如何突出显示QTreeView中的一些项目（不继承）

Question

我正在寻找一种方法来突出显示QTreeView的行，而无需重新实现QTreeView子类。

我见过类似的问题：

• highlight-specific-substrings-in-a-qtreeview
• how-to-make-item-view-render-rich-html-text-in-qt
• set-bold-rows-in-a-qtreeview

但他们都使用委托。原因是我在小部件工具中创建搜索文本，该工具浏览所有小部件并查找并突出显示其中的文本。因此，我不能使用委托。

有没有可能的解决方案？ 在它上面画一个半透明的物品？

以下是存储小部件的工具代码以及在其中搜索文本的方式。

class GUI_EXPORT QgsSearchHighlightOptionWidget : public QObject
{
    Q_OBJECT
  public:

    /**
     * Constructor
     * \param widget the widget used to search text into
     */
    explicit QgsSearchHighlightOptionWidget( QWidget *widget = nullptr );

    /**
     * Returns if it valid: if the widget type is handled and if the widget is not still available
     */
    bool isValid() { return mWidget && mValid; }

    /**
     * search for a text pattern and highlight the widget if the text is found
     * \returns true if the text pattern is found
     */
    bool searchHighlight( const QString &searchText );

    /**
     *  reset the style to the original state
     */
    void reset();

    /**
     * return the widget
     */
    QWidget *widget() { return mWidget; }

    bool eventFilter( QObject *obj, QEvent *event ) override;

  private slots:
    void widgetDestroyed();

  private:
    QPointer< QWidget > mWidget;
    QString mStyleSheet;
    bool mValid = true;
    bool mChangedStyle = false;
    std::function < bool( QString )> mTextFound = []( QString searchText ) {Q_UNUSED( searchText ); return false;};
    bool mInstalledFilter = false;
};

QgsSearchHighlightOptionWidget::QgsSearchHighlightOptionWidget( QWidget *widget )
  : QObject( widget )
  , mWidget( widget )
{
  if ( qobject_cast<QLabel *>( widget ) )
  {
    mStyleSheet = QStringLiteral( "QLabel { background-color: yellow; color: blue;}" );
    mTextFound = [ = ]( QString searchText ) {return qobject_cast<QLabel *>( mWidget )->text().contains( searchText, Qt::CaseInsensitive );};
  }
  else if ( qobject_cast<QCheckBox *>( widget ) )
  {
    mStyleSheet = QStringLiteral( "QCheckBox { background-color: yellow; color: blue;}" );
    mTextFound = [ = ]( QString searchText ) {return qobject_cast<QCheckBox *>( mWidget )->text().contains( searchText, Qt::CaseInsensitive );};
  }
  else if ( qobject_cast<QAbstractButton *>( widget ) )
  {
    mStyleSheet = QStringLiteral( "QAbstractButton { background-color: yellow; color: blue;}" );
    mTextFound = [ = ]( QString searchText ) {return qobject_cast<QAbstractButton *>( mWidget )->text().contains( searchText, Qt::CaseInsensitive );};
  }
  else if ( qobject_cast<QGroupBox *>( widget ) )
  {
    mStyleSheet = QStringLiteral( "QGroupBox::title { background-color: yellow; color: blue;}" );
    mTextFound = [ = ]( QString searchText ) {return qobject_cast<QGroupBox *>( mWidget )->title().contains( searchText, Qt::CaseInsensitive );};
  }
  else if ( qobject_cast<QTreeView *>( widget ) )
  {
    // TODO - style individual matching items
    mTextFound = [ = ]( QString searchText )
    {
      QTreeView *tree = qobject_cast<QTreeView *>( mWidget );
      if ( !tree )
        return false;
      QModelIndexList hits = tree->model()->match( tree->model()->index( 0, 0 ), Qt::DisplayRole, searchText, 1, Qt::MatchContains | Qt::MatchRecursive );
      return !hits.isEmpty();
    };
  }
  else
  {
    mValid = false;
  }
  if ( mValid )
  {
    mStyleSheet.prepend( "/*!search!*/" ).append( "/*!search!*/" );
    QgsDebugMsgLevel( mStyleSheet, 4 );
    connect( mWidget, &QWidget::destroyed, this, &QgsSearchHighlightOptionWidget::widgetDestroyed );
  }
}

