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Qt Namespace Reference
^{[QtCore module]}

The Qt namespace contains miscellaneous identifiers used throughout the Qt library. More...

#include <Qt>

• Qt 3 support members

Types

• flags Alignment
• enum AlignmentFlag { AlignLeft, AlignRight, AlignHCenter, AlignJustify, ..., AlignVertical_Mask }
• enum AnchorAttribute { AnchorName, AnchorHref }
• enum ArrowType { NoArrow, UpArrow, DownArrow, LeftArrow, RightArrow }
• enum AspectRatioMode { IgnoreAspectRatio, KeepAspectRatio, KeepAspectRatioByExpanding }
• enum BGMode { TransparentMode, OpaqueMode }
• enum BrushStyle { NoBrush, SolidPattern, Dense1Pattern, Dense2Pattern, ..., TexturePattern }
• enum CaseSensitivity { CaseInsensitive, CaseSensitive }
• enum CheckState { Unchecked, PartiallyChecked, Checked }
• enum ClipOperation { NoClip, ReplaceClip, IntersectClip, UniteClip }
• enum ConnectionType { DirectConnection, QueuedConnection, AutoConnection }
• enum ContextMenuPolicy { NoContextMenu, DefaultContextMenu, ActionsContextMenu, CustomContextMenu }
• enum Corner { TopLeftCorner, TopRightCorner, BottomLeftCorner, BottomRightCorner }
• enum CursorShape { ArrowCursor, UpArrowCursor, CrossCursor, WaitCursor, ..., BitmapCursor }
• enum DateFormat { TextDate, ISODate, LocalDate }
• enum DayOfWeek { Monday, Tuesday, Wednesday, Thursday, ..., Sunday }
• enum Dock { DockUnmanaged, DockTornOff, DockTop, DockBottom, ..., DockMinimized }
• enum DockWidgetArea { LeftDockWidgetArea, RightDockWidgetArea, TopDockWidgetArea, BottomDockWidgetArea, AllDockWidgetAreas }
• flags DockWidgetAreas
• enum DropAction { CopyAction, MoveAction, LinkAction, ActionMask, TargetMoveAction, IgnoreAction }
• flags DropActions
• enum FillRule { OddEvenFill, WindingFill }
• enum FocusPolicy { TabFocus, ClickFocus, StrongFocus, WheelFocus, NoFocus }
• enum FocusReason { MouseFocusReason, TabFocusReason, BacktabFocusReason, ActiveWindowFocusReason, ..., OtherFocusReason }
• enum GlobalColor { white, black, red, darkRed, ..., color1 }
• typedef HANDLE
• enum HitTestAccuracy { ExactHit, FuzzyHit }
• enum ImageConversionFlag { AutoColor, ColorOnly, MonoOnly, DiffuseDither, ..., AvoidDither }
• flags ImageConversionFlags
• enum InputMethodQuery { ImMicroFocus, ImFont, ImCursorPosition, ImSurroundingText, ImCurrentSelection }
• enum ItemDataRole { DisplayRole, DecorationRole, EditRole, ToolTipRole, ..., UserRole }
• enum ItemFlag { ItemIsSelectable, ItemIsEditable, ItemIsDragEnabled, ItemIsDropEnabled, ..., ItemIsTristate }
• flags ItemFlags
• enum Key { Key_Escape, Key_Tab, Key_Backtab, Key_Backspace, ..., Key_Yes }
• enum KeyboardModifier { NoModifier, ShiftModifier, ControlModifier, AltModifier, MetaModifier, KeypadModifier }
• flags KeyboardModifiers
• enum LayoutDirection { LeftToRight, RightToLeft }
• enum MatchFlag { MatchExactly, MatchContains, MatchStartsWith, MatchEndsWith, ..., MatchRecursive }
• flags MatchFlags
• enum Modifier { SHIFT, META, CTRL, ALT, UNICODE_ACCEL }
• enum MouseButton { NoButton, LeftButton, RightButton, MidButton, XButton1, XButton2 }
• flags MouseButtons
• enum Orientation { Horizontal, Vertical }
• flags Orientations
• enum PenCapStyle { FlatCap, SquareCap, RoundCap }
• enum PenJoinStyle { MiterJoin, BevelJoin, RoundJoin }
• enum PenStyle { NoPen, SolidLine, DashLine, DotLine, ..., CustomDashLine }
• enum ScrollBarPolicy { ScrollBarAsNeeded, ScrollBarAlwaysOff, ScrollBarAlwaysOn }
• enum ShortcutContext { WidgetShortcut, WindowShortcut, ApplicationShortcut }
• enum SortOrder { AscendingOrder, DescendingOrder }
• enum TextElideMode { ElideLeft, ElideRight, ElideMiddle }
• enum TextFlag { TextSingleLine, TextDontClip, TextExpandTabs, TextShowMnemonic, ..., TextIncludeTrailingSpaces }
• enum TextFormat { PlainText, RichText, AutoText, LogText }
• enum TimeSpec { LocalTime, UTC }
• enum ToolBarArea { LeftToolBarArea, RightToolBarArea, TopToolBarArea, BottomToolBarArea, AllToolBarAreas }
• flags ToolBarAreas
• enum ToolButtonStyle { ToolButtonIconOnly, ToolButtonTextOnly, ToolButtonTextBesideIcon, ToolButtonTextUnderIcon }
• enum TransformationMode { FastTransformation, SmoothTransformation }
• enum UIEffect { UI_General, UI_AnimateMenu, UI_FadeMenu, UI_AnimateCombo, ..., UI_AnimateToolBox }
• typedef WFlags
• enum WhiteSpaceMode { WhiteSpaceNormal, WhiteSpacePre, WhiteSpaceNoWrap }
• enum WidgetAttribute { WA_AcceptDrops, WA_DeleteOnClose, WA_QuitOnClose, WA_KeyCompression, ..., WA_ShowModal }
• flags WindowFlags
• enum WindowModality { NonModal, WindowModal, ApplicationModal }
• enum WindowState { WindowNoState, WindowMinimized, WindowMaximized, WindowFullScreen, WindowActive }
• flags WindowStates
• enum WindowType { Widget, Window, Dialog, Sheet, ..., WMacNoSheet }

