QtBase
v6.3.1
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The QStyleOption class stores the parameters used by QStyle functions. More...
#include <qstyleoption.h>
Public Types | |
enum | OptionType { SO_Default , SO_FocusRect , SO_Button , SO_Tab , SO_MenuItem , SO_Frame , SO_ProgressBar , SO_ToolBox , SO_Header , SO_DockWidget , SO_ViewItem , SO_TabWidgetFrame , SO_TabBarBase , SO_RubberBand , SO_ToolBar , SO_GraphicsItem , SO_Complex = 0xf0000 , SO_Slider , SO_SpinBox , SO_ToolButton , SO_ComboBox , SO_TitleBar , SO_GroupBox , SO_SizeGrip , SO_CustomBase = 0xf00 , SO_ComplexCustomBase = 0xf000000 } |
enum | StyleOptionType { Type = SO_Default } |
enum | StyleOptionVersion { Version = 1 } |
Public Member Functions | |
QStyleOption (int version=QStyleOption::Version, int type=SO_Default) | |
QStyleOption (const QStyleOption &other) | |
~QStyleOption () | |
void | initFrom (const QWidget *w) |
QStyleOption & | operator= (const QStyleOption &other) |
Public Attributes | |
int | version |
int | type |
QStyle::State | state |
Qt::LayoutDirection | direction |
QRect | rect |
QFontMetrics | fontMetrics |
QPalette | palette |
QObject * | styleObject |
Related Functions | |
(Note that these are not member functions.) | |
template< typename T > T | qstyleoption_cast (const QStyleOption *option) |
the text of the title bar More... | |
template< typename T > T | qstyleoption_cast (QStyleOption *option) |
The QStyleOption class stores the parameters used by QStyle functions.
\inmodule QtWidgets
QStyleOption and its subclasses contain all the information that QStyle functions need to draw a graphical element.
For performance reasons, there are few member functions and the access to the member variables is direct (i.e., using the . or
->
operator). This makes the structures straightforward to use and emphasizes that these are simply parameters used by the style functions.
The caller of a QStyle function usually creates QStyleOption objects on the stack. This combined with Qt's extensive use of \l{implicit sharing} for types such as QString, QPalette, and QColor ensures that no memory allocation needlessly takes place.
The following code snippet shows how to use a specific QStyleOption subclass to paint a push button:
In our example, the control is a QStyle::CE_PushButton, and according to the QStyle::drawControl() documentation the corresponding class is QStyleOptionButton.
When reimplementing QStyle functions that take a QStyleOption parameter, you often need to cast the QStyleOption to a subclass. For safety, you can use qstyleoption_cast() to ensure that the pointer type is correct. For example:
The qstyleoption_cast() function will return 0 if the object to which option
points is not of the correct type.
For an example demonstrating how style options can be used, see the \l {widgets/styles}{Styles} example.
Definition at line 74 of file qstyleoption.h.
This enum is used internally by QStyleOption, its subclasses, and qstyleoption_cast() to determine the type of style option. In general you do not need to worry about this unless you want to create your own QStyleOption subclass and your own styles.
\value SO_Button \l QStyleOptionButton \value SO_ComboBox \l QStyleOptionComboBox \value SO_Complex \l QStyleOptionComplex \value SO_Default QStyleOption \value SO_DockWidget \l QStyleOptionDockWidget \value SO_FocusRect \l QStyleOptionFocusRect \value SO_Frame \l QStyleOptionFrame \value SO_GraphicsItem \l QStyleOptionGraphicsItem \value SO_GroupBox \l QStyleOptionGroupBox \value SO_Header \l QStyleOptionHeader \value SO_MenuItem \l QStyleOptionMenuItem \value SO_ProgressBar \l QStyleOptionProgressBar \value SO_RubberBand \l QStyleOptionRubberBand \value SO_SizeGrip \l QStyleOptionSizeGrip \value SO_Slider \l QStyleOptionSlider \value SO_SpinBox \l QStyleOptionSpinBox \value SO_Tab \l QStyleOptionTab \value SO_TabBarBase \l QStyleOptionTabBarBase \value SO_TabWidgetFrame \l QStyleOptionTabWidgetFrame \value SO_TitleBar \l QStyleOptionTitleBar \value SO_ToolBar \l QStyleOptionToolBar \value SO_ToolBox \l QStyleOptionToolBox \value SO_ToolButton \l QStyleOptionToolButton \value SO_ViewItem \l QStyleOptionViewItem (used in Interviews)
The following values are used for custom controls:
\value SO_CustomBase Reserved for custom QStyleOptions; all custom controls values must be above this value \value SO_ComplexCustomBase Reserved for custom QStyleOptions; all custom complex controls values must be above this value
Definition at line 77 of file qstyleoption.h.
