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com.trolltech.qt.gui
Class QStyleOption

java.lang.Object
  extended by com.trolltech.qt.QSignalEmitter
      extended by com.trolltech.qt.QtJambiObject
          extended by com.trolltech.qt.gui.QStyleOption
All Implemented Interfaces:
QtJambiInterface
Direct Known Subclasses:
QStyleOptionButton, QStyleOptionComplex, QStyleOptionDockWidget, QStyleOptionFocusRect, QStyleOptionFrame, QStyleOptionGraphicsItem, QStyleOptionHeader, QStyleOptionMenuItem, QStyleOptionProgressBar, QStyleOptionRubberBand, QStyleOptionTab, QStyleOptionTabBarBase, QStyleOptionTabWidgetFrame, QStyleOptionToolBar, QStyleOptionToolBox, QStyleOptionViewItem

public class QStyleOption
extends QtJambiObject

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() 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_FrameFocusRect) {
            const QStyleOptionFocusRect *focusRectOption =
                    qstyleoption_cast<const QStyleOptionFocusRect *>(option);
            if (focusRectOption) {
                // ...
            }
        }
        // ...
    }

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 Styles example.

See Also:
QStyle, QStylePainter

Nested Class Summary
static class QStyleOption.OptionType
          This enum is used internally by QStyleOption, its subclasses, and qstyleoption_cast() to determine the type of style option.
static class QStyleOption.StyleOptionType
          This enum is used to hold information about the type of the style option, and is defined for each QStyleOption subclass.
static class QStyleOption.StyleOptionVersion
          This enum is used to hold information about the version of the style option, and is defined for each QStyleOption subclass.
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I>
 
Constructor Summary
QStyleOption()
          Equivalent to QStyleOption(QStyleOption::Version, SO_Default).
QStyleOption(int version)
          Equivalent to QStyleOption(version, SO_Default).
QStyleOption(int version, int type)
          Constructs a QStyleOption with the specified version and type.
QStyleOption(QStyleOption other)
          Constructs a copy of other.
 
Method Summary
 Qt.LayoutDirection direction()
          Returns the text layout direction that should be used when drawing text in the control.
 QFontMetrics fontMetrics()
          Returns the font metrics that should be used when drawing text in the control.
static QStyleOption fromNativePointer(QNativePointer nativePointer)
          This function returns the QStyleOption instance pointed to by nativePointer
 void initFrom(QWidget w)
          Initializes the state, direction, rect, palette, and fontMetrics member variables based on the specified w.
static QNativePointer nativePointerArray(QStyleOption[] array)
          This function returns a QNativePointer that is pointing to the specified QStyleOption array.
 QPalette palette()
          Returns the palette that should be used when painting the control.
 QRect rect()
          Returns the area that should be used for various calculations and painting.
 void setDirection(Qt.LayoutDirection direction)
          Sets the text layout direction that should be used when drawing text in the control to direction.
 void setFontMetrics(QFontMetrics fontMetrics)
          Sets the font metrics that should be used when drawing text in the control to fontMetrics.
 void setPalette(QPalette palette)
          Sets the palette that should be used when painting the control to palette.
 void setRect(QRect rect)
          Sets the area that should be used for various calculations and painting to rect.
 void setState(QStyle.State state)
          Sets the style flags that are used when drawing the control to state.
 void setState(QStyle.StateFlag... state)
          Sets the style flags that are used when drawing the control to state.
 void setType(int type)
          Sets the option type of the style option to type.
 void setVersion(int version)
          Sets the version of the style option to version.
 QStyle.State state()
          Returns the style flags that are used when drawing the control.
 int type()
          Returns the option type of the style option.
 int version()
          Returns the version of the style option.
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Constructor Detail

QStyleOption

public QStyleOption(QStyleOption other)

Constructs a copy of other.


QStyleOption

public QStyleOption(int version)

Equivalent to QStyleOption(version, SO_Default).


QStyleOption

public QStyleOption()

Equivalent to QStyleOption(QStyleOption::Version, SO_Default).