Functions

• QString convertFromPlainText ( const QString & plain, WhiteSpaceMode mode = WhiteSpacePre )
• QString escape ( const QString & plain )
• bool mightBeRichText ( const QString & text )

Detailed Description

The Qt namespace contains miscellaneous identifiers used throughout the Qt library.

Type Documentation

enum Qt::AlignmentFlag
flags Qt::Alignment

This enum type is used to describe alignment. It contains horizontal and vertical flags that can be combined to produce the required effect.

The TextElideMode enum can also be used in many situations to fine-tune the appearance of aligned text.

The horizontal flags are:

The vertical flags are:

You can use only one of the horizontal flags at a time. There is one two-dimensional flag:

You can use at most one horizontal and one vertical flag at a time. Qt::AlignCenter counts as both horizontal and vertical.

Three enum values are useful in applications that can be run in right-to-left mode:

Masks:

Conflicting combinations of flags have undefined meanings.

The Alignment type is a typedef for QFlags<AlignmentFlag>. It stores an OR combination of AlignmentFlag values.

enum Qt::AnchorAttribute

An anchor has one or more of the following attributes:

enum Qt::ArrowType

enum Qt::AspectRatioMode

This enum type defines what happens to the aspect ratio when scaling an rectangle.

See also QSize::scale() and QImage::scaled().

enum Qt::BGMode

Background mode:

enum Qt::BrushStyle

This enum type defines the brush styles supported by Qt, i.e. the fill pattern of shapes drawn using QPainter.

See also QBrush.

enum Qt::CaseSensitivity

enum Qt::CheckState

This enum describes the state of checkable items, controls, and widgets.

See also QCheckBox, Qt::ItemFlags, and Qt::ItemDataRole.

enum Qt::ClipOperation

enum Qt::ConnectionType

This enum describes the types of connection that can be used between signals and slots. In particular, it determines whether a particular signal is delivered to a slot immediately or queued for delivery at a later time.

With queued connections, the parameters must be of types that are known to Qt's meta-object system, because Qt needs to copy the arguments to store them in an event behind the scenes. If you try to use a queued connection and get the error message

    QObject::connect: Cannot queue arguments of type 'MyType'

call qRegisterMetaType() to register the data type before you establish the connection.

See also Thread Support in Qt, QObject::connect(), and qRegisterMetaType().

enum Qt::ContextMenuPolicy

This enum type defines the various policies a widget can have with respect to showing a context menu.

enum Qt::Corner

This enum type specifies a corner in a rectangle:

enum Qt::CursorShape

This enum type defines the various cursors that can be used.

enum Qt::DateFormat

enum Qt::DayOfWeek

enum Qt::Dock

Each dock window can be in one of the following positions:

enum Qt::DockWidgetArea
flags Qt::DockWidgetAreas

The DockWidgetAreas type is a typedef for QFlags<DockWidgetArea>. It stores an OR combination of DockWidgetArea values.

enum Qt::DropAction
flags Qt::DropActions

The DropActions type is a typedef for QFlags<DropAction>. It stores an OR combination of DropAction values.

enum Qt::FillRule

Specifies which method should be used to fill the paths and polygons.

enum Qt::FocusPolicy

This enum type defines the various policies a widget can have with respect to acquiring keyboard focus.

enum Qt::FocusReason

This enum specifies why the focus changed. It will be passed through QWidget::setFocus and can be retrieved in the QFocusEvent sent to the widget upon focus change.