bool QgsSearchHighlightOptionWidget::searchHighlight( const QString &searchText )
{
  bool found = false;
  if ( !mWidget )
    return found;

  if ( !searchText.isEmpty() )
  {
    found = mTextFound( searchText );
  }

  if ( found && !mChangedStyle )
  {
    if ( !mWidget->isVisible() )
    {
      // show the widget to get initial stylesheet in case it's modified
      QgsDebugMsg( QString( "installing event filter on: %1 (%2)" )
                   .arg( mWidget->objectName() )
                   .arg( qobject_cast<QLabel *>( mWidget ) ? qobject_cast<QLabel *>( mWidget )->text() : QString() ) );
      mWidget->installEventFilter( this );
      mInstalledFilter = true;
    }
    else
    {
      mWidget->setStyleSheet( mWidget->styleSheet() + mStyleSheet );
      mChangedStyle = true;
    }
  }

  return found;
}

bool QgsSearchHighlightOptionWidget::eventFilter( QObject *obj, QEvent *event )
{
  if ( mInstalledFilter && event->type() == QEvent::Show && obj == mWidget )
  {
    mWidget->removeEventFilter( this );
    mInstalledFilter = false;
    // instead of catching the event and calling show again
    // it might be better to use a timer to change the style
    // after the widget is shown
#if 1
    mWidget->show();
    mWidget->setStyleSheet( mWidget->styleSheet() + mStyleSheet );
    return true;
#else
    QTimer::singleShot( 500, this, [ = ]
    {
      mWidget->setStyleSheet( mWidget->styleSheet() + mStyleSheet );
      mChangedStyle = true;
    } );
#endif
  }
  return QObject::eventFilter( obj, event );
}

void QgsSearchHighlightOptionWidget::reset()
{
  if ( mWidget && mValid )
  {
    if ( mChangedStyle )
    {
      QString ss = mWidget->styleSheet();
      ss.remove( mStyleSheet );
      mWidget->setStyleSheet( ss );
      mChangedStyle = false;
    }
    else if ( mInstalledFilter )
    {
      mWidget->removeEventFilter( this );
      mInstalledFilter = false;
    }
  }
}

void QgsSearchHighlightOptionWidget::widgetDestroyed()
{
  mWidget = nullptr;
  mValid = false;
}

以下是从对话框中实际注册小部件的代码：

void QgsOptionsDialogBase::registerTextSearchWidgets()
{
  mRegisteredSearchWidgets.clear();

  for ( int i = 0; i < mOptStackedWidget->count(); i++ )
  {
    Q_FOREACH ( QWidget *w, mOptStackedWidget->widget( i )->findChildren<QWidget *>() )
    {
      QgsSearchHighlightOptionWidget *shw = new QgsSearchHighlightOptionWidget( w );
      if ( shw->isValid() )
      {
        QgsDebugMsgLevel( QString( "Registering: %1" ).arg( w->objectName() ), 4 );
        mRegisteredSearchWidgets.append( qMakePair( shw, i ) );
      }
      else
      {
        delete shw;
      }
    }
  }
}

Answer 1

阅读文档，我不知道如何直接进行。 以下是一些建议。希望有一个适合你：

1）您可以使用QTreeWidget代替QTreeView吗？ 有了这个，它应该很容易。 使用item功能，例如该项目setBackground()。

2）如何过滤树而不是突出显示？使用setRowHidden()？

3）如果您还没有，也可以尝试使用QTreeView::keyboardSearch()并查看其功能。

4）您可以使用select*并在搜索框中添加下一个/上一个按钮。即你跳过树，选择当前的搜索结果。