QCPLayer

Inheritance diagram for QCPLayer:

Public Types
enum	LayerMode { lmLogical , lmBuffered }

Public Types inherited from QObject
typedef	QObjectList

Public Member Functions
	QCPLayer (QCustomPlot *parentPlot, const QString &layerName)

QList< QCPLayerable * >	children () const

int	index () const

LayerMode	mode () const

QString	name () const

QCustomPlot *	parentPlot () const

void	replot ()

void	setMode (LayerMode mode)

void	setVisible (bool visible)

bool	visible () const

Public Member Functions inherited from QObject
	QObject (QObject *parent)

QBindable< QString >	bindableObjectName ()

bool	blockSignals (bool block)

const QObjectList &	children () const const

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *method, Qt::ConnectionType type) const const

void	deleteLater ()

void	destroyed (QObject *obj)

bool	disconnect (const char signal, const QObject receiver, const char *method) const const

bool	disconnect (const QObject receiver, const char method) const const

void	dumpObjectInfo () const const

void	dumpObjectTree () const const

QList< QByteArray >	dynamicPropertyNames () const const

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

T	findChild (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (Qt::FindChildOptions options) const const

bool	inherits (const char *className) const const

void	installEventFilter (QObject *filterObj)

bool	isQuickItemType () const const

bool	isWidgetType () const const

bool	isWindowType () const const

void	killTimer (int id)

virtual const QMetaObject *	metaObject () const const

void	moveToThread (QThread *targetThread)

QString	objectName () const const

void	objectNameChanged (const QString &objectName)

QObject *	parent () const const

QVariant	property (const char *name) const const

	Q_CLASSINFO (Name, Value)

	Q_EMIT Q_EMIT

	Q_ENUM (...)

	Q_ENUM_NS (...)

	Q_ENUMS (...)

	Q_FLAG (...)

	Q_FLAG_NS (...)

	Q_FLAGS (...)

	Q_GADGET Q_GADGET

	Q_GADGET_EXPORT (EXPORT_MACRO)

	Q_INTERFACES (...)

	Q_INVOKABLE Q_INVOKABLE

	Q_MOC_INCLUDE Q_MOC_INCLUDE

	Q_NAMESPACE Q_NAMESPACE

	Q_NAMESPACE_EXPORT (EXPORT_MACRO)

	Q_OBJECT Q_OBJECT

	Q_PROPERTY (...)

	Q_REVISION Q_REVISION

	Q_SET_OBJECT_NAME (Object)

	Q_SIGNAL Q_SIGNAL

	Q_SIGNALS Q_SIGNALS

	Q_SLOT Q_SLOT

	Q_SLOTS Q_SLOTS

T	qobject_cast (const QObject *object)

T	qobject_cast (QObject *object)

	QT_NO_NARROWING_CONVERSIONS_IN_CONNECT QT_NO_NARROWING_CONVERSIONS_IN_CONNECT

void	removeEventFilter (QObject *obj)

void	setObjectName (const QString &name)

void	setObjectName (QAnyStringView name)

void	setParent (QObject *parent)

bool	setProperty (const char *name, const QVariant &value)

bool	setProperty (const char *name, QVariant &&value)

bool	signalsBlocked () const const

int	startTimer (int interval, Qt::TimerType timerType)

int	startTimer (std::chrono::milliseconds interval, Qt::TimerType timerType)

QThread *	thread () const const

Protected Member Functions
void	addChild (QCPLayerable *layerable, bool prepend)

void	draw (QCPPainter *painter)

void	drawToPaintBuffer ()

void	removeChild (QCPLayerable *layerable)

Protected Member Functions inherited from QObject
virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const QMetaMethod &signal)

bool	isSignalConnected (const QMetaMethod &signal) const const

int	receivers (const char *signal) const const

QObject *	sender () const const

int	senderSignalIndex () const const

virtual void	timerEvent (QTimerEvent *event)

Protected Attributes
QList< QCPLayerable * >	mChildren

int	mIndex

LayerMode	mMode

QString	mName

QWeakPointer< QCPAbstractPaintBuffer >	mPaintBuffer

QCustomPlot *	mParentPlot

bool	mVisible

Additional Inherited Members
Properties inherited from QObject
	objectName

Static Public Member Functions inherited from QObject
QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject context, Functor functor, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)

bool	disconnect (const QMetaObject::Connection &connection)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method)

bool	disconnect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method)

QString	tr (const char sourceText, const char disambiguation, int n)

Detailed Description

A layer that may contain objects, to control the rendering order.

The Layering system of QCustomPlot is the mechanism to control the rendering order of the elements inside the plot.

It is based on the two classes QCPLayer and QCPLayerable. QCustomPlot holds an ordered list of one or more instances of QCPLayer (see QCustomPlot::addLayer, QCustomPlot::layer, QCustomPlot::moveLayer, etc.). When replotting, QCustomPlot goes through the list of layers bottom to top and successively draws the layerables of the layers into the paint buffer(s).

