qt-everywhere-src-5.14.1/qtbase/src/widgets/itemviews/qabstractitemdelegate.cpp - orbit - Git at Google

 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtWidgets module of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU Lesser General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU Lesser
 ** General Public License version 3 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.LGPL3 included in the
 ** packaging of this file. Please review the following information to
 ** ensure the GNU Lesser General Public License version 3 requirements
 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 2.0 or (at your option) the GNU General
 ** Public license version 3 or any later version approved by the KDE Free
 ** Qt Foundation. The licenses are as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
 ** included in the packaging of this file. Please review the following
 ** information to ensure the GNU General Public License requirements will
 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and
 ** https://www.gnu.org/licenses/gpl-3.0.html.
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "qabstractitemdelegate.h"

 #include <qabstractitemmodel.h>
 #include <qabstractitemview.h>
 #include <qfontmetrics.h>
 #if QT_CONFIG(whatsthis)
 #include <qwhatsthis.h>
 #endif
 #include <qtooltip.h>
 #include <qevent.h>
 #include <qstring.h>
 #include <qdebug.h>
 #if QT_CONFIG(lineedit)
 #include <qlineedit.h>
 #endif
 #if QT_CONFIG(textedit)
 #include <qtextedit.h>
 #include <qplaintextedit.h>
 #endif
 #include <qapplication.h>
 #include <qvalidator.h>
 #include <qjsonvalue.h>
 #include <private/qtextengine_p.h>
 #include <private/qabstractitemdelegate_p.h>

 #include <qpa/qplatformintegration.h>
 #if QT_CONFIG(draganddrop)
 #include <qpa/qplatformdrag.h>
 #include <private/qdnd_p.h>
 #endif
 #include <private/qguiapplication_p.h>

 QT_BEGIN_NAMESPACE

 /*!
     \class QAbstractItemDelegate

     \brief The QAbstractItemDelegate class is used to display and edit
     data items from a model.

     \ingroup model-view
     \inmodule QtWidgets

     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 \l{Model/View Classes}
     and is part of Qt's \l{Model/View Programming}{model/view framework}.

     To render an item in a custom way, you must implement paint() and
     sizeHint(). The QStyledItemDelegate class provides default implementations for
     these functions; if you do not need custom rendering, subclass that
     class instead.

     We give an example of drawing a progress bar in items; in our case
     for a package management program.

     \image widgetdelegate.png

     We create the \c WidgetDelegate class, which inherits from
     QStyledItemDelegate. We do the drawing in the paint() function:

     \snippet widgetdelegate.cpp 0

     Notice that we use a QStyleOptionProgressBar and initialize its
     members. We can then use the current QStyle to draw it.

     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().

     \sa {model-view-programming}{Model/View Programming}, QStyledItemDelegate,
         {Pixelator Example}, QStyledItemDelegate, QStyle
 */

 /*!
     \enum QAbstractItemDelegate::EndEditHint

     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.

     \value NoHint           There is no recommended action to be performed.

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

     \value EditNextItem     The view should use the delegate to open an
                             editor on the next item in the view.
     \value 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 data locally in order to increase
     performance or conserve network bandwidth.

     \value SubmitModelCache If the model caches data, it should write out
                             cached data to the underlying data store.
     \value 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.
 */

 /*!
   \fn void QAbstractItemDelegate::commitData(QWidget *editor)

   This signal must be emitted when the \a editor widget has completed
   editing the data, and wants to write it back into the model.
 */

 /*!
     \fn void QAbstractItemDelegate::closeEditor(QWidget *editor, QAbstractItemDelegate::EndEditHint hint)

     This signal is emitted when the user has finished editing an item using
     the specified \a editor.

     The \a 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 \c EditNextItem is specified,
     the view should use a delegate to open an editor on the next item in the
     model.

     \sa EndEditHint
 */

 /*!
     \fn void QAbstractItemDelegate::sizeHintChanged(const QModelIndex &index)
     \since 4.4

     This signal must be emitted when the sizeHint() of \a index changed.

