QCPLegend Class Reference

Manages a legend inside a QCustomPlot. More...

Inheritance diagram for QCPLegend:

Public Types
enum	SelectablePart

Public Types inherited from QCPLayoutGrid
enum	FillOrder

Public Types inherited from QCPLayoutElement
enum	UpdatePhase

enum	SizeConstraintRect

Public Functions
	QCPLegend ()

QPen	borderPen () const

QBrush	brush () const

QFont	font () const

QColor	textColor () const

QSize	iconSize () const

int	iconTextPadding () const

QPen	iconBorderPen () const

SelectableParts	selectableParts () const

SelectableParts	selectedParts () const

QPen	selectedBorderPen () const

QPen	selectedIconBorderPen () const

QBrush	selectedBrush () const

QFont	selectedFont () const

QColor	selectedTextColor () const

void	setBorderPen (const QPen &pen)

void	setBrush (const QBrush &brush)

void	setFont (const QFont &font)

void	setTextColor (const QColor &color)

void	setIconSize (const QSize &size)

void	setIconSize (int width, int height)

void	setIconTextPadding (int padding)

void	setIconBorderPen (const QPen &pen)

Q_SLOT void	setSelectableParts (const SelectableParts &selectableParts)

Q_SLOT void	setSelectedParts (const SelectableParts &selectedParts)

void	setSelectedBorderPen (const QPen &pen)

void	setSelectedIconBorderPen (const QPen &pen)

void	setSelectedBrush (const QBrush &brush)

void	setSelectedFont (const QFont &font)

void	setSelectedTextColor (const QColor &color)

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

QCPAbstractLegendItem *	item (int index) const

QCPPlottableLegendItem *	itemWithPlottable (const QCPAbstractPlottable *plottable) const

int	itemCount () const

bool	hasItem (QCPAbstractLegendItem *item) const

bool	hasItemWithPlottable (const QCPAbstractPlottable *plottable) const

bool	addItem (QCPAbstractLegendItem *item)

bool	removeItem (int index)

bool	removeItem (QCPAbstractLegendItem *item)

void	clearItems ()

QList< QCPAbstractLegendItem * >	selectedItems () const

Public Functions inherited from QCPLayoutGrid
	QCPLayoutGrid ()

int	rowCount () const

int	columnCount () const

QList< double >	columnStretchFactors () const

QList< double >	rowStretchFactors () const

int	columnSpacing () const

int	rowSpacing () const

int	wrap () const

FillOrder	fillOrder () const

void	setColumnStretchFactor (int column, double factor)

void	setColumnStretchFactors (const QList< double > &factors)

void	setRowStretchFactor (int row, double factor)

void	setRowStretchFactors (const QList< double > &factors)

void	setColumnSpacing (int pixels)

void	setRowSpacing (int pixels)

void	setWrap (int count)

void	setFillOrder (FillOrder order, bool rearrange=true)

virtual void	updateLayout ()

virtual int	elementCount () const

virtual QCPLayoutElement *	elementAt (int index) const

virtual QCPLayoutElement *	takeAt (int index)

virtual bool	take (QCPLayoutElement *element)

virtual QList< QCPLayoutElement * >	elements (bool recursive) const

virtual void	simplify ()

virtual QSize	minimumOuterSizeHint () const

virtual QSize	maximumOuterSizeHint () const

QCPLayoutElement *	element (int row, int column) const

bool	addElement (int row, int column, QCPLayoutElement *element)

bool	addElement (QCPLayoutElement *element)

bool	hasElement (int row, int column)

void	expandTo (int newRowCount, int newColumnCount)

void	insertRow (int newIndex)

void	insertColumn (int newIndex)

int	rowColToIndex (int row, int column) const

void	indexToRowCol (int index, int &row, int &column) const

Public Functions inherited from QCPLayout
	QCPLayout ()

virtual void	update (UpdatePhase phase)

bool	removeAt (int index)

bool	remove (QCPLayoutElement *element)

void	clear ()

Public Functions inherited from QCPLayoutElement
	QCPLayoutElement (QCustomPlot *parentPlot=0)

