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com.trolltech.qt.gui
Class QGraphicsSimpleTextItem

java.lang.Object
  extended by com.trolltech.qt.QSignalEmitter
      extended by com.trolltech.qt.QtJambiObject
          extended by com.trolltech.qt.gui.QAbstractGraphicsShapeItem
              extended by com.trolltech.qt.gui.QGraphicsSimpleTextItem
All Implemented Interfaces:
QGraphicsItemInterface, QtJambiInterface

public class QGraphicsSimpleTextItem
extends QAbstractGraphicsShapeItem

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.

See Also:
QGraphicsTextItem, QGraphicsPathItem, QGraphicsRectItem, QGraphicsEllipseItem, QGraphicsPixmapItem, QGraphicsPolygonItem, QGraphicsLineItem, The Graphics View Framework

Nested Class Summary
static class QGraphicsSimpleTextItem.enum_1
          Press link for info on QGraphicsSimpleTextItem.enum_1
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
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
QGraphicsSimpleTextItem()
          Equivalent to QGraphicsSimpleTextItem(, 0).
QGraphicsSimpleTextItem(QGraphicsItemInterface parent)
          Equivalent to QGraphicsSimpleTextItem(parent, 0).
QGraphicsSimpleTextItem(QGraphicsItemInterface parent, QGraphicsScene scene)
          Constructs a QGraphicsSimpleTextItem, using parent as the default plain text.
QGraphicsSimpleTextItem(java.lang.String text)
          Creates a new parentless QGraphicsSimpleTextItem with the specified text.
QGraphicsSimpleTextItem(java.lang.String text, QGraphicsItemInterface parent)
          Creates a new QGraphicsSimpleTextItem with the specified text and parent.
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
 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)
          

 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)
          
 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)
          
 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.gui.QAbstractGraphicsShapeItem
acceptDrops, acceptedMouseButtons, acceptsHoverEvents, addToIndex, advance, brush, childItems, childrenBoundingRect, clearFocus, collidesWithItem, collidesWithPath, collidingItems, contextMenuEvent, cursor, data, deviceTransform, dragEnterEvent, dragLeaveEvent, dragMoveEvent, dropEvent, ensureVisible, ensureVisible, flags, focusInEvent, focusOutEvent, group, handlesChildEvents, hasCursor, hasFocus, hide, hoverEnterEvent, hoverLeaveEvent, hoverMoveEvent, inputMethodEvent, inputMethodQuery, installSceneEventFilter, isAncestorOf, isEnabled, isObscured, isObscured, isObscured, isSelected, isVisible, itemChange, keyPressEvent, keyReleaseEvent, mapFromItem, mapFromItem, mapFromItem, mapFromItem, mapFromItem, mapFromItem, mapFromParent, mapFromParent, mapFromParent, mapFromParent, mapFromParent, mapFromParent, mapFromScene, mapFromScene, mapFromScene, mapFromScene, mapFromScene, mapFromScene, mapToItem, mapToItem, mapToItem, mapToItem, mapToItem, mapToItem, mapToParent, mapToParent, mapToParent, mapToParent, mapToParent, mapToParent, mapToScene, mapToScene, mapToScene, mapToScene, mapToScene, mapToScene, mouseDoubleClickEvent, mouseMoveEvent, mousePressEvent, mouseReleaseEvent, moveBy, parentItem, pen, pos, prepareGeometryChange, removeFromIndex, removeSceneEventFilter, resetTransform, rotate, scale, scene, sceneBoundingRect, sceneEvent, sceneEventFilter, scenePos, sceneTransform, setAcceptDrops, setAcceptedMouseButtons, setAcceptsHoverEvents, setBrush, setCursor, setData, setEnabled, setFlag, setFlags, setFocus, setGroup, setHandlesChildEvents, setParentItem, setPen, setPos, setPos, setSelected, setToolTip, setTransform, setVisible, setZValue, shear, show, toolTip, topLevelItem, transform, translate, unsetCursor, update, update, wheelEvent, x, y, zValue
 
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

QGraphicsSimpleTextItem

public QGraphicsSimpleTextItem(java.lang.String text,
                               QGraphicsItemInterface parent)
Creates a new QGraphicsSimpleTextItem with the specified text and parent.


