A pie chart. More...

#include <Wt/Chart/WPieChart.h>

Inheritance diagram for Wt::Chart::WPieChart:

Public Member Functions
	WPieChart ()
	Creates a new pie chart.

void	setLabelsColumn (int column)
	Sets the model column that holds the labels. More...

int	labelsColumn () const
	Returns the model column used for the labels. More...

void	setDataColumn (int modelColumn)
	Sets the model column that holds the data. More...

int	dataColumn () const
	Returns the model column used for the data. More...

void	setBrush (int modelRow, const WBrush &brush)
	Customizes the brush used for a pie segment. More...

WBrush	brush (int modelRow) const
	Returns the brush used for a pie segment. More...

void	setExplode (int modelRow, double factor)
	Sets the explosion factor for a pie segment. More...

double	explode (int modelRow) const
	Returns the explosion factor for a segment. More...

void	setPerspectiveEnabled (bool enabled, double height=1.0)
	Enables a 3D perspective effect on the pie. More...

bool	isPerspectiveEnabled () const
	Returns whether a 3D effect is enabled. More...

void	setShadowEnabled (bool enabled)
	Enables a shadow effect. More...

bool	isShadowEnabled () const
	Returns whether a shadow effect is enabled. More...

void	setStartAngle (double degrees)
	Sets the angle of the first segment. More...

double	startAngle () const
	Returns the angle of the first segment. More...

void	setAvoidLabelRendering (double percent)
	Sets the percentage value to avoid rendering of label texts. More...

double	avoidLabelRendering () const
	Returns the percentage to avoid label rendering. More...

void	setDisplayLabels (WFlags< LabelOption > options)
	Configures if and how labels should be displayed. More...

WFlags< LabelOption >	displayLabels () const
	Returns options set for displaying labels. More...

void	setLabelFormat (const WString &format)
	Sets the label format. More...

WString	labelFormat () const
	Returns the label format string. More...

std::unique_ptr< WWidget >	createLegendItemWidget (int index, WFlags< LabelOption > options)
	Creates a widget which renders the a legend item. More...

virtual void	addDataPointArea (int row, int column, std::unique_ptr< WAbstractArea > area) const
	Adds a data point area (used for displaying e.g. tooltips). More...

virtual std::unique_ptr< WContainerWidget >	createLabelWidget (std::unique_ptr< WWidget > textWidget, WPainter *painter, const WRectF &rect, Wt::WFlags< AlignmentFlag > alignmentFlags) const
	createLabelWidget possition textWidget where the text would be rendered. Assuming that textWidget is added to a container with same dimensions as the WPieChart. This should be used in combinaltion with drawLabel(). More...

virtual void	paint (WPainter &painter, const WRectF &rectangle=WRectF()) const override
	Paint the chart in a rectangle of the given painter. More...

Public Member Functions inherited from Wt::Chart::WAbstractChart
virtual	~WAbstractChart ()
	Destructor.

void	setModel (const std::shared_ptr< WAbstractItemModel > &model)
	Sets the model. More...

void	setModel (const std::shared_ptr< WAbstractChartModel > &model)
	Sets the model. More...

std::shared_ptr< WAbstractChartModel >	model () const
	Returns the model. More...

std::shared_ptr< WAbstractItemModel >	itemModel () const
	Returns the model. More...

void	setBackground (const WBrush &background)
	Sets a background for the chart. More...

const WBrush &	background () const
	Returns the background of the chart. More...

void	setPalette (const std::shared_ptr< WChartPalette > &palette)
	Set a palette for the chart. More...

std::shared_ptr< WChartPalette >	palette () const
	Returns the palette for the chart. More...

void	setPlotAreaPadding (int padding, WFlags< Side > sides=AllSides)
	Set an internal margin for the main plot area. More...

int	plotAreaPadding (Side side) const
	Returns the internal margin for the main plot area. More...

void	setAutoLayoutEnabled (bool enabled=true)
	Configures the chart layout to be automatic. More...

bool	isAutoLayoutEnabled () const
	Returns whether chart layout is computed automatically. More...

void	setTitle (const WString &title)
	Set a chart title. More...

const WString &	title () const
	Return the chart title. More...

void	setTitleFont (const WFont &titleFont)
	Set the font for the chart title. More...

const WFont &	titleFont () const
	Returns the font for the chart title. More...

