollMode ( ScrollMode mode )
void setIconSize ( const QSize & size )
void setIndexWidget ( const QModelIndex & index, QWidget * widget )
void setItemDelegate ( QAbstractItemDelegate * delegate )
void setItemDelegateForColumn ( int column, QAbstractItemDelegate * delegate )
void setItemDelegateForRow ( int row, QAbstractItemDelegate * delegate )
virtual void setModel ( QAbstractItemModel * model )
void setSelectionBehavior ( QAbstractItemView::SelectionBehavior behavior )
void setSelectionMode ( QAbstractItemView::SelectionMode mode )
virtual void setSelectionModel ( QItemSelectionModel * selectionModel )
void setTabKeyNavigation ( bool enable )
void setTextElideMode ( Qt::TextElideMode mode )
void setVerticalScrollMode ( ScrollMode mode )
bool showDropIndicator () const
virtual int sizeHintForColumn ( int column ) const
QSize sizeHintForIndex ( const QModelIndex & index ) const
virtual int sizeHintForRow ( int row ) const
bool tabKeyNavigation () const
Qt::TextElideMode textElideMode () const
ScrollMode verticalScrollMode () const
virtual QRect visualRect ( const QModelIndex & index ) const = 0

Reimplemented Public Functions

virtual QVariant inputMethodQuery ( Qt::InputMethodQuery query ) const

Public Slots

void clearSelection ()
void edit ( const QModelIndex & index )
virtual void reset ()
void scrollToBottom ()
void scrollToTop ()
virtual void selectAll ()
void setCurrentIndex ( const QModelIndex & index )
virtual void setRootIndex ( const QModelIndex & index )
void update ( const QModelIndex & index )
  • 19 public slots inherited from QWidget
  • 1 public slot inherited from QObject

Signals

void activated ( const QModelIndex & index )
void clicked ( const QModelIndex & index )
void doubleClicked ( const QModelIndex & index )
void entered ( const QModelIndex & index )
void pressed ( const QModelIndex & index )
void viewportEntered ()

Protected Types

enum CursorAction { MoveUp, MoveDown, MoveLeft, MoveRight, ..., MovePrevious }
enum DropIndicatorPosition { OnItem, AboveItem, BelowItem, OnViewport }
enum State { NoState, DraggingState, DragSelectingState, EditingState, ..., AnimatingState }

Protected Functions

QPoint dirtyRegionOffset () const
DropIndicatorPosition dropIndicatorPosition () const
virtual bool edit ( const QModelIndex & index, EditTrigger trigger, QEvent * event )
void executeDelayedItemsLayout ()
virtual int horizontalOffset () const = 0
virtual bool isIndexHidden ( const QModelIndex & index ) const = 0
virtual QModelIndex moveCursor ( CursorAction cursorAction, Qt::KeyboardModifiers modifiers ) = 0
void scheduleDelayedItemsLayout ()
void scrollDirtyRegion ( int dx, int dy )
virtual QModelIndexList selectedIndexes () const
virtual QItemSelectionModel::SelectionFlags selectionCommand ( const QModelIndex & index, const QEvent * event = 0 ) const
void setDirtyRegion ( const QRegion & region )
virtual void setSelection ( const QRect & rect, QItemSelectionModel::SelectionFlags flags ) = 0
void setState ( State state )
virtual void startDrag ( Qt::DropActions supportedActions )
State state () const
virtual int verticalOffset () const = 0
virtual QStyleOptionViewItem viewOptions () const
virtual QRegion visualRegionForSelection ( const QItemSelection & selection ) const = 0

