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java.lang.Objectcom.trolltech.qt.internal.QSignalEmitterInternal
com.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:
public void paintEvent(QPaintEvent event) { QStyleOptionButton optioni = new QStyleOptionButton(); option.initFrom(this); option.state() = isDown() ? QStyle.State.State_Sunken : QStyle.State.State_Raised; if (isDefault()) option.features().setFlag(QStyleOptionButton.ButtonFeature.DefaultButton); option.setText(text()); option.setIcon(icon()); QPainter painter = new QPainter(this); style().drawControl(QStyle.ControlElement.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 drawPrimitive(QStyle.PrimitiveElement element, QStyleOption option, QPainter painter, QWidget widget) { if (element.equals(PrimitiveElement.PE_FrameFocusRect)) { QStyleOptionFocusRect focusRectOption = (QStyleOptionFocusRect) option; if (focusRectOption != null) { // ... } } // ... }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.
QStyle
, and 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, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9 |
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal |
Field Summary |
---|
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
currentSender |
Constructor Summary | |
---|---|
QStyleOption()
Constructs a QStyleOption with the specified version and type. |
|
QStyleOption(int version)
Constructs a QStyleOption with the specified version and type. |
|
QStyleOption(int version,
int type)
Constructs a QStyleOption with the specified version and type. |
|
QStyleOption(QStyleOption other)
Constructs a copy of other. |
Method Summary | |
---|---|
QStyleOption |
clone()
This method is reimplemented for internal reasons |
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. |
void |
initFrom(QWidget w)
Initializes the state, direction, rect, palette, and fontMetrics member variables based on the specified widget. |
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. |
void |
setDirection(Qt.LayoutDirection direction)
This variable holds the text layout direction that should be used when drawing text in the control. |
void |
setFontMetrics(QFontMetrics fontMetrics)
This variable holds the font metrics that should be used when drawing text in the control. |
void |
setPalette(QPalette palette)
This variable holds the palette that should be used when painting the control. |
void |
setRect(QRect rect)
This variable holds the area that should be used for various calculations and painting. |
void |
setState(QStyle.State state)
This variable holds the style flags that are used when drawing the control. |
void |
setType(int type)
This variable holds the option type of the style option. |
void |
setVersion(int version)
This variable holds the version of the style option. |
QStyle.State |
state()
This variable holds the style flags that are used when drawing the control. |
int |
type()
This variable holds the option type of the style option. |
int |
version()
This variable holds the version of the style option. |
Methods inherited from class com.trolltech.qt.QtJambiObject |
---|
dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr |
Methods inherited from class com.trolltech.qt.QSignalEmitter |
---|
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread |
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal |
---|
__qt_signalInitialization |
Methods inherited from class java.lang.Object |
---|
getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface com.trolltech.qt.QtJambiInterface |
---|
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership |
Constructor Detail |
---|
public QStyleOption(QStyleOption other)
public QStyleOption(int version)
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
.
public QStyleOption()
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
.
public QStyleOption(int version, int type)
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 |
---|
public final void initFrom(QWidget w)
This is a convenience function; the member variables can also be initialized manually.
QWidget::layoutDirection()
, QWidget::rect()
, QWidget::palette()
, and QWidget::fontMetrics()
.
public final void setPalette(QPalette palette)
initFrom()
.
public final QPalette palette()
initFrom()
.
public final void setVersion(int version)
The default value is 1.
public final int version()
The default value is 1.
public final void setDirection(Qt.LayoutDirection direction)
Qt::LeftToRight
. initFrom()
.
public final Qt.LayoutDirection direction()
Qt::LeftToRight
. initFrom()
.
public final void setRect(QRect rect)
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.
initFrom()
.
public final QRect rect()
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.
initFrom()
.
public final void setType(int type)
SO_Default
. OptionType
.
public final int type()
SO_Default
. OptionType
.
public final void setState(QStyle.State state)
QStyle::State_None
. initFrom()
, QStyle::drawPrimitive()
, QStyle::drawControl()
, QStyle::drawComplexControl()
, and QStyle::State.
public final QStyle.State state()
QStyle::State_None
. initFrom()
, QStyle::drawPrimitive()
, QStyle::drawControl()
, QStyle::drawComplexControl()
, and QStyle::State.
public final void setFontMetrics(QFontMetrics fontMetrics)
initFrom()
.
public final QFontMetrics fontMetrics()
initFrom()
.
public QStyleOption clone()
clone
in class java.lang.Object
|
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