     Views automatically connect to this signal and relayout items as necessary.
 */


 /*!
     Creates a new abstract item delegate with the given \a parent.
 */
 QAbstractItemDelegate::QAbstractItemDelegate(QObject *parent)
     : QObject(*new QAbstractItemDelegatePrivate, parent)
 {

 }

 /*!
     \internal

     Creates a new abstract item delegate with the given \a parent.
 */
 QAbstractItemDelegate::QAbstractItemDelegate(QObjectPrivate &dd, QObject *parent)
     : QObject(dd, parent)
 {

 }

 /*!
     Destroys the abstract item delegate.
 */
 QAbstractItemDelegate::~QAbstractItemDelegate()
 {

 }

 /*!
     \fn void QAbstractItemDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const = 0;

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

     If you reimplement this you must also reimplement sizeHint().
 */

 /*!
     \fn QSize QAbstractItemDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const = 0

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

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

 /*!
     Returns the editor to be used for editing the data item with the
     given \a index. Note that the index contains information about the
     model being used. The editor's parent widget is specified by \a parent,
     and the item options by \a option.

     The base implementation returns \nullptr. If you want custom editing you
     will need to reimplement this function.

     The returned editor widget should have Qt::StrongFocus;
     otherwise, \l{QMouseEvent}s received by the widget will propagate
     to the view. The view's background will shine through unless the
     editor paints its own background (e.g., with
     \l{QWidget::}{setAutoFillBackground()}).

     \sa destroyEditor(), setModelData(), setEditorData()
 */
 QWidget *QAbstractItemDelegate::createEditor(QWidget *,
                                              const QStyleOptionViewItem &,
                                              const QModelIndex &) const
 {
     return 0;
 }


 /*!
     Called when the \a editor is no longer needed for editing the data item
     with the given \a 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 function.

     \since 5.0
     \sa createEditor()
 */
 void QAbstractItemDelegate::destroyEditor(QWidget *editor, const QModelIndex &index) const
 {
     Q_UNUSED(index);
     editor->deleteLater();
 }

 /*!
     Sets the contents of the given \a editor to the data for the item
     at the given \a 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.

     \sa setModelData()
 */
 void QAbstractItemDelegate::setEditorData(QWidget *,
                                           const QModelIndex &) const
 {
     // do nothing
 }

 /*!
     Sets the data for the item at the given \a index in the \a model
     to the contents of the given \a editor.

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

     \sa setEditorData()
 */
 void QAbstractItemDelegate::setModelData(QWidget *,
                                          QAbstractItemModel *,
                                          const QModelIndex &) const
 {
     // do nothing
 }

 /*!
     Updates the geometry of the \a editor for the item with the given
     \a index, according to the rectangle specified in the \a 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.
 */
 void QAbstractItemDelegate::updateEditorGeometry(QWidget *,
                                                  const QStyleOptionViewItem &,
                                                  const QModelIndex &) const
 {
     // do nothing
 }

 /*!
     When editing of an item starts, this function is called with the
     \a event that triggered the editing, the \a model, the \a index of
     the item, and the \a option used for rendering the item.

     Mouse events are sent to editorEvent() even if they don't 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 \c false (indicating that it has not
     handled the event).
 */
 bool QAbstractItemDelegate::editorEvent(QEvent *,
                                         QAbstractItemModel *,
                                         const QStyleOptionViewItem &,
                                         const QModelIndex &)
 {
     // do nothing
     return false;
 }

 #if QT_DEPRECATED_SINCE(5, 13)
 /*!
     \obsolete

     Use QFontMetrics::elidedText() instead.

     \oldcode
         QFontMetrics fm = ...
         QString str = QAbstractItemDelegate::elidedText(fm, width, mode, text);
     \newcode
         QFontMetrics fm = ...
         QString str = fm.elidedText(text, mode, width);
     \endcode
 */

 QString QAbstractItemDelegate::elidedText(const QFontMetrics &fontMetrics, int width,
                                           Qt::TextElideMode mode, const QString &text)
 {
     return fontMetrics.elidedText(text, mode, width);
 }
 #endif

 /*!
     \since 4.3
     Whenever a help event occurs, this function is called with the \a event
     \a view \a option and the \a index that corresponds to the item where the
     event occurs.

     Returns \c true if the delegate can handle the event; otherwise returns \c 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.

