Package com.pd4ml

Class CustomTag

java.lang.Object

com.pd4ml.util.Base

com.pd4ml.CustomTag

Direct Known Subclasses:

BatikSvgCustomTag, MathMLCustomTag, ORCodeCustomTag, PD4MLSvgCustomTag

public class CustomTag
extends com.pd4ml.util.Base

Base class for handlers of custom HTML tags, which render content PD4ML does not support natively, for example charts or barcodes. Register a handler with PD4ML.addCustomTagHandler(String, CustomTag).

The registered object serves as a factory: for each occurrence of the tag in the document PD4ML calls getInstance(String, FontCache), and the returned instance reports the size of the element (getWidth(int), getHeight(int)) and draws it (paint(float, float, float, float, float, float, Graphics2D)). The element is laid out as an inline replaced element, like an image; CSS width and height on the tag override the reported size.

A subclass typically overrides getInstance(String, FontCache) to return a new instance of itself, parses its parameters from getInnerCode(), and overrides the size and paint methods. The default implementation draws a placeholder box.

Field Summary

Fields inherited from class com.pd4ml.util.Base

AES_128BIT, AES_256BIT, LOG_ALL, LOG_CACHE, LOG_CSS, LOG_DEBUG, LOG_ERROR, LOG_FATAL, LOG_FONTS, LOG_INFO, LOG_MINIMAL, LOG_PARSE, LOG_TRACE, LOG_USAGE, LOG_VERBOSE, LOG_WARN, NO_LOG, PD4ML_LOG_LEVEL, RC4_128BIT, RC4_40BIT

Constructor Summary

Constructors

Constructor	Description
CustomTag()	Creates the handler object to register with PD4ML.addCustomTagHandler(String, CustomTag).
CustomTag(java.lang.String code, com.pd4ml.fonts.FontCache fontCache, CustomTag prime)	Creates the handler instance for one occurrence of the tag; used by getInstance(String, FontCache).

Method Summary

Modifier and Type	Method	Description
int	getHeight(int base)	Returns the natural height of the element.
java.lang.String	getInnerCode()	Returns the source code of the tag occurrence: the complete element as it appears in the document, including the opening tag with its attributes, the content and the closing tag, for example <chart type="pie">...</chart>.
CustomTag	getInstance(java.lang.String code, com.pd4ml.fonts.FontCache fontCache)	Creates the handler instance for one occurrence of the tag.
int	getWidth(int base)	Returns the natural width of the element.
boolean	isEmptyTag()	Tells the parser whether the tag is an empty element without content or closing tag, like <br>.
void	paint(float x, float y, float width, float height, float containerWidth, float containerHeight, java.awt.Graphics2D g)	Draws the element.
void	paint(float x, float y, java.awt.Graphics2D g)	Draws the element at the given position, at its natural size.
void	setElement(com.pd4ml.html.doc.elements.Element element)	Called by PD4ML to pass the document element of this tag occurrence, for example to read its computed style.
void	setHeight(int height)	Sets the height the default getHeight(int) reports.
void	setInnerCode(java.lang.String code)	Replaces the source code of the tag occurrence.
void	setWidth(int width)	Sets the width the default getWidth(int) reports.

Methods inherited from class com.pd4ml.util.Base

log, log2, printLog, shouldForceException

Methods inherited from class java.lang.Object

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

Constructor Detail

CustomTag

public CustomTag()

Creates the handler object to register with PD4ML.addCustomTagHandler(String, CustomTag).

CustomTag

public CustomTag(java.lang.String code,
                 com.pd4ml.fonts.FontCache fontCache,
                 CustomTag prime)

Creates the handler instance for one occurrence of the tag; used by getInstance(String, FontCache).

Parameters:

code - the source code of the tag occurrence

fontCache - the font cache of the conversion

prime - the registered handler that creates this instance

Method Detail

getInstance

public CustomTag getInstance(java.lang.String code,
                             com.pd4ml.fonts.FontCache fontCache)

Creates the handler instance for one occurrence of the tag. PD4ML calls it on the registered handler while parsing the document. Subclasses override it to return an instance of themselves, typically created with CustomTag(String, FontCache, CustomTag).

Parameters:

code - the source code of the tag occurrence; see getInnerCode()

fontCache - the font cache of the conversion

Returns:

the handler instance for this occurrence

setElement

public void setElement(com.pd4ml.html.doc.elements.Element element)

Called by PD4ML to pass the document element of this tag occurrence, for example to read its computed style.

Parameters:

element - the element

getInnerCode

public java.lang.String getInnerCode()

Returns the source code of the tag occurrence: the complete element as it appears in the document, including the opening tag with its attributes, the content and the closing tag, for example <chart type="pie">...</chart>.

Returns:

the source code

setInnerCode

public void setInnerCode(java.lang.String code)

Replaces the source code of the tag occurrence.

Parameters:

code - the new source code

getWidth

public int getWidth(int base)
             throws java.io.IOException

Returns the natural width of the element. The default implementation returns the value set with setWidth(int).

Parameters:

base - the width available in the containing block, in pixels, for handlers that adapt their size to it

Returns:

the width in pixels

Throws:

java.io.IOException - if the size cannot be determined

getHeight

public int getHeight(int base)
              throws java.io.IOException

Returns the natural height of the element. The default implementation returns the value set with setHeight(int).

Parameters:

base - the width available in the containing block, in pixels

Returns:

the height in pixels

Throws:

java.io.IOException - if the size cannot be determined

setWidth

public void setWidth(int width)

Sets the width the default getWidth(int) reports.

Parameters:

width - the width in pixels

setHeight

public void setHeight(int height)

Sets the height the default getHeight(int) reports.

Parameters:

height - the height in pixels

paint

public void paint(float x,
                  float y,
                  float width,
                  float height,
                  float containerWidth,
                  float containerHeight,
                  java.awt.Graphics2D g)
           throws java.io.IOException

Draws the element. PD4ML calls this method for each output page the element appears on. The default implementation calls paint(float, float, Graphics2D).

Parameters:

x - the left edge of the element box in the coordinate system of g

y - the top edge of the element box

width - the width of the element box, after CSS sizing

height - the height of the element box, after CSS sizing

containerWidth - the width of the area the element is placed in

containerHeight - the height of the area the element is placed in

g - the graphics context to draw on; for PDF output, a PDF-generating implementation

Throws:

java.io.IOException - if drawing fails

paint

public void paint(float x,
                  float y,
                  java.awt.Graphics2D g)
           throws java.io.IOException

Draws the element at the given position, at its natural size. The default implementation draws a placeholder box labeled "DUMMY".

Parameters:

x - the left edge of the element box in the coordinate system of g

y - the top edge of the element box

g - the graphics context to draw on

Throws:

java.io.IOException - if drawing fails

isEmptyTag

public boolean isEmptyTag()

Tells the parser whether the tag is an empty element without content or closing tag, like <br>. The default implementation returns false: the parser reads everything up to the matching closing tag as part of the element.

Returns:

true if the tag has no content and no closing tag