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## com.trolltech.qt.gui
Class QStyledItemDelegate

    java.lang.Object
      com.trolltech.qt.internal.QSignalEmitterInternal
          com.trolltech.qt.QSignalEmitter
              com.trolltech.qt.QtJambiObject
                  com.trolltech.qt.core.QObject
                      com.trolltech.qt.gui.QAbstractItemDelegate
                          com.trolltech.qt.gui.QStyledItemDelegate

All Implemented Interfaces:
  QtJambiInterface

    public class QStyledItemDelegate

extends QAbstractItemDelegate

The QStyledItemDelegate class provides display and editing facilities for data items from a model. When displaying data from models in Qt item views, e.g., a `QTableView`, the individual items are drawn by a delegate. Also, when an item is edited, it provides an editor widget, which is placed on top of the item view while editing takes place. QStyledItemDelegate is the default delegate for all Qt item views, and is installed upon them when they are created.

The QStyledItemDelegate class is one of the Model/View Classes and is part of Qt's model/view framework. The delegate allows the display and editing of items to be developed independently from the model and view.

The data of items in models are assigned an `ItemDataRole` ; each item can store a `QVariant` for each role. QStyledItemDelegate implements display and editing for the most common datatypes expected by users, including booleans, integers, and strings.

The data will be drawn differently depending on which role they have in the model. The following table describes the roles and the data types the delegate can handle for each of them. It is often sufficient to unsure that the model returns appropriate data for each of the roles to determine the appearance of items in views.

Role | Accepted Types
--- | ---
`Qt::BackgroundRole` | `QBrush`
`Qt::BackgroundColorRole` | `QColor` (obsolete; use `Qt::BackgroundRole` instead)
`Qt::CheckStateRole` | `Qt::CheckState`
`Qt::DecorationRole` | `QIcon` and `QColor`
`Qt::DisplayRole` | QString and types with a string representation
`Qt::EditRole` | See `QItemEditorFactory` for details
`Qt::FontRole` | `QFont`
`Qt::SizeHintRole` | `QSize`
`Qt::TextAlignmentRole` | Qt::Alignment
`Qt::ForegroundRole` | `QBrush`
`Qt::TextColorRole` | `QColor` (obsolete; use `Qt::ForegroundRole` instead)

Editors are created with a `QItemEditorFactory`; a default static instance provided by `QItemEditorFactory` is installed on all item delegates. You can set a custom factory using `setItemEditorFactory()` or set a new default factory with `QItemEditorFactory::setDefaultFactory()`. It is the data stored in the item model with the `EditRole` that is edited. See the `QItemEditorFactory` class for a more high-level introduction to item editor factories. The Color Editor Factory example shows how to create custom editors with a factory.

## Subclassing QStyledItemDelegate

If the delegate does not support painting of the data types you need or you want to customize the drawing of items, you need to subclass QStyledItemDelegate, and reimplement paint() and possibly sizeHint(). The paint() function is called individually for each item, and with sizeHint(), you can specify the hint for each of them.

When reimplementing paint(), one would typically handle the datatypes one would like to draw and use the superclass implementation for other types.

The painting of check box indicators are performed by the current style. The style also specifies the size and the bounding rectangles in which to draw the data for the different data roles. The bounding rectangle of the item itself is also calculated by the style. When drawing already supported datatypes, it is therefore a good idea to ask the style for these bounding rectangles. The `QStyle` class description describes this in more detail.

If you wish to change any of the bounding rectangles calculated by the style or the painting of check box indicators, you can subclass `QStyle`. Note, however, that the size of the items can also be affected by reimplementing sizeHint().

It is possible for a custom delegate to provide editors without the use of an editor item factory. In this case, the following virtual functions must be reimplemented:

- createEditor() returns the widget used to change data from the model and can be reimplemented to customize editing behavior.
- setEditorData() provides the widget with data to manipulate.
- updateEditorGeometry() ensures that the editor is displayed correctly with respect to the item view.
- setModelData() returns updated data to the model.

The Star Delegate example creates editors by reimplementing these methods.

