This enum describes the different hints that the delegate can give to the model and view components to make editing data in a model a comfortable experience for the user.

These hints let the delegate influence the behavior of the view:

Custom views may interpret the concepts of next and previous differently.

The following hints are most useful when models are used that cache data, such as those that manipulate data locally in order to increase performance or conserve network bandwidth.

Although models and views should respond to these hints in appropriate ways, custom components may ignore any or all of them if they are not relevant.

Construct a new abstract item delegate with the given parent.

Destroys the abstract item delegate.

This signal is emitted when the user has finished editing an item.

The specified editor represents the widget which was used to modify the item.

The hint provides a way for the delegate to influence how the model and view behave after editing is completed. It indicates to these components what action should be performed next to provide a comfortable editing experience for the user. For example, if EditNextItem is specified the view should use a delegate to open an editor on the next item in the model.

See also

EndEditHint

This signal must be emitted when the editor widget has completed the edit process. The slot method is responsible for calling the setEditorData() method to save the data back into the model.

Returns the editor widget which should be used for editing the data with the given index. The editor's parent widget is specified by parent and the item options by option. The base implementation returns a nullptr.

To use custom editing you will need to reimplement this method in a custom delegate class. The returned editor widget should set the Qt::StrongFocus flag, otherwise QMouseEvents received by the widget will propagate to the view.

See also

setModelData(), setEditorData()

Reimplemented in QItemDelegate::createEditor(), QStyledItemDelegate::createEditor(), QSqlRelationalDelegate::createEditor()

Called when the editor is no longer needed for editing the data item with the given index and should be destroyed. The default behavior is a call to deleteLater on the editor. It is possible e.g. to avoid this delete by reimplementing this method.

See also

createEditor()

When editing of an item starts this method is called with the event that triggered the editing, the model, the index of the item, and the option used for rendering the item. Mouse events are sent to editorEvent() even if they do not start editing of the item. This can, for instance, be useful if you wish to open a context menu when the right mouse button is pressed on an item.

The base implementation returns false (indicating that it has not handled the event).

Reimplemented in QItemDelegate::editorEvent(), QStyledItemDelegate::editorEvent()

Deprecated:

Use QFontMetrics::elidedText() instead.

If you have code similar to the following rewrite as shown.

Whenever a help event occurs, this method is called with the given event, view, option, and the index that corresponds to the item where the event occurs. Returns true if the delegate can handle the event, otherwise returns false. A return value of true indicates that the data obtained using the index had the required role.

For QEvent::ToolTip and QEvent::WhatsThis events that were handled successfully, the relevant popup may be shown depending on the user's system configuration.

See also

QHelpEvent

This pure abstract function must be reimplemented if you want to provide custom rendering. Use the painter and style option to render the item specified by the item index.

If you reimplement this method, also reimplement sizeHint().

Implemented in QItemDelegate::paint(), QStyledItemDelegate::paint()

Sets the contents of the given editor to the data for the item at the given index. The index contains information about the model being used.

The base implementation does nothing. If you want custom editing you will need to reimplement this function.

See also

setModelData()

Reimplemented in QItemDelegate::setEditorData(), QStyledItemDelegate::setEditorData(), QSqlRelationalDelegate::setEditorData()

Sets the data for the item at the given index in the model to the contents of the given editor.

The base implementation does nothing. If you want custom editing you will need to reimplement this function.

See also

setEditorData()

Reimplemented in QItemDelegate::setModelData(), QStyledItemDelegate::setModelData(), QSqlRelationalDelegate::setModelData()

This pure abstract method must be reimplemented if you want to provide custom rendering. The options are specified by option and the model item by index.

If you reimplement this you must also reimplement paint().

Implemented in QItemDelegate::sizeHint(), QStyledItemDelegate::sizeHint()

This signal must be emitted when the sizeHint() of index changed. Views automatically connect to this signal and relayout items as necessary.

Updates the geometry of the editor for the item with the given index to match the rectangle specified in option. If the item has an internal layout, the editor will be laid out accordingly. The index contains information about the model being used.

The base implementation for this method does nothing. If you want custom editing you must reimplement this method.

Reimplemented in QItemDelegate::updateEditorGeometry(), QStyledItemDelegate::updateEditorGeometry()