Public Member Functions inherited from Wt::WPaintedWidget
	WPaintedWidget ()
	Create a new painted widget.

	~WPaintedWidget ()
	Destructor.

void	setPreferredMethod (RenderMethod method)
	Sets the preferred rendering method. More...

RenderMethod	preferredMethod () const
	Returns the preferred rendering method. More...

void	update (WFlags< PaintFlag > flags=None)
	Lets the widget repaint itself. More...

virtual void	resize (const WLength &width, const WLength &height) override
	Resizes the widget. More...

void	addArea (std::unique_ptr< WAbstractArea > area)
	Adds an interactive area. More...

void	insertArea (int index, std::unique_ptr< WAbstractArea > area)
	Inserts an interactive area. More...

std::unique_ptr< WAbstractArea >	removeArea (WAbstractArea *area)
	Removes an interactive area. More...

WAbstractArea *	area (int index) const
	Returns the interactive area at the given index. More...

const std::vector< WAbstractArea * >	areas () const
	Returns the interactive areas set for this widget. More...

JSlot &	repaintSlot ()
	A JavaScript slot that repaints the widget when triggered. More...

Public Member Functions inherited from Wt::WInteractWidget
	WInteractWidget ()
	Create an InteractWidget.

EventSignal< WKeyEvent > &	keyWentDown ()
	Event signal emitted when a keyboard key is pushed down. More...

EventSignal< WKeyEvent > &	keyPressed ()
	Event signal emitted when a "character" was entered. More...

EventSignal< WKeyEvent > &	keyWentUp ()
	Event signal emitted when a keyboard key is released. More...

EventSignal &	enterPressed ()
	Event signal emitted when enter was pressed. More...

EventSignal &	escapePressed ()
	Event signal emitted when escape was pressed. More...

EventSignal< WMouseEvent > &	clicked ()
	Event signal emitted when the primary mouse button was clicked on this widget. More...

EventSignal< WMouseEvent > &	doubleClicked ()
	Event signal emitted when the primary mouse button was double clicked on this widget. More...

EventSignal< WMouseEvent > &	mouseWentDown ()
	Event signal emitted when a mouse button was pushed down on this widget. More...

EventSignal< WMouseEvent > &	mouseWentUp ()
	Event signal emitted when a mouse button was released on this widget. More...

EventSignal< WMouseEvent > &	mouseWentOut ()
	Event signal emitted when the mouse went out of this widget. More...

EventSignal< WMouseEvent > &	mouseWentOver ()
	Event signal emitted when the mouse entered this widget. More...

EventSignal< WMouseEvent > &	mouseMoved ()
	Event signal emitted when the mouse moved over this widget. More...

EventSignal< WMouseEvent > &	mouseDragged ()
	Event signal emitted when the mouse is dragged over this widget. More...

EventSignal< WMouseEvent > &	mouseWheel ()
	Event signal emitted when the mouse scroll wheel was used. More...

EventSignal< WTouchEvent > &	touchStarted ()
	Event signal emitted when a finger is placed on the screen. More...

EventSignal< WTouchEvent > &	touchEnded ()
	Event signal emitted when a finger is removed from the screen. More...

EventSignal< WTouchEvent > &	touchMoved ()
	Event signal emitted when a finger, which is already placed on the screen, is moved across the screen. More...

EventSignal< WGestureEvent > &	gestureStarted ()
	Event signal emitted when a gesture is started. More...

EventSignal< WGestureEvent > &	gestureChanged ()
	Event signal emitted when a gesture is changed. More...

EventSignal< WGestureEvent > &	gestureEnded ()
	Event signal emitted when a gesture is ended. More...

void	setDraggable (const std::string &mimeType, WWidget dragWidget=nullptr, bool isDragWidgetOnly=false, WObject sourceWidget=nullptr)
	Configure dragging for drag and drop. More...

void	unsetDraggable ()
	Disable drag & drop for this widget. More...

void	setMouseOverDelay (int delay)
	Sets a delay for the mouse over event. More...

int	mouseOverDelay () const
	Returns the mouse over signal delay. More...

virtual void	setPopup (bool popup) override
	Lets the widget overlay over other sibling widgets. More...

virtual void	load () override
	Loads content just before the widget is used. More...

virtual bool	isEnabled () const override
	Returns whether the widget is enabled. More...

Public Member Functions inherited from Wt::WWebWidget
	WWebWidget ()
	Construct a WebWidget.

virtual std::vector< WWidget * >	children () const override
	Returns child widgets. More...

Signal &	childrenChanged ()
	Signal emitted when children have been added or removed. More...

virtual void	setPositionScheme (PositionScheme scheme) override
	Sets the CSS position scheme. More...

virtual PositionScheme	positionScheme () const override
	Returns the CSS position scheme. More...

virtual void	setOffsets (const WLength &offset, WFlags< Side > sides=AllSides) override
	Sets CSS offsets for a non-statically positioned widget. More...

virtual WLength	offset (Side s) const override
	Returns a CSS offset. More...

virtual WLength	width () const override
	Returns the width. More...

virtual WLength	height () const override
	Returns the height. More...

virtual void	setMinimumSize (const WLength &width, const WLength &height) override
	Sets a minimum size. More...

virtual WLength	minimumWidth () const override
	Returns the minimum width. More...

virtual WLength	minimumHeight () const override
	Returns the minimum height. More...

virtual void	setMaximumSize (const WLength &width, const WLength &height) override
	Sets a maximum size. More...

virtual WLength	maximumWidth () const override
	Returns the maximum width. More...

virtual WLength	maximumHeight () const override
	Returns the maximum height. More...

virtual void	setLineHeight (const WLength &height) override
	Sets the CSS line height for contained text.

virtual WLength	lineHeight () const override
	Returns the CSS line height for contained text. More...

virtual void	setFloatSide (Side s) override
	Specifies a CSS float side. More...

virtual Side	floatSide () const override
	Returns the CSS float side. More...

virtual void	setClearSides (WFlags< Side > sides) override
	Sets the sides that should be cleared of floats. More...

virtual WFlags< Side >	clearSides () const override
	Returns the sides that should remain empty. More...

virtual void	setMargin (const WLength &margin, WFlags< Side > sides=AllSides) override
	Sets CSS margins around the widget. More...

virtual WLength	margin (Side side) const override
	Returns a CSS margin set. More...

virtual void	setHiddenKeepsGeometry (bool enabled) override
	Sets whether the widget keeps its geometry when hidden. More...

virtual bool	hiddenKeepsGeometry () const override
	Returns whether the widget keeps its geometry when hidden. More...

virtual void	setHidden (bool hidden, const WAnimation &animation=WAnimation()) override
	Hides or shows the widget. More...

virtual bool	isHidden () const override
	Returns whether the widget is set hidden. More...

virtual bool	isVisible () const override
	Returns whether the widget is visible. More...

virtual void	setDisabled (bool disabled) override
	Sets whether the widget is disabled. More...

virtual bool	isDisabled () const override
	Returns whether the widget is set disabled. More...

virtual bool	isPopup () const override
	Returns whether the widget is overlayed. More...

virtual void	setInline (bool isInline) override
	Sets whether the widget is displayed inline or as a block. More...

virtual bool	isInline () const override
	Returns whether the widget is displayed inline or as block. More...

virtual void	setDecorationStyle (const WCssDecorationStyle &style) override
	Sets a CSS decoration style. More...

virtual WCssDecorationStyle &	decorationStyle () override
	Returns the decoration style of this widget. More...

virtual void	setStyleClass (const WString &styleClass) override
	Sets (one or more) CSS style classes. More...

virtual WString	styleClass () const override
	Returns the CSS style class. More...

virtual void	addStyleClass (const WString &styleClass, bool force=false) override
	Adds a CSS style class. More...

virtual void	removeStyleClass (const WString &styleClass, bool force=false) override
	Removes a CSS style class. More...

virtual bool	hasStyleClass (const WString &styleClass) const override
	Returns whether the widget has a style class.

virtual void	setVerticalAlignment (AlignmentFlag alignment, const WLength &length=WLength()) override
	Sets the vertical alignment. More...

virtual AlignmentFlag	verticalAlignment () const override
	Returns the vertical alignment. More...

virtual WLength	verticalAlignmentLength () const override
	Returns the fixed vertical alignment that was set. More...

virtual void	setToolTip (const WString &text, TextFormat textFormat=TextFormat::Plain) override
	Sets a tooltip. More...

virtual void	setDeferredToolTip (bool enable, TextFormat textFormat=TextFormat::Plain) override
	Enable deferred tooltip. More...

virtual WString	toolTip () const override
	Returns the tooltip.

virtual void	refresh () override
	Refresh the widget. More...

virtual void	setAttributeValue (const std::string &name, const WString &value) override
	Sets an attribute value. More...

virtual WString	attributeValue (const std::string &name) const override
	Returns an attribute value. More...

virtual void	setJavaScriptMember (const std::string &name, const std::string &value) override
	Sets a JavaScript member. More...

virtual std::string	javaScriptMember (const std::string &name) const override
	Returns the value of a JavaScript member. More...

virtual void	callJavaScriptMember (const std::string &name, const std::string &args) override
	Calls a JavaScript member. More...

virtual bool	loaded () const override
	Returns whether this widget has been loaded. More...

virtual void	setId (const std::string &id) override
	Sets the CSS Id. More...

virtual WWidget *	find (const std::string &name) override
	Finds a descendent widget by name. More...

virtual WWidget *	findById (const std::string &id) override
	Finds a descendent widget by id.

virtual void	setSelectable (bool selectable) override
	Sets as selectable. More...

virtual void	doJavaScript (const std::string &javascript) override
	Executes the given JavaScript statements when the widget is rendered or updated. More...

virtual const std::string	id () const override
	Returns the (unique) identifier for this object. More...

void	setLoadLaterWhenInvisible (bool)
	Change the way the widget is loaded when invisible. More...

std::string	htmlTagName () const
	returns the current html tag name More...

void	setHtmlTagName (const std::string &tag)
	set the custom HTML tag name More...

virtual void	setCanReceiveFocus (bool enabled) override
	Sets whether the widget can receive focus. More...

virtual bool	canReceiveFocus () const override
	Returns whether the widget can receive focus. More...

virtual bool	setFirstFocus () override
	Set focus on the widget's first descendant. More...

virtual void	setFocus (bool focus) override
	Sets focus. More...

virtual bool	hasFocus () const override
	Returns whether the widget currently has the focus.

virtual void	setTabIndex (int index) override
	Sets the tab index. More...

virtual int	tabIndex () const override
	Returns the tab index. More...

EventSignal &	blurred ()
	Signal emitted when the widget lost focus. More...

EventSignal &	focussed ()
	Signal emitted when the widget recieved focus. More...

virtual bool	scrollVisibilityEnabled () const final override
	Returns whether scroll visibility detection is enabled for this widget. More...

virtual void	setScrollVisibilityEnabled (bool enabled) final override
	Sets whether scroll visibility detection is enabled for this widget. More...

virtual int	scrollVisibilityMargin () const final override
	Returns the margin around the viewport within which the widget is considered visible. More...

virtual void	setScrollVisibilityMargin (int margin) final override
	Sets the margin around the viewport within which the widget is considered visible. More...

virtual Signal< bool > &	scrollVisibilityChanged () final override
	Signal triggered when the scroll visibility of this widget changes. More...

virtual bool	isScrollVisible () const final override
	Returns whether this widget is currently considered scroll visible. More...

virtual void	setThemeStyleEnabled (bool enabled) final override
	Sets whether theme styling for a widget is enabled or disabled. More...

virtual bool	isThemeStyleEnabled () const final override
	Returns whether this widget is currently styled by the chosen theme. More...

virtual void	setObjectName (const std::string &name) override
	Sets an object name. More...

void	setFocus ()
	Sets focus. More...

virtual void	setFocus (bool focus)=0
	Sets focus. More...

Public Member Functions inherited from Wt::WWidget
virtual	~WWidget ()
	Destructor. More...

WWidget *	parent () const
	Returns the parent widget.

virtual std::unique_ptr< WWidget >	removeWidget (WWidget *widget)
	Removes a child widget.

template<typename Widget >
std::unique_ptr< Widget >	removeWidget (Widget *widget)
	Removes a child widget. More...

std::unique_ptr< WWidget >	removeFromParent ()
	Removes the widget from its parent. More...

void	setWidth (const WLength &width)
	Sets the width. More...

void	setHeight (const WLength &height)
	Sets the height. More...

virtual void	positionAt (const WWidget *widget, Orientation orientation=Orientation::Vertical)
	Positions a widget next to another widget. More...

virtual void	toggleStyleClass (const WString &styleClass, bool add, bool force=false)
	Toggles a CSS style class.

std::string	jsRef () const
	Returns a JavaScript expression to the corresponding DOM node. More...

void	setFocus ()
	Sets focus. More...

virtual void	acceptDrops (const std::string &mimeType, const WString &hoverStyleClass=WString())
	Sets a mime type to be accepted for dropping. More...

virtual void	stopAcceptDrops (const std::string &mimeType)
	Indicates that a mime type is no longer accepted for dropping. More...

virtual void	htmlText (std::ostream &out)
	Streams the (X)HTML representation. More...

bool	isRendered () const
	Returns whether the widget is rendered. More...

void	hide ()
	Hides the widget. More...

void	animateHide (const WAnimation &animation)
	Hides the widget using an animation. More...

void	show ()
	Shows the widget. More...

void	animateShow (const WAnimation &animation)
	Shows the widget using an animation. More...

void	enable ()
	Enables the widget. More...

void	disable ()
	Disable thes widget. More...

bool	layoutSizeAware () const
	Returns whether the widget is layout size aware. More...

Public Member Functions inherited from Wt::WObject
void	addChild (std::unique_ptr< WObject > child)
	Add a child WObject whose lifetime is determined by this WObject.

template<typename Child >
Child *	addChild (std::unique_ptr< Child > child)
	Add a child WObject, returning a raw pointer. More...

std::unique_ptr< WObject >	removeChild (WObject *child)
	Remove a child WObject, so its lifetime is no longer determined by this WObject.

template<typename Child >
std::unique_ptr< Child >	removeChild (Child *child)
	Remove a child WObject, so its lifetime is no longer determined by this WObject. More...

virtual std::string	objectName () const
	Returns the object name. More...

void	resetLearnedSlots ()
	Resets learned stateless slot implementations. More...

template<class T >
void	resetLearnedSlot (void(T::*method)())
	Resets a learned stateless slot implementation. More...

template<class T >
WStatelessSlot *	implementStateless (void(T::*method)())
	Declares a slot to be stateless and learn client-side behaviour on first invocation. More...

template<class T >
WStatelessSlot *	implementStateless (void(T::method)(), void(T::undoMethod)())
	Declares a slot to be stateless and learn client-side behaviour in advance. More...

void	isNotStateless ()
	Marks the current function as not stateless. More...

template<class T >
WStatelessSlot *	implementJavaScript (void(T::*method)(), const std::string &jsCode)
	Provides a JavaScript implementation for a method. More...

Public Member Functions inherited from Wt::Core::observable
	observable () noexcept
	Default constructor.

virtual	~observable ()
	Destructor. More...

template<typename... Args, typename C >
auto	bindSafe (void(C::*method)(Args...)) noexcept
	Protects a method call against object destruction. More...

template<typename... Args, typename C >
auto	bindSafe (void(C::*method)(Args...) const) const noexcept
	Protects a const method call against object destruction. More...

template<typename Function >
auto	bindSafe (const Function &function) noexcept
	Protects a function against object destruction. More...

Protected Member Functions
void	paintEvent (Wt::WPaintDevice *paintDevice) override
	Paints the widget. More...

virtual void	drawLabel (WPainter *painter, const WRectF &rect, WFlags< AlignmentFlag > alignmentFlags, const WString &text, int row) const
	drawLabel draw a label on the chart. Will be called by paint. More...

Protected Member Functions inherited from Wt::WPaintedWidget
WJavaScriptHandle< WTransform >	createJSTransform ()
	Create a WTransform that is accessible from JavaScript, associated with this WPaintedWidget.

WJavaScriptHandle< WBrush >	createJSBrush ()
	Create a WBrush that is accessible from JavaScript, associated with this WPaintedWidget.

WJavaScriptHandle< WPen >	createJSPen ()
	Create a WPen that is accessible from JavaScript, associated with this WPaintedWidget.

WJavaScriptHandle< WPainterPath >	createJSPainterPath ()
	Create a WPainterPath that is accessible from JavaScript, associated with this WPaintedWidget.

WJavaScriptHandle< WRectF >	createJSRect ()
	Create a WRectF that is accessible from JavaScript, associated with this WPaintedWidget.

WJavaScriptHandle< WPointF >	createJSPoint ()
	Create a WPointF that is accessible from JavaScript, associated with this WPaintedWidget.

virtual void	layoutSizeChanged (int width, int height) override
	Virtual method that indicates a size change. More...

virtual RenderMethod	getMethod () const
	Returns the actual method used for rendering. More...

virtual std::unique_ptr< WPaintDevice >	createPaintDevice () const
	Creates a paint device. More...

virtual void	enableAjax () override
	Progresses to an Ajax-enabled widget. More...

virtual void	render (WFlags< RenderFlag > flags) override
	Renders the widget. More...

std::string	objJsRef () const
	Returns a JavaScript reference to the client side representation of the WPaintedWidget. More...

Protected Member Functions inherited from Wt::WInteractWidget
virtual void	propagateSetEnabled (bool enabled) override
	Propagates that a widget was enabled or disabled through children. More...

Protected Member Functions inherited from Wt::WWebWidget
virtual WStatelessSlot *	getStateless (Method method) override
	On-demand stateless slot implementation. More...

Protected Member Functions inherited from Wt::WWidget
void	setLayoutSizeAware (bool sizeAware)
	Sets the widget to be aware of its size set by a layout manager. More...

	WWidget ()
	Creates a widget.

virtual void	dropEvent (WDropEvent dropEvent)
	Handles a drop event. More...

virtual int	boxPadding (Orientation orientation) const
	Returns the widget's built-in padding. More...

virtual int	boxBorder (Orientation orientation) const
	Returns the widget's built-in border width. More...

void	scheduleRender (WFlags< RepaintFlag > flags=None)
	Schedules rerendering of the widget. More...

Additional Inherited Members
Public Types inherited from Wt::WObject
typedef void(WObject::*	Method) ()
	Typedef for a WObject method without arguments.

Static Public Member Functions inherited from Wt::WWebWidget
static std::string	jsStringLiteral (const std::string &v, char delimiter='\'')
	Turn a CharEncoding::UTF8 encoded string into a JavaScript string literal. More...

Static Public Member Functions inherited from Wt::WWidget
static WString	tr (const char *key)
	Short hand for WString::tr() More...

Detailed Description

A pie chart.

A pie chart renders a single data series as segments of a circle, so that the area of each segment is proportional to the value in the data series.

To use a pie chart, you need to set a model using setModel(), and use setLabelsColumn() and setDataColumn() to specify the model column that contains the category labels and data.

The pie chart may be customized visually by enabling a 3D effect (setPerspectiveEnabled()), or by specifying the angle of the first segment. One or more segments may be exploded, which separates the segment from the rest of the pie chart, using setExplode().

The segments may be labeled in various ways using setDisplayLabels().

CSS

Styling through CSS is not applicable.

Example of a pie chart

See also: WCartesianChart

Member Function Documentation

◆ addDataPointArea()

void Wt::Chart::WPieChart::addDataPointArea	(	int	row,
		int	column,
		std::unique_ptr< WAbstractArea >	area
	)		const

virtual

Adds a data point area (used for displaying e.g. tooltips).