Reimplemented Protected Functions

virtual void dragEnterEvent ( QDragEnterEvent * event )
virtual void dragLeaveEvent ( QDragLeaveEvent * event )
virtual void dragMoveEvent ( QDragMoveEvent * event )
virtual void dropEvent ( QDropEvent * event )
virtual bool event ( QEvent * event )
virtual void focusInEvent ( QFocusEvent * event )
virtual bool focusNextPrevChild ( bool next )
virtual void focusOutEvent ( QFocusEvent * event )
virtual void inputMethodEvent ( QInputMethodEvent * event )
virtual void keyPressEvent ( QKeyEvent * event )
virtual void mouseDoubleClickEvent ( QMouseEvent * event )
virtual void mouseMoveEvent ( QMouseEvent * event )
virtual void mousePressEvent ( QMouseEvent * event )
virtual void mouseReleaseEvent ( QMouseEvent * event )
virtual void resizeEvent ( QResizeEvent * event )
virtual void timerEvent ( QTimerEvent * event )
virtual bool viewportEvent ( QEvent * event )

Protected Slots

virtual void closeEditor ( QWidget * editor, QAbstractItemDelegate::EndEditHint hint )
virtual void commitData ( QWidget * editor )
virtual void currentChanged ( const QModelIndex & current, const QModelIndex & previous )
virtual void dataChanged ( const QModelIndex & topLeft, const QModelIndex & bottomRight )
virtual void editorDestroyed ( QObject * editor )
virtual void rowsAboutToBeRemoved ( const QModelIndex & parent, int start, int end )
virtual void rowsInserted ( const QModelIndex & parent, int start, int end )
virtual void selectionChanged ( const QItemSelection & selected, const QItemSelection & deselected )
virtual void updateGeometries ()

Additional Inherited Members

  • 4 static public members inherited from QWidget
  • 7 static public members inherited from QObject

Detailed Description

The QAbstractItemView class provides the basic functionality for item view classes.

QAbstractItemView class is the base class for every standard view that uses a QAbstractItemModel. QAbstractItemView is an abstract class and cannot itself be instantiated. It provides a standard interface for interoperating with models through the signals and slots mechanism, enabling subclasses to be kept up-to-date with changes to their models. This class provides standard support for keyboard and mouse navigation, viewport scrolling, item editing, and selections. The keyboard navigation implements this functionality:

KeysFunctionality
Arrow keysChanges the current item and selects it.
Ctrl+Arrow keysChanges the current item but does not select it.
Shift+Arrow keysChanges the current item and selects it. The previously selected item(s) is not deselected.
Ctr+SpaceToggles selection of the current item.
Tab/BacktabChanges the current item to the next/previous item.
Home/EndSelects the first/last item in the model.
Page up/Page downScrolls the rows shown up/down by the number of visible rows in the view.
Ctrl+ASelects all items in the model.

Note that the above table assumes that the selection mode allows the operations. For instance, you cannot select items if the selection mode is QAbstractItemView::NoSelection.

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

The view classes that inherit QAbstractItemView only need to implement their own view-specific functionality, such as drawing items, returning the geometry of items, finding items, etc.

QAbstractItemView provides common slots such as edit() and setCurrentIndex(). Many protected slots are also provided, including dataChanged(), rowsInserted(), rowsAboutToBeRemoved(), selectionChanged(), and currentChanged().

The root item is returned by rootIndex(), and the current item by currentIndex(). To make sure that an item is visible use scrollTo().

Some of QAbstractItemView's functions are concerned with scrolling, for example setHorizontalScrollMode() and setVerticalScrollMode(). To set the range of the scroll bars, you can, for example, reimplement the view's resizeEvent() function:

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

Note that the range is not updated until the widget is shown.

Several other functions are concerned with selection control; for example setSelectionMode(), and setSelectionBehavior(). This class provides a default selection model to work with (selectionModel()), but this can be replaced by using setSelectionModel() with an instance of QItemSelectionModel.

For complete control over the display and editing of items you can specify a delegate with setItemDelegate().

QAbstractItemView provides a lot of protected functions. Some are concerned with editing, for example, edit(), and commitData(), whilst others are keyboard and mouse event handlers.

Note: If you inherit QAbstractItemView and intend to update the contents of the viewport, you should use viewport->update() instead of update() as all painting operations take place on the viewport.

See also View Classes, Model/View Programming, QAbstractItemModel, and Chart Example.

Member Type Documentation

enum QAbstractItemView::CursorAction

This enum describes the different ways to navigate between items,

ConstantValueDescription
QAbstractItemView::MoveUp0Move to the item above the current item.
QAbstractItemView::MoveDown1Move to the item below the current item.
QAbstractItemView::MoveLeft2Move to the item left of the current item.
QAbstractItemView::MoveRight3Move to the item right of the current item.
QAbstractItemView::MoveHome4Move to the top-left corner item.
QAbstractItemView::MoveEnd5Move to the bottom-right corner item.
QAbstractItemView::MovePageUp6Move one page up above the current item.
QAbstractItemView::MovePageDown7Move one page down below the current item.
QAbstractItemView::MoveNext8Move to the item after the current item.
QAbstractItemView::MovePrevious9Move to the item before the current item.

See also moveCursor().

enum QAbstractItemView::DragDropMode

Describes the various drag and drop events the view can act upon. By default the view does not support dragging or dropping (NoDragDrop).

ConstantValueDescription
QAbstractItemView::NoDragDrop0Does not support dragging or dropping.
QAbstractItemView::DragOnly1The view supports dragging of its own items
QAbstractItemView::DropOnly2The view accepts drops
QAbstractItemView::DragDrop3The view supports both dragging and dropping
QAbstractItemView::InternalMove4The view accepts move (not copy) operations only from itself.

Note that the model used needs to provide support for drag and drop operations.

This enum was introduced or modified in Qt 4.2.

See also setDragDropMode() and Using drag and drop with item views.

enum QAbstractItemView::DropIndicatorPosition

This enum indicates the position of the drop indicator in relation to the index at the current mouse position:

ConstantValueDescription
QAbstractItemView::OnItem0The item will be dropped on the index.
QAbstractItemView::AboveItem1The item will be dropped above the index.
QAbstractItemView::BelowItem2The item will be dropped below the index.
QAbstractItemView::OnViewport3The item will be dropped onto a region of the viewport with no items. The way each view handles items dropped onto the viewport depends on the behavior of the underlying model in use.

enum QAbstractItemView::EditTrigger
flags QAbstractItemView::EditTriggers

This enum describes actions which will initiate item editing.

ConstantValueDescription
QAbstractItemView::NoEditTriggers0No editing possible.
QAbstractItemView::CurrentChanged1Editing start whenever current item changes.
QAbstractItemView::DoubleClicked2Editing starts when an item is double clicked.
QAbstractItemView::SelectedClicked4Editing starts when clicking on an already selected item.
QAbstractItemView::EditKeyPressed8Editing starts when the platform edit key has been pressed over an item.
QAbstractItemView::AnyKeyPressed16Editing starts when any key is pressed over an item.
QAbstractItemView::AllEditTriggers31Editing starts for all above actions.

The EditTriggers type is a typedef for QFlags<EditTrigger>. It stores an OR combination of EditTrigger values.

enum QAbstractItemView::ScrollHint

ConstantValueDescription
QAbstractItemView::EnsureVisible0Scroll to ensure that the item is visible.
QAbstractItemView::PositionAtTop1Scroll to position the item at the top of the viewport.
QAbstractItemView::PositionAtBottom2Scroll to position the item at the bottom of the viewport.
QAbstractItemView::PositionAtCenter3Scroll to position the item at the center of the viewport.

enum QAbstractItemView::ScrollMode

ConstantValueDescription
QAbstractItemView::ScrollPerItem0The view will scroll the contents one item at a time.
QAbstractItemView::ScrollPerPixel1The view will scroll the contents one pixel at a time.

This enum was introduced or modified in Qt 4.2.

enum QAbstractItemView::SelectionBehavior

ConstantValueDescription
QAbstractItemView::SelectItems0Selecting single items.
QAbstractItemView::SelectRows1Selecting only rows.
QAbstractItemView::SelectColumns2Selecting only columns.

enum QAbstractItemView::SelectionMode

This enum indicates how the view responds to user selections:

ConstantValueDescription
QAbstractItemView::SingleSelection1When the user selects an item, any already-selected item becomes unselected, and the user cannot unselect the selected item by clicking on it.
QAbstractItemView::ContiguousSelection4When the user selects an item in the usual way, the selection is cleared and the new item selected. However, if the user presses the Shift key while clicking on an item, all items between the current item and the clicked item are selected or unselected, depending on the state of the clicked item.
QAbstractItemView::ExtendedSelection3When the user selects an item in the usual way, the selection is cleared and the new item selected. However, if the user presses the Ctrl key when clicking on an item, the clicked item gets toggled and all other items are left untouched. If the user presses the Shift key while clicking on an item, all items between the current item and the clicked item are selected or unselected, depending on the state of the clicked item. Multiple items can be selected by dragging the mouse over them.
QAbstractItemView::MultiSelection2When the user selects an item in the usual way, the selection status of that item is toggled and the other items are left alone. Multiple items can be toggled by dragging the mouse over them.
QAbstractItemView::NoSelection0Items cannot be selected.

The most commonly used modes are SingleSelection and ExtendedSelection.

enum QAbstractItemView::State

Describes the different states the view can be in. This is usually only interesting when reimplementing your own view.

ConstantValueDescription
QAbstractItemView::NoState0The is the default state.
QAbstractItemView::DraggingState1The user is dragging items.
QAbstractItemView::DragSelectingState2The user is selecting items.
QAbstractItemView::EditingState3The user is editing an item in a widget editor.
QAbstractItemView::ExpandingState4The user is opening a branch of items.
QAbstractItemView::CollapsingState5The user is closing a branch of items.
QAbstractItemView::AnimatingState6The item view is performing an animation.

Property Documentation

alternatingRowColors : bool

This property holds whether to draw the background using alternating colors.

If this property is true, the item background will be drawn using QPalette::Base and QPalette::AlternateBase; otherwise the background will be drawn using the QPalette::Base color.

By default, this property is false.

Access functions:

bool alternatingRowColors () const
void setAlternatingRowColors ( bool enable )

autoScroll : bool

This property holds whether autoscrolling in drag move events is enabled.

If this property is set to true (the default), the QAbstractItemView automatically scrolls the contents of the view if the user drags within 16 pixels of the viewport edge. If the current item changes, then the view will scroll automatically to ensure that the current item is fully visible.

This property only works if the viewport accepts drops. Autoscroll is switched off by setting this property to false.

Access functions:

bool hasAutoScroll () const
void setAutoScroll ( bool enable )

autoScrollMargin : int

This property holds the size of the area when auto scrolling is triggered.

This property controls the size of the area at the edge of the viewport that triggers autoscrolling. The default value is 16 pixels.

This property was introduced in Qt 4.4.

Access functions:

int autoScrollMargin () const
void setAutoScrollMargin ( int margin )

defaultDropAction : Qt::DropAction

This property holds the drop action that will be used by default in QAbstractItemView::drag().

If the property is not set, the drop action is CopyAction when the supported actions support CopyAction.

This property was introduced in Qt 4.6.

Access functions:

Qt::DropAction defaultDropAction () const
void setDefaultDropAction ( Qt::DropAction dropAction )

See also showDropIndicator and dragDropOverwriteMode.

dragDropMode : DragDropMode

This property holds the drag and drop event the view will act upon.

This property was introduced in Qt 4.2.

Access functions:

DragDropMode dragDropMode () const
void setDragDropMode ( DragDropMode behavior )

See also showDropIndicator and dragDropOverwriteMode.

dragDropOverwriteMode : bool

This property holds the view's drag and drop behavior.

If its value is true, the selected data will overwrite the existing item data when dropped, while moving the data will clear the item. If its value is false, the selected data will be inserted as a new item when the data is dropped. When the data is moved, the item is removed as well.

The default value is false, as in the QListView and QTreeView subclasses. In the QTableView subclass, on the other hand, the property has been set to true.