     \sa QHelpEvent
 */
 bool QAbstractItemDelegate::helpEvent(QHelpEvent *event,
                                       QAbstractItemView *view,
                                       const QStyleOptionViewItem &option,
                                       const QModelIndex &index)
 {
     Q_D(QAbstractItemDelegate);
     Q_UNUSED(d);
     Q_UNUSED(index);
     Q_UNUSED(option);

     if (!event || !view)
         return false;
     switch (event->type()) {
 #ifndef QT_NO_TOOLTIP
     case QEvent::ToolTip: {
         QHelpEvent *he = static_cast<QHelpEvent*>(event);
         const int precision = inherits("QItemDelegate") ? 10 : 6; // keep in sync with DBL_DIG in qitemdelegate.cpp
         const QString tooltip = d->textForRole(Qt::ToolTipRole, index.data(Qt::ToolTipRole), option.locale, precision);
         if (!tooltip.isEmpty()) {
             QToolTip::showText(he->globalPos(), tooltip, view);
             return true;
         }
         break;}
 #endif
 #if QT_CONFIG(whatsthis)
     case QEvent::QueryWhatsThis: {
         if (index.data(Qt::WhatsThisRole).isValid())
             return true;
         break; }
     case QEvent::WhatsThis: {
         QHelpEvent *he = static_cast<QHelpEvent*>(event);
         const int precision = inherits("QItemDelegate") ? 10 : 6; // keep in sync with DBL_DIG in qitemdelegate.cpp
         const QString whatsthis = d->textForRole(Qt::WhatsThisRole, index.data(Qt::WhatsThisRole), option.locale, precision);
         if (!whatsthis.isEmpty()) {
             QWhatsThis::showText(he->globalPos(), whatsthis, view);
             return true;
         }
         break ; }
 #endif
     default:
         break;
     }
     return false;
 }

 /*!
     \internal

     This virtual method is reserved and will be used in Qt 5.1.
 */
 QVector<int> QAbstractItemDelegate::paintingRoles() const
 {
     return QVector<int>();
 }

 QAbstractItemDelegatePrivate::QAbstractItemDelegatePrivate()
     : QObjectPrivate()
 {
 }

 static bool editorHandlesKeyEvent(QWidget *editor, const QKeyEvent *event)
 {
 #if QT_CONFIG(textedit)
     // do not filter enter / return / tab / backtab for QTextEdit or QPlainTextEdit
     if (qobject_cast<QTextEdit *>(editor) || qobject_cast<QPlainTextEdit *>(editor)) {
         switch (event->key()) {
         case Qt::Key_Tab:
         case Qt::Key_Backtab:
         case Qt::Key_Enter:
         case Qt::Key_Return:
             return true;

         default:
             break;
         }
     }
 #endif // QT_CONFIG(textedit)

     Q_UNUSED(editor);
     Q_UNUSED(event);
     return false;
 }

 bool QAbstractItemDelegatePrivate::editorEventFilter(QObject *object, QEvent *event)
 {
     Q_Q(QAbstractItemDelegate);

     QWidget *editor = qobject_cast<QWidget*>(object);
     if (!editor)
         return false;
     if (event->type() == QEvent::KeyPress) {
         QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
         if (editorHandlesKeyEvent(editor, keyEvent))
             return false;

 #ifndef QT_NO_SHORTCUT
         if (keyEvent->matches(QKeySequence::Cancel)) {
             // don't commit data
             emit q->closeEditor(editor, QAbstractItemDelegate::RevertModelCache);
             return true;
         }
 #endif

         switch (keyEvent->key()) {
         case Qt::Key_Tab:
             if (tryFixup(editor)) {
                 emit q->commitData(editor);
                 emit q->closeEditor(editor, QAbstractItemDelegate::EditNextItem);
             }
             return true;
         case Qt::Key_Backtab:
             if (tryFixup(editor)) {
                 emit q->commitData(editor);
                 emit q->closeEditor(editor, QAbstractItemDelegate::EditPreviousItem);
             }
             return true;
         case Qt::Key_Enter:
         case Qt::Key_Return:
             // We want the editor to be able to process the key press
             // before committing the data (e.g. so it can do
             // validation/fixup of the input).
             if (!tryFixup(editor))
                 return true;

             QMetaObject::invokeMethod(q, "_q_commitDataAndCloseEditor",
                                       Qt::QueuedConnection, Q_ARG(QWidget*, editor));
             return false;
         default:
             return false;
         }
     } else if (event->type() == QEvent::FocusOut || (event->type() == QEvent::Hide && editor->isWindow())) {
         //the Hide event will take care of he editors that are in fact complete dialogs
         if (!editor->isActiveWindow() || (QApplication::focusWidget() != editor)) {
             QWidget *w = QApplication::focusWidget();
             while (w) { // don't worry about focus changes internally in the editor
                 if (w == editor)
                     return false;
                 w = w->parentWidget();
             }
 #if QT_CONFIG(draganddrop)
             // The window may lose focus during an drag operation.
             // i.e when dragging involves the taskbar on Windows.
             QPlatformDrag *platformDrag = QGuiApplicationPrivate::instance()->platformIntegration()->drag();
             if (platformDrag && platformDrag->currentDrag()) {
                 return false;
             }
 #endif
             if (tryFixup(editor))
                 emit q->commitData(editor);