You may want to specialize this is if you wish to modify (or delete) the area.

Note: Currently, an area is only created if the ItemDataRole::ToolTip data at the data point is not empty.

◆ avoidLabelRendering()

double Wt::Chart::WPieChart::avoidLabelRendering ( ) const

Returns the percentage to avoid label rendering.

See also: setAvoidLabelRendering(double)

◆ brush()

WBrush Wt::Chart::WPieChart::brush ( int modelRow ) const

Returns the brush used for a pie segment.

See also: setBrush(int, const WBrush&)

◆ createLabelWidget()

std::unique_ptr< WContainerWidget > Wt::Chart::WPieChart::createLabelWidget	(	std::unique_ptr< WWidget >	textWidget,
		WPainter *	painter,
		const WRectF &	rect,
		Wt::WFlags< AlignmentFlag >	alignmentFlags
	)		const

virtual

createLabelWidget possition textWidget where the text would be rendered. Assuming that textWidget is added to a container with same dimensions as the WPieChart. This should be used in combinaltion with drawLabel().

Returns: The new WContainerWidget that contains textWidget and can be placed on an other layer that has the same dimensions as the WPieChart.

See also: drawLabel()

Usage example, PieChart with label links.

class PChart : public Wt::Chart::WPieChart {
private:
  Wt::WContainerWidget *widgetsLayer_;
public:
  PChart(Wt::WContainerWidget *widgetsLayer) :
    widgetsLayer_(widgetsLayer)
  {
    widgetsLayer_->resize(800, 300);
    resize(800, 300);
    widgetsLayer_->setPositionScheme(Wt::PositionScheme::Relative);
  }
  virtual void drawLabel(Wt::WPainter* painter, const Wt::WRectF& rect,
                           Wt::WFlags<Wt::AlignmentFlag> alignmentFlags,
                           const Wt::WString& text, int row) const
  {
    if (model()->link(row, dataColumn()) == 0) {
      WPieChart::drawLabel(painter, rect, alignmentFlags, text, row);
    } else {
      auto a = std::make_unique<Wt::WAnchor>(
                 *model()->link(row, dataColumn()), text);
      widgetsLayer_->addWidget(createLabelWidget(std::move(a), painter, rect, alignmentFlags));
    }
  }
};

◆ createLegendItemWidget()

std::unique_ptr< WWidget > Wt::Chart::WPieChart::createLegendItemWidget	(	int	index,
		WFlags< LabelOption >	options
	)

Creates a widget which renders the a legend item.

Depending on the passed LabelOption flags, the legend item widget, will contain a text (with or without the percentage) and/or a span with the segment's color.

◆ dataColumn()

int Wt::Chart::WPieChart::dataColumn ( ) const

Returns the model column used for the data.

See also: setDataColumn(int)

◆ displayLabels()

WFlags<LabelOption> Wt::Chart::WPieChart::displayLabels ( ) const

Returns options set for displaying labels.

See also: WPieChart::setDisplayLabels()

◆ drawLabel()

void Wt::Chart::WPieChart::drawLabel	(	WPainter *	painter,
		const WRectF &	rect,
		WFlags< AlignmentFlag >	alignmentFlags,
		const WString &	text,
		int	row
	)		const

protectedvirtual

drawLabel draw a label on the chart. Will be called by paint.

You may want to specialize this if you wish to replace the label by a widget.

See also: createLabelWidget() if you wish to replace the label by a Widget.

◆ explode()

double Wt::Chart::WPieChart::explode ( int modelRow ) const

Returns the explosion factor for a segment.

See also: setExplode(int, double)

◆ isPerspectiveEnabled()

bool Wt::Chart::WPieChart::isPerspectiveEnabled ( ) const

Returns whether a 3D effect is enabled.

See also: setPerspectiveEnabled(bool, double)

◆ isShadowEnabled()

bool Wt::Chart::WPieChart::isShadowEnabled ( ) const

Returns whether a shadow effect is enabled.

