Qt Namespace

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

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The Qt Company Ltd.

Publié le 27 décembre 2024 - Mis à jour le 27 décembre 2024

Header: Qt
CMake:

find_package(Qt6 REQUIRED COMPONENTS Core)

target_link_libraries(mytarget PRIVATE Qt6::Core)
qmake: QT += core

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:

Constant	Value	Description
Qt::AlignLeft	0x0001	Aligns with the left edge.
Qt::AlignRight	0x0002	Aligns with the right edge.
Qt::AlignHCenter	0x0004	Centers horizontally in the available space.
Qt::AlignJustify	0x0008	Justifies the text in the available space.

The vertical flags are:

Constant	Value	Description
Qt::AlignTop	0x0020	Aligns with the top.
Qt::AlignBottom	0x0040	Aligns with the bottom.
Qt::AlignVCenter	0x0080	Centers vertically in the available space.
Qt::AlignBaseline	0x0100	Aligns with the baseline.

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

Constant	Value	Description
Qt::AlignCenter	AlignVCenter \| AlignHCenter	Centers in both dimensions.

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:

Constant	Value	Description
Qt::AlignAbsolute	0x0010	If the widget's layout direction is Qt::RightToLeft (instead of Qt::LeftToRight, the default), Qt::AlignLeft refers to the right edge and Qt::AlignRight to the left edge. This is normally the desired behavior. If you want Qt::AlignLeft to always mean "left" and Qt::AlignRight to always mean "right", combine the flag with Qt::AlignAbsolute.
Qt::AlignLeading	AlignLeft	Synonym for Qt::AlignLeft.
Qt::AlignTrailing	AlignRight	Synonym for Qt::AlignRight.

Masks:

Constant
Qt::AlignHorizontal_Mask	AlignLeft \| AlignRight \| AlignHCenter \| AlignJustify \| AlignAbsolute
Qt::AlignVertical_Mask	AlignTop \| AlignBottom \| AlignVCenter \| AlignBaseline

Conflicting combinations of flags have undefined meanings.

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

Specifies a side of a layout item that can be anchored. This is used by QGraphicsAnchorLayout.

Constant	Value	Description
Qt::AnchorLeft	0	The left side of a layout item.
Qt::AnchorHorizontalCenter	1	A "virtual" side that is centered between the left and the right side of a layout item.
Qt::AnchorRight	2	The right side of a layout item.
Qt::AnchorTop	3	The top side of a layout item.
Qt::AnchorVerticalCenter	4	A "virtual" side that is centered between the top and the bottom side of a layout item.
Qt::AnchorBottom	5	The bottom side of a layout item.

This enum describes attributes that change the behavior of application-wide features. These are enabled and disabled using QCoreApplication::setAttribute(), and can be tested for with QCoreApplication::testAttribute().

Constant	Value	Description
Qt::AA_DontShowIconsInMenus	2	Actions with the Icon property won't be shown in any menus unless specifically set by the QAction::iconVisibleInMenu property. Menus that are currently open or menus already created in the native macOS menubar may not pick up a change in this attribute. Changes in the QAction::iconVisibleInMenu property will always be picked up.
Qt::AA_DontShowShortcutsInContextMenus