com.mxgraph.canvas

Class mxGraphicsCanvas2D

java.lang.Object

com.mxgraph.canvas.mxGraphicsCanvas2D

All Implemented Interfaces:

mxICanvas2D

public class mxGraphicsCanvas2D
extends Object
implements mxICanvas2D

Used for exporting images. To render to an image from a given XML string, graph size and background color, the following code is used: BufferedImage image = mxUtils.createBufferedImage(width, height, background); Graphics2D g2 = image.createGraphics(); mxUtils.setAntiAlias(g2, true, true); XMLReader reader = SAXParserFactory.newInstance().newSAXParser().getXMLReader(); reader.setContentHandler(new mxSaxOutputHandler(new mxGraphicsCanvas2D(g2))); reader.parse(new InputSource(new StringReader(xml))); Text rendering is available for plain text and HTML markup, the latter with optional word wrapping. CSS support is limited to the following: http://docs.oracle.com/javase/6/docs/api/index.html?javax/swing/text/html/CSS.html

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	mxGraphicsCanvas2D.CanvasState

Field Summary

Fields

Modifier and Type	Field and Description
static int	COLOR_CACHE_SIZE Specifies the size of the cache used to store parsed colors
protected LinkedHashMap<String,Color>	colorCache Caches parsed colors.
protected GeneralPath	currentPath Holds the current path.
protected Graphics2D	graphics Reference to the graphics instance for painting.
static int	IMAGE_SCALING Specifies the image scaling quality.
static int	JAVA_TEXT_WIDTH_DELTA Specifies the additional pixels when computing the text width for HTML labels.
protected int	lastCap Stroke caching.
protected boolean	lastDashed Stroke caching.
protected Object	lastDashPattern Stroke caching.
protected Font	lastFont Font caching.
protected String	lastFontFamily Font caching.
protected int	lastFontSize Font caching.
protected int	lastFontStyle Font caching.
protected int	lastJoin Stroke caching.
protected float	lastMiterLimit Stroke caching.
protected Stroke	lastStroke Stroke caching.
protected float	lastStrokeWidth Stroke caching.
protected CellRendererPane	rendererPane Optional renderer pane to be used for HTML label rendering.
protected Stack<mxGraphicsCanvas2D.CanvasState>	stack Stack of states for save/restore.
protected mxGraphicsCanvas2D.CanvasState	state Represents the current state of the canvas.
protected boolean	textEnabled Specifies if text output should be rendered.

Constructor Summary

Constructors

Constructor and Description
mxGraphicsCanvas2D(Graphics2D g) Constructs a new graphics export canvas.

