javax.swing.text.html

Class HTMLDocument.HTMLReader

Enclosing Class:
HTMLDocument

public class HTMLDocument.HTMLReader
extends HTMLEditorKit.ParserCallback

An HTML reader to load an HTML document with an HTML element structure. This is a set of callbacks from the parser, implemented to create a set of elements tagged with attributes. The parse builds up tokens (ElementSpec) that describe the element subtree desired, and burst it into the document under the protection of a write lock using the insert method on the document outer class.

The reader can be configured by registering actions (of type HTMLDocument.HTMLReader.TagAction) that describe how to handle the action. The idea behind the actions provided is that the most natural text editing operations can be provided if the element structure boils down to paragraphs with runs of some kind of style in them. Some things are more naturally specified structurally, so arbitrary structure should be allowed above the paragraphs, but will need to be edited with structural actions. The implication of this is that some of the HTML elements specified in the stream being parsed will be collapsed into attributes, and in some cases paragraphs will be synthesized. When HTML elements have been converted to attributes, the attribute key will be of type HTML.Tag, and the value will be of type AttributeSet so that no information is lost. This enables many of the existing actions to work so that the user can type input, hit the return key, backspace, delete, etc and have a reasonable result. Selections can be created, and attributes applied or removed, etc. With this in mind, the work done by the reader can be categorized into the following kinds of tasks:

Currently, <APPLET>, <PARAM>, <MAP>, <AREA>, <LINK>, <SCRIPT> and <STYLE> are unsupported.

The assignment of the actions described is shown in the following table for the tags defined in HTML.Tag.

TagAction
HTML.Tag.A CharacterAction
HTML.Tag.ADDRESS CharacterAction
HTML.Tag.APPLET HiddenAction
HTML.Tag.AREA AreaAction
HTML.Tag.B CharacterAction
HTML.Tag.BASE BaseAction
HTML.Tag.BASEFONT CharacterAction
HTML.Tag.BIG CharacterAction
HTML.Tag.BLOCKQUOTEBlockAction
HTML.Tag.BODY BlockAction
HTML.Tag.BR SpecialAction
HTML.Tag.CAPTION BlockAction
HTML.Tag.CENTER BlockAction
HTML.Tag.CITE CharacterAction
HTML.Tag.CODE CharacterAction
HTML.Tag.DD BlockAction
HTML.Tag.DFN CharacterAction
HTML.Tag.DIR BlockAction
HTML.Tag.DIV BlockAction
HTML.Tag.DL BlockAction
HTML.Tag.DT ParagraphAction
HTML.Tag.EM CharacterAction
HTML.Tag.FONT CharacterAction
HTML.Tag.FORM As of 1.4 a BlockAction
HTML.Tag.FRAME SpecialAction
HTML.Tag.FRAMESET BlockAction
HTML.Tag.H1 ParagraphAction
HTML.Tag.H2 ParagraphAction
HTML.Tag.H3 ParagraphAction
HTML.Tag.H4 ParagraphAction
HTML.Tag.H5 ParagraphAction
HTML.Tag.H6 ParagraphAction
HTML.Tag.HEAD HeadAction
HTML.Tag.HR SpecialAction
HTML.Tag.HTML BlockAction
HTML.Tag.I CharacterAction
HTML.Tag.IMG SpecialAction
HTML.Tag.INPUT FormAction
HTML.Tag.ISINDEX IsndexAction
HTML.Tag.KBD CharacterAction
HTML.Tag.LI BlockAction
HTML.Tag.LINK LinkAction
HTML.Tag.MAP MapAction
HTML.Tag.MENU BlockAction
HTML.Tag.META MetaAction
HTML.Tag.NOFRAMES BlockAction
HTML.Tag.OBJECT SpecialAction
HTML.Tag.OL BlockAction
HTML.Tag.OPTION FormAction
HTML.Tag.P ParagraphAction
HTML.Tag.PARAM HiddenAction
HTML.Tag.PRE PreAction
HTML.Tag.SAMP CharacterAction
HTML.Tag.SCRIPT HiddenAction
HTML.Tag.SELECT FormAction
HTML.Tag.SMALL CharacterAction
HTML.Tag.STRIKE CharacterAction
HTML.Tag.S CharacterAction
HTML.Tag.STRONG CharacterAction
HTML.Tag.STYLE StyleAction
HTML.Tag.SUB CharacterAction
HTML.Tag.SUP CharacterAction
HTML.Tag.TABLE BlockAction
HTML.Tag.TD BlockAction
HTML.Tag.TEXTAREA FormAction
HTML.Tag.TH BlockAction
HTML.Tag.TITLE TitleAction
HTML.Tag.TR BlockAction
HTML.Tag.TT CharacterAction
HTML.Tag.U CharacterAction
HTML.Tag.UL BlockAction
HTML.Tag.VAR CharacterAction

Once </html> is encountered, the Actions are no longer notified.

Nested Class Summary

class
HTMLDocument.HTMLReader.BlockAction
class
HTMLDocument.HTMLReader.CharacterAction
class
HTMLDocument.HTMLReader.FormAction
Action to support forms by building all of the elements used to represent form controls.
class
HTMLDocument.HTMLReader.HiddenAction
class
HTMLDocument.HTMLReader.IsindexAction
class
HTMLDocument.HTMLReader.ParagraphAction
class
HTMLDocument.HTMLReader.PreAction
class
HTMLDocument.HTMLReader.SpecialAction
class
HTMLDocument.HTMLReader.TagAction
An action to be performed in response to parsing a tag.

