Wt  4.10.4
Public Member Functions | Protected Member Functions | List of all members
Wt::WSvgImage Class Reference

A paint device for rendering using Scalable Vector Graphics (SVG). More...

#include <Wt/WSvgImage.h>

Inheritance diagram for Wt::WSvgImage:
[legend]

Public Member Functions

 WSvgImage (const WLength &width, const WLength &height, bool paintUpdate=false)
 Create an SVG paint device. More...
 
 ~WSvgImage ()
 Destructor.
 
virtual WFlags< PaintDeviceFeatureFlagfeatures () const override
 Returns device features.
 
virtual void setChanged (WFlags< PainterChangeFlag > flags) override
 Indicates changes in painter state. More...
 
virtual void drawArc (const WRectF &rect, double startAngle, double spanAngle) override
 Draws an arc. More...
 
virtual void drawImage (const WRectF &rect, const std::string &imgUri, int imgWidth, int imgHeight, const WRectF &sourceRect) override
 Draws an image. More...
 
virtual void drawLine (double x1, double y1, double x2, double y2) override
 Draws a line. More...
 
virtual void drawRect (const WRectF &rectangle) override
 Draws a rectangle. More...
 
virtual void drawPath (const WPainterPath &path) override
 Draws a path. More...
 
virtual void drawText (const WRectF &rect, WFlags< AlignmentFlag > alignmentFlags, TextFlag textFlag, const WString &text, const WPointF *clipPoint) override
 Draws text. More...
 
virtual WTextItem measureText (const WString &text, double maxWidth=-1, bool wordWrap=false) override
 Measures rendered text size. More...
 
virtual WFontMetrics fontMetrics () override
 Returns font metrics. More...
 
virtual void init () override
 Initializes the device for painting. More...
 
virtual void done () override
 Finishes painting on the device. More...
 
virtual bool paintActive () const override
 Returns whether painting is active. More...
 
virtual std::string rendered () override
 Internal method.
 
virtual WLength width () const override
 Returns the device width. More...
 
virtual WLength height () const override
 Returns the device height. More...
 
virtual void handleRequest (const Http::Request &request, Http::Response &response) override
 Handles a request. More...
 
- Public Member Functions inherited from Wt::WResource
 WResource ()
 Creates a new resource.
 
 ~WResource ()
 Destroys the resource. More...
 
void suggestFileName (const Wt::WString &name, ContentDisposition disposition=ContentDisposition::Attachment)
 Suggests a filename to the user for the data streamed by this resource. More...
 
const Wt::WStringsuggestedFileName () const
 Returns the suggested file name. More...
 
void setDispositionType (ContentDisposition cd)
 Configures the Content-Disposition header. More...
 
ContentDisposition dispositionType () const
 Returns the currently configured content disposition. More...
 
void setChanged ()
 Generates a new URL for this resource and emits the changed signal. More...
 
void setInvalidAfterChanged (bool enabled)
 Return "page not found" for prior resource URLs after change. More...
 
bool invalidAfterChanged () const
 Should "page not found" be returned for outdated resource URLs. More...
 
void setInternalPath (const std::string &path)
 Sets an internal path for this resource. More...
 
std::string internalPath () const
 Returns the internal path. More...
 
const std::string & generateUrl ()
 Generates an URL for this resource. More...
 
const std::string & url () const
 Returns the current URL for this resource. More...
 
SignaldataChanged ()
 Signal emitted when the data presented in this resource has changed. More...
 
void setUploadProgress (bool enabled)
 Indicate interest in upload progress. More...
 