Note: This is not intended to prevent overwriting of items. The model's implementation of flags() should do that by not returning Qt::ItemIsDropEnabled.

This property was introduced in Qt 4.2.

Access functions:

bool dragDropOverwriteMode () const
void setDragDropOverwriteMode ( bool overwrite )

See also dragDropMode.

dragEnabled : bool

This property holds whether the view supports dragging of its own items.

Access functions:

bool dragEnabled () const
void setDragEnabled ( bool enable )

See also showDropIndicator, DragDropMode, dragDropOverwriteMode, and acceptDrops.

editTriggers : EditTriggers

This property holds which actions will initiate item editing.

This property is a selection of flags defined by EditTrigger, combined using the OR operator. The view will only initiate the editing of an item if the action performed is set in this property.

Access functions:

EditTriggers editTriggers () const
void setEditTriggers ( EditTriggers triggers )

horizontalScrollMode : ScrollMode

This property holds how the view scrolls its contents in the horizontal direction.

This property controls how the view scroll its contents horizontally. Scrolling can be done either per pixel or per item.

This property was introduced in Qt 4.2.

Access functions:

ScrollMode horizontalScrollMode () const
void setHorizontalScrollMode ( ScrollMode mode )

iconSize : QSize

This property holds the size of items' icons.

Setting this property when the view is visible will cause the items to be laid out again.

Access functions:

QSize iconSize () const
void setIconSize ( const QSize & size )

selectionBehavior : SelectionBehavior

This property holds which selection behavior the view uses.

This property holds whether selections are done in terms of single items, rows or columns.

Access functions:

QAbstractItemView::SelectionBehavior selectionBehavior () const
void setSelectionBehavior ( QAbstractItemView::SelectionBehavior behavior )

See also SelectionMode and SelectionBehavior.

selectionMode : SelectionMode

This property holds which selection mode the view operates in.

This property controls whether the user can select one or many items and, in many-item selections, whether the selection must be a continuous range of items.

Access functions:

QAbstractItemView::SelectionMode selectionMode () const
void setSelectionMode ( QAbstractItemView::SelectionMode mode )

See also SelectionMode and SelectionBehavior.

showDropIndicator : bool

This property holds whether the drop indicator is shown when dragging items and dropping.

Access functions:

bool showDropIndicator () const
void setDropIndicatorShown ( bool enable )

See also dragEnabled, DragDropMode, dragDropOverwriteMode, and acceptDrops.

tabKeyNavigation : bool

This property holds whether item navigation with tab and backtab is enabled.

Access functions:

bool tabKeyNavigation () const
void setTabKeyNavigation ( bool enable )

textElideMode : Qt::TextElideMode

This property holds the position of the "..." in elided text.

The default value for all item views is Qt::ElideRight.

Access functions:

Qt::TextElideMode textElideMode () const
void setTextElideMode ( Qt::TextElideMode mode )

verticalScrollMode : ScrollMode

This property holds how the view scrolls its contents in the vertical direction.

This property controls how the view scroll its contents vertically. Scrolling can be done either per pixel or per item.

This property was introduced in Qt 4.2.

Access functions:

ScrollMode verticalScrollMode () const
void setVerticalScrollMode ( ScrollMode mode )

Member Function Documentation

QAbstractItemView::QAbstractItemView ( QWidget * parent = 0 )

Constructs an abstract item view with the given parent.

QAbstractItemView::~QAbstractItemView ()

Destroys the view.

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

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().

void QAbstractItemView::clearSelection () [slot]

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

See also setSelection() and selectAll().

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

This signal is emitted when a mouse button is 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().

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

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().

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

Commit the data in the editor to the model.

See also closeEditor().

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

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().

void QAbstractItemView::dataChanged ( const QModelIndex & topLeft, const QModelIndex & bottomRight ) [virtual protected slot]

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

QPoint QAbstractItemView::dirtyRegionOffset () const [protected]

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().

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

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().

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

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().

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

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.

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

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().

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

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().