             // If the application loses focus while editing, then the focus needs to go back
             // to the itemview when the editor closes. This ensures that when the application
             // is active again it will have the focus on the itemview as expected.
             const bool manuallyFixFocus = (event->type() == QEvent::FocusOut) && !editor->hasFocus() &&
                     editor->parentWidget() &&
                     (static_cast<QFocusEvent *>(event)->reason() == Qt::ActiveWindowFocusReason);
             emit q->closeEditor(editor, QAbstractItemDelegate::NoHint);
             if (manuallyFixFocus)
                 editor->parentWidget()->setFocus();
         }
 #ifndef QT_NO_SHORTCUT
     } else if (event->type() == QEvent::ShortcutOverride) {
         if (static_cast<QKeyEvent*>(event)->matches(QKeySequence::Cancel)) {
             event->accept();
             return true;
         }
 #endif
     }
     return false;
 }

 bool QAbstractItemDelegatePrivate::tryFixup(QWidget *editor)
 {
 #if QT_CONFIG(lineedit)
     if (QLineEdit *e = qobject_cast<QLineEdit*>(editor)) {
         if (!e->hasAcceptableInput()) {
 #if QT_CONFIG(validator)
             if (const QValidator *validator = e->validator()) {
                 QString text = e->text();
                 validator->fixup(text);
                 e->setText(text);
             }
 #endif
             return e->hasAcceptableInput();
         }
     }
 #else
     Q_UNUSED(editor)
 #endif // QT_CONFIG(lineedit)

     return true;
 }

 QString QAbstractItemDelegatePrivate::textForRole(Qt::ItemDataRole role, const QVariant &value, const QLocale &locale, int precision) const
 {
     const QLocale::FormatType formatType = (role == Qt::DisplayRole) ? QLocale::ShortFormat : QLocale::LongFormat;
     QString text;
     switch (value.userType()) {
     case QMetaType::Float:
         text = locale.toString(value.toFloat());
         break;
     case QVariant::Double:
         text = locale.toString(value.toDouble(), 'g', precision);
         break;
     case QVariant::Int:
     case QVariant::LongLong:
         text = locale.toString(value.toLongLong());
         break;
     case QVariant::UInt:
     case QVariant::ULongLong:
         text = locale.toString(value.toULongLong());
         break;
     case QVariant::Date:
         text = locale.toString(value.toDate(), formatType);
         break;
     case QVariant::Time:
         text = locale.toString(value.toTime(), formatType);
         break;
     case QVariant::DateTime:
         text = locale.toString(value.toDateTime(), formatType);
         break;
     case QVariant::Type(QMetaType::QJsonValue): {
         const QJsonValue val = value.toJsonValue();
         if (val.isBool()) {
             text = QVariant(val.toBool()).toString();
             break;
         }
         if (val.isDouble()) {
             text = locale.toString(val.toDouble(), 'g', precision);
             break;
         }
         // val is a string (or null) here
         Q_FALLTHROUGH();
     }
     default: {
         text = value.toString();
         if (role == Qt::DisplayRole)
             text.replace(QLatin1Char('\n'), QChar::LineSeparator);
         break;
     }
     }
     return text;
 }

 void QAbstractItemDelegatePrivate::_q_commitDataAndCloseEditor(QWidget *editor)
 {
     Q_Q(QAbstractItemDelegate);
     emit q->commitData(editor);
     emit q->closeEditor(editor, QAbstractItemDelegate::SubmitModelCache);
 }

