org.htmlunit.javascript.host.canvas

Class CanvasRenderingContext2D

java.lang.Object

org.htmlunit.corejs.javascript.SlotMapOwner

org.htmlunit.corejs.javascript.ScriptableObject

org.htmlunit.javascript.HtmlUnitScriptable

org.htmlunit.javascript.host.canvas.CanvasRenderingContext2D

All Implemented Interfaces:

Serializable, Cloneable, org.htmlunit.corejs.javascript.ConstProperties, org.htmlunit.corejs.javascript.debug.DebuggableObject, org.htmlunit.corejs.javascript.Scriptable, org.htmlunit.corejs.javascript.SymbolScriptable

public class CanvasRenderingContext2D
extends HtmlUnitScriptable

A JavaScript object for CanvasRenderingContext2D.

Author:

Ahmed Ashour, Marc Guillemot, Frank Danek, Ronald Brill

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.htmlunit.corejs.javascript.ScriptableObject

org.htmlunit.corejs.javascript.ScriptableObject.DescriptorInfo, org.htmlunit.corejs.javascript.ScriptableObject.KeyComparator, org.htmlunit.corejs.javascript.ScriptableObject.LambdaGetterFunction, org.htmlunit.corejs.javascript.ScriptableObject.LambdaSetterFunction

Field Summary

Fields inherited from class org.htmlunit.corejs.javascript.ScriptableObject

CONST, DONTENUM, EMPTY, PERMANENT, READONLY, UNINITIALIZED_CONST

Fields inherited from interface org.htmlunit.corejs.javascript.Scriptable

NOT_FOUND

Constructor Summary

Constructors

Constructor and Description
CanvasRenderingContext2D() Default constructor.
CanvasRenderingContext2D(HTMLCanvasElement canvas) Constructs in association with HTMLCanvasElement.