QCPLayout *	layout () const

QRect	rect () const

QRect	outerRect () const

QMargins	margins () const

QMargins	minimumMargins () const

QCP::MarginSides	autoMargins () const

QSize	minimumSize () const

QSize	maximumSize () const

SizeConstraintRect	sizeConstraintRect () const

QCPMarginGroup *	marginGroup (QCP::MarginSide side) const

QHash< QCP::MarginSide, QCPMarginGroup * >	marginGroups () const

void	setOuterRect (const QRect &rect)

void	setMargins (const QMargins &margins)

void	setMinimumMargins (const QMargins &margins)

void	setAutoMargins (QCP::MarginSides sides)

void	setMinimumSize (const QSize &size)

void	setMinimumSize (int width, int height)

void	setMaximumSize (const QSize &size)

void	setMaximumSize (int width, int height)

void	setSizeConstraintRect (SizeConstraintRect constraintRect)

void	setMarginGroup (QCP::MarginSides sides, QCPMarginGroup *group)

Public Functions inherited from QCPLayerable
	QCPLayerable (QCustomPlot plot, QString targetLayer=QString(), QCPLayerable parentLayerable=0)

bool	visible () const

QCustomPlot *	parentPlot () const

QCPLayerable *	parentLayerable () const

QCPLayer *	layer () 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

Signals
void	selectionChanged (QCPLegend::SelectableParts parts)

void	selectableChanged (QCPLegend::SelectableParts parts)

Signals inherited from QCPLayerable
void	layerChanged (QCPLayer *newLayer)

Protected Functions
virtual void	parentPlotInitialized (QCustomPlot *parentPlot)

virtual QCP::Interaction	selectionCategory () const

virtual void	applyDefaultAntialiasingHint (QCPPainter *painter) const

virtual void	draw (QCPPainter *painter)

virtual void	selectEvent (QMouseEvent event, bool additive, const QVariant &details, bool selectionStateChanged)

virtual void	deselectEvent (bool *selectionStateChanged)

QPen	getBorderPen () const

QBrush	getBrush () const

Protected Functions inherited from QCPLayoutGrid
void	getMinimumRowColSizes (QVector< int > minColWidths, QVector< int > minRowHeights) const

void	getMaximumRowColSizes (QVector< int > maxColWidths, QVector< int > maxRowHeights) const

Protected Functions inherited from QCPLayout
void	sizeConstraintsChanged () const

void	adoptElement (QCPLayoutElement *el)

void	releaseElement (QCPLayoutElement *el)

QVector< int >	getSectionSizes (QVector< int > maxSizes, QVector< int > minSizes, QVector< double > stretchFactors, int totalSize) const

Protected Functions inherited from QCPLayoutElement
virtual int	calculateAutoMargin (QCP::MarginSide side)

virtual void	layoutChanged ()

Protected Functions inherited from QCPLayerable
virtual QRect	clipRect () const

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
Protected Static Functions inherited from QCPLayout
static QSize	getFinalMinimumOuterSize (const QCPLayoutElement *el)

static QSize	getFinalMaximumOuterSize (const QCPLayoutElement *el)

Detailed Description

Manages a legend inside a QCustomPlot.

A legend is a small box somewhere in the plot which lists plottables with their name and icon.

A legend is populated with legend items by calling QCPAbstractPlottable::addToLegend on the plottable, for which a legend item shall be created. In the case of the main legend (QCustomPlot::legend), simply adding plottables to the plot while QCustomPlot::setAutoAddPlottableToLegend is set to true (the default) creates corresponding legend items. The legend item associated with a certain plottable can be removed with QCPAbstractPlottable::removeFromLegend. However, QCPLegend also offers an interface to add and manipulate legend items directly: item, itemWithPlottable, itemCount, addItem, removeItem, etc.

Since QCPLegend derives from QCPLayoutGrid, it can be placed in any position a QCPLayoutElement may be positioned. The legend items are themselves QCPLayoutElements which are placed in the grid layout of the legend. QCPLegend only adds an interface specialized for handling child elements of type QCPAbstractLegendItem, as mentioned above. In principle, any other layout elements may also be added to a legend via the normal QCPLayoutGrid interface. See the special page about The Layout System for examples on how to add other elements to the legend and move it outside the axis rect.

Use the methods setFillOrder and setWrap inherited from QCPLayoutGrid to control in which order (column first or row first) the legend is filled up when calling addItem, and at which column or row wrapping occurs. The default fill order for legends is foRowsFirst.

By default, every QCustomPlot has one legend (QCustomPlot::legend) which is placed in the inset layout of the main axis rect (QCPAxisRect::insetLayout). To move the legend to another position inside the axis rect, use the methods of the QCPLayoutInset. To move the legend outside of the axis rect, place it anywhere else with the QCPLayout/QCPLayoutElement interface.