 QT_END_NAMESPACE

 #include "moc_qabstractitemdelegate.cpp"
	/****************************************************************************
	**
	** Copyright (C) 2016 The Qt Company Ltd.
	** Contact: https://www.qt.io/licensing/
	**
	** This file is part of the QtWidgets module of the Qt Toolkit.
	**
	** $QT_BEGIN_LICENSE:LGPL$
	** Commercial License Usage
	** Licensees holding valid commercial Qt licenses may use this file in
	** accordance with the commercial license agreement provided with the
	** Software or, alternatively, in accordance with the terms contained in
	** a written agreement between you and The Qt Company. For licensing terms
	** and conditions see https://www.qt.io/terms-conditions. For further
	** information use the contact form at https://www.qt.io/contact-us.
	**
	** GNU Lesser General Public License Usage
	** Alternatively, this file may be used under the terms of the GNU Lesser
	** General Public License version 3 as published by the Free Software
	** Foundation and appearing in the file LICENSE.LGPL3 included in the
	** packaging of this file. Please review the following information to
	** ensure the GNU Lesser General Public License version 3 requirements
	** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
	**
	** GNU General Public License Usage
	** Alternatively, this file may be used under the terms of the GNU
	** General Public License version 2.0 or (at your option) the GNU General
	** Public license version 3 or any later version approved by the KDE Free
	** Qt Foundation. The licenses are as published by the Free Software
	** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
	** included in the packaging of this file. Please review the following
	** information to ensure the GNU General Public License requirements will
	** be met: https://www.gnu.org/licenses/gpl-2.0.html and
	** https://www.gnu.org/licenses/gpl-3.0.html.
	**
	** $QT_END_LICENSE$
	**
	****************************************************************************/

	#include "qabstractitemdelegate.h"

	#include <qabstractitemmodel.h>
	#include <qabstractitemview.h>
	#include <qfontmetrics.h>
	#if QT_CONFIG(whatsthis)
	#include <qwhatsthis.h>
	#endif
	#include <qtooltip.h>
	#include <qevent.h>
	#include <qstring.h>
	#include <qdebug.h>
	#if QT_CONFIG(lineedit)
	#include <qlineedit.h>
	#endif
	#if QT_CONFIG(textedit)
	#include <qtextedit.h>
	#include <qplaintextedit.h>
	#endif
	#include <qapplication.h>
	#include <qvalidator.h>
	#include <qjsonvalue.h>
	#include <private/qtextengine_p.h>
	#include <private/qabstractitemdelegate_p.h>

	#include <qpa/qplatformintegration.h>
	#if QT_CONFIG(draganddrop)
	#include <qpa/qplatformdrag.h>
	#include <private/qdnd_p.h>
	#endif
	#include <private/qguiapplication_p.h>

	QT_BEGIN_NAMESPACE

	/*!
	\class QAbstractItemDelegate

	\brief The QAbstractItemDelegate class is used to display and edit
	data items from a model.

	\ingroup model-view
	\inmodule QtWidgets

	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 \l{Model/View Classes}
	and is part of Qt's \l{Model/View Programming}{model/view framework}.

	To render an item in a custom way, you must implement paint() and
	sizeHint(). The QStyledItemDelegate class provides default implementations for
	these functions; if you do not need custom rendering, subclass that
	class instead.

	We give an example of drawing a progress bar in items; in our case
	for a package management program.

	\image widgetdelegate.png

	We create the \c WidgetDelegate class, which inherits from
	QStyledItemDelegate. We do the drawing in the paint() function:

	\snippet widgetdelegate.cpp 0

	Notice that we use a QStyleOptionProgressBar and initialize its
	members. We can then use the current QStyle to draw it.

	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().

	\sa {model-view-programming}{Model/View Programming}, QStyledItemDelegate,
	{Pixelator Example}, QStyledItemDelegate, QStyle
	*/

	/*!
	\enum QAbstractItemDelegate::EndEditHint

	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.

	\value NoHint There is no recommended action to be performed.

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

	\value EditNextItem The view should use the delegate to open an
	editor on the next item in the view.
	\value 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 data locally in order to increase
	performance or conserve network bandwidth.

	\value SubmitModelCache If the model caches data, it should write out
	cached data to the underlying data store.
	\value 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.
	*/

	/*!
	\fn void QAbstractItemDelegate::commitData(QWidget *editor)

	This signal must be emitted when the \a editor widget has completed
	editing the data, and wants to write it back into the model.
	*/

	/*!
	\fn void QAbstractItemDelegate::closeEditor(QWidget *editor, QAbstractItemDelegate::EndEditHint hint)

	This signal is emitted when the user has finished editing an item using
	the specified \a editor.

	The \a 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 \c EditNextItem is specified,
	the view should use a delegate to open an editor on the next item in the
	model.

	\sa EndEditHint
	*/

	/*!
	\fn void QAbstractItemDelegate::sizeHintChanged(const QModelIndex &index)
	\since 4.4

	This signal must be emitted when the sizeHint() of \a index changed.