A QCPLayer contains an ordered list of QCPLayerable instances. QCPLayerable is an abstract base class from which almost all visible objects derive, like axes, grids, graphs, items, etc.

Default layers

Initially, QCustomPlot has six layers: "background", "grid", "main", "axes", "legend" and "overlay" (in that order). On top is the "overlay" layer, which only contains the QCustomPlot's selection rect (QCustomPlot::selectionRect). The next two layers "axes" and "legend" contain the default axes and legend, so they will be drawn above plottables. In the middle, there is the "main" layer. It is initially empty and set as the current layer (see QCustomPlot::setCurrentLayer). This means, all new plottables, items etc. are created on this layer by default. Then comes the "grid" layer which contains the QCPGrid instances (which belong tightly to QCPAxis, see QCPAxis::grid). The Axis rect background shall be drawn behind everything else, thus the default QCPAxisRect instance is placed on the "background" layer. Of course, the layer affiliation of the individual objects can be changed as required (QCPLayerable::setLayer).

Controlling the rendering order via layers

Controlling the ordering of layerables in the plot is easy: Create a new layer in the position you want the layerable to be in, e.g. above "main", with QCustomPlot::addLayer. Then set the current layer with QCustomPlot::setCurrentLayer to that new layer and finally create the objects normally. They will be placed on the new layer automatically, due to the current layer setting. Alternatively you could have also ignored the current layer setting and just moved the objects with QCPLayerable::setLayer to the desired layer after creating them.

It is also possible to move whole layers. For example, If you want the grid to be shown in front of all plottables/items on the "main" layer, just move it above "main" with QCustomPlot::moveLayer.

The rendering order within one layer is simply by order of creation or insertion. The item created last (or added last to the layer), is drawn on top of all other objects on that layer.

When a layer is deleted, the objects on it are not deleted with it, but fall on the layer below the deleted layer, see QCustomPlot::removeLayer.

Replotting only a specific layer

If the layer mode (setMode) is set to lmBuffered, you can replot only this specific layer by calling replot. In certain situations this can provide better replot performance, compared with a full replot of all layers. Upon creation of a new layer, the layer mode is initialized to lmLogical. The only layer that is set to lmBuffered in a new QCustomPlot instance is the "overlay" layer, containing the selection rect.

Definition at line 682 of file qcustomplot.h.

Member Enumeration Documentation

◆ LayerMode

enum QCPLayer::LayerMode

Defines the different rendering modes of a layer. Depending on the mode, certain layers can be replotted individually, without the need to replot (possibly complex) layerables on other layers.

See also: setMode

Enumerator
lmLogical	Layer is used only for rendering order, and shares paint buffer with all other adjacent logical layers.
lmBuffered	Layer has its own paint buffer and may be replotted individually (see replot).

Definition at line 702 of file qcustomplot.h.

Constructor & Destructor Documentation

◆ QCPLayer()

QCPLayer::QCPLayer	(	QCustomPlot *	parentPlot,
		const QString &	layerName )

Creates a new QCPLayer instance.

Normally you shouldn't directly instantiate layers, use QCustomPlot::addLayer instead.

Warning: It is not checked that layerName is actually a unique layer name in parentPlot. This check is only performed by QCustomPlot::addLayer.

Definition at line 1067 of file qcustomplot.cpp.

◆ ~QCPLayer()

QCPLayer::~QCPLayer ( )

virtual

Definition at line 1079 of file qcustomplot.cpp.

Member Function Documentation

◆ addChild()

void QCPLayer::addChild	(	QCPLayerable *	layerable,
		bool	prepend )

protected

Adds the layerable to the list of this layer. If prepend is set to true, the layerable will be prepended to the list, i.e. be drawn beneath the other layerables already in the list.

This function does not change the mLayer member of layerable to this layer. (Use QCPLayerable::setLayer to change the layer of an object, not this function.)

See also: removeChild

Definition at line 1224 of file qcustomplot.cpp.

◆ children()

QList< QCPLayerable * > QCPLayer::children ( ) const

inline

Returns a list of all layerables on this layer. The order corresponds to the rendering order: layerables with higher indices are drawn above layerables with lower indices.

Definition at line 714 of file qcustomplot.h.

◆ draw()

void QCPLayer::draw ( QCPPainter * painter )

protected

Draws the contents of this layer with the provided painter.

See also: replot, drawToPaintBuffer

Definition at line 1143 of file qcustomplot.cpp.

◆ drawToPaintBuffer()

void QCPLayer::drawToPaintBuffer ( )

protected

Draws the contents of this layer into the paint buffer which is associated with this layer. The association is established by the parent QCustomPlot, which manages all paint buffers (see QCustomPlot::setupPaintBuffers).