DropIndicatorPosition QAbstractItemView::dropIndicatorPosition () const [protected]

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

This function was introduced in Qt 4.1.

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

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().

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

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().

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

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

See also closeEditor().

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

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().

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

Reimplemented from QObject::event().

void QAbstractItemView::executeDelayedItemsLayout () [protected]

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

See also scheduleDelayedItemsLayout().

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

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().

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

Reimplemented from QWidget::focusNextPrevChild().

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

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().

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

Returns the horizontal offset of the view.

In the base class this is a pure virtual function.

See also verticalOffset().

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

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().

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

Reimplemented from QWidget::inputMethodEvent().

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

Reimplemented from QWidget::inputMethodQuery().

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

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().

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

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.

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

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().

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

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.

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

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.

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

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.

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

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.

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

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().

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

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().

void QAbstractItemView::reset () [virtual slot]

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.

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

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().

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

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().

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

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().

void QAbstractItemView::scheduleDelayedItemsLayout () [protected]

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().

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

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().

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

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.

void QAbstractItemView::scrollToBottom () [slot]

Scrolls the view to the bottom.

This function was introduced in Qt 4.1.

See also scrollTo() and scrollToTop().

void QAbstractItemView::scrollToTop () [slot]

Scrolls the view to the top.

This function was introduced in Qt 4.1.

See also scrollTo() and scrollToBottom().

void QAbstractItemView::selectAll () [virtual slot]

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().

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

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().

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

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().

QItemSelectionModel::SelectionFlags QAbstractItemView::selectionCommand ( const QModelIndex & index, const QEvent * event = 0 ) const [virtual protected]

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().

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

Sets the current item to be the item at index.

Unless the current selection mode is NoSelection, the item is also be 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.

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

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().

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

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().

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

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

See also rootIndex().

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

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().

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

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().

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

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

See also state().

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

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().

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

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().

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

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

State QAbstractItemView::state () const [protected]

Returns the item view's state.

See also setState().

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

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().

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

Updates the area occupied by the given index.

This function was introduced in Qt 4.3.

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

Updates the geometry of the child widgets of the view.

This function was introduced in Qt 4.4.

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

Returns the vertical offset of the view.

In the base class this is a pure virtual function.

See also horizontalOffset().

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

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

void QAbstractItemView::viewportEntered () [signal]

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().

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

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.

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

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().

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

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().

Notes provided by the Qt Community
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Votes: 0

Coverage: Qt 4.8

Picture of francescmm francescmm

Lab Rat
3 notes

Avoiding bottleneck at update ( const QModelIndex & index ) slot

It is important to clarify that update() slot method does not update the viewport of the widget if the QRect to visualize not intersects with the current QRect. The code especifies that is to avoid bottleneck issues.

  1. void QAbstractItemView::update(const QModelIndex &index)
  2. {
  3.     Q_D(QAbstractItemView);
  4.     if (index.isValid()) {
  5.         const QRect rect = visualRect(index);
  6.         //this test is important for peformance reason
  7.         //For example in dataChanged we simply update all the cells without checking
  8.         //it can be a major bottleneck to update rects that aren't even part of the viewport
  9.         if (d->viewport->rect().intersects(rect))
  10.             d->viewport->update(rect);
  11.     }
  12. }

It is related when we try to scrollTo() in a View.

[Revisions]

Informative
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Votes: 0

Coverage: Qt library 4.7, Qt 4.8

Picture of Moschops Moschops

Ant Farmer
2 notes

Clarification on parameters of QAbstractItemView::selectionChanged

The documentation states “The previous selection (which may be empty), is specified by deselected, and the new selection by selected”. Based on my experimentation, this is not correct.

The parameter deselected does not specify the previous selection. The parameter deselected actually specifies items that were in the previous selection and are not in the current selection (i.e. it specifies items that have been deselected, as the name implies).

I also suspect that the parameter selected is not actually what is selected, but what is newly selected (i.e. items that were not selected before and are selected now – I’d typically expect this to have just one item in it, and it may be empty)

[Revisions]