	Views automatically connect to this signal and relayout items as necessary.
	*/


	/*!
	Creates a new abstract item delegate with the given \a parent.
	*/
	QAbstractItemDelegate::QAbstractItemDelegate(QObject *parent)
	: QObject(*new QAbstractItemDelegatePrivate, parent)
	{

	}

	/*!
	\internal

	Creates a new abstract item delegate with the given \a parent.
	*/
	QAbstractItemDelegate::QAbstractItemDelegate(QObjectPrivate &dd, QObject *parent)
	: QObject(dd, parent)
	{

	}

	/*!
	Destroys the abstract item delegate.
	*/
	QAbstractItemDelegate::~QAbstractItemDelegate()
	{

	}

	/*!
	\fn void QAbstractItemDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const = 0;

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

	If you reimplement this you must also reimplement sizeHint().
	*/

	/*!
	\fn QSize QAbstractItemDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const = 0

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

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

	/*!
	Returns the editor to be used for editing the data item with the
	given \a index. Note that the index contains information about the
	model being used. The editor's parent widget is specified by \a parent,
	and the item options by \a option.

	The base implementation returns \nullptr. If you want custom editing you
	will need to reimplement this function.

	The returned editor widget should have Qt::StrongFocus;
	otherwise, \l{QMouseEvent}s received by the widget will propagate
	to the view. The view's background will shine through unless the
	editor paints its own background (e.g., with
	\l{QWidget::}{setAutoFillBackground()}).

	\sa destroyEditor(), setModelData(), setEditorData()
	*/
	QWidget QAbstractItemDelegate::createEditor(QWidget ,
	const QStyleOptionViewItem &,
	const QModelIndex &) const
	{
	return 0;
	}


	/*!
	Called when the \a editor is no longer needed for editing the data item
	with the given \a 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 function.

	\since 5.0
	\sa createEditor()
	*/
	void QAbstractItemDelegate::destroyEditor(QWidget *editor, const QModelIndex &index) const
	{
	Q_UNUSED(index);
	editor->deleteLater();
	}

	/*!
	Sets the contents of the given \a editor to the data for the item
	at the given \a 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.

	\sa setModelData()
	*/
	void QAbstractItemDelegate::setEditorData(QWidget *,
	const QModelIndex &) const
	{
	// do nothing
	}

	/*!
	Sets the data for the item at the given \a index in the \a model
	to the contents of the given \a editor.

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

	\sa setEditorData()
	*/
	void QAbstractItemDelegate::setModelData(QWidget *,
	QAbstractItemModel *,
	const QModelIndex &) const
	{
	// do nothing
	}

	/*!
	Updates the geometry of the \a editor for the item with the given
	\a index, according to the rectangle specified in the \a 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.
	*/
	void QAbstractItemDelegate::updateEditorGeometry(QWidget *,
	const QStyleOptionViewItem &,
	const QModelIndex &) const
	{
	// do nothing
	}

	/*!
	When editing of an item starts, this function is called with the
	\a event that triggered the editing, the \a model, the \a index of
	the item, and the \a option used for rendering the item.

	Mouse events are sent to editorEvent() even if they don't 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 \c false (indicating that it has not
	handled the event).
	*/
	bool QAbstractItemDelegate::editorEvent(QEvent *,
	QAbstractItemModel *,
	const QStyleOptionViewItem &,
	const QModelIndex &)
	{
	// do nothing
	return false;
	}

	#if QT_DEPRECATED_SINCE(5, 13)
	/*!
	\obsolete

	Use QFontMetrics::elidedText() instead.

	\oldcode
	QFontMetrics fm = ...
	QString str = QAbstractItemDelegate::elidedText(fm, width, mode, text);
	\newcode
	QFontMetrics fm = ...
	QString str = fm.elidedText(text, mode, width);
	\endcode
	*/

	QString QAbstractItemDelegate::elidedText(const QFontMetrics &fontMetrics, int width,
	Qt::TextElideMode mode, const QString &text)
	{
	return fontMetrics.elidedText(text, mode, width);
	}
	#endif

	/*!
	\since 4.3
	Whenever a help event occurs, this function is called with the \a event
	\a view \a option and the \a index that corresponds to the item where the
	event occurs.

	Returns \c true if the delegate can handle the event; otherwise returns \c 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.