See also: draw

Definition at line 1166 of file qcustomplot.cpp.

◆ index()

int QCPLayer::index ( ) const

inline

Returns the index this layer has in the QCustomPlot. The index is the integer number by which this layer can be accessed via QCustomPlot::layer.

Layers with higher indices will be drawn above layers with lower indices.

Definition at line 713 of file qcustomplot.h.

◆ mode()

LayerMode QCPLayer::mode ( ) const

inline

Definition at line 716 of file qcustomplot.h.

◆ name()

QString QCPLayer::name ( ) const

inline

Definition at line 712 of file qcustomplot.h.

◆ parentPlot()

QCustomPlot * QCPLayer::parentPlot ( ) const

inline

Definition at line 711 of file qcustomplot.h.

◆ removeChild()

void QCPLayer::removeChild ( QCPLayerable * layerable )

protected

Removes the layerable from the list of this layer.

This function does not change the mLayer member of layerable. (Use QCPLayerable::setLayer to change the layer of an object, not this function.)

See also: addChild

Definition at line 1247 of file qcustomplot.cpp.

◆ replot()

void QCPLayer::replot ( )

If the layer mode (setMode) is set to lmBuffered, this method allows replotting only the layerables on this specific layer, without the need to replot all other layers (as a call to QCustomPlot::replot would do).

QCustomPlot also makes sure to replot all layers instead of only this one, if the layer ordering or any layerable-layer-association has changed since the last full replot and any other paint buffers were thus invalidated.

If the layer mode is lmLogical however, this method simply calls QCustomPlot::replot on the parent QCustomPlot instance.

See also: draw

Definition at line 1198 of file qcustomplot.cpp.

◆ setMode()

void QCPLayer::setMode ( QCPLayer::LayerMode mode )

Sets the rendering mode of this layer.

If mode is set to lmBuffered for a layer, it will be given a dedicated paint buffer by the parent QCustomPlot instance. This means it may be replotted individually by calling QCPLayer::replot, without needing to replot all other layers.

Layers which are set to lmLogical (the default) are used only to define the rendering order and can't be replotted individually.

Note that each layer which is set to lmBuffered requires additional paint buffers for the layers below, above and for the layer itself. This increases the memory consumption and (slightly) decreases the repainting speed because multiple paint buffers need to be joined. So you should carefully choose which layers benefit from having their own paint buffer. A typical example would be a layer which contains certain layerables (e.g. items) that need to be changed and thus replotted regularly, while all other layerables on other layers stay static. By default, only the topmost layer called "overlay" is in mode lmBuffered, and contains the selection rect.

See also: replot

Definition at line 1127 of file qcustomplot.cpp.

◆ setVisible()

void QCPLayer::setVisible ( bool visible )

Sets whether this layer is visible or not. If visible is set to false, all layerables on this layer will be invisible.

This function doesn't change the visibility property of the layerables (QCPLayerable::setVisible), but the QCPLayerable::realVisibility of each layerable takes the visibility of the parent layer into account.

Definition at line 1101 of file qcustomplot.cpp.

◆ visible()

bool QCPLayer::visible ( ) const

inline

Definition at line 715 of file qcustomplot.h.

Member Data Documentation

◆ mChildren

QList<QCPLayerable*> QCPLayer::mChildren

protected

Definition at line 730 of file qcustomplot.h.

◆ mIndex

int QCPLayer::mIndex

protected

Definition at line 729 of file qcustomplot.h.

◆ mMode

LayerMode QCPLayer::mMode

protected

Definition at line 732 of file qcustomplot.h.

◆ mName

QString QCPLayer::mName

protected

Definition at line 728 of file qcustomplot.h.

◆ mPaintBuffer

QWeakPointer<QCPAbstractPaintBuffer> QCPLayer::mPaintBuffer

protected

Definition at line 735 of file qcustomplot.h.

◆ mParentPlot

QCustomPlot* QCPLayer::mParentPlot

protected

Definition at line 727 of file qcustomplot.h.

◆ mVisible

bool QCPLayer::mVisible

protected

Definition at line 731 of file qcustomplot.h.

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

KDE's Doxygen guidelines are available online.

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QCPLayer

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Default layers

Controlling the rendering order via layers

Replotting only a specific layer

Member Enumeration Documentation

◆ LayerMode

Constructor & Destructor Documentation

◆ QCPLayer()

◆ ~QCPLayer()

Member Function Documentation

◆ addChild()

◆ children()

◆ draw()

◆ drawToPaintBuffer()

◆ index()

◆ mode()

◆ name()

◆ parentPlot()

◆ removeChild()

◆ replot()

◆ setMode()

◆ setVisible()

◆ visible()

Member Data Documentation

◆ mChildren

◆ mIndex

◆ mMode

◆ mName

◆ mPaintBuffer

◆ mParentPlot

◆ mVisible