Member Enumeration Documentation

§ SelectablePart

enum QCPLegend::SelectablePart

Defines the selectable parts of a legend

See also: setSelectedParts, setSelectableParts

Enumerator
spNone	`0x000` None
spLegendBox	`0x001` The legend box (frame)
spItems	`0x002` Legend items individually (see selectedItems)

Constructor & Destructor Documentation

§ QCPLegend()

QCPLegend::QCPLegend ( )

explicit

Constructs a new QCPLegend instance with default values.

Note that by default, QCustomPlot already contains a legend ready to be used as QCustomPlot::legend

Member Function Documentation

§ setBorderPen()

void QCPLegend::setBorderPen ( const QPen & pen )

Sets the pen, the border of the entire legend is drawn with.

§ setBrush()

void QCPLegend::setBrush ( const QBrush & brush )

Sets the brush of the legend background.

§ setFont()

void QCPLegend::setFont ( const QFont & font )

Sets the default font of legend text. Legend items that draw text (e.g. the name of a graph) will use this font by default. However, a different font can be specified on a per-item-basis by accessing the specific legend item.

This function will also set font on all already existing legend items.

See also: QCPAbstractLegendItem::setFont

§ setTextColor()

void QCPLegend::setTextColor ( const QColor & color )

Sets the default color of legend text. Legend items that draw text (e.g. the name of a graph) will use this color by default. However, a different colors can be specified on a per-item-basis by accessing the specific legend item.

This function will also set color on all already existing legend items.

See also: QCPAbstractLegendItem::setTextColor

§ setIconSize() [1/2]

void QCPLegend::setIconSize ( const QSize & size )

Sets the size of legend icons. Legend items that draw an icon (e.g. a visual representation of the graph) will use this size by default.

§ setIconSize() [2/2]

void QCPLegend::setIconSize	(	int	width,
		int	height
	)

This is an overloaded function.

§ setIconTextPadding()

void QCPLegend::setIconTextPadding ( int padding )

Sets the horizontal space in pixels between the legend icon and the text next to it. Legend items that draw an icon (e.g. a visual representation of the graph) and text (e.g. the name of the graph) will use this space by default.

§ setIconBorderPen()

void QCPLegend::setIconBorderPen ( const QPen & pen )

Sets the pen used to draw a border around each legend icon. Legend items that draw an icon (e.g. a visual representation of the graph) will use this pen by default.

If no border is wanted, set this to Qt::NoPen.

§ setSelectableParts()

void QCPLegend::setSelectableParts ( const SelectableParts & selectable )

Sets whether the user can (de-)select the parts in selectable by clicking on the QCustomPlot surface. (When QCustomPlot::setInteractions contains QCP::iSelectLegend.)

However, even when selectable is set to a value not allowing the selection of a specific part, it is still possible to set the selection of this part manually, by calling setSelectedParts directly.

See also: SelectablePart, setSelectedParts

§ setSelectedParts()

void QCPLegend::setSelectedParts ( const SelectableParts & selected )

Sets the selected state of the respective legend parts described by SelectablePart. When a part is selected, it uses a different pen/font and brush. If some legend items are selected and selected doesn't contain spItems, those items become deselected.

The entire selection mechanism is handled automatically when QCustomPlot::setInteractions contains iSelectLegend. You only need to call this function when you wish to change the selection state manually.

This function can change the selection state of a part even when setSelectableParts was set to a value that actually excludes the part.

emits the selectionChanged signal when selected is different from the previous selection state.

Note that it doesn't make sense to set the selected state spItems here when it wasn't set before, because there's no way to specify which exact items to newly select. Do this by calling QCPAbstractLegendItem::setSelected directly on the legend item you wish to select.

See also: SelectablePart, setSelectableParts, selectTest, setSelectedBorderPen, setSelectedIconBorderPen, setSelectedBrush, setSelectedFont

§ setSelectedBorderPen()

void QCPLegend::setSelectedBorderPen ( const QPen & pen )

When the legend box is selected, this pen is used to draw the border instead of the normal pen set via setBorderPen.

See also: setSelectedParts, setSelectableParts, setSelectedBrush

§ setSelectedIconBorderPen()

void QCPLegend::setSelectedIconBorderPen ( const QPen & pen )

Sets the pen legend items will use to draw their icon borders, when they are selected.

See also: setSelectedParts, setSelectableParts, setSelectedFont

§ setSelectedBrush()

void QCPLegend::setSelectedBrush ( const QBrush & brush )

When the legend box is selected, this brush is used to draw the legend background instead of the normal brush set via setBrush.

See also: setSelectedParts, setSelectableParts, setSelectedBorderPen

§ setSelectedFont()

void QCPLegend::setSelectedFont ( const QFont & font )

Sets the default font that is used by legend items when they are selected.

This function will also set font on all already existing legend items.

See also: setFont, QCPAbstractLegendItem::setSelectedFont

§ setSelectedTextColor()

void QCPLegend::setSelectedTextColor ( const QColor & color )

Sets the default text color that is used by legend items when they are selected.

This function will also set color on all already existing legend items.

See also: setTextColor, QCPAbstractLegendItem::setSelectedTextColor

§ selectTest()

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

virtual

Layout elements are sensitive to events inside their outer rect. If pos is within the outer rect, this method returns a value corresponding to 0.99 times the parent plot's selection tolerance. However, layout elements are not selectable by default. So if onlySelectable is true, -1.0 is returned.

See QCPLayerable::selectTest for a general explanation of this virtual method.

QCPLayoutElement subclasses may reimplement this method to provide more specific selection test behaviour.

Reimplemented from QCPLayoutElement.

§ item()

QCPAbstractLegendItem * QCPLegend::item ( int index ) const

Returns the item with index i.

Note that the linear index depends on the current fill order (setFillOrder).

See also: itemCount, addItem, itemWithPlottable

§ itemWithPlottable()

QCPPlottableLegendItem * QCPLegend::itemWithPlottable ( const QCPAbstractPlottable * plottable ) const

Returns the QCPPlottableLegendItem which is associated with plottable (e.g. a QCPGraph*). If such an item isn't in the legend, returns 0.

See also: hasItemWithPlottable

§ itemCount()

int QCPLegend::itemCount ( ) const

Returns the number of items currently in the legend.

Note that if empty cells are in the legend (e.g. by calling methods of the QCPLayoutGrid base class which allows creating empty cells), they are included in the returned count.

See also: item

§ hasItem()

bool QCPLegend::hasItem ( QCPAbstractLegendItem * item ) const

Returns whether the legend contains item.

See also: hasItemWithPlottable

§ hasItemWithPlottable()

bool QCPLegend::hasItemWithPlottable ( const QCPAbstractPlottable * plottable ) const

Returns whether the legend contains a QCPPlottableLegendItem which is associated with plottable (e.g. a QCPGraph*). If such an item isn't in the legend, returns false.

See also: itemWithPlottable

§ addItem()

bool QCPLegend::addItem ( QCPAbstractLegendItem * item )

Adds item to the legend, if it's not present already. The element is arranged according to the current fill order (setFillOrder) and wrapping (setWrap).

Returns true on sucess, i.e. if the item wasn't in the list already and has been successfuly added.

The legend takes ownership of the item.

See also: removeItem, item, hasItem

§ removeItem() [1/2]

bool QCPLegend::removeItem ( int index )

This is an overloaded function.

Removes the item with the specified index from the legend and deletes it.

After successful removal, the legend is reordered according to the current fill order (setFillOrder) and wrapping (setWrap), so no empty cell remains where the removed item was. If you don't want this, rather use the raw element interface of QCPLayoutGrid.

Returns true, if successful. Unlike QCPLayoutGrid::removeAt, this method only removes elements derived from QCPAbstractLegendItem.

See also: itemCount, clearItems

§ removeItem() [2/2]

bool QCPLegend::removeItem ( QCPAbstractLegendItem * item )

This is an overloaded function.

Removes item from the legend and deletes it.

Returns true, if successful.

See also: clearItems

§ clearItems()

void QCPLegend::clearItems ( )

Removes all items from the legend.

§ selectedItems()

QList< QCPAbstractLegendItem * > QCPLegend::selectedItems ( ) const

Returns the legend items that are currently selected. If no items are selected, the list is empty.

See also: QCPAbstractLegendItem::setSelected, setSelectable

§ selectionChanged

void QCPLegend::selectionChanged ( QCPLegend::SelectableParts selection )

signal

This signal is emitted when the selection state of this legend has changed.

See also: setSelectedParts, setSelectableParts

§ parentPlotInitialized()

void QCPLegend::parentPlotInitialized ( QCustomPlot * parentPlot )

protectedvirtual

propagates the parent plot initialization to all child elements, by calling QCPLayerable::initializeParentPlot on them.

Reimplemented from QCPLayoutElement.

§ selectionCategory()

QCP::Interaction QCPLegend::selectionCategory ( ) const

protectedvirtual

Returns the selection category this layerable shall belong to. The selection category is used in conjunction with QCustomPlot::setInteractions to control which objects are selectable and which aren't.

Subclasses that don't fit any of the normal QCP::Interaction values can use QCP::iSelectOther. This is what the default implementation returns.

See also: QCustomPlot::setInteractions

Reimplemented from QCPLayerable.

§ applyDefaultAntialiasingHint()

void QCPLegend::applyDefaultAntialiasingHint ( QCPPainter * painter ) const

protectedvirtual

A convenience function to easily set the QPainter::Antialiased hint on the provided painter before drawing main legend elements.

This is the antialiasing state the painter passed to the draw method is in by default.

This function takes into account the local setting of the antialiasing flag as well as the overrides set with QCustomPlot::setAntialiasedElements and QCustomPlot::setNotAntialiasedElements.

For general information about this virtual method, see the base class implementation.

See also: setAntialiased

Reimplemented from QCPLayoutElement.

§ draw()

void QCPLegend::draw ( QCPPainter * painter )

protectedvirtual

Draws the legend box with the provided painter. The individual legend items are layerables themselves, thus are drawn independently.

Reimplemented from QCPLayoutElement.

§ selectEvent()

void QCPLegend::selectEvent	(	QMouseEvent *	event,
		bool	additive,
		const QVariant &	details,
		bool *	selectionStateChanged
	)

protectedvirtual

This event is called when the layerable shall be selected, as a consequence of a click by the user. Subclasses should react to it by setting their selection state appropriately. The default implementation does nothing.

event is the mouse event that caused the selection. additive indicates, whether the user was holding the multi-select-modifier while performing the selection (see QCustomPlot::setMultiSelectModifier). if additive is true, the selection state must be toggled (i.e. become selected when unselected and unselected when selected).

Every selectEvent is preceded by a call to selectTest, which has returned positively (i.e. returned a value greater than 0 and less than the selection tolerance of the parent QCustomPlot). The details data you output from selectTest is fed back via details here. You may use it to transport any kind of information from the selectTest to the possibly subsequent selectEvent. Usually details is used to transfer which part was clicked, if it is a layerable that has multiple individually selectable parts (like QCPAxis). This way selectEvent doesn't need to do the calculation again to find out which part was actually clicked.

selectionStateChanged is an output parameter. If the pointer is non-null, this function must set the value either to true or false, depending on whether the selection state of this layerable was actually changed. For layerables that only are selectable as a whole and not in parts, this is simple: if additive is true, selectionStateChanged must also be set to true, because the selection toggles. If additive is false, selectionStateChanged is only set to true, if the layerable was previously unselected and now is switched to the selected state.

See also: selectTest, deselectEvent

Reimplemented from QCPLayerable.

§ deselectEvent()

void QCPLegend::deselectEvent ( bool * selectionStateChanged )

protectedvirtual

This event is called when the layerable shall be deselected, either as consequence of a user interaction or a call to QCustomPlot::deselectAll. Subclasses should react to it by unsetting their selection appropriately.

just as in selectEvent, the output parameter selectionStateChanged (if non-null), must return true or false when the selection state of this layerable has changed or not changed, respectively.

See also: selectTest, selectEvent

Reimplemented from QCPLayerable.

§ getBorderPen()

QPen QCPLegend::getBorderPen ( ) const

protected

Returns the pen used to paint the border of the legend, taking into account the selection state of the legend box.

§ getBrush()

QBrush QCPLegend::getBrush ( ) const

protected

Returns the brush used to paint the background of the legend, taking into account the selection state of the legend box.

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

src/layoutelements/layoutelement-legend.h
src/layoutelements/layoutelement-legend.cpp

Public Types

Public Functions

Signals

Protected Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

§ SelectablePart

Constructor & Destructor Documentation

§ QCPLegend()

Member Function Documentation

§ setBorderPen()

§ setBrush()

§ setFont()

§ setTextColor()

§ setIconSize() [1/2]

§ setIconSize() [2/2]

§ setIconTextPadding()

§ setIconBorderPen()

§ setSelectableParts()

§ setSelectedParts()

§ setSelectedBorderPen()

§ setSelectedIconBorderPen()

§ setSelectedBrush()

§ setSelectedFont()

§ setSelectedTextColor()

§ selectTest()

§ item()

§ itemWithPlottable()

§ itemCount()

§ hasItem()

§ hasItemWithPlottable()

§ addItem()

§ removeItem() [1/2]

§ removeItem() [2/2]

§ clearItems()

§ selectedItems()

§ selectionChanged

§ parentPlotInitialized()

§ selectionCategory()

§ applyDefaultAntialiasingHint()

§ draw()

§ selectEvent()

§ deselectEvent()

§ getBorderPen()

§ getBrush()