No good reason, really.

See also Keyboard Focus.

enum Qt::GlobalColor

Qt's predefined QColor objects:

See also QColor.

typedef Qt::HANDLE

Platform-specific handle type for system objects. This is equivalent to void * on Windows and Mac OS X, and embedded Linux, and to unsigned long on X11.

Warning: Using this type is not portable.

enum Qt::HitTestAccuracy

This enum contains the types of accuracy that can be used by the QTextDocument class when testing for mouse clicks on text documents.

This enum is defined in the <QTextDocument> header file.

enum Qt::ImageConversionFlag
flags Qt::ImageConversionFlags

The options marked "(default)" are set if no other values from the list are included (since the defaults are zero):

Color/Mono preference (ignored for QBitmap):

Dithering mode preference for RGB channels:

Dithering mode preference for alpha channel:

Color matching versus dithering preference:

The ImageConversionFlags type is a typedef for QFlags<ImageConversionFlag>. It stores an OR combination of ImageConversionFlag values.

enum Qt::InputMethodQuery

enum Qt::ItemDataRole

Each item in the model has a set of data elements associated with it, each with its own role. The roles are used by the view to indicate to the model which type of data it needs.

The general purpose roles are:

Roles describing appearance and meta data:

Accessibility roles:

User roles:

enum Qt::ItemFlag
flags Qt::ItemFlags

This enum describes the properties of an item:

Note that checkable items need to be given both a suitable set of flags and an initial state, indicating whether the item is checked or not. This is handled automatically for model/view components, but needs to be explicitly set for instances of QListWidgetItem, QTableWidgetItem, and QTreeWidgetItem.

The ItemFlags type is a typedef for QFlags<ItemFlag>. It stores an OR combination of ItemFlag values.

See also QAbstractItemModel.

enum Qt::Key

The key names used by Qt.

See also QKeyEvent::key().

enum Qt::KeyboardModifier
flags Qt::KeyboardModifiers

This enum describes the modifier keys.

Note: On Mac OS X, the ControlModifier value corresponds to the Command keys on the Macintosh keyboard, and the MetaModifier value corresponds to the Control keys.

The KeyboardModifiers type is a typedef for QFlags<KeyboardModifier>. It stores an OR combination of KeyboardModifier values.

See also MouseButton and Modifier.

enum Qt::LayoutDirection

Specifies the direction of Qt's layouts:

Right-to-left layouts are necessary for certain languages, notably Arabic and Hebrew.

See also QApplication::setLayoutDirection() and QWidget::setLayoutDirection().

enum Qt::MatchFlag
flags Qt::MatchFlags

This enum describes the type of matches that can be used when searching for items in a model.

The MatchFlags type is a typedef for QFlags<MatchFlag>. It stores an OR combination of MatchFlag values.

enum Qt::Modifier

This enum provides shorter names for the keyboard modifier keys supported by Qt.

Note: On Mac OS X, the CTRL value corresponds to the Command keys on the Macintosh keyboard, and the META value corresponds to the Control keys.

See also KeyboardModifier and MouseButton.

enum Qt::MouseButton
flags Qt::MouseButtons

This enum type describes the different mouse buttons.

The MouseButtons type is a typedef for QFlags<MouseButton>. It stores an OR combination of MouseButton values.

See also KeyboardModifier and Modifier.

enum Qt::Orientation
flags Qt::Orientations

This type is used to signify an object's orientation.

Orientation is used with QScrollBar for example.

The Orientations type is a typedef for QFlags<Orientation>. It stores an OR combination of Orientation values.

enum Qt::PenCapStyle

This enum type defines the pen cap styles supported by Qt, i.e. the line end caps that can be drawn using QPainter.

Qt::SquareCap	Qt::FlatCap	Qt::RoundCap

See also QPen.

enum Qt::PenJoinStyle

This enum type defines the pen join styles supported by Qt, i.e. which joins between two connected lines can be drawn using QPainter.