Signal< ::uint64_t, ::uint64_t > & dataReceived ()
 Signal emitted when data has been received for this resource. More...
 
void write (std::ostream &out, const Http::ParameterMap &parameters=Http::ParameterMap(), const Http::UploadedFileMap &files=Http::UploadedFileMap())
 Stream the resource to a stream. More...
 
virtual void handleAbort (const Http::Request &request)
 Handles a continued request being aborted. More...
 
void haveMoreData ()
 Indicate that more data is available. More...
 
void setTakesUpdateLock (bool enabled)
 Set whether this resource takes the WApplication's update lock. More...
 
bool takesUpdateLock () const
 Returns whether this resources takes the WApplication's update lock. 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< WObjectremoveChild (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 const std::string id () const
 Returns the (unique) identifier for this object. More...
 
virtual void setObjectName (const std::string &name)
 Sets an object name. 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...
 
- Public Member Functions inherited from Wt::WPaintDevice
virtual ~WPaintDevice ()
 Destructor. More...
 

Protected Member Functions

virtual WPainterpainter () const override
 Returns the painter that is currently painting on the device. More...
 
virtual void setPainter (WPainter *painter) override
 Sets the painter.
 
- Protected Member Functions inherited from Wt::WResource
void beingDeleted ()
 Prepares the resource for deletion. More...
 
- Protected Member Functions inherited from Wt::WObject
virtual WStatelessSlot * getStateless (Method method)
 On-demand stateless slot implementation. More...
 

Additional Inherited Members

- Public Types inherited from Wt::WObject
typedef void(WObject::* Method) ()
 Typedef for a WObject method without arguments.
 
- Public Types inherited from Wt::WPaintDevice
typedef PaintDeviceFeatureFlag FeatureFlag
 Typedef for enum Wt::PaintDeviceFeatureFlag.
 

Detailed Description

A paint device for rendering using Scalable Vector Graphics (SVG).

The WSvgImage is primarily used by WPaintedWidget to render to the browser in Support Vector Graphics (SVG) format.

You may also use the WSvgImage as an independent resource, for example in conjunction with a WAnchor or WImage, or to make a hard copy of an image in SVG format, using write():

Wt::WSvgImage svgImage(800, 400);
Wt::WPainter p(&svgImage);
chart->paint(p);
p.end();
std::ofstream f("chart.svg");
svgImage.write(f);
A cartesian chart.
Definition: WCartesianChart.h:408
virtual void paint(WPainter &painter, const WRectF &rectangle=WRectF()) const override
Paint the chart in a rectangle of the given painter.
Definition: WCartesianChart.C:2702
Vector graphics painting class.
Definition: WPainter.h:147

Constructor & Destructor Documentation

◆ WSvgImage()

Wt::WSvgImage::WSvgImage ( const WLength width,
const WLength height,
bool  paintUpdate = false 
)

Create an SVG paint device.

If paintUpdate is true, then only an SVG fragment will be rendered that can be used to update the DOM of an existing SVG image, instead of a full SVG image.

Member Function Documentation

◆ done()

void Wt::WSvgImage::done ( )
overridevirtual

Finishes painting on the device.

This method is called when a WPainter stopped painting.

See also
WPainter::end()

Implements Wt::WPaintDevice.

◆ drawArc()

void Wt::WSvgImage::drawArc ( const WRectF rect,
double  startAngle,
double  spanAngle 
)
overridevirtual

Draws an arc.

The arc describes the segment of an ellipse enclosed by the rect. The segment starts at startAngle, and spans an angle given by spanAngle. These angles have as unit degree, and are measured counter-clockwise starting from the 3 o'clock position.

The arc must be stroked, filled, and transformed using the current painter settings.

Implements Wt::WPaintDevice.

◆ drawImage()

void Wt::WSvgImage::drawImage ( const WRectF rect,
const std::string &  imageUri,
int  imgWidth,
int  imgHeight,
const WRectF sourceRect 
)
overridevirtual

Draws an image.

Draws sourceRect from the image with URL imageUri and original dimensions imgWidth and imgHeight to the location, into the rectangle defined by rect.

The image is transformed using the current painter settings.

Implements Wt::WPaintDevice.

◆ drawLine()

void Wt::WSvgImage::drawLine ( double  x1,
double  y1,
double  x2,
double  y2 
)
overridevirtual

Draws a line.

