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java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.gui.QAbstractGraphicsShapeItem
com.trolltech.qt.gui.QGraphicsSimpleTextItem
public class QGraphicsSimpleTextItem
The QGraphicsSimpleTextItem class provides a simple text path item that you can add to a QGraphicsScene.
To set the item's text, you can either pass a QString to QGraphicsSimpleTextItem's constructor, or call setText to change the text later. To set the text fill color, call setBrush.
The simple text item can have both a fill and an outline; setBrush will set the text fill (i.e., text color), and setPen sets the pen that will be used to draw the text outline. (The latter can be slow, especially for complex pens, and items with long text content.) If all you want is to draw a simple line of text, you should call setBrush only, and leave the pen unset; QGraphicsSimpleTextItem's pen is by default Qt::NoPen.
QGraphicsSimpleTextItem uses the text's formatted size and the associated font to provide a reasonable implementation of boundingRect, shape, and contains. You can set the font by calling setFont.
QGraphicsSimpleText does not display rich text; instead, you can use QGraphicsTextItem, which provides full text control capabilities.
Nested Class Summary | |
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static class |
QGraphicsSimpleTextItem.enum_1
Press link for info on QGraphicsSimpleTextItem.enum_1 |
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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QGraphicsSimpleTextItem()
Equivalent to QGraphicsSimpleTextItem(, 0). |
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QGraphicsSimpleTextItem(QGraphicsItemInterface parent)
Equivalent to QGraphicsSimpleTextItem(parent, 0). |
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QGraphicsSimpleTextItem(QGraphicsItemInterface parent,
QGraphicsScene scene)
Constructs a QGraphicsSimpleTextItem, using parent as the default plain text. |
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QGraphicsSimpleTextItem(java.lang.String text)
Creates a new parentless QGraphicsSimpleTextItem with the specified text. |
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QGraphicsSimpleTextItem(java.lang.String text,
QGraphicsItemInterface parent)
Creates a new QGraphicsSimpleTextItem with the specified text and parent. |
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QGraphicsSimpleTextItem(java.lang.String text,
QGraphicsItemInterface parent,
QGraphicsScene scene)
Creates a new QGraphicsSimpleTextItem with the specified text and parent, and adds it to scene. |
Method Summary | |
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QRectF |
boundingRect()
This pure virtual function defines the outer bounds of the item as a rectangle; all painting must be restricted to inside an item's bounding rect. |
boolean |
contains(QPointF point)
Returns true if this item contains point, which is in local coordinates; otherwise, false is returned. |
java.lang.Object |
extension(java.lang.Object variant)
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QFont |
font()
Returns the font that is used to draw the item's text. |
static QGraphicsSimpleTextItem |
fromNativePointer(QNativePointer nativePointer)
This function returns the QGraphicsSimpleTextItem instance pointed to by nativePointer |
boolean |
isObscuredBy(QGraphicsItemInterface item)
Returns true if this item's bounding rect is completely obscured by the opaque shape of item. The base implementation maps item's opaqueArea to this item's coordinate system, and then checks if this item's boundingRect is fully contained within the mapped shape. You can reimplement this function to provide a custom algorithm for determining whether this item is obscured by item. |
QPainterPath |
opaqueArea()
This virtual function returns a shape representing the area where this item is opaque. An area is opaque if it is filled using an opaque brush or color (i.e., not transparent). This function is used by isObscuredBy, which is called by underlying items to determine if they are obscured by this item. The default implementation returns an empty QPainterPath, indicating that this item is completely transparent and does not obscure any other items. |
void |
paint(QPainter painter,
QStyleOptionGraphicsItem option,
QWidget widget)
This function, which is usually called by QGraphicsView, paints the contents of an item in local coordinates. |
void |
setExtension(QGraphicsItem.Extension extension,
java.lang.Object variant)
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void |
setFont(QFont font)
Sets the font that is used to draw the item's text to font. |
void |
setText(java.lang.String text)
Sets the item's text to text. |
QPainterPath |
shape()
Returns the shape of this item as a QPainterPath in local coordinates. |
boolean |
supportsExtension(QGraphicsItem.Extension extension)
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java.lang.String |
text()
Returns the item's text. |
int |
type()
Returns the type of an item as an int. |
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 QGraphicsSimpleTextItem(java.lang.String text, QGraphicsItemInterface parent)
public QGraphicsSimpleTextItem(java.lang.String text)
public QGraphicsSimpleTextItem(java.lang.String text, QGraphicsItemInterface parent, QGraphicsScene scene)
public QGraphicsSimpleTextItem(QGraphicsItemInterface parent)
Equivalent to QGraphicsSimpleTextItem(parent, 0).
public QGraphicsSimpleTextItem()
Equivalent to QGraphicsSimpleTextItem(, 0).
public QGraphicsSimpleTextItem(QGraphicsItemInterface parent, QGraphicsScene scene)
Constructs a QGraphicsSimpleTextItem, using parent as the default plain text.
scene is passed to QGraphicsItem's constructor.
Method Detail |
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public final QFont font()
Returns the font that is used to draw the item's text.
public final void setFont(QFont font)
Sets the font that is used to draw the item's text to font.
public final void setText(java.lang.String text)
Sets the item's text to text. The text will be displayed as plain text. Newline characters ('\n') as well as characters of type QChar::LineSeparator will cause item to break the text into multiple lines.
public final java.lang.String text()
Returns the item's text.
public QRectF boundingRect()
This pure virtual function defines the outer bounds of the item as a rectangle; all painting must be restricted to inside an item's bounding rect. QGraphicsView uses this to determine whether the item requires redrawing.
