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QCPItemStraightLine Class Reference

A straight line that spans infinitely in both directions. More...

Inheritance diagram for QCPItemStraightLine:
Inheritance graph

Public Functions

 QCPItemStraightLine (QCustomPlot *parentPlot)
QPen pen () const
QPen selectedPen () const
void setPen (const QPen &pen)
void setSelectedPen (const QPen &pen)
virtual double selectTest (const QPointF &pos, bool onlySelectable, QVariant *details=0) const
- Public Functions inherited from QCPAbstractItem
 QCPAbstractItem (QCustomPlot *parentPlot)
bool clipToAxisRect () const
QCPAxisRectclipAxisRect () const
bool selectable () const
bool selected () const
void setClipToAxisRect (bool clip)
void setClipAxisRect (QCPAxisRect *rect)
Q_SLOT void setSelectable (bool selectable)
Q_SLOT void setSelected (bool selected)
QList< QCPItemPosition * > positions () const
QList< QCPItemAnchor * > anchors () const
QCPItemPositionposition (const QString &name) const
QCPItemAnchoranchor (const QString &name) const
bool hasAnchor (const QString &name) const
- Public Functions inherited from QCPLayerable
 QCPLayerable (QCustomPlot *plot, QString targetLayer=QString(), QCPLayerable *parentLayerable=0)
bool visible () const
QCustomPlotparentPlot () const
QCPLayerableparentLayerable () const
QCPLayerlayer () const
bool antialiased () const
void setVisible (bool on)
Q_SLOT bool setLayer (QCPLayer *layer)
bool setLayer (const QString &layerName)
void setAntialiased (bool enabled)
bool realVisibility () const

Public Members

QCPItemPosition *const point1
QCPItemPosition *const point2

Protected Functions

virtual void draw (QCPPainter *painter)
QLineF getRectClippedStraightLine (const QCPVector2D &point1, const QCPVector2D &vec, const QRect &rect) const
QPen mainPen () const
- Protected Functions inherited from QCPAbstractItem
virtual QCP::Interaction selectionCategory () const
virtual QRect clipRect () const
virtual void applyDefaultAntialiasingHint (QCPPainter *painter) const
virtual void selectEvent (QMouseEvent *event, bool additive, const QVariant &details, bool *selectionStateChanged)
virtual void deselectEvent (bool *selectionStateChanged)
virtual QPointF anchorPixelPosition (int anchorId) const
double rectDistance (const QRectF &rect, const QPointF &pos, bool filledRect) const
QCPItemPositioncreatePosition (const QString &name)
QCPItemAnchorcreateAnchor (const QString &name, int anchorId)
- Protected Functions inherited from QCPLayerable
virtual void parentPlotInitialized (QCustomPlot *parentPlot)
virtual void mousePressEvent (QMouseEvent *event, const QVariant &details)
virtual void mouseMoveEvent (QMouseEvent *event, const QPointF &startPos)
virtual void mouseReleaseEvent (QMouseEvent *event, const QPointF &startPos)
virtual void mouseDoubleClickEvent (QMouseEvent *event, const QVariant &details)
virtual void wheelEvent (QWheelEvent *event)
void initializeParentPlot (QCustomPlot *parentPlot)
void setParentLayerable (QCPLayerable *parentLayerable)
bool moveToLayer (QCPLayer *layer, bool prepend)
void applyAntialiasingHint (QCPPainter *painter, bool localAntialiased, QCP::AntialiasedElement overrideElement) const

Additional Inherited Members

- Signals inherited from QCPAbstractItem
void selectionChanged (bool selected)
void selectableChanged (bool selectable)
- Signals inherited from QCPLayerable
void layerChanged (QCPLayer *newLayer)

Detailed Description

A straight line that spans infinitely in both directions.

Straight line example. Blue dotted circles are anchors, solid blue discs are positions.

It has two positions, point1 and point2, which define the straight line.

Constructor & Destructor Documentation

§ QCPItemStraightLine()

QCPItemStraightLine::QCPItemStraightLine ( QCustomPlot parentPlot)

Creates a straight line item and sets default values.

The created item is automatically registered with parentPlot. This QCustomPlot instance takes ownership of the item, so do not delete it manually but use QCustomPlot::removeItem() instead.

Member Function Documentation

§ setPen()

void QCPItemStraightLine::setPen ( const QPen &  pen)

Sets the pen that will be used to draw the line

See also

§ setSelectedPen()

void QCPItemStraightLine::setSelectedPen ( const QPen &  pen)

Sets the pen that will be used to draw the line when selected

See also
setPen, setSelected

§ selectTest()

double QCPItemStraightLine::selectTest ( const QPointF &  pos,
bool  onlySelectable,
QVariant *  details = 0 
) const

This function is used to decide whether a click hits a layerable object or not.

pos is a point in pixel coordinates on the QCustomPlot surface. This function returns the shortest pixel distance of this point to the object. If the object is either invisible or the distance couldn't be determined, -1.0 is returned. Further, if onlySelectable is true and the object is not selectable, -1.0 is returned, too.

If the object is represented not by single lines but by an area like a QCPItemText or the bars of a QCPBars plottable, a click inside the area should also be considered a hit. In these cases this function thus returns a constant value greater zero but still below the parent plot's selection tolerance. (typically the selectionTolerance multiplied by 0.99).

Providing a constant value for area objects allows selecting line objects even when they are obscured by such area objects, by clicking close to the lines (i.e. closer than 0.99*selectionTolerance).

The actual setting of the selection state is not done by this function. This is handled by the parent QCustomPlot when the mouseReleaseEvent occurs, and the finally selected object is notified via the selectEvent/deselectEvent methods.

details is an optional output parameter. Every layerable subclass may place any information in details. This information will be passed to selectEvent when the parent QCustomPlot decides on the basis of this selectTest call, that the object was successfully selected. The subsequent call to selectEvent will carry the details. This is useful for multi-part objects (like QCPAxis). This way, a possibly complex calculation to decide which part was clicked is only done once in selectTest. The result (i.e. the actually clicked part) can then be placed in details. So in the subsequent selectEvent, the decision which part was selected doesn't have to be done a second time for a single selection operation.

You may pass 0 as details to indicate that you are not interested in those selection details.

See also
selectEvent, deselectEvent, mousePressEvent, wheelEvent, QCustomPlot::setInteractions

Implements QCPAbstractItem.

§ draw()

void QCPItemStraightLine::draw ( QCPPainter painter)

Draws this item with the provided painter.

The cliprect of the provided painter is set to the rect returned by clipRect before this function is called. The clipRect depends on the clipping settings defined by setClipToAxisRect and setClipAxisRect.

Implements QCPAbstractItem.

§ getRectClippedStraightLine()

QLineF QCPItemStraightLine::getRectClippedStraightLine ( const QCPVector2D base,
const QCPVector2D vec,
const QRect &  rect 
) const

Returns the section of the straight line defined by base and direction vector vec, that is visible in the specified rect.

This is a helper function for draw.

§ mainPen()

QPen QCPItemStraightLine::mainPen ( ) const

Returns the pen that should be used for drawing lines. Returns mPen when the item is not selected and mSelectedPen when it is.

The documentation for this class was generated from the following files: