Following Classes are available for reference:

 

QAbstractButton

QAbstractItemModel

QAbstractItemView

QAbstractListModel

QAbstractPrintDialog

QAbstractScrollArea

QAbstractSlider

QAbstractSpinBox

QAbstractTableModel

QAction

QApplication

QBitmap

QBoxLayout

QBrush

QCalendarWidget

QCheckBox

QClipboard

QColor

QColorDialog

QComboBox

QCommandLinkButton

QCommonStyle

QConicalGradient

QCoreApplication

QCursor

QDateEdit

QDateTime

QDateTimeEdit

QDesktopWidget

QDial

QDialog

QDir

QDirModel

QDockWidget

QDoubleSpinBox

QDragEnterEvent

QDragLeaveEvent

QDragMoveEvent

QDropEvent

QErrorMessage

QEvent

QEventLoop

QFileDialog

QFileSystemModel

QFocusEvent

QFocusFrame

QFont

QFontComboBox

QFontDatabase

QFontDialog

QFontInfo

QFormLayout

QFrame

QFtp

QGradient

QGridLayout

QGroupBox

QHBoxLayout

QHeaderView

QHttp

QIcon

QImage

QImageReader

QImageWriter

QInputDialog

QInputEvent

QKeyEvent

QKeySequence

QLabel

QLatin1Char

QLatin1String

QLayout

QLayoutItem

QLCDNumber

QLine

QLinearGradient

QLineEdit

QList

QListView

QListWidget

QListWidgetItem

QMainWindow

QMenu

QMenuBar

QMessageBox

QModelIndex

QMouseEvent

QMoveEvent

QObject

QPageSetupDialog

QPaintDevice

QPainter

QPaintEvent

QPalette

QPen

QPicture

QPixmap

QPoint

QPointF

QPrintDialog

QPrintPreviewDialog

QProgressBar

QProgressDialog

QPushButton

QRadialGradient

QRadioButton

QRect

QRectF

QRegion

QResizeEvent

QResource

QScrollArea

QScrollBar

QSignalMapper

QSize

QSizeF

QSizeGrip

QSizePolicy

QSlider

QSound

QSpinBox

QSplashScreen

QSplitter

QStandardItem

QStandardItemModel

QStatusBar

QStringList

QStringListModel

QStyle

QStyledItemDelegate

QStyleHintReturn

QStyleHintReturnMask

QStyleHintReturnVariant

QStyleOption

QStyleOptionButton

QStyleOptionComboBox

QStyleOptionComplex

QStyleOptionDockWidget

QStyleOptionFocusRect

QStyleOptionFrame

QStyleOptionGroupBox

QStyleOptionHeader

QStyleOptionMenuItem

QStyleOptionProgressBar

QStyleOptionSizeGrip

QStyleOptionSlider

QStyleOptionSpinBox

QStyleOptionTab

QStyleOptionTabBarBase

QStyleOptionTabWidgetFrame

QStyleOptionTitleBar

QStyleOptionToolBar

QStyleOptionToolBox

QStyleOptionToolButton

QStyleOptionViewItem

QStylePainter

QSystemTrayIcon

QTabBar

QTableView

QTableWidget

QTableWidgetItem

QTabWidget

QTextBlock

QTextBlockFormat

QTextBlockGroup

QTextBoundaryFinder

QTextBrowser

QTextCharFormat

QTextCodec

QTextCursor

QTextDecoder

QTextDocument

QTextDocumentFragment

QTextDocumentWriter

QTextEdit

QTextEncoder

QTextFormat

QTextFragment

QTextFrame

QTextFrameFormat

QTextImageFormat

QTextInlineObject

QTextItem

QTextLayout

QTextLength

QTextLine

QTextObject

QTextStream

QTimeEdit

QTimer

QToolBar

QToolBox

QToolButton

QTreeView

QTreeWidget

QTreeWidgetItem

QUrl

QVariant

QVBoxLayout

QWebFrame

QWebHistory

QWebHistoryInterface

QWebHistoryItem

QWebHitTestResult

QWebPage

QWebPluginFactory

QWebSecurityOrigin

QWebSettings

QWebView

QWheelEvent

QWidget

QWidgetAction

QWidgetItem

QWindowsStyle

QWindowsXPStyle

QWizard