This enum is used to hold information about the type of the style option, and is defined for each QStyleOption subclass.
\value Type The type of style option provided (\l{SO_Default} for this class).
The type is used internally by QStyleOption, its subclasses, and qstyleoption_cast() to determine the type of style option. In general you do not need to worry about this unless you want to create your own QStyleOption subclass and your own styles.
Enumerator | |
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Type |
Definition at line 90 of file qstyleoption.h.
This enum is used to hold information about the version of the style option, and is defined for each QStyleOption subclass.
\value Version 1
The version is used by QStyleOption subclasses to implement extensions without breaking compatibility. If you use qstyleoption_cast(), you normally do not need to check it.
Enumerator | |
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Version |
Definition at line 91 of file qstyleoption.h.
QStyleOption::QStyleOption | ( | int | version = QStyleOption::Version , |
int | type = SO_Default |
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Constructs a QStyleOption with the specified version and type.
The version has no special meaning for QStyleOption; it can be used by subclasses to distinguish between different version of the same option type.
The \l state member variable is initialized to QStyle::State_None.
Definition at line 152 of file qstyleoption.cpp.
QStyleOption::QStyleOption | ( | const QStyleOption & | other | ) |
Constructs a copy of other.
Definition at line 220 of file qstyleoption.cpp.
QStyleOption::~QStyleOption | ( | ) |
Destroys this style option object.
Definition at line 162 of file qstyleoption.cpp.
Initializes the \l state, \l direction, \l rect, \l palette, \l fontMetrics and \l styleObject member variables based on the specified widget.
This is a convenience function; the member variables can also be initialized manually.
Definition at line 179 of file qstyleoption.cpp.
QStyleOption & QStyleOption::operator= | ( | const QStyleOption & | other | ) |
Assign other to this QStyleOption.
Definition at line 230 of file qstyleoption.cpp.
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related |
the text of the title bar
\variable QStyleOptionTitleBar::text
The default value is an empty string.
\variable QStyleOptionTitleBar::icon
the icon for the title bar
The default value is an empty icon, i.e. an icon with neither a pixmap nor a filename.
\variable QStyleOptionTitleBar::titleBarState
the state of the title bar
This is basically the window state of the underlying widget. The default value is 0.
\variable QStyleOptionTitleBar::titleBarFlags
the widget flags for the title bar
The default value is Qt::Widget.
Returns a T or \nullptr depending on the \l{QStyleOption::type}{type} and \l{QStyleOption::version}{version} of the given option.
Example:
Definition at line 700 of file qstyleoption.h.
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related |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
Returns a T or \nullptr depending on the type of the given option.
Definition at line 712 of file qstyleoption.h.
Qt::LayoutDirection QStyleOption::direction |
Definition at line 96 of file qstyleoption.h.
QFontMetrics QStyleOption::fontMetrics |
Definition at line 98 of file qstyleoption.h.
QPalette QStyleOption::palette |
Definition at line 99 of file qstyleoption.h.
QRect QStyleOption::rect |
Definition at line 97 of file qstyleoption.h.
QStyle::State QStyleOption::state |
Definition at line 95 of file qstyleoption.h.
QObject* QStyleOption::styleObject |
Definition at line 100 of file qstyleoption.h.
int QStyleOption::type |
Definition at line 94 of file qstyleoption.h.
int QStyleOption::version |
Definition at line 93 of file qstyleoption.h.