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java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.gui.QStyleOption
public class QStyleOption
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.
Nested Class Summary | |
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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 |
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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 | |
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QStyleOption()
Equivalent to QStyleOption(QStyleOption::Version, SO_Default). |
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QStyleOption(int version)
Equivalent to QStyleOption(version, SO_Default). |
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QStyleOption(int version,
int type)
Constructs a QStyleOption with the specified version and type. |
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QStyleOption(QStyleOption other)
Constructs a copy of other. |
Method Summary | |
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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 |
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dispose, disposed, finalize, reassignNativeResources, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
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blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread |
Methods inherited from class java.lang.Object |
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clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
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disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
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public QStyleOption(QStyleOption other)
Constructs a copy of other.
public QStyleOption(int version)
Equivalent to QStyleOption(version, SO_Default).
public QStyleOption()
Equivalent to QStyleOption(QStyleOption::Version, SO_Default).
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.
Method Detail |
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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.
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.
public final QPalette palette()
Returns the palette that should be used when painting the control.
By default, the application's default palette is used.
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.
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.
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.
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.
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.
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.
public final void setType(int type)
Sets the option type of the style option to type.
The default value is SO_Default.
public final int type()
Returns the option type of the style option.
The default value is SO_Default.
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.
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.
public final QStyle.State state()
Returns the style flags that are used when drawing the control.
The default value is QStyle::State_None.
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.
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.
public static QStyleOption fromNativePointer(QNativePointer nativePointer)
nativePointer
- the QNativePointer of which object should be returned.public static QNativePointer nativePointerArray(QStyleOption[] array)
array
- the array that the returned pointer will point to.
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