See also: setShadowEnabled()

◆ labelFormat()

WString Wt::Chart::WPieChart::labelFormat ( ) const

Returns the label format string.

See also: setLabelFormat()

◆ labelsColumn()

int Wt::Chart::WPieChart::labelsColumn ( ) const

Returns the model column used for the labels.

See also: setLabelsColumn(int)

◆ paint()

void Wt::Chart::WPieChart::paint	(	WPainter &	painter,
		const WRectF &	rectangle = `WRectF()`
	)		const

overridevirtual

Paint the chart in a rectangle of the given painter.

Paints the chart inside the painter, in the area indicated by rectangle. When rectangle is a null rectangle, the entire painter window is used.

Implements Wt::Chart::WAbstractChart.

◆ paintEvent()

void Wt::Chart::WPieChart::paintEvent ( Wt::WPaintDevice * paintDevice )

overrideprotectedvirtual

Paints the widget.

You should reimplement this method to paint the contents of the widget, using the given paintDevice.

Implements Wt::WPaintedWidget.

◆ setAvoidLabelRendering()

void Wt::Chart::WPieChart::setAvoidLabelRendering ( double percent )

Sets the percentage value to avoid rendering of label texts.

The default value is 0 percent.

◆ setBrush()

void Wt::Chart::WPieChart::setBrush	(	int	modelRow,
		const WBrush &	brush
	)

Customizes the brush used for a pie segment.

By default, the brush is taken from the palette(). You can use this method to override the palette's brush for a particular modelRow.

See also: setPalette(WChartPalette *)

◆ setDataColumn()

void Wt::Chart::WPieChart::setDataColumn ( int modelColumn )

Sets the model column that holds the data.

The data column should contain data that can be converted to a number, but should not necessarily be of a number type, see also asNumber(const boost::any&).

The default value is -1 (not defined).

See also: setModel(WAbstractItemModel *), setLabelsColumn(int)

◆ setDisplayLabels()

void Wt::Chart::WPieChart::setDisplayLabels ( WFlags< LabelOption > options )

Configures if and how labels should be displayed.

The options must be the logical OR of a placement option (LabelOption::Inside or LabelOption::Outside) and LabelOption::TextLabel and/or LabelOption::TextPercentage. If both LabelOption::TextLabel and LabelOption::TextPercentage are specified, then these are combined as "<label>: <percentage>".

The default value is LabelOption::None.

◆ setExplode()

void Wt::Chart::WPieChart::setExplode	(	int	modelRow,
		double	factor
	)

Sets the explosion factor for a pie segment.

Separates the segment corresponding to model row modelRow from the rest of the pie. The factor is a positive number that represents the distance from the center as a fraction of the pie radius. Thus, 0 corresponds to no separation, and 0.1 to a 10% separation, and 1 to a separation where the segment tip is on the outer perimeter of the pie.

The default value is 0.

◆ setLabelFormat()

void Wt::Chart::WPieChart::setLabelFormat ( const WString & format )

Sets the label format.

Sets a format string which is used to format label (percentage) values.

The format string must be a format string that is accepted by snprintf() and which formats one double. If the format string is an empty string, then WLocale::toString() is used.

The default value is "%.3g%%".

See also: labelFormat()

◆ setLabelsColumn()

void Wt::Chart::WPieChart::setLabelsColumn ( int column )

Sets the model column that holds the labels.

The labels are used only when setDisplayLabels() is called with the LabelOption::TextLabel option.

The default value is -1 (not defined).

See also: setModel(WAbstractItemModel *), setDisplayLabels(), setDataColumn(int)

◆ setPerspectiveEnabled()

void Wt::Chart::WPieChart::setPerspectiveEnabled	(	bool	enabled,
		double	height = `1.0`
	)

Enables a 3D perspective effect on the pie.

A 3D perspective effect is added, which may be customized by specifying the simulated height of the pie. The height is defined as a fraction of the pie radius.

The default value is false.

◆ setShadowEnabled()

void Wt::Chart::WPieChart::setShadowEnabled ( bool enabled )

Enables a shadow effect.

A soft shadow effect is added.