#include <qabstractitemdelegate.h>
Inheritance diagram for QAbstractItemDelegate:
A QAbstractItemDelegate provides the interface and common functionality for delegates in the model/view architecture. Delegates display individual items in views, and handle the editing of model data.
The QAbstractItemDelegate class is one of the {Model/View Classes} and is part of Qt's {Model/View Programming}{model/view framework}.
To render an item in a custom way, you must implement paint() and sizeHint(). The QItemDelegate class provides default implementations for these functions; if you do not need custom rendering, subclass that class instead.
To provide custom editing, there are two approaches that can be used. The first approach is to create an editor widget and display it directly on top of the item. To do this you must reimplement createEditor() to provide an editor widget, setEditorData() to populate the editor with the data from the model, and setModelData() so that the delegate can update the model with data from the editor.
The second approach is to handle user events directly by reimplementing editorEvent().
Definition at line 40 of file qabstractitemdelegate.h.
Public Types | |
| enum | EndEditHint |
Signals | |
| void | commitData (QWidget *editor) |
| void | closeEditor (QWidget *editor, QAbstractItemDelegate::EndEditHint hint=NoHint) |
Public Member Functions | |
| QAbstractItemDelegate (QObject *parent=0) | |
| virtual | ~QAbstractItemDelegate () |
| virtual void | paint (QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const=0 |
| virtual QSize | sizeHint (const QStyleOptionViewItem &option, const QModelIndex &index) const=0 |
| virtual QWidget * | createEditor (QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const |
| virtual void | setEditorData (QWidget *editor, const QModelIndex &index) const |
| virtual void | setModelData (QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const |
| virtual void | updateEditorGeometry (QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const |
| virtual bool | editorEvent (QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index) |
Static Public Member Functions | |
| static QString | elidedText (const QFontMetrics &fontMetrics, int width, Qt::TextElideMode mode, const QString &text) |
Protected Member Functions | |
| QAbstractItemDelegate (QObjectPrivate &, QObject *parent=0) | |
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.
NoHint There is no recommended action to be performed.
These hints let the delegate influence the behavior of the view:
EditNextItem The view should use the delegate to open an editor on the next item in the view. EditPreviousItem The view should use the delegate to open an editor on the previous item in the view.
Note that 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 date locally in order to increase performance or conserve network bandwidth.
SubmitModelCache If the model caches data, it should write out cached data to the underlying data store. RevertModelCache If the model caches data, it should discard cached data and replace it with data from the underlying data store.
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.
Definition at line 46 of file qabstractitemdelegate.h.
00046 { 00047 NoHint, 00048 EditNextItem, 00049 EditPreviousItem, 00050 SubmitModelCache, 00051 RevertModelCache 00052 };
| QAbstractItemDelegate::QAbstractItemDelegate | ( | QObject * | parent = 0 |
) | [explicit] |
Creates a new abstract item delegate with the given parent.
Definition at line 128 of file qabstractitemdelegate.cpp.
| QAbstractItemDelegate::~QAbstractItemDelegate | ( | ) | [virtual] |
| QAbstractItemDelegate::QAbstractItemDelegate | ( | QObjectPrivate & | , | |
| QObject * | parent = 0 | |||
| ) | [protected] |
| void QAbstractItemDelegate::paint | ( | QPainter * | painter, | |
| const QStyleOptionViewItem & | option, | |||
| const QModelIndex & | index | |||
| ) | const [pure virtual] |
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 you must also reimplement sizeHint().
Referenced by QListViewPrivate::drawItems(), QTreeView::drawRow(), PieView::paintEvent(), and MainWindow::printImage().
| QSize QAbstractItemDelegate::sizeHint | ( | const QStyleOptionViewItem & | option, | |
| const QModelIndex & | index | |||
| ) | const [pure virtual] |
This pure abstract function 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().
Referenced by QListViewPrivate::itemSize().
| QWidget * QAbstractItemDelegate::createEditor | ( | QWidget * | parent, | |
| const QStyleOptionViewItem & | option, | |||
| const QModelIndex & | index | |||
| ) | const [virtual] |
Returns the editor to be used for editing the data item with the given index. Note that the index contains information about the model being used. The editor's parent widget is specified by parent, and the item options by option.
The base implementation returns 0. If you want custom editing you will need to reimplement this function.
Definition at line 184 of file qabstractitemdelegate.cpp.
Referenced by QAbstractItemViewPrivate::editor().
| void QAbstractItemDelegate::setEditorData | ( | QWidget * | editor, | |
| const QModelIndex & | index | |||
| ) | const [virtual] |
Sets the contents of the given editor to the data for the item at the given index. Note that 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.
Definition at line 201 of file qabstractitemdelegate.cpp.
Referenced by QDataWidgetMapperPrivate::_q_closeEditor(), QDataWidgetMapperPrivate::populate(), and QAbstractItemViewPrivate::updateEditorData().
| void QAbstractItemDelegate::setModelData | ( | QWidget * | editor, | |
| QAbstractItemModel * | model, | |||
| const QModelIndex & | index | |||
| ) | const [virtual] |
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.
Definition at line 216 of file qabstractitemdelegate.cpp.
Referenced by QDataWidgetMapperPrivate::_q_commitData(), and QAbstractItemView::commitData().
| void QAbstractItemDelegate::updateEditorGeometry | ( | QWidget * | editor, | |
| const QStyleOptionViewItem & | option, | |||
| const QModelIndex & | index | |||
| ) | const [virtual] |
Updates the geometry of the editor for the item with the given index, according to the rectangle specified in the option. If the item has an internal layout, the editor will be laid out accordingly. Note that the index contains information about the model being used.
The base implementation does nothing. If you want custom editing you must reimplement this function.
Definition at line 233 of file qabstractitemdelegate.cpp.
Referenced by QAbstractItemView::updateEditorGeometries().
| bool QAbstractItemDelegate::editorEvent | ( | QEvent * | event, | |
| QAbstractItemModel * | model, | |||
| const QStyleOptionViewItem & | option, | |||
| const QModelIndex & | index | |||
| ) | [virtual] |
Whenever an event occurs, this function is called with the event model option and the index that corresponds to the item being edited.
The base implementation returns false (indicating that it has not handled the event).
Definition at line 247 of file qabstractitemdelegate.cpp.
Referenced by QAbstractItemViewPrivate::sendDelegateEvent().
| QString QAbstractItemDelegate::elidedText | ( | const QFontMetrics & | fontMetrics, | |
| int | width, | |||
| Qt::TextElideMode | mode, | |||
| const QString & | text | |||
| ) | [static] |
Use QFontMetrics::elidedText() instead.
QFontMetrics fm = ... QString str = QAbstractItemDelegate::elidedText(fm, width, mode, text); QFontMetrics fm = ... QString str = fm.elidedText(text, mode, width);
Definition at line 270 of file qabstractitemdelegate.cpp.
References QFontMetrics::elidedText().
Referenced by qdesigner_internal::SheetDelegate::paint().
00272 { 00273 return fontMetrics.elidedText(text, mode, width); 00274 }
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| void QAbstractItemDelegate::commitData | ( | QWidget * | editor | ) | [signal] |
This signal must be emitted when the editor widget has completed editing the data, and wants to write it back into the model.
Referenced by PPDOptionsEditor::cbChanged(), SpreadSheetDelegate::commitAndCloseEditor(), qdesigner_internal::ColorDelegate::createEditor(), ImageDelegate::emitCommitData(), qdesigner_internal::ConnectionDelegate::emitCommitData(), qdesigner_internal::QPropertyEditorDelegate::eventFilter(), QItemDelegate::eventFilter(), and qdesigner_internal::QPropertyEditorDelegate::sync().
| void QAbstractItemDelegate::closeEditor | ( | QWidget * | editor, | |
| QAbstractItemDelegate::EndEditHint | hint = NoHint | |||
| ) | [signal] |
This signal is emitted when the user has finished editing an item using the specified editor.
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.
Referenced by SpreadSheetDelegate::commitAndCloseEditor(), and QItemDelegate::eventFilter().
1.5.1