Although the item's shape can be arbitrary, the bounding rect is always rectangular, and it is unaffected by the items' transformation (scale, rotate, etc.).
If you want to change the item's bounding rectangle, you must first call prepareGeometryChange. This notifies the scene of the imminent change, so that its can update its item geometry index; otherwise, the scene will be unaware of the item's new geometry, and the results are undefined (typically, rendering artifacts are left around in the view).
Reimplement this function to let QGraphicsView determine what parts of the widget, if any, need to be redrawn.
Note: For shapes that paint an outline / stroke, it is important to include half the pen width in the bounding rect. It is not necessary to compensate for antialiasing, though.
Example:
QRectF CircleItem::boundingRect() const { qreal penWidth = 1; return QRectF(-radius - penWidth / 2, -radius - penWidth / 2, diameter + penWidth, diameter + penWidth); }
boundingRect
in interface QGraphicsItemInterface
boundingRect
in class QAbstractGraphicsShapeItem
public boolean contains(QPointF point)
Returns true if this item contains point, which is in local coordinates; otherwise, false is returned. It is most often called from QGraphicsView to determine what item is under the cursor, and for that reason, the implementation of this function should be as light-weight as possible.
By default, this function calls shape, but you can reimplement it in a subclass to provide a (perhaps more efficient) implementation.
contains
in interface QGraphicsItemInterface
contains
in class QAbstractGraphicsShapeItem
public java.lang.Object extension(java.lang.Object variant)
extension
in interface QGraphicsItemInterface
extension
in class QAbstractGraphicsShapeItem
public boolean isObscuredBy(QGraphicsItemInterface item)
Returns true if this item's bounding rect is completely obscured by the opaque shape of item.
The base implementation maps item's opaqueArea to this item's coordinate system, and then checks if this item's boundingRect is fully contained within the mapped shape.
You can reimplement this function to provide a custom algorithm for determining whether this item is obscured by item.
isObscuredBy
in interface QGraphicsItemInterface
isObscuredBy
in class QAbstractGraphicsShapeItem
public QPainterPath opaqueArea()
This virtual function returns a shape representing the area where this item is opaque. An area is opaque if it is filled using an opaque brush or color (i.e., not transparent).
This function is used by isObscuredBy, which is called by underlying items to determine if they are obscured by this item.
The default implementation returns an empty QPainterPath, indicating that this item is completely transparent and does not obscure any other items.
opaqueArea
in interface QGraphicsItemInterface
opaqueArea
in class QAbstractGraphicsShapeItem
public void paint(QPainter painter, QStyleOptionGraphicsItem option, QWidget widget)
This function, which is usually called by QGraphicsView, paints the contents of an item in local coordinates.
Reimplement this function in a QGraphicsItem subclass to provide the item's painting implementation, using painter. The option parameter provides style options for the item, such as its state, exposed area and its level-of-detail hints. The widget argument is optional. If provided, it points to the widget that is being painted on; otherwise, it is 0.
void RoundRectItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) { painter->drawRoundRect(-10, -10, 20, 20); }
The painter's pen is 0-width by default, and its pen is initialized to the QPalette::Text brush from the paint device's palette. The brush is initialized to QPalette::Window.
All painting is done in local coordinates.
paint
in interface QGraphicsItemInterface
paint
in class QAbstractGraphicsShapeItem
public void setExtension(QGraphicsItem.Extension extension, java.lang.Object variant)
setExtension
in interface QGraphicsItemInterface
setExtension
in class QAbstractGraphicsShapeItem
public QPainterPath shape()
Returns the shape of this item as a QPainterPath in local coordinates. The shape is used for many things, including collision detection, hit tests, and for the QGraphicsScene::items() functions.
The default implementation calls boundingRect to return a simple rectangular shape, but subclasses can reimplement this function to return a more accurate shape for non-rectangular items. For example, a round item may choose to return an elliptic shape for better collision detection. For example:
QPainterPath RoundItem::shape() const { QPainterPath path; path.addEllipse(boundingRect()); return path; }
This function is called by the default implementations of contains and collidesWithPath.
shape
in interface QGraphicsItemInterface
shape
in class QAbstractGraphicsShapeItem
public boolean supportsExtension(QGraphicsItem.Extension extension)
supportsExtension
in interface QGraphicsItemInterface
supportsExtension
in class QAbstractGraphicsShapeItem
public int type()
Returns the type of an item as an int. All standard graphicsitem classes are associated with a unique value; see QGraphicsItem::Type. This type information is used by qgraphicsitem_cast() to distinguish between types.
Reimplementing this function and declaring a Type enum value equal to your custom item's type will enable use of qgraphicsitem_cast() with the item. Custom items must return a value larger than or equal to UserType (65536).
The default implementation (in QGraphicsItem) returns UserType.
type
in interface QGraphicsItemInterface
type
in class QAbstractGraphicsShapeItem
public static QGraphicsSimpleTextItem fromNativePointer(QNativePointer nativePointer)
nativePointer
- the QNativePointer of which object should be returned.
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