Qt::BevelJoin	Qt::MiterJoin	Qt::RoundJoin

See also QPen.

enum Qt::PenStyle

This enum type defines the pen styles that can be drawn using QPainter. The styles are:

Qt::SolidLine	Qt::DashLine	Qt::DotLine
Qt::DashDotLine	Qt::DashDotDotLine	Qt::CustomDashLine

See also QPen.

enum Qt::ScrollBarPolicy

This enum type describes the various modes of QAbstractScrollArea's scroll bars.

(The modes for the horizontal and vertical scroll bars are independent.)

enum Qt::ShortcutContext

For a QEvent::Shortcut event to occur, the shortcut's key sequence must be entered by the user in a context where the shortcut is active. The possible contexts are these:

enum Qt::SortOrder

This enum describes how the items in a widget are sorted.

enum Qt::TextElideMode

This enum specifies where the ellipsis should appear when displaying texts that don't fit:

Qt::ElideMiddle is normally the most appropriate choice for URLs (e.g., "http://www.trolltech.cn/news...s/Beijing-Office-Opening.pdf"), whereas Qt::ElideRight is appropriate for other strings (e.g., "Deploying Applications on Ma...").

See also QAbstractItemView::textElideMode, QAbstractItemDelegate::elidedText(), and AlignmentFlag.

enum Qt::TextFlag

This enum type is used to define some modifier flags. Some of these flags only make sense in the context of printing:

You can use as many modifier flags as you want, except that Qt::TextSingleLine and Qt::TextWordWrap cannot be combined.

Flags that are inappropriate for a given use are generally ignored.

enum Qt::TextFormat

This enum is used in widgets that can display both plain text and rich text, e.g. QLabel. It is used for deciding whether a text string should be interpreted as one or the other. This is normally done by passing one of the enum values to a setTextFormat() function.

enum Qt::TimeSpec

enum Qt::ToolBarArea
flags Qt::ToolBarAreas

The ToolBarAreas type is a typedef for QFlags<ToolBarArea>. It stores an OR combination of ToolBarArea values.

enum Qt::ToolButtonStyle

The style of the tool button, describing how the button's text and icon should be displayed.

enum Qt::TransformationMode

This enum type defines whether image transformations (e.g., scaling) should be smooth or not.

See also QImage::scaled().

enum Qt::UIEffect

See also QApplication::setEffectEnabled().

typedef Qt::WFlags

Synonym for Qt::WindowFlags.

enum Qt::WhiteSpaceMode

This enum describes the types of whitespace mode that are used by the QTextDocument class to meet the requirements of different kinds of textual information.

This enum is defined in the <QTextDocument> header file.

enum Qt::WidgetAttribute

This enum type is used to specify various widget attributes. Attributes are set and cleared with QWidget::setAttribute(), and queried with QWidget::testAttribute(), although some have special convenience functions which are mentioned below.

enum Qt::WindowModality

This enum specifies the behavior of a modal window. A modal window is one that blocks input to other windows. Note that windows that are children of a modal window are not blocked.

The values are:

See also QWidget::windowModality and QDialog.

enum Qt::WindowState
flags Qt::WindowStates

This enum type is used to specify the current state of a top-level window.

The states are

The WindowStates type is a typedef for QFlags<WindowState>. It stores an OR combination of WindowState values.

enum Qt::WindowType
flags Qt::WindowFlags

This enum type is used to specify various window-system properties for the widget. They are fairly unusual but necessary in a few cases. Some of these flags depend on whether the underlying window manager supports them.

The main types are

There are also a number of flags which you can use to customize the appearance of top-level windows. These have no effect on other windows:

Obsolete flags:

The WindowFlags type is a typedef for QFlags<WindowType>. It stores an OR combination of WindowType values.

Function Documentation

QString Qt::convertFromPlainText ( const QString & plain, WhiteSpaceMode mode = WhiteSpacePre )

Converts the plain text string plain to an HTML-formatted paragraph while preserving most of its look.

mode defines how whitespace is handled.

This function is defined in the <QTextDocument> header file.

See also escape() and mightBeRichText().

QString Qt::escape ( const QString & plain )

Converts the plain text string plain to a HTML string with HTML metacharacters <, >, and & replaced by HTML entities.

Example:

    QString plain = "#include <QtCore>"
    QString html = Qt::escape(plain);
    // html == "#include &lt;QtCore&gt;"

This function is defined in the <QTextDocument> header file.

See also convertFromPlainText() and mightBeRichText().

bool Qt::mightBeRichText ( const QString & text )

Returns true if the string text is likely to be rich text; otherwise returns false.

This function uses a fast and therefore simple heuristic. It mainly checks whether there is something that looks like a tag before the first line break. Although the result may be correct for common cases, there is no guarantee.

This function is defined in the <QTextDocument> header file.