Method Summary

Modifier and Type	Method and Description
void	arc(double x, double y, double radius, double startAngle, double endAngle, boolean anticlockwise) Draws an arc.
void	arcTo(double x1, double y1, double x2, double y2, double radius) Draws an arc.
void	beginPath() Begins the subpaths.
void	bezierCurveTo(double cp1x, double cp1y, double cp2x, double cp2y, double x, double y) Draws a cubic Bézier curve.
void	clearRect(double x, double y, double w, double h) Clears the specified rectangular area.
static void	clip(org.htmlunit.corejs.javascript.Context context, org.htmlunit.corejs.javascript.Scriptable scope, org.htmlunit.corejs.javascript.Scriptable thisObj, Object[] args, org.htmlunit.corejs.javascript.Function function) Creates a new clipping region.
void	closePath() Closes the current subpath.
static ImageData	createImageData(org.htmlunit.corejs.javascript.Context context, org.htmlunit.corejs.javascript.Scriptable scope, org.htmlunit.corejs.javascript.Scriptable thisObj, Object[] args, org.htmlunit.corejs.javascript.Function function) Returns the ImageData object.
CanvasGradient	createLinearGradient(double x0, double y0, double r0, double x1, Object y1, Object r1) Creates linear gradient.
void	createPattern() Creates a pattern.
CanvasGradient	createRadialGradient(double x0, double y0, double r0, double x1, double y1, double r1) Creates a gradient.
void	drawImage(Object image, int sx, int sy, Object sWidth, Object sHeight, Object dx, Object dy, Object dWidth, Object dHeight) Draws images onto the canvas.
void	ellipse(double x, double y, double radiusX, double radiusY, double rotation, double startAngle, double endAngle, boolean anticlockwise) Paints the specified ellipse.
void	fill() Fills the shape.
void	fillRect(int x, int y, int w, int h) Paints the specified rectangular area.
void	fillText(String text, double x, double y) Fills a given text at the given (x, y) position.
HTMLCanvasElement	getCanvas() Returns the associated HTMLCanvasElement.
HtmlUnitScriptable	getFillStyle() Returns the fillStyle property.
double	getGlobalAlpha() Specifies the alpha (transparency) value that is applied to shapes and images before they are drawn onto the canvas.
ImageData	getImageData(int sx, int sy, int sw, int sh) Returns the ImageData object.
double	getLineWidth() Returns the lineWidth property.
HtmlUnitScriptable	getStrokeStyle() Returns the strokeStyle property.
void	isPointInPath() Dummy placeholder.
void	jsConstructor() JavaScript constructor.
void	lineDash() Dummy placeholder.
void	lineData() Dummy placeholder.
void	lineTo(double x, double y) Connect the last point to the given point.
TextMetrics	measureText(Object text) Calculate TextMetrics for the given text.
void	moveTo(double x, double y) Creates a new subpath.
void	putImageData(ImageData imageData, int dx, int dy, Object dirtyX, Object dirtyY, Object dirtyWidth, Object dirtyHeight) Paints data from the given ImageData object onto the canvas.
void	quadraticCurveTo(double controlPointX, double controlPointY, double endPointX, double endPointY) Draws a quadratic Bézier curve.
void	rect(double x, double y, double w, double h) Renders a rectangle.
void	restore() Pops state stack and restore state.
void	rotate(double angle) Adds a rotation to the transformation matrix.
void	save() Pushes state on state stack.
void	scale(Object x, Object y) Changes the transformation matrix to apply a scaling transformation with the given characteristics.
void	setFillStyle(String fillStyle) Sets the fillStyle property.
void	setGlobalAlpha(double globalAlpha) Sets the globalAlpha property.
void	setLineDash() Dummy placeholder.
void	setLineWidth(Object lineWidth) Sets the lineWidth property.
void	setStrokeStyle(String strokeStyle) Sets the strokeStyle property.
void	setTransform(double m11, double m12, double m21, double m22, double dx, double dy) Resets (overrides) the current transformation to the identity matrix, and then invokes a transformation described by the arguments of this method.
void	stroke() Calculates the strokes of all the subpaths of the current path.
void	strokeRect(int x, int y, int w, int h) Strokes the specified rectangular area.
void	strokeText() Dummy placeholder.
String	toDataURL(String type) Returns the Data URL.
void	transform(double m11, double m12, double m21, double m22, double dx, double dy) Multiplies the current transformation with the matrix described by the arguments of this method.
void	translate(int x, int y) Changes the transformation matrix to apply a translation transformation with the given characteristics.

Methods inherited from class org.htmlunit.javascript.HtmlUnitScriptable

clone, equivalentValues, get, getBrowserVersion, getClassName, getDefaultValue, getDomNodeOrDie, getDomNodeOrNull, getPrototype, getScriptableFor, getWindow, getWindow, getWindowFromTopCallScope, getWithPreemption, has, hasInstance, initParentScope, makeScriptableFor, put, setClassName, setDomNode, setDomNode, setParentScope, setupPromise, setupRejectedPromise

Methods inherited from class org.htmlunit.corejs.javascript.ScriptableObject

applyDescriptorToAttributeBitset, associateValue, avoidObjectDetection, buildDataDescriptor, callMethod, callMethod, checkNotSealed, checkPropertyChangeForSlot, checkPropertyChangeForSlot, checkPropertyDefinition, checkSlotRemoval, defineBuiltInProperty, defineBuiltInProperty, defineBuiltInProperty, defineBuiltInProperty, defineClass, defineClass, defineClass, defineConst, defineConstProperty, defineFunctionProperties, defineOwnProperties, defineOwnProperty, defineOwnProperty, defineProperty, defineProperty, defineProperty, defineProperty, defineProperty, defineProperty, defineProperty, defineProperty, defineProperty, defineProperty, delete, delete, delete, deleteProperty, deleteProperty, deleteProperty, ensureScriptable, ensureScriptableObject, ensureScriptableObjectButNotSymbol, ensureSymbolScriptable, ensureType, get, get, get, getAllIds, getArrayPrototype, getAssociatedValue, getAttributes, getAttributes, getAttributes, getAttributes, getAttributes, getClassPrototype, getDefaultValue, getExternalArrayData, getExternalArrayLength, getFunctionPrototype, getGeneratorFunctionPrototype, getGetterOrSetter, getGetterOrSetter, getIds, getObjectPrototype, getOwnPropertyDescriptor, getParentScope, getProperty, getProperty, getProperty, getPropertyIds, getPrototype, getSuperProperty, getSuperProperty, getSuperProperty, getTopLevelScope, getTopScopeValue, getTypedProperty, getTypedProperty, getTypeOf, has, has, hasProperty, hasProperty, hasProperty, isAccessorDescriptor, isConst, isDataDescriptor, isDataDescriptor, isEmpty, isExtensible, isFalse, isGenericDescriptor, isGetterOrSetter, isGetterOrSetter, isSealed, isTrue, preventExtensions, put, put, putConst, putConstProperty, putOwnProperty, putOwnProperty, putOwnProperty, putProperty, putProperty, putProperty, putSuperProperty, putSuperProperty, putSuperProperty, querySlot, redefineProperty, sameValue, sealObject, setAttributes, setAttributes, setAttributes, setAttributes, setAttributes, setCommonDescriptorProperties, setExternalArrayData, setGetterOrSetter, setPrototype, size