QStyleOption

public QStyleOption(int version,
                    int type)

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 state member variable is initialized to QStyle::State_None.

See Also:
version, type
Method Detail

initFrom

public final void initFrom(QWidget w)

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

This is a convenience function; the member variables can also be initialized manually.

See Also:
QWidget::layoutDirection, QWidget::rect, QWidget::palette, QWidget::fontMetrics

setPalette

public final void setPalette(QPalette palette)

Sets the palette that should be used when painting the control to palette.

By default, the application's default palette is used.

See Also:
palette, initFrom

palette

public final QPalette palette()

Returns the palette that should be used when painting the control.

By default, the application's default palette is used.

See Also:
setPalette, initFrom

setVersion

public final void setVersion(int version)

Sets the version of the style option to version.

This value can be used by subclasses to implement extensions without breaking compatibility. If you use the qstyleoption_cast() function, you normally don't need to check it.

The default value is 1.

See Also:
version

version

public final int version()

Returns the version of the style option.

This value can be used by subclasses to implement extensions without breaking compatibility. If you use the qstyleoption_cast() function, you normally don't need to check it.

The default value is 1.

See Also:
setVersion

setDirection

public final void setDirection(Qt.LayoutDirection direction)

Sets the text layout direction that should be used when drawing text in the control to direction.

By default, the layout direction is Qt::LeftToRight.

See Also:
direction, initFrom

direction

public final Qt.LayoutDirection direction()

Returns the text layout direction that should be used when drawing text in the control.

By default, the layout direction is Qt::LeftToRight.

See Also:
setDirection, initFrom

setRect

public final void setRect(QRect rect)

Sets the area that should be used for various calculations and painting to rect.

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

The default value is a null rectangle, i.e. a rectangle with both the width and the height set to 0.

See Also:
rect, initFrom

rect

public final QRect rect()

Returns the area that should be used for various calculations and painting.

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

The default value is a null rectangle, i.e. a rectangle with both the width and the height set to 0.

See Also:
setRect, initFrom

setType

public final void setType(int type)

Sets the option type of the style option to type.

The default value is SO_Default.

See Also:
type, OptionType

type

public final int type()

Returns the option type of the style option.

The default value is SO_Default.

See Also:
setType, OptionType

setState

public final void setState(QStyle.StateFlag... state)

Sets the style flags that are used when drawing the control to state.

The default value is QStyle::State_None.

See Also:
state, initFrom, QStyle::drawPrimitive, QStyle::drawControl, QStyle::drawComplexControl, QStyle::State

setState

public final void setState(QStyle.State state)

Sets the style flags that are used when drawing the control to state.

The default value is QStyle::State_None.

See Also:
state, initFrom, QStyle::drawPrimitive, QStyle::drawControl, QStyle::drawComplexControl, QStyle::State

state

public final QStyle.State state()

Returns the style flags that are used when drawing the control.

The default value is QStyle::State_None.

See Also:
setState, initFrom, QStyle::drawPrimitive, QStyle::drawControl, QStyle::drawComplexControl, QStyle::State

setFontMetrics

public final void setFontMetrics(QFontMetrics fontMetrics)

Sets the font metrics that should be used when drawing text in the control to fontMetrics.

By default, the application's default font is used.

See Also:
fontMetrics, initFrom

fontMetrics

public final QFontMetrics fontMetrics()

Returns the font metrics that should be used when drawing text in the control.

By default, the application's default font is used.

See Also:
setFontMetrics, initFrom

fromNativePointer

public static QStyleOption fromNativePointer(QNativePointer nativePointer)
This function returns the QStyleOption instance pointed to by nativePointer

Parameters:
nativePointer - the QNativePointer of which object should be returned.

nativePointerArray

public static QNativePointer nativePointerArray(QStyleOption[] array)
This function returns a QNativePointer that is pointing to the specified QStyleOption array.

Parameters:
array - the array that the returned pointer will point to.
Returns:
a QNativePointer that is pointing to the specified array.

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