The QStyledItemDelegate 類為來自模型的數據項，提供顯示和編輯設施。 更多...
| 頭： | #include <QStyledItemDelegate> |
| qmake: | QT += widgets |
| Since: | Qt 4.4 |
| 繼承： | QAbstractItemDelegate |
| QStyledItemDelegate (QObject * parent = Q_NULLPTR) | |
| ~QStyledItemDelegate () | |
| virtual QString | displayText (const QVariant & value , const QLocale & locale ) const |
| QItemEditorFactory * | itemEditorFactory () const |
| void | setItemEditorFactory (QItemEditorFactory * factory ) |
| virtual QWidget * | createEditor (QWidget * parent , const QStyleOptionViewItem & option , const QModelIndex & index ) const |
| virtual void | paint (QPainter * painter , 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 QSize | sizeHint (const QStyleOptionViewItem & option , const QModelIndex & index ) const |
| virtual void | updateEditorGeometry (QWidget * editor , const QStyleOptionViewItem & option , const QModelIndex & index ) const |
| virtual void | initStyleOption (QStyleOptionViewItem * option , const QModelIndex & index ) const |
| virtual bool | editorEvent (QEvent * event , QAbstractItemModel * model , const QStyleOptionViewItem & option , const QModelIndex & index ) |
| virtual bool | eventFilter (QObject * editor , QEvent * event ) |
The QStyledItemDelegate 類為來自模型的數據項，提供顯示和編輯設施。
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 類是一種 模型/視圖類 且屬於 Qt 的 模型/視圖框架 . 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 ensure that the model returns appropriate data for each of the roles to determine the appearance of items in views.
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.
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 ()。 paint () function is called individually for each item, and with sizeHint (), you can specify the hint for each of them.
當重實現 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:
The Star Delegate 範例通過重實現這些方法創建編輯器。
從 Qt 4.4 起，有 2 個委托類： QItemDelegate and QStyledItemDelegate 。不管怎樣，默認委托為 QStyledItemDelegate . These two classes are independent alternatives to painting and providing editors for items in views. The difference between them is that QStyledItemDelegate uses the current style to paint its items. We therefore recommend using QStyledItemDelegate as the base class when implementing custom delegates or when working with Qt style sheets. The code required for either class should be equal unless the custom delegate needs 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.
另請參閱 委托類 , QItemDelegate , QAbstractItemDelegate , QStyle , 自鏇框委托範例 , 星號委托範例 ，和 色彩編輯器工廠範例 .
構造項委托采用給定 parent .
銷毀項委托。
[虛擬]
QWidget
*QStyledItemDelegate::
createEditor
(
QWidget
*
parent
, const
QStyleOptionViewItem
&
option
, const
QModelIndex
&
index
) const
重實現自 QAbstractItemDelegate::createEditor ().
Returns the widget used to edit the item specified by index for editing. The parent widget and style option are used to control how the editor widget appears.
另請參閱 QAbstractItemDelegate::createEditor ().
[虛擬]
QString
QStyledItemDelegate::
displayText
(const
QVariant
&
value
, const
QLocale
&
locale
) const
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.
默認實現使用 QLocale::toString to convert value 成 QString .
This function is not called for empty model indices, i.e., indices for which the model returns an invalid QVariant .
另請參閱 QAbstractItemModel::data ().
[virtual protected]
bool
QStyledItemDelegate::
editorEvent
(
QEvent
*
event
,
QAbstractItemModel
*
model
, const
QStyleOptionViewItem
&
option
, const
QModelIndex
&
index
)
重實現自 QAbstractItemDelegate::editorEvent ().
[virtual protected]
bool
QStyledItemDelegate::
eventFilter
(
QObject
*
editor
,
QEvent
*
event
)
重實現自 QObject::eventFilter ().
返迴
true
若給定
editor
有效
QWidget
和給定
event
有處理；否則返迴
false
. The following key press events are handled by default:
若 editor 類型為 QTextEdit or QPlainTextEdit then Enter and 返迴 keys are not handled.
In the case of Tab , Backtab , Enter and 返迴 key press events, the editor 's data is comitted to the model and the editor is closed. If the event 是 Tab key press the view will open an editor on the next item in the view. Likewise, if the event 是 Backtab key press the view will open an editor on the previous item in the view.
If the event is a Esc key press event, the editor is closed without committing its data.
另請參閱 commitData () 和 closeEditor ().
[virtual protected]
void
QStyledItemDelegate::
initStyleOption
(
QStyleOptionViewItem
*
option
, const
QModelIndex
&
index
) const
初始化 option with the values using the index index 。此方法對子類是有用的，當需要 QStyleOptionViewItem ，但不希望自己填充所有信息。
另請參閱 QStyleOption::initFrom ().
Returns the editor factory used by the item delegate. If no editor factory is set, the function will return null.
另請參閱 setItemEditorFactory ().
[虛擬]
void
QStyledItemDelegate::
paint
(
QPainter
*
painter
, const
QStyleOptionViewItem
&
option
, const
QModelIndex
&
index
) const
重實現自 QAbstractItemDelegate::paint ().
Renders the delegate using the given painter 和樣式 option 為項指定通過 index .
This function paints the item using the view's QStyle .
When reimplementing paint in a subclass. Use the initStyleOption () to set up the option in the same way as the QStyledItemDelegate .
Whenever possible, use the option while painting. Especially its rect variable to decide where to draw and its state to determine if it is enabled or selected.
After painting, you should ensure that the painter is returned to the state it was supplied in when this function was called. For example, it may be useful to call QPainter::save () before painting and QPainter::restore () afterwards.
另請參閱 QItemDelegate::paint (), QStyle::drawControl ()，和 QStyle::CE_ItemViewItem .
[虛擬]
void
QStyledItemDelegate::
setEditorData
(
QWidget
*
editor
, const
QModelIndex
&
index
) const
重實現自 QAbstractItemDelegate::setEditorData ().
Sets the data to be displayed and edited by the editor from the data model item specified by the model index .
The default implementation stores the data in the editor 小部件的 用戶特性 .
另請參閱 QMetaProperty::isUser ().
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.
另請參閱 itemEditorFactory ().
[虛擬]
void
QStyledItemDelegate::
setModelData
(
QWidget
*
editor
,
QAbstractItemModel
*
model
, const
QModelIndex
&
index
) const
重實現自 QAbstractItemDelegate::setModelData ().
獲取數據從 editor 小部件並把它存儲在指定 model 在項 index .
The default implementation gets the value to be stored in the data model from the editor 小部件的 用戶特性 .
另請參閱 QMetaProperty::isUser ().
[虛擬]
QSize
QStyledItemDelegate::
sizeHint
(const
QStyleOptionViewItem
&
option
, const
QModelIndex
&
index
) const
重實現自 QAbstractItemDelegate::sizeHint ().
返迴委托要顯示項所需的大小指定通過 index ，考慮樣式信息提供通過 option .
此函數使用視圖的 QStyle 以確定項大小。
另請參閱 QStyle::sizeFromContents () 和 QStyle::CT_ItemViewItem .
[虛擬]
void
QStyledItemDelegate::
updateEditorGeometry
(
QWidget
*
editor
, const
QStyleOptionViewItem
&
option
, const
QModelIndex
&
index
) const
重實現自 QAbstractItemDelegate::updateEditorGeometry ().
更新 editor 為項指定通過 index 根據樣式 option 給定。