Methods inherited from class org.htmlunit.corejs.javascript.SlotMapOwner

createSlotMap

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CanvasRenderingContext2D

public CanvasRenderingContext2D()

Default constructor.

CanvasRenderingContext2D

public CanvasRenderingContext2D(HTMLCanvasElement canvas)

Constructs in association with HTMLCanvasElement.

Parameters:

canvas - the HTMLCanvasElement

Method Detail

jsConstructor

public void jsConstructor()

JavaScript constructor.

getGlobalAlpha

public double getGlobalAlpha()

Specifies the alpha (transparency) value that is applied to shapes and images before they are drawn onto the canvas.

Returns:

the globalAlpha property

setGlobalAlpha

public void setGlobalAlpha(double globalAlpha)

Sets the globalAlpha property.

Parameters:

globalAlpha - the globalAlpha property

getFillStyle

public HtmlUnitScriptable getFillStyle()

Returns the fillStyle property.

Returns:

the fillStyle property

setFillStyle

public void setFillStyle(String fillStyle)

Sets the fillStyle property.

Parameters:

fillStyle - the fillStyle property

getStrokeStyle

public HtmlUnitScriptable getStrokeStyle()

Returns the strokeStyle property.

Returns:

the strokeStyle property

setStrokeStyle

public void setStrokeStyle(String strokeStyle)

Sets the strokeStyle property.

Parameters:

strokeStyle - the strokeStyle property

getLineWidth

public double getLineWidth()

Returns the lineWidth property.

Returns:

the lineWidth property

setLineWidth

public void setLineWidth(Object lineWidth)

Sets the lineWidth property.

Parameters:

lineWidth - the lineWidth property

arc

public void arc(double x,
                double y,
                double radius,
                double startAngle,
                double endAngle,
                boolean anticlockwise)

Draws an arc.

Parameters:

x - the x

y - the y

radius - the radius

startAngle - the start angle

endAngle - the end angle

anticlockwise - is anti-clockwise

arcTo

public void arcTo(double x1,
                  double y1,
                  double x2,
                  double y2,
                  double radius)

Draws an arc.

Parameters:

x1 - the x1

y1 - the y1

x2 - the x2

y2 - the y2

radius - the radius

beginPath

public void beginPath()

Begins the subpaths.

bezierCurveTo

public void bezierCurveTo(double cp1x,
                          double cp1y,
                          double cp2x,
                          double cp2y,
                          double x,
                          double y)

Draws a cubic Bézier curve.

Parameters:

cp1x - the cp1x

cp1y - the cp1y

cp2x - the cp2x

cp2y - the cp2y

x - the x

y - the y

clearRect

public void clearRect(double x,
                      double y,
                      double w,
                      double h)

Clears the specified rectangular area.

Parameters:

x - the x

y - the y

w - the width

h - the height

clip

public static void clip(org.htmlunit.corejs.javascript.Context context,
                        org.htmlunit.corejs.javascript.Scriptable scope,
                        org.htmlunit.corejs.javascript.Scriptable thisObj,
                        Object[] args,
                        org.htmlunit.corejs.javascript.Function function)

Creates a new clipping region.