Method Summary

Modifier and Type	Method and Description
void	begin() Begins a new path.
protected mxGraphicsCanvas2D.CanvasState	cloneState(mxGraphicsCanvas2D.CanvasState state) Returns a clone of thec given state.
void	close() Closes the current path.
protected Font	createFont(String family, int style, int size) Hook for subclassers to implement font caching.
protected String	createHtmlDocument(String text, String style) Creates a HTML document for the given text and CSS style.
protected String	createHtmlDocument(String text, String align, String valign, int w, int h, boolean wrap, String overflow, boolean clip) Creates a HTML document around the given markup.
protected Graphics2D	createImageGraphics(double x, double y, double w, double h, boolean flipH, boolean flipV) Creates a graphic instance for rendering an image.
protected Graphics2D	createTextGraphics(double x, double y, double w, double h, double rotation, boolean clip, String align, String valign) Returns a new graphics instance with the correct color and font for text rendering.
void	curveTo(double x1, double y1, double x2, double y2, double x3, double y3) Draws a bezier curve to the given point.
protected void	drawImage(Graphics2D graphics, Image image, int x, int y)
void	ellipse(double x, double y, double w, double h) Next fill or stroke should draw an ellipse.
void	fill() Fills the current path.
void	fillAndStroke() Fills and paints the outline of the current path.
protected String	getFontName(String family) Returns a font name for the given CSS values for font-family.
Graphics2D	getGraphics() Returns the graphics instance.
protected Rectangle	getImageBounds(Image img, double x, double y, double w, double h, boolean aspect)
protected Dimension	getImageSize(Image image) Returns the size for the given image.
protected Point2D	getMargin(String align, String valign)
protected JLabel	getTextRenderer() Hook to return the renderer for HTML formatted text.
protected void	htmlText(double x, double y, double w, double h, String str, String align, String valign, boolean wrap, String format, String overflow, boolean clip, double rotation) Draws the given HTML text.
void	image(double x, double y, double w, double h, String src, boolean aspect, boolean flipH, boolean flipV) Draws the given image.
boolean	isTextEnabled() Returns true if text should be rendered.
void	lineTo(double x, double y) Draws a line to the given path.
protected Image	loadImage(String src) Hook for image caching.
void	moveTo(double x, double y) Moves to the given path.
protected void	paintCurrentPath(boolean filled, boolean stroked)
protected void	paintShadow(boolean filled, boolean stroked)
protected Color	parseColor(String hex) Helper method that uses mxUtils.parseColor(String).
protected Color	parseColor(String hex, double alpha) Helper method that uses mxUtils.parseColor(String).
void	plainText(double x, double y, double w, double h, String str, String align, String valign, boolean wrap, String format, String overflow, boolean clip, double rotation) Draws the given text.
void	quadTo(double x1, double y1, double x2, double y2) Draws a quadratic curve to the given point.
void	rect(double x, double y, double w, double h) Next fill or stroke should draw a rectangle.
void	restore() Restores the last canvas state.
void	rotate(double theta, boolean flipH, boolean flipV, double cx, double cy) Rotates the canvas by the given angle around the given center.
void	roundrect(double x, double y, double w, double h, double dx, double dy) Implements a rounded rectangle using a path.
void	save() Saves the current canvas state.
void	scale(double value) Uniformaly scales the canvas by the given amount.
protected Image	scaleImage(Image img, int w, int h) Uses IMAGE_SCALING to scale the given image.
void	setAlpha(double value) Default value 1.
void	setDashed(boolean value) Sets the dashed state.
void	setDashPattern(String value) Sets the dash pattern.
void	setFillAlpha(double value) Default value 1.
void	setFillColor(String value) Default value mxConstants.NONE.
void	setFontBackgroundColor(String value) Default value "#000000".
void	setFontBorderColor(String value) Default value "#000000".
void	setFontColor(String value) Default value "#000000".
void	setFontFamily(String value) Default value mxConstants.DEFAULT_FONTFAMILY.
void	setFontSize(double value) Default value mxConstants.DEFAULT_FONTSIZE.
void	setFontStyle(int value) Default value 0.
void	setGradient(String color1, String color2, double x, double y, double w, double h, String direction, double alpha1, double alpha2) Prepares the canvas to draw a gradient.
void	setGraphics(Graphics2D value) Sets the graphics instance.
void	setLineCap(String value) Sets the linecap.
void	setLineJoin(String value) Sets the linejoin.
void	setMiterLimit(double value) Sets the miterlimit.
void	setShadow(boolean value) Enables or disables the painting of shadows.
void	setShadowAlpha(double value) Default value mxConstants.NONE.
void	setShadowColor(String value) Default value mxConstants.NONE.
void	setShadowOffset(double dx, double dy) Default value mxConstants.NONE.
void	setStrokeAlpha(double value) Default value 1.
void	setStrokeColor(String value) Caches color conversion as it is expensive.
void	setStrokeWidth(double value) Sets the stroke width.
void	setTextEnabled(boolean value) Disables or enables text rendering.
void	stroke() Paints the outline of the current path.
void	text(double x, double y, double w, double h, String str, String align, String valign, boolean wrap, String format, String overflow, boolean clip, double rotation, String textDirection) Draws the given text.
void	translate(double dx, double dy) Translates the canvas by the given amount.
protected void	updateFont()
protected void	updateStroke()

Methods inherited from class java.lang.Object

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

Field Detail

IMAGE_SCALING

public static int IMAGE_SCALING

Specifies the image scaling quality. Default is Image.SCALE_SMOOTH. See scaleImage(Image, int, int)

JAVA_TEXT_WIDTH_DELTA

public static int JAVA_TEXT_WIDTH_DELTA

Specifies the additional pixels when computing the text width for HTML labels. Default is 2.

COLOR_CACHE_SIZE

public static int COLOR_CACHE_SIZE

Specifies the size of the cache used to store parsed colors

graphics

protected Graphics2D graphics

Reference to the graphics instance for painting.

textEnabled

protected boolean textEnabled

Specifies if text output should be rendered. Default is true.

state

protected transient mxGraphicsCanvas2D.CanvasState state

Represents the current state of the canvas.

stack

protected transient Stack<mxGraphicsCanvas2D.CanvasState> stack

Stack of states for save/restore.

currentPath

protected transient GeneralPath currentPath

Holds the current path.

rendererPane

protected CellRendererPane rendererPane

Optional renderer pane to be used for HTML label rendering.

lastFont

protected transient Font lastFont

Font caching.

lastFontStyle

protected transient int lastFontStyle

Font caching.