## QStyledItemDelegate and QItemDelegate

QStyledItemDelegate has taken over the job as default delegate - leaving `QItemDelegate` behind. They will now co-exist peacefully as independent alternatives to painting and providing editors for items in views. The difference between them is that the new delegate uses the current style to paint its items. We therefore recommend using QStyledItemDelegate as base when implementing custom delegates. The code required should be equal unless the custom delegate also wishes to use the style for drawing.

If you wish to customize the painting of item views, you should implement a custom style. Please see the `QStyle` class documentation for details.

See also:
  Delegate Classes, `QItemDelegate`, `QAbstractItemDelegate`, `QStyle`, Spin Box Delegate Example, Star Delegate Example, and Color Editor Factory Example.

Nested Class Summary

Nested classes/interfaces inherited from class com.trolltech.qt.gui.QAbstractItemDelegate
`QAbstractItemDelegate.EndEditHint`

Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
`QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9`

Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
`com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal`

Field Summary

Fields inherited from class com.trolltech.qt.gui.QAbstractItemDelegate
`closeEditor, commitData, sizeHintChanged`

Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
`currentSender`

Constructor Summary
`QStyledItemDelegate()` Constructs an item delegate with the given `parent`.
`QStyledItemDelegate(QObject parent)` Constructs an item delegate with the given `parent`.

Method Summary
`java.lang.String` | `displayText(java.lang.Object value, QLocale locale)` This function returns the string that the delegate will use to display the `Qt::DisplayRole` of the model in `locale`.
`protected void` | `initStyleOption(QStyleOptionViewItem option, com.trolltech.qt.core.QModelIndex index)` Initialize `option` with the values using the index `index`.
`QItemEditorFactory` | `itemEditorFactory()` Returns the editor factory used by the item delegate.
`void` | `setItemEditorFactory(QItemEditorFactory factory)` Sets the editor factory to be used by the item delegate to be the `factory` specified.

Methods inherited from class com.trolltech.qt.gui.QAbstractItemDelegate
`createEditor, editorEvent, helpEvent, paint, setEditorData, setModelData, sizeHint, updateEditorGeometry`

Methods inherited from class com.trolltech.qt.core.QObject
`childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, event, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, indexOfProperty, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, properties, property, removeEventFilter, setObjectName, setParent, setProperty, startTimer, timerEvent, toString, userProperty`

Methods inherited from class com.trolltech.qt.QtJambiObject
`dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr`

Methods inherited from class com.trolltech.qt.QSignalEmitter
`blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread`

Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
`__qt_signalInitialization`

Methods inherited from class java.lang.Object
`clone, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Methods inherited from interface com.trolltech.qt.QtJambiInterface
`disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership`

Constructor Detail

### QStyledItemDelegate

    public QStyledItemDelegate()

  Constructs an item delegate with the given `parent`.

### QStyledItemDelegate

    public QStyledItemDelegate(QObject parent)

  Constructs an item delegate with the given `parent`.

Method Detail

### itemEditorFactory

    public final QItemEditorFactory itemEditorFactory()

  Returns the editor factory used by the item delegate. If no editor factory is set, the function will return null.

See also:
  `setItemEditorFactory()`.

### setItemEditorFactory

    public final void setItemEditorFactory(QItemEditorFactory factory)

  Sets the editor factory to be used by the item delegate to be the `factory` specified. If no editor factory is set, the item delegate will use the default editor factory.

See also:
  `itemEditorFactory()`.

### displayText

    public java.lang.String displayText(java.lang.Object value,
                                        QLocale locale)

  This function returns the string that the delegate will use to display the `Qt::DisplayRole` of the model in `locale`. `value` is the value of the `Qt::DisplayRole` provided by the model.

  The default implementation uses the QLocale::toString to convert `value` into a QString.

### initStyleOption

    protected void initStyleOption(QStyleOptionViewItem option,
                                   com.trolltech.qt.core.QModelIndex index)

  Initialize `option` with the values using the index `index`. This method is useful for subclasses when they need a `QStyleOptionViewItem`, but don't want to fill in all the information themselves. This function will check the version of the `QStyleOptionViewItem` and fill in the additional values for a `QStyleOptionViewItemV2`, `QStyleOptionViewItemV3` and `QStyleOptionViewItemV4`.

See also:
  `QStyleOption::initFrom()`.

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