Field Summary

protected MutableAttributeSet
charAttr
protected Vector
parseBuffer

Fields inherited from class javax.swing.text.html.HTMLEditorKit.ParserCallback

IMPLIED

Constructor Summary

HTMLReader(int offset)
HTMLReader(int offset, int popDepth, int pushDepth, HTML.Tag insertTag)

Method Summary

protected void
addContent(char[] data, int offs, int length)
Adds some text with the current character attributes.
protected void
addContent(char[] data, int offs, int length, boolean generateImpliedPIfNecessary)
Adds some text with the current character attributes.
protected void
addSpecialElement(HTML.Tag t, MutableAttributeSet a)
Adds content that is basically specified entirely in the attribute set.
protected void
blockClose(HTML.Tag t)
Adds an instruction to the parse buffer to close out a block element of the given type.
protected void
blockOpen(HTML.Tag t, MutableAttributeSet attr)
Adds an instruction to the parse buffer to create a block element with the given attributes.
void
flush()
The last method called on the reader.
void
handleComment(char[] data, int pos)
void
handleEndOfLineString(String eol)
This is invoked after the stream has been parsed, but before flush.
void
handleEndTag(HTML.Tag t, int pos)
Callback from the parser.
void
handleSimpleTag(HTML.Tag t, MutableAttributeSet a, int pos)
Callback from the parser.
void
handleStartTag(HTML.Tag t, MutableAttributeSet a, int pos)
Callback from the parser.
void
handleText(char[] data, int pos)
Called by the parser to indicate a block of text was encountered.
protected void
popCharacterStyle()
Pops a previously pushed character style off the stack to return to a previous style.
protected void
preContent(char[] data)
Adds the given content that was encountered in a PRE element.
protected void
pushCharacterStyle()
Pushes the current character style on a stack in preparation for forming a new nested character style.
protected void
registerTag(HTML.Tag t, HTMLDocument.HTMLReader.TagAction a)
Registers a handler for the given tag.
protected void
textAreaContent(char[] data)
Adds the given content to the textarea document.

Methods inherited from class javax.swing.text.html.HTMLEditorKit.ParserCallback

flush, handleComment, handleEndOfLineString, handleEndTag, handleError, handleSimpleTag, handleStartTag, handleText

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

charAttr

protected MutableAttributeSet charAttr

parseBuffer

protected Vector parseBuffer

Constructor Details

HTMLReader

public HTMLReader(int offset)

HTMLReader

public HTMLReader(int offset,
                  int popDepth,
                  int pushDepth,
                  HTML.Tag insertTag)

Method Details

addContent

protected void addContent(char[] data,
                          int offs,
                          int length)
Adds some text with the current character attributes.
Parameters:

addContent

protected void addContent(char[] data,
                          int offs,
                          int length,
                          boolean generateImpliedPIfNecessary)
Adds some text with the current character attributes.
Parameters:

addSpecialElement

protected void addSpecialElement(HTML.Tag t,
                                 MutableAttributeSet a)
Adds content that is basically specified entirely in the attribute set.

blockClose

protected void blockClose(HTML.Tag t)
Adds an instruction to the parse buffer to close out a block element of the given type.

blockOpen

protected void blockOpen(HTML.Tag t,
                         MutableAttributeSet attr)
Adds an instruction to the parse buffer to create a block element with the given attributes.

flush

public void flush()
            throws BadLocationException
The last method called on the reader. It allows any pending changes to be flushed into the document. Since this is currently loading synchronously, the entire set of changes are pushed in at this point.
Overrides:
flush in interface HTMLEditorKit.ParserCallback

handleComment

public void handleComment(char[] data,
                          int pos)
Overrides:
handleComment in interface HTMLEditorKit.ParserCallback

handleEndOfLineString

public void handleEndOfLineString(String eol)
This is invoked after the stream has been parsed, but before flush. eol will be one of \n, \r or \r\n, which ever is encountered the most in parsing the stream.
Overrides:
handleEndOfLineString in interface HTMLEditorKit.ParserCallback
Since:
1.3

handleEndTag

public void handleEndTag(HTML.Tag t,
                         int pos)
Callback from the parser. Route to the appropriate handler for the tag.
Overrides:
handleEndTag in interface HTMLEditorKit.ParserCallback

handleSimpleTag

public void handleSimpleTag(HTML.Tag t,
                            MutableAttributeSet a,
                            int pos)
Callback from the parser. Route to the appropriate handler for the tag.
Overrides:
handleSimpleTag in interface HTMLEditorKit.ParserCallback

handleStartTag

public void handleStartTag(HTML.Tag t,
                           MutableAttributeSet a,
                           int pos)
Callback from the parser. Route to the appropriate handler for the tag.
Overrides:
handleStartTag in interface HTMLEditorKit.ParserCallback

handleText

public void handleText(char[] data,
                       int pos)
Called by the parser to indicate a block of text was encountered.
Overrides:
handleText in interface HTMLEditorKit.ParserCallback

popCharacterStyle

protected void popCharacterStyle()
Pops a previously pushed character style off the stack to return to a previous style.

preContent

protected void preContent(char[] data)
Adds the given content that was encountered in a PRE element. This synthesizes lines to hold the runs of text, and makes calls to addContent to actually add the text.

pushCharacterStyle

protected void pushCharacterStyle()
Pushes the current character style on a stack in preparation for forming a new nested character style.

registerTag

protected void registerTag(HTML.Tag t,
                           HTMLDocument.HTMLReader.TagAction a)
Registers a handler for the given tag. By default all of the well-known tags will have been registered. This can be used to change the handling of a particular tag or to add support for custom tags.

textAreaContent

protected void textAreaContent(char[] data)
Adds the given content to the textarea document. This method gets called when we are in a textarea context. Therefore all text that is seen belongs to the text area and is hence added to the TextAreaDocument associated with the text area.