lastFontSize

protected transient int lastFontSize

Font caching.

lastFontFamily

protected transient String lastFontFamily

Font caching.

lastStroke

protected transient Stroke lastStroke

Stroke caching.

lastStrokeWidth

protected transient float lastStrokeWidth

Stroke caching.

lastCap

protected transient int lastCap

Stroke caching.

lastJoin

protected transient int lastJoin

Stroke caching.

lastMiterLimit

protected transient float lastMiterLimit

Stroke caching.

lastDashed

protected transient boolean lastDashed

Stroke caching.

lastDashPattern

protected transient Object lastDashPattern

Stroke caching.

colorCache

protected transient LinkedHashMap<String,Color> colorCache

Caches parsed colors.

Constructor Detail

mxGraphicsCanvas2D

public mxGraphicsCanvas2D(Graphics2D g)

Constructs a new graphics export canvas.

Method Detail

setGraphics

public void setGraphics(Graphics2D value)

Sets the graphics instance.

getGraphics

public Graphics2D getGraphics()

Returns the graphics instance.

isTextEnabled

public boolean isTextEnabled()

Returns true if text should be rendered.

setTextEnabled

public void setTextEnabled(boolean value)

Disables or enables text rendering.

save

public void save()

Saves the current canvas state.

Specified by:

save in interface mxICanvas2D

restore

public void restore()

Restores the last canvas state.

Specified by:

restore in interface mxICanvas2D

cloneState

protected mxGraphicsCanvas2D.CanvasState cloneState(mxGraphicsCanvas2D.CanvasState state)

Returns a clone of thec given state.

scale

public void scale(double value)

Description copied from interface: mxICanvas2D

Uniformaly scales the canvas by the given amount.

Specified by:

scale in interface mxICanvas2D

Parameters:

value - The new scale value.

translate

public void translate(double dx,
                      double dy)

Description copied from interface: mxICanvas2D

Translates the canvas by the given amount.

Specified by:

translate in interface mxICanvas2D

Parameters:

dx - X-coordinate of the translation.

dy - Y-coordinate of the translation.

rotate

public void rotate(double theta,
                   boolean flipH,
                   boolean flipV,
                   double cx,
                   double cy)

Description copied from interface: mxICanvas2D

Rotates the canvas by the given angle around the given center. This method may add rendering overhead and should be used with care.

Specified by:

rotate in interface mxICanvas2D

Parameters:

theta - Rotation angle in degrees (0 - 360).

flipH - Specifies if drawing should be flipped horizontally.

flipV - Specifies if drawing should be flipped vertically.

cx - X-coordinate of the center point.

cy - Y-coordinate of the center point.

setStrokeWidth

public void setStrokeWidth(double value)

Description copied from interface: mxICanvas2D

Sets the stroke width. This should default to 1 if unset.

Specified by:

setStrokeWidth in interface mxICanvas2D

Parameters:

value - Width of the stroke. The value should be multiplied by the current scale.

setStrokeColor

public void setStrokeColor(String value)

Caches color conversion as it is expensive.

Specified by:

setStrokeColor in interface mxICanvas2D

Parameters:

value - Hex representation of the color or mxConstants.NONE.

setDashed

public void setDashed(boolean value)

Description copied from interface: mxICanvas2D

Sets the dashed state. This should default to false if unset.

Specified by:

setDashed in interface mxICanvas2D

Parameters:

value - Boolean representing the dashed state.

setDashPattern

public void setDashPattern(String value)

Description copied from interface: mxICanvas2D

Sets the dash pattern. This should default to "3 3" if unset.

Specified by:

setDashPattern in interface mxICanvas2D

Parameters:

value - Space separated list of floats representing the dash pattern. The value should be multiplied by the current scale.

setLineCap

public void setLineCap(String value)

Description copied from interface: mxICanvas2D

Sets the linecap. This should default to "flat" if unset.

Specified by:

setLineCap in interface mxICanvas2D

Parameters:

value - "flat", "square" or "round".

setLineJoin

public void setLineJoin(String value)

Description copied from interface: mxICanvas2D

Sets the linejoin. This should default to "miter" if unset.

Specified by:

setLineJoin in interface mxICanvas2D

Parameters:

value - "miter", "round" or "bevel".

setMiterLimit

public void setMiterLimit(double value)

Description copied from interface: mxICanvas2D

Sets the miterlimit. This should default to 10 if unset.

Specified by:

setMiterLimit in interface mxICanvas2D

setFontSize

public void setFontSize(double value)

Description copied from interface: mxICanvas2D

Default value mxConstants.DEFAULT_FONTSIZE.