Parameters:

context - the JavaScript context

scope - the scope

thisObj - the scriptable

args - the arguments passed into the method

function - the function

closePath

public void closePath()

Closes the current subpath.

createImageData

public static ImageData createImageData(org.htmlunit.corejs.javascript.Context context,
                                        org.htmlunit.corejs.javascript.Scriptable scope,
                                        org.htmlunit.corejs.javascript.Scriptable thisObj,
                                        Object[] args,
                                        org.htmlunit.corejs.javascript.Function function)

Returns the ImageData object. this may accept a variable number of arguments.

Parameters:

context - the JavaScript context

scope - the scope

thisObj - the scriptable

args - the arguments passed into the method

function - the function

Returns:

the ImageData object

createLinearGradient

public CanvasGradient createLinearGradient(double x0,
                                           double y0,
                                           double r0,
                                           double x1,
                                           Object y1,
                                           Object r1)

Creates linear gradient.

Parameters:

x0 - the x0

y0 - the y0

r0 - the r0

x1 - the x1

y1 - the y1

r1 - the r1

Returns:

the new CanvasGradient

createPattern

public void createPattern()

Creates a pattern.

createRadialGradient

public CanvasGradient createRadialGradient(double x0,
                                           double y0,
                                           double r0,
                                           double x1,
                                           double y1,
                                           double r1)

Creates a gradient.

Parameters:

x0 - the x axis of the coordinate of the start circle

y0 - the y axis of the coordinate of the start circle

r0 - the radius of the start circle

x1 - the x axis of the coordinate of the end circle

y1 - the y axis of the coordinate of the end circle

r1 - the radius of the end circle

Returns:

the new CanvasGradient

drawImage

public void drawImage(Object image,
                      int sx,
                      int sy,
                      Object sWidth,
                      Object sHeight,
                      Object dx,
                      Object dy,
                      Object dWidth,
                      Object dHeight)

Draws images onto the canvas.

Parameters:

image - an element to draw into the context

sx - the X coordinate of the top left corner of the sub-rectangle of the source image to draw into the destination context

sy - the Y coordinate of the top left corner of the sub-rectangle of the source image to draw into the destination context

sWidth - the width of the sub-rectangle of the source image to draw into the destination context

sHeight - the height of the sub-rectangle of the source image to draw into the destination context

dx - the X coordinate in the destination canvas at which to place the top-left corner of the source image

dy - the Y coordinate in the destination canvas at which to place the top-left corner of the source image

dWidth - the width to draw the image in the destination canvas. This allows scaling of the drawn image

dHeight - the height to draw the image in the destination canvas. This allows scaling of the drawn image

toDataURL

public String toDataURL(String type)

Returns the Data URL.

Parameters:

type - an optional type

Returns:

the dataURL

ellipse

public void ellipse(double x,
                    double y,
                    double radiusX,
                    double radiusY,
                    double rotation,
                    double startAngle,
                    double endAngle,
                    boolean anticlockwise)

Paints the specified ellipse.

Parameters:

x - the x

y - the y

radiusX - the radiusX

radiusY - the radiusY

rotation - the rotation

startAngle - the startAngle

endAngle - the endAngle

anticlockwise - the anticlockwise

fill

public void fill()

Fills the shape.

fillRect

public void fillRect(int x,
                     int y,
                     int w,
                     int h)

Paints the specified rectangular area.

Parameters:

x - the x

y - the y

w - the width

h - the height

fillText

public void fillText(String text,
                     double x,
                     double y)

Fills a given text at the given (x, y) position.

Parameters:

text - the text

x - the x

y - the y

getImageData

public ImageData getImageData(int sx,
                              int sy,
                              int sw,
                              int sh)

Returns the ImageData object.

Parameters:

sx - x

sy - y

sw - width

sh - height

Returns:

the ImageData object

lineDash

public void lineDash()

Dummy placeholder.

lineData

public void lineData()

Dummy placeholder.

isPointInPath

public void isPointInPath()

Dummy placeholder.

lineTo

public void lineTo(double x,
                   double y)

Connect the last point to the given point.