	\sa QHelpEvent
	*/
	bool QAbstractItemDelegate::helpEvent(QHelpEvent *event,
	QAbstractItemView *view,
	const QStyleOptionViewItem &option,
	const QModelIndex &index)
	{
	Q_D(QAbstractItemDelegate);
	Q_UNUSED(d);
	Q_UNUSED(index);
	Q_UNUSED(option);

	if (!event \|\| !view)
	return false;
	switch (event->type()) {
	#ifndef QT_NO_TOOLTIP
	case QEvent::ToolTip: {
	QHelpEvent he = static_cast<QHelpEvent>(event);
	const int precision = inherits("QItemDelegate") ? 10 : 6; // keep in sync with DBL_DIG in qitemdelegate.cpp
	const QString tooltip = d->textForRole(Qt::ToolTipRole, index.data(Qt::ToolTipRole), option.locale, precision);
	if (!tooltip.isEmpty()) {
	QToolTip::showText(he->globalPos(), tooltip, view);
	return true;
	}
	break;}
	#endif
	#if QT_CONFIG(whatsthis)
	case QEvent::QueryWhatsThis: {
	if (index.data(Qt::WhatsThisRole).isValid())
	return true;
	break; }
	case QEvent::WhatsThis: {
	QHelpEvent he = static_cast<QHelpEvent>(event);
	const int precision = inherits("QItemDelegate") ? 10 : 6; // keep in sync with DBL_DIG in qitemdelegate.cpp
	const QString whatsthis = d->textForRole(Qt::WhatsThisRole, index.data(Qt::WhatsThisRole), option.locale, precision);
	if (!whatsthis.isEmpty()) {
	QWhatsThis::showText(he->globalPos(), whatsthis, view);
	return true;
	}
	break ; }
	#endif
	default:
	break;
	}
	return false;
	}

	/*!
	\internal

	This virtual method is reserved and will be used in Qt 5.1.
	*/
	QVector<int> QAbstractItemDelegate::paintingRoles() const
	{
	return QVector<int>();
	}

	QAbstractItemDelegatePrivate::QAbstractItemDelegatePrivate()
	: QObjectPrivate()
	{
	}

	static bool editorHandlesKeyEvent(QWidget editor, const QKeyEvent event)
	{
	#if QT_CONFIG(textedit)
	// do not filter enter / return / tab / backtab for QTextEdit or QPlainTextEdit
	if (qobject_cast<QTextEdit >(editor) \|\| qobject_cast<QPlainTextEdit >(editor)) {
	switch (event->key()) {
	case Qt::Key_Tab:
	case Qt::Key_Backtab:
	case Qt::Key_Enter:
	case Qt::Key_Return:
	return true;

	default:
	break;
	}
	}
	#endif // QT_CONFIG(textedit)

	Q_UNUSED(editor);
	Q_UNUSED(event);
	return false;
	}

	bool QAbstractItemDelegatePrivate::editorEventFilter(QObject object, QEvent event)
	{
	Q_Q(QAbstractItemDelegate);

	QWidget editor = qobject_cast<QWidget>(object);
	if (!editor)
	return false;
	if (event->type() == QEvent::KeyPress) {
	QKeyEvent keyEvent = static_cast<QKeyEvent >(event);
	if (editorHandlesKeyEvent(editor, keyEvent))
	return false;

	#ifndef QT_NO_SHORTCUT
	if (keyEvent->matches(QKeySequence::Cancel)) {
	// don't commit data
	emit q->closeEditor(editor, QAbstractItemDelegate::RevertModelCache);
	return true;
	}
	#endif

	switch (keyEvent->key()) {
	case Qt::Key_Tab:
	if (tryFixup(editor)) {
	emit q->commitData(editor);
	emit q->closeEditor(editor, QAbstractItemDelegate::EditNextItem);
	}
	return true;
	case Qt::Key_Backtab:
	if (tryFixup(editor)) {
	emit q->commitData(editor);
	emit q->closeEditor(editor, QAbstractItemDelegate::EditPreviousItem);
	}
	return true;
	case Qt::Key_Enter:
	case Qt::Key_Return:
	// We want the editor to be able to process the key press
	// before committing the data (e.g. so it can do
	// validation/fixup of the input).
	if (!tryFixup(editor))
	return true;

