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QStyleOption Class Reference
^{[QtGui module]}

The QStyleOption class stores the parameters used by QStyle functions. More...

Inherited by QStyleOptionButton, QStyleOptionComplex, QStyleOptionDockWidget, QStyleOptionFocusRect, QStyleOptionFrame, QStyleOptionHeader, QStyleOptionMenuItem, QStyleOptionProgressBar, QStyleOptionRubberBand, QStyleOptionTab, QStyleOptionTabBarBase, QStyleOptionTabWidgetFrame, QStyleOptionToolBar, QStyleOptionToolBox and QStyleOptionViewItem.

Types

• enum OptionType { SO_Default, SO_FocusRect, SO_Button, SO_Tab, ..., SO_ComplexCustomBase }

Methods

• __init__ (self, int version = QStyleOption.Version, int type = QStyleOption.SO_Default)
• __init__ (self, QStyleOption other)
• init (self, QWidget w)
• initFrom (self, QWidget w)

Members

• Qt.LayoutDirection direction
• QFontMetrics fontMetrics
• QPalette palette
• QRect rect
• QStyle.State state
• int type
• int version

Static Members

• int Type
• int Version

The QStyleOption class stores the parameters used by QStyle functions.

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 low-level feel 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 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:

    void MyPushButton.paintEvent(QPaintEvent *)
    {
        QStyleOptionButton option;
        option.initFrom(this);
        option.state = isDown() ? QStyle.State_Sunken : QStyle.State_Raised;
        if (isDefault())
            option.features |= QStyleOptionButton.DefaultButton;
        option.text = text();
        option.icon = icon();

        QPainter painter(this);
        style().drawControl(QStyle.CE_PushButton, &option, &painter, this);
    }

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<T>() to ensure that the pointer type is correct. For example:

    void MyStyle.drawPrimitive(PrimitiveElement element,
                                const QStyleOption *option,
                                QPainter *painter,
                                const QWidget *widget)
    {
        if (element == PE_FocusRect) {
            const QStyleOptionFocusRect *focusRectOption =
                    qstyleoption_cast<const QStyleOptionFocusRect *>(option);
            if (focusRectOption) {
                ...
            }
        } else {
            ...
        }
    }

qstyleoption_cast<T>() will return 0 if the object to which option points isn't of the correct type.

See also QStyle and QStylePainter.

Type Documentation

QStyleOption.OptionType

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.

Method Documentation

QStyleOption.__init__ (self, int version = QStyleOption.Version, int type = QStyleOption.SO_Default)

Constructs a QStyleOption with version version and type 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 state member variable is initialized to QStyle.State_None.

See also version and type.

QStyleOption.__init__ (self, QStyleOption other)

Constructs a copy of other.

QStyleOption.init (self, QWidget w)

QStyleOption.initFrom (self, QWidget w)

Initializes the state, direction, rect, palette, and fontMetrics member variables based on widget.

This function is provided only for convenience. You can also initialize the variables manually if you want.

This function was introduced in Qt 4.1.

See also QWidget.layoutDirection(), QWidget.rect(), QWidget.palette(), and QWidget.fontMetrics().

Member Documentation

Qt.LayoutDirection direction

This variable holds the text layout direction that should be used when drawing text in the control.

QFontMetrics fontMetrics

This variable holds the font metrics that should be used when drawing text in the control.

QPalette palette

This variable holds the palette that should be used when painting the control.

QRect rect

This variable holds the area that should be used for various calculations and painting.

This can have different meanings for different types of elements. For example, for QStyle.CE_PushButton it would be the rectangle for the entire button, while for QStyle.CE_PushButtonLabel it would be just the area for the push button label.

QStyle.State state

This variable holds the style flags that are used when drawing the control.

See also QStyle.drawPrimitive(), QStyle.drawControl(), QStyle.drawComplexControl(), and QStyle.State.

int Type

This member should be treated as a constant.

Equals SO_Default.

int type

int Version

This member should be treated as a constant.

Equals 1.

int version