Specified by:

setFontSize in interface mxICanvas2D

setFontColor

public void setFontColor(String value)

Description copied from interface: mxICanvas2D

Default value "#000000".

Specified by:

setFontColor in interface mxICanvas2D

Parameters:

value - Hex representation of the color or mxConstants.NONE.

setFontBackgroundColor

public void setFontBackgroundColor(String value)

Description copied from interface: mxICanvas2D

Default value "#000000".

Specified by:

setFontBackgroundColor in interface mxICanvas2D

Parameters:

value - Hex representation of the color or mxConstants.NONE.

setFontBorderColor

public void setFontBorderColor(String value)

Description copied from interface: mxICanvas2D

Default value "#000000".

Specified by:

setFontBorderColor in interface mxICanvas2D

Parameters:

value - Hex representation of the color or mxConstants.NONE.

setFontFamily

public void setFontFamily(String value)

Description copied from interface: mxICanvas2D

Default value mxConstants.DEFAULT_FONTFAMILY.

Specified by:

setFontFamily in interface mxICanvas2D

setFontStyle

public void setFontStyle(int value)

Description copied from interface: mxICanvas2D

Default value 0. See mxConstants.STYLE_FONTSTYLE.

Specified by:

setFontStyle in interface mxICanvas2D

setAlpha

public void setAlpha(double value)

Description copied from interface: mxICanvas2D

Default value 1. This method may add rendering overhead and should be used with care.

Specified by:

setAlpha in interface mxICanvas2D

setFillAlpha

public void setFillAlpha(double value)

Description copied from interface: mxICanvas2D

Default value 1. This method may add rendering overhead and should be used with care.

Specified by:

setFillAlpha in interface mxICanvas2D

setStrokeAlpha

public void setStrokeAlpha(double value)

Description copied from interface: mxICanvas2D

Default value 1. This method may add rendering overhead and should be used with care.

Specified by:

setStrokeAlpha in interface mxICanvas2D

setFillColor

public void setFillColor(String value)

Description copied from interface: mxICanvas2D

Default value mxConstants.NONE.

Specified by:

setFillColor in interface mxICanvas2D

Parameters:

value - Hex representation of the color or mxConstants.NONE.

setGradient

public void setGradient(String color1,
                        String color2,
                        double x,
                        double y,
                        double w,
                        double h,
                        String direction,
                        double alpha1,
                        double alpha2)

Description copied from interface: mxICanvas2D

Prepares the canvas to draw a gradient.

Specified by:

setGradient in interface mxICanvas2D

direction - Direction may be null. Use default value mxConstants.DIRECTION_SOUTH.

parseColor

protected Color parseColor(String hex)

Helper method that uses mxUtils.parseColor(String).

parseColor

protected Color parseColor(String hex,
                           double alpha)

Helper method that uses mxUtils.parseColor(String).

rect

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

Description copied from interface: mxICanvas2D

Next fill or stroke should draw a rectangle.

Specified by:

rect in interface mxICanvas2D

roundrect

public void roundrect(double x,
                      double y,
                      double w,
                      double h,
                      double dx,
                      double dy)

Implements a rounded rectangle using a path.

Specified by:

roundrect in interface mxICanvas2D

ellipse

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

Description copied from interface: mxICanvas2D

Next fill or stroke should draw an ellipse.

Specified by:

ellipse in interface mxICanvas2D

image

public void image(double x,
                  double y,
                  double w,
                  double h,
                  String src,
                  boolean aspect,
                  boolean flipH,
                  boolean flipV)

Description copied from interface: mxICanvas2D

Draws the given image.

Specified by:

image in interface mxICanvas2D

drawImage

protected void drawImage(Graphics2D graphics,
                         Image image,
                         int x,
                         int y)

loadImage

protected Image loadImage(String src)

Hook for image caching.

getImageBounds

protected final Rectangle getImageBounds(Image img,
                                         double x,
                                         double y,
                                         double w,
                                         double h,
                                         boolean aspect)

getImageSize

protected Dimension getImageSize(Image image)

Returns the size for the given image.

scaleImage

protected Image scaleImage(Image img,
                           int w,
                           int h)

Uses IMAGE_SCALING to scale the given image.

createImageGraphics

protected final Graphics2D createImageGraphics(double x,
                                               double y,
                                               double w,
                                               double h,
                                               boolean flipH,
                                               boolean flipV)

Creates a graphic instance for rendering an image.

createHtmlDocument

protected String createHtmlDocument(String text,
                                    String align,
                                    String valign,
                                    int w,
                                    int h,
                                    boolean wrap,
                                    String overflow,
                                    boolean clip)