QGraphicsSimpleTextItem

public QGraphicsSimpleTextItem(java.lang.String text)
Creates a new parentless QGraphicsSimpleTextItem with the specified text.


QGraphicsSimpleTextItem

public QGraphicsSimpleTextItem(java.lang.String text,
                               QGraphicsItemInterface parent,
                               QGraphicsScene scene)
Creates a new QGraphicsSimpleTextItem with the specified text and parent, and adds it to scene.


QGraphicsSimpleTextItem

public QGraphicsSimpleTextItem(QGraphicsItemInterface parent)

Equivalent to QGraphicsSimpleTextItem(parent, 0).


QGraphicsSimpleTextItem

public QGraphicsSimpleTextItem()

Equivalent to QGraphicsSimpleTextItem(, 0).


QGraphicsSimpleTextItem

public QGraphicsSimpleTextItem(QGraphicsItemInterface parent,
                               QGraphicsScene scene)

Constructs a QGraphicsSimpleTextItem, using parent as the default plain text.

scene is passed to QGraphicsItem's constructor.

See Also:
QGraphicsScene::addItem
Method Detail

font

public final QFont font()

Returns the font that is used to draw the item's text.

See Also:
setFont

setFont

public final void setFont(QFont font)

Sets the font that is used to draw the item's text to font.

See Also:
font

setText

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.

See Also:
text

text

public final java.lang.String text()

Returns the item's text.

See Also:
setText

boundingRect

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);
    }

Specified by:
boundingRect in interface QGraphicsItemInterface
Specified by:
boundingRect in class QAbstractGraphicsShapeItem
See Also:
shape, contains, The Graphics View Coordinate System, prepareGeometryChange

contains

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.

Specified by:
contains in interface QGraphicsItemInterface
Overrides:
contains in class QAbstractGraphicsShapeItem
See Also:
shape, boundingRect, collidesWithPath

extension

public java.lang.Object extension(java.lang.Object variant)

Specified by:
extension in interface QGraphicsItemInterface
Overrides:
extension in class QAbstractGraphicsShapeItem
See Also:
setExtension

isObscuredBy

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.

Specified by:
isObscuredBy in interface QGraphicsItemInterface
Overrides:
isObscuredBy in class QAbstractGraphicsShapeItem
See Also:
opaqueArea, isObscured

opaqueArea

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.

Specified by:
opaqueArea in interface QGraphicsItemInterface
Overrides:
opaqueArea in class QAbstractGraphicsShapeItem
See Also:
isObscuredBy, isObscured, shape

paint

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.

Specified by:
paint in interface QGraphicsItemInterface
Specified by:
paint in class QAbstractGraphicsShapeItem

setExtension

public void setExtension(QGraphicsItem.Extension extension,
                         java.lang.Object variant)

Specified by:
setExtension in interface QGraphicsItemInterface
Overrides:
setExtension in class QAbstractGraphicsShapeItem
See Also:
extension

shape

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.

Specified by:
shape in interface QGraphicsItemInterface
Overrides:
shape in class QAbstractGraphicsShapeItem
See Also:
boundingRect, contains, prepareGeometryChange

supportsExtension

public boolean supportsExtension(QGraphicsItem.Extension extension)

Specified by:
supportsExtension in interface QGraphicsItemInterface
Overrides:
supportsExtension in class QAbstractGraphicsShapeItem

type

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.

Specified by:
type in interface QGraphicsItemInterface
Overrides:
type in class QAbstractGraphicsShapeItem

fromNativePointer

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

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

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