Digikam::DImgChildItem Class Reference

Inheritance diagram for Digikam::DImgChildItem:

Signals
void	geometryChanged ()
void	geometryOnImageChanged ()
void	positionChanged ()
	These signals are emitted in any case when the geometry changed: Either after changing the geometry relative to the original image, or when the size of the parent GraphicsDImgItem changed (zooming).
void	positionOnImageChanged ()
	These signals are emitted when the geometry, relative to the original image, of this item has changed.
void	sizeChanged ()
void	sizeOnImageChanged ()

Public Member Functions
	DImgChildItem (QGraphicsItem *const parent=nullptr)
	This is a base class for items that are positioned on top of a GraphicsDImgItem, positioned in relative coordinates, i.e.
QRectF	boundingRect () const override
	Reimplemented.
void	moveBy (qreal dx, qreal dy)
QPoint	originalPos () const
QRect	originalRect () const
QSize	originalSize () const
GraphicsDImgItem *	parentDImgItem () const
	If the parent item is a GraphicsDImgItem, return it, if the parent item is null or of a different class, returns nullptr.
QRectF	rect () const
QPointF	relativePos () const
QRectF	relativeRect () const
QSizeF	relativeSize () const
void	setOriginalPos (const QPointF &posInOriginal)
	Sets the position and size of this item, in coordinates of the original image.
void	setOriginalPos (qreal x, qreal y)
void	setOriginalRect (const QRectF &rect)
void	setOriginalRect (qreal x, qreal y, qreal width, qreal height)
void	setOriginalSize (const QSizeF &sizeInOriginal)
void	setOriginalSize (qreal width, qreal height)
void	setPos (const QPointF &zoomedPos)
	Sets the position and size of this item, in coordinates of the parent DImg item.
void	setPos (qreal x, qreal y)
void	setRect (const QRectF &rect)
void	setRect (qreal x, qreal y, qreal width, qreal height)
void	setRectInSceneCoordinates (const QRectF &rect)
	Equivalent to mapping the scene coordinates to the parent item, and calling setRect().
void	setRelativePos (const QPointF &relativePosition)
	Sets the position and size of this item, relative to the DImg displayed in the parent item.
void	setRelativePos (qreal x, qreal y)
void	setRelativeRect (const QRectF &rect)
void	setRelativeRect (qreal x, qreal y, qreal width, qreal height)
void	setRelativeSize (const QSizeF &relativeSize)
void	setRelativeSize (qreal width, qreal height)
void	setSize (const QSizeF &zoomedSize)
void	setSize (qreal width, qreal height)
QSizeF	size () const

Protected Slots
void	imageSizeChanged (const QSizeF &)

Protected Member Functions
QVariant	itemChange (GraphicsItemChange change, const QVariant &value) override

Constructor & Destructor Documentation

DImgChildItem()

Digikam::DImgChildItem::DImgChildItem ( QGraphicsItem *const parent = nullptr )

explicit

[0;1], on the image. From the set relative size, the boundingRect() is calculated.

This is a simple example. Just create new SimpleRectChildItem(item); where item is a GrahpicsDImgItem, and at the center of the image, a rectangle of 1% the size of the image will be drawn.

class SimpleRectChildItem : public DImgChildItem { public:

SimpleRectChildItem(QGraphicsItem* const parent)
    : DImgChildItem(parent)
{
    setRelativePos(0.5, 0.5);
    setRelativeSize(0.01, 0.01);
}

void paint(QPainter* painter, const QStyleOptionGraphicsItem*, QWidget*)
{
    painter->setPen(Qt::red);
    painter->drawRect(boundingRect());
}

};

Member Function Documentation

boundingRect()

QRectF Digikam::DImgChildItem::boundingRect ( ) const

override

Returns

a rectangle starting at (0,0) (pos() in parent coordinates) and has a size determined by the relative size.

originalRect()

QRect Digikam::DImgChildItem::originalRect

(

)

const

Returns

the position and size in coordinates of the original image.

Note

the return value is integer based. At high zoom rates, different values of relativeRect() or zoomedRect() may result in the same originalRect(), when one pixel in the original is represented by more than one pixel on screen.

positionChanged

void Digikam::DImgChildItem::positionChanged ( )

signal

positionChanged() is equivalent to listening to xChanged() and yChanged().

positionOnImageChanged

void Digikam::DImgChildItem::positionOnImageChanged ( )

signal

This happens by calling any of the methods above.

rect()

QRectF Digikam::DImgChildItem::rect

(

)

const

Returns

position and size of this item, in coordinates of the parent DImg with the current zoom. This is the same result as QRectF(pos(), boundingRect()), boundingRect is virtual and may be overridden by base classes.

relativeRect()

QRectF Digikam::DImgChildItem::relativeRect

(

)

const

Returns

the position and size relative to the DImg displayed in the parent item. All four values are in the interval [0-1].

setOriginalPos()

void Digikam::DImgChildItem::setOriginalPos

(

const QPointF &

posInOriginal

)

Requires a valid parent item.

setPos()

void Digikam::DImgChildItem::setPos

(

const QPointF &

zoomedPos

)

This is accepting unscaled parent coordinates, just like the "normal" setPos() does. Requires a valid parent item.

setRelativePos()

void Digikam::DImgChildItem::setRelativePos

(

const QPointF &

relativePosition

)

The values of

Parameters

relativePosition

must be in the interval [0-1].