Parameters:

x - the x

y - the y

measureText

public TextMetrics measureText(Object text)

Calculate TextMetrics for the given text.

Parameters:

text - the text to measure

Returns:

the text metrics

moveTo

public void moveTo(double x,
                   double y)

Creates a new subpath.

Parameters:

x - the x

y - the y

putImageData

public void putImageData(ImageData imageData,
                         int dx,
                         int dy,
                         Object dirtyX,
                         Object dirtyY,
                         Object dirtyWidth,
                         Object dirtyHeight)

Paints data from the given ImageData object onto the canvas.

Parameters:

imageData - an ImageData object containing the array of pixel values

dx - horizontal position (x coordinate) at which to place the image data in the destination canvas

dy - vertical position (y coordinate) at which to place the image data in the destination canvas

dirtyX - horizontal position (x coordinate) of the top-left corner from which the image data will be extracted. Defaults to 0.

dirtyY - vertical position (y coordinate) of the top-left corner from which the image data will be extracted. Defaults to 0.

dirtyWidth - width of the rectangle to be painted. Defaults to the width of the image data.

dirtyHeight - height of the rectangle to be painted. Defaults to the height of the image data.

quadraticCurveTo

public void quadraticCurveTo(double controlPointX,
                             double controlPointY,
                             double endPointX,
                             double endPointY)

Draws a quadratic Bézier curve.

Parameters:

controlPointX - the x-coordinate of the control point

controlPointY - the y-coordinate of the control point

endPointX - the x-coordinate of the end point

endPointY - the y-coordinate of the end point

rect

public void rect(double x,
                 double y,
                 double w,
                 double h)

Renders a rectangle.

Parameters:

x - the x

y - the y

w - the width

h - the height

restore

public void restore()

Pops state stack and restore state.

rotate

public void rotate(double angle)

Adds a rotation to the transformation matrix.

Parameters:

angle - the angle

save

public void save()

Pushes state on state stack.

scale

public void scale(Object x,
                  Object y)

Changes the transformation matrix to apply a scaling transformation with the given characteristics.

Parameters:

x - the scale factor in the horizontal direction

y - the scale factor in the vertical direction

setLineDash

public void setLineDash()

Dummy placeholder.

setTransform

public void setTransform(double m11,
                         double m12,
                         double m21,
                         double m22,
                         double dx,
                         double dy)

Resets (overrides) the current transformation to the identity matrix, and then invokes a transformation described by the arguments of this method. This lets you scale, rotate, translate (move), and skew the context.

Parameters:

m11 - Horizontal scaling. A value of 1 results in no scaling

m12 - Vertical skewing

m21 - Horizontal skewing

m22 - Vertical scaling. A value of 1 results in no scaling

dx - Horizontal translation (moving)

dy - Vertical translation (moving).

stroke

public void stroke()

Calculates the strokes of all the subpaths of the current path.

strokeRect

public void strokeRect(int x,
                       int y,
                       int w,
                       int h)

Strokes the specified rectangular area.

Parameters:

x - the x

y - the y

w - the width

h - the height

strokeText

public void strokeText()

Dummy placeholder.

transform

public void transform(double m11,
                      double m12,
                      double m21,
                      double m22,
                      double dx,
                      double dy)

Multiplies the current transformation with the matrix described by the arguments of this method. This lets you scale, rotate, translate (move), and skew the context.

Parameters:

m11 - Horizontal scaling. A value of 1 results in no scaling

m12 - Vertical skewing

m21 - Horizontal skewing

m22 - Vertical scaling. A value of 1 results in no scaling

dx - Horizontal translation (moving)

dy - Vertical translation (moving).

translate

public void translate(int x,
                      int y)

Changes the transformation matrix to apply a translation transformation with the given characteristics.

Parameters:

x - the translation distance in the horizontal direction

y - the translation distance in the vertical direction

getCanvas

public HTMLCanvasElement getCanvas()

Returns the associated HTMLCanvasElement.

Returns:

the associated HTMLCanvasElement