The line must be stroked and transformed using the current painter settings.

Implements Wt::WPaintDevice.

◆ drawPath()

void Wt::WSvgImage::drawPath ( const WPainterPath path)
overridevirtual

Draws a path.

The path must be stroked, filled, and transformed using the current painter settings.

Implements Wt::WPaintDevice.

◆ drawRect()

void Wt::WSvgImage::drawRect ( const WRectF rectangle)
overridevirtual

Draws a rectangle.

The rect must be stroked, filled, and transformed using the current painter settings.

Implements Wt::WPaintDevice.

◆ drawText()

void Wt::WSvgImage::drawText ( const WRectF rect,
WFlags< AlignmentFlag alignmentFlags,
TextFlag  textFlag,
const WString text,
const WPointF clipPoint 
)
overridevirtual

Draws text.

The text must be rendered, stroked and transformed using the current painter settings.

If clipPoint is not null, a check is performed whether the point is inside of the current clip area. If not, the text is not drawn.

Implements Wt::WPaintDevice.

◆ fontMetrics()

WFontMetrics Wt::WSvgImage::fontMetrics ( )
overridevirtual

Returns font metrics.

This returns font metrics for the current font.

Throws a std::logic_error if the underlying device does not provide font metrics.

Implements Wt::WPaintDevice.

◆ handleRequest()

void Wt::WSvgImage::handleRequest ( const Http::Request request,
Http::Response response 
)
overridevirtual

Handles a request.

Reimplement this method so that a proper response is generated for the given request. From the request object you can access request parameters and whether the request is a continuation request. In the response object, you should set the mime type and stream the output data.

A request may also concern a continuation, indicated in Http::Request::continuation(), in which case the next part for a previously created continuation should be served.

While handling a request, which may happen at any time together with event handling, the library makes sure that the resource is not being concurrently deleted, but multiple requests may happend simultaneously for a single resource.

Implements Wt::WResource.

◆ height()

virtual WLength Wt::WSvgImage::height ( ) const
overridevirtual

Returns the device height.

The device height, in pixels, establishes the height of the device coordinate system.

Implements Wt::WPaintDevice.

◆ init()

void Wt::WSvgImage::init ( )
overridevirtual

Initializes the device for painting.

This method is called when a WPainter starts painting.

See also
WPainter::begin(WPaintDevice *), painter()

Implements Wt::WPaintDevice.

◆ measureText()

WTextItem Wt::WSvgImage::measureText ( const WString text,
double  maxWidth = -1,
bool  wordWrap = false 
)
overridevirtual

Measures rendered text size.

Returns the bounding rect of the given text when rendered using the current font.

If maxWidth != -1, then the text is truncated to fit in the width.

If wordWrap = true then text is truncated only at word boundaries. Note that in this case the whitespace at the truncated position is included in the text but not accounted for by the returned width (since usually you will not render the whitespace at the end of a line).

Throws a std::logic_error if the underlying device does not provide font metrics.

Implements Wt::WPaintDevice.

◆ paintActive()

virtual bool Wt::WSvgImage::paintActive ( ) const
overridevirtual

Returns whether painting is active.

See also
init(), painter()

Implements Wt::WPaintDevice.

◆ painter()

virtual WPainter* Wt::WSvgImage::painter ( ) const
overrideprotectedvirtual

Returns the painter that is currently painting on the device.

See also
init()

Implements Wt::WPaintDevice.

◆ setChanged()

void Wt::WSvgImage::setChanged ( WFlags< PainterChangeFlag flags)
overridevirtual

Indicates changes in painter state.

The flags argument is the logical OR of one or more change flags.

See also
ChangeFlag

Implements Wt::WPaintDevice.

◆ width()

virtual WLength Wt::WSvgImage::width ( ) const
overridevirtual

Returns the device width.

The device width, in pixels, establishes the width of the device coordinate system.

Implements Wt::WPaintDevice.