A paint device for rendering using the HTML 5 <canvas> element. More...
#include <Wt/WCanvasPaintDevice>
Inherits Wt::WObject, and Wt::WPaintDevice.
Public Member Functions | |
WCanvasPaintDevice (const WLength &width, const WLength &height, WObject *parent=0) | |
Create a canvas paint device. | |
virtual void | setChanged (WFlags< ChangeFlag > flags) |
Indicates changes in painter state. | |
virtual void | drawArc (const WRectF &rect, double startAngle, double spanAngle) |
Draws an arc. | |
virtual void | drawImage (const WRectF &rect, const std::string &imgUri, int imgWidth, int imgHeight, const WRectF &sourceRect) |
Draws an image. | |
virtual void | drawLine (double x1, double y1, double x2, double y2) |
Draws a line. | |
virtual void | drawPath (const WPainterPath &path) |
Draws a path. | |
virtual void | drawText (const WRectF &rect, WFlags< AlignmentFlag > flags, const WString &text) |
Draws text. | |
virtual void | init () |
Initializes the device for painting. | |
virtual void | done () |
Finishes painting on the device. | |
virtual bool | paintActive () const |
Returns whether painting is active. | |
virtual WLength | width () const |
Returns the device width. | |
virtual WLength | height () const |
Returns the device height. | |
virtual WFlags< PaintFlag > | paintFlags () const |
Returns the paint flags. | |
Protected Member Functions | |
virtual WPainter * | painter () const |
Returns the painter that is currently painting on the device. | |
virtual void | setPainter (WPainter *painter) |
Sets the painter. | |
virtual void | setPaintFlags (WFlags< PaintFlag > paintFlags) |
Sets paint flags. |
A paint device for rendering using the HTML 5 <canvas> element.
The WCanvasPaintDevice is used by WPaintedWidget to render to the browser using the HTML 5 <canvas> element. You usually will not use the device directly, but rather rely on WPaintedWidget to use this device when appropriate.
void Wt::WCanvasPaintDevice::done | ( | ) | [virtual] |
Finishes painting on the device.
This method is called when a WPainter stopped painting.
Implements Wt::WPaintDevice.
void Wt::WCanvasPaintDevice::drawArc | ( | const WRectF & | rect, | |
double | startAngle, | |||
double | spanAngle | |||
) | [virtual] |
Draws an arc.
The arc is defined as in WPainter::drawArc(const WRectF&, startAngle, spanAngle), but the angle is expressed in degrees.
The arc must be stroked, filled, and transformed using the current painter settings.
Implements Wt::WPaintDevice.
void Wt::WCanvasPaintDevice::drawImage | ( | const WRectF & | rect, | |
const std::string & | imageUri, | |||
int | imgWidth, | |||
int | imgHeight, | |||
const WRectF & | sourceRect | |||
) | [virtual] |
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.
void Wt::WCanvasPaintDevice::drawLine | ( | double | x1, | |
double | y1, | |||
double | x2, | |||
double | y2 | |||
) | [virtual] |
Draws a line.
The line must be stroked and transformed using the current painter settings.
Implements Wt::WPaintDevice.
void Wt::WCanvasPaintDevice::drawPath | ( | const WPainterPath & | path | ) | [virtual] |
Draws a path.
The path must be stroked, filled, and transformed using the current painter settings.
Implements Wt::WPaintDevice.
void Wt::WCanvasPaintDevice::drawText | ( | const WRectF & | rect, | |
WFlags< AlignmentFlag > | flags, | |||
const WString & | text | |||
) | [virtual] |
Draws text.
The text must be rendered, stroked and transformed using the current painter settings.
Implements Wt::WPaintDevice.
virtual WLength Wt::WCanvasPaintDevice::height | ( | ) | const [inline, virtual] |
Returns the device height.
The device height, in pixels, establishes the height of the device coordinate system.
Implements Wt::WPaintDevice.
void Wt::WCanvasPaintDevice::init | ( | ) | [virtual] |
Initializes the device for painting.
This method is called when a WPainter starts painting.
Implements Wt::WPaintDevice.
virtual bool Wt::WCanvasPaintDevice::paintActive | ( | ) | const [inline, virtual] |
virtual WPainter* Wt::WCanvasPaintDevice::painter | ( | ) | const [inline, protected, virtual] |
Returns the painter that is currently painting on the device.
Implements Wt::WPaintDevice.
void Wt::WCanvasPaintDevice::setChanged | ( | WFlags< ChangeFlag > | flags | ) | [virtual] |
Indicates changes in painter state.
The flags
argument is the logical OR of one or more change flags.
Implements Wt::WPaintDevice.
virtual WLength Wt::WCanvasPaintDevice::width | ( | ) | const [inline, virtual] |
Returns the device width.
The device width, in pixels, establishes the width of the device coordinate system.
Implements Wt::WPaintDevice.