Creates a HTML document around the given markup.

createHtmlDocument

protected String createHtmlDocument(String text,
                                    String style)

Creates a HTML document for the given text and CSS style.

getTextRenderer

protected JLabel getTextRenderer()

Hook to return the renderer for HTML formatted text. This implementation returns the shared instance of mxLighweightLabel.

getMargin

protected Point2D getMargin(String align,
                            String valign)

htmlText

protected void htmlText(double x,
                        double y,
                        double w,
                        double h,
                        String str,
                        String align,
                        String valign,
                        boolean wrap,
                        String format,
                        String overflow,
                        boolean clip,
                        double rotation)

Draws the given HTML text.

text

public void text(double x,
                 double y,
                 double w,
                 double h,
                 String str,
                 String align,
                 String valign,
                 boolean wrap,
                 String format,
                 String overflow,
                 boolean clip,
                 double rotation,
                 String textDirection)

Draws the given text.

Specified by:

text in interface mxICanvas2D

plainText

public void plainText(double x,
                      double y,
                      double w,
                      double h,
                      String str,
                      String align,
                      String valign,
                      boolean wrap,
                      String format,
                      String overflow,
                      boolean clip,
                      double rotation)

Draws the given text.

createTextGraphics

protected final Graphics2D createTextGraphics(double x,
                                              double y,
                                              double w,
                                              double h,
                                              double rotation,
                                              boolean clip,
                                              String align,
                                              String valign)

Returns a new graphics instance with the correct color and font for text rendering.

begin

public void begin()

Description copied from interface: mxICanvas2D

Begins a new path.

Specified by:

begin in interface mxICanvas2D

moveTo

public void moveTo(double x,
                   double y)

Description copied from interface: mxICanvas2D

Moves to the given path.

Specified by:

moveTo in interface mxICanvas2D

lineTo

public void lineTo(double x,
                   double y)

Description copied from interface: mxICanvas2D

Draws a line to the given path.

Specified by:

lineTo in interface mxICanvas2D

quadTo

public void quadTo(double x1,
                   double y1,
                   double x2,
                   double y2)

Description copied from interface: mxICanvas2D

Draws a quadratic curve to the given point.

Specified by:

quadTo in interface mxICanvas2D

curveTo

public void curveTo(double x1,
                    double y1,
                    double x2,
                    double y2,
                    double x3,
                    double y3)

Description copied from interface: mxICanvas2D

Draws a bezier curve to the given point.

Specified by:

curveTo in interface mxICanvas2D

close

public void close()

Closes the current path.

Specified by:

close in interface mxICanvas2D

stroke

public void stroke()

Description copied from interface: mxICanvas2D

Paints the outline of the current path.

Specified by:

stroke in interface mxICanvas2D

fill

public void fill()

Description copied from interface: mxICanvas2D

Fills the current path.

Specified by:

fill in interface mxICanvas2D

fillAndStroke

public void fillAndStroke()

Description copied from interface: mxICanvas2D

Fills and paints the outline of the current path.

Specified by:

fillAndStroke in interface mxICanvas2D

paintCurrentPath

protected void paintCurrentPath(boolean filled,
                                boolean stroked)

paintShadow

protected void paintShadow(boolean filled,
                           boolean stroked)

setShadow

public void setShadow(boolean value)

Description copied from interface: mxICanvas2D

Enables or disables the painting of shadows.

Specified by:

setShadow in interface mxICanvas2D

Parameters:

value - Whether the shadow should be enabled.

setShadowColor

public void setShadowColor(String value)

Description copied from interface: mxICanvas2D

Default value mxConstants.NONE.

Specified by:

setShadowColor in interface mxICanvas2D

Parameters:

value - Hex representation of the color or mxConstants.NONE.

setShadowAlpha

public void setShadowAlpha(double value)

Description copied from interface: mxICanvas2D

Default value mxConstants.NONE.

Specified by:

setShadowAlpha in interface mxICanvas2D

Parameters:

value - Hex representation of the color or mxConstants.NONE.

setShadowOffset

public void setShadowOffset(double dx,
                            double dy)

Description copied from interface: mxICanvas2D

Default value mxConstants.NONE.

Specified by:

setShadowOffset in interface mxICanvas2D

updateFont

protected void updateFont()

createFont

protected Font createFont(String family,
                          int style,
                          int size)

Hook for subclassers to implement font caching.

getFontName

protected String getFontName(String family)

Returns a font name for the given CSS values for font-family. This implementation returns the first entry for comma-separated lists of entries.

updateStroke

protected void updateStroke()