	QMetaObject::invokeMethod(q, "_q_commitDataAndCloseEditor",
	Qt::QueuedConnection, Q_ARG(QWidget*, editor));
	return false;
	default:
	return false;
	}
	} else if (event->type() == QEvent::FocusOut \|\| (event->type() == QEvent::Hide && editor->isWindow())) {
	//the Hide event will take care of he editors that are in fact complete dialogs
	if (!editor->isActiveWindow() \|\| (QApplication::focusWidget() != editor)) {
	QWidget *w = QApplication::focusWidget();
	while (w) { // don't worry about focus changes internally in the editor
	if (w == editor)
	return false;
	w = w->parentWidget();
	}
	#if QT_CONFIG(draganddrop)
	// The window may lose focus during an drag operation.
	// i.e when dragging involves the taskbar on Windows.
	QPlatformDrag *platformDrag = QGuiApplicationPrivate::instance()->platformIntegration()->drag();
	if (platformDrag && platformDrag->currentDrag()) {
	return false;
	}
	#endif
	if (tryFixup(editor))
	emit q->commitData(editor);

	// If the application loses focus while editing, then the focus needs to go back
	// to the itemview when the editor closes. This ensures that when the application
	// is active again it will have the focus on the itemview as expected.
	const bool manuallyFixFocus = (event->type() == QEvent::FocusOut) && !editor->hasFocus() &&
	editor->parentWidget() &&
	(static_cast<QFocusEvent *>(event)->reason() == Qt::ActiveWindowFocusReason);
	emit q->closeEditor(editor, QAbstractItemDelegate::NoHint);
	if (manuallyFixFocus)
	editor->parentWidget()->setFocus();
	}
	#ifndef QT_NO_SHORTCUT
	} else if (event->type() == QEvent::ShortcutOverride) {
	if (static_cast<QKeyEvent*>(event)->matches(QKeySequence::Cancel)) {
	event->accept();
	return true;
	}
	#endif
	}
	return false;
	}

	bool QAbstractItemDelegatePrivate::tryFixup(QWidget *editor)
	{
	#if QT_CONFIG(lineedit)
	if (QLineEdit e = qobject_cast<QLineEdit>(editor)) {
	if (!e->hasAcceptableInput()) {
	#if QT_CONFIG(validator)
	if (const QValidator *validator = e->validator()) {
	QString text = e->text();
	validator->fixup(text);
	e->setText(text);
	}
	#endif
	return e->hasAcceptableInput();
	}
	}
	#else
	Q_UNUSED(editor)
	#endif // QT_CONFIG(lineedit)

	return true;
	}

	QString QAbstractItemDelegatePrivate::textForRole(Qt::ItemDataRole role, const QVariant &value, const QLocale &locale, int precision) const
	{
	const QLocale::FormatType formatType = (role == Qt::DisplayRole) ? QLocale::ShortFormat : QLocale::LongFormat;
	QString text;
	switch (value.userType()) {
	case QMetaType::Float:
	text = locale.toString(value.toFloat());
	break;
	case QVariant::Double:
	text = locale.toString(value.toDouble(), 'g', precision);
	break;
	case QVariant::Int:
	case QVariant::LongLong:
	text = locale.toString(value.toLongLong());
	break;
	case QVariant::UInt:
	case QVariant::ULongLong:
	text = locale.toString(value.toULongLong());
	break;
	case QVariant::Date:
	text = locale.toString(value.toDate(), formatType);
	break;
	case QVariant::Time:
	text = locale.toString(value.toTime(), formatType);
	break;
	case QVariant::DateTime:
	text = locale.toString(value.toDateTime(), formatType);
	break;
	case QVariant::Type(QMetaType::QJsonValue): {
	const QJsonValue val = value.toJsonValue();
	if (val.isBool()) {
	text = QVariant(val.toBool()).toString();
	break;
	}
	if (val.isDouble()) {
	text = locale.toString(val.toDouble(), 'g', precision);
	break;
	}
	// val is a string (or null) here
	Q_FALLTHROUGH();
	}
	default: {
	text = value.toString();
	if (role == Qt::DisplayRole)
	text.replace(QLatin1Char('\n'), QChar::LineSeparator);
	break;
	}
	}
	return text;
	}

	void QAbstractItemDelegatePrivate::_q_commitDataAndCloseEditor(QWidget *editor)
	{
	Q_Q(QAbstractItemDelegate);
	emit q->commitData(editor);
	emit q->closeEditor(editor, QAbstractItemDelegate::SubmitModelCache);
	}

	QT_END_NAMESPACE

	#include "moc_qabstractitemdelegate.cpp"