Module java.desktop
Package javax.swing.text

Class AbstractWriter

  • Direct Known Subclasses:
    HTMLWriter, MinimalHTMLWriter
    public abstract class AbstractWriter
extends Object
    AbstractWriter is an abstract class that actually does the work of writing out the element tree including the attributes. In terms of how much is written out per line, the writer defaults to 100. But this value can be set by subclasses.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected static char NEWLINE
      How the text packages models newlines.

    • Method Summary

      Modifier and Type Method Description
      protected void decrIndent()
      Decrements the indent level.
      protected boolean getCanWrapLines()
      Returns whether or not the lines can be wrapped.
      protected int getCurrentLineLength()
      Returns the current line length.
      protected Document getDocument()
      Fetches the document.
      protected ElementIterator getElementIterator()
      Fetches the ElementIterator.
      int getEndOffset()
      Returns the last offset to be output.
      protected int getIndentLevel()
      Returns the current indentation level.
      protected int getIndentSpace()
      Returns the amount of space to indent.
      protected int getLineLength()
      Returns the maximum line length.
      String getLineSeparator()
      Returns the string used to represent newlines.
      int getStartOffset()
      Returns the first offset to be output.
      protected String getText​(Element elem)
      Returns the text associated with the element.
      protected Writer getWriter()
      Returns the Writer that is used to output the content.
      protected void incrIndent()
      Increments the indent level.
      protected void indent()
      Does indentation.
      protected boolean inRange​(Element next)
      This method determines whether the current element is in the range specified.
      protected boolean isLineEmpty()
      Returns true if the current line should be considered empty.
      protected void output​(char[] content, int start, int length)
      The last stop in writing out content.
      protected void setCanWrapLines​(boolean newValue)
      Sets whether or not lines can be wrapped.
      protected void setCurrentLineLength​(int length)
      Sets the current line length.
      protected void setIndentSpace​(int space)
      Enables subclasses to specify how many spaces an indent maps to.
      protected void setLineLength​(int l)
      Enables subclasses to set the number of characters they want written per line.
      void setLineSeparator​(String value)
      Sets the String used to represent newlines.
      protected void text​(Element elem)
      Writes out text.
      protected abstract void write()
      This abstract method needs to be implemented by subclasses.
      protected void write​(char ch)
      Writes out a character.
      protected void write​(char[] chars, int startIndex, int length)
      All write methods call into this one.
      protected void write​(String content)
      Writes out a string.
      protected void writeAttributes​(AttributeSet attr)
      Writes out the set of attributes as " <name>=<value>" pairs.
      protected void writeLineSeparator()
      Writes the line separator.

    • Constructor Detail

      • AbstractWriter

        protected AbstractWriter​(Writer w,
                         Document doc)
        Creates a new AbstractWriter. Initializes the ElementIterator with the default root of the document.
        Parameters:
        w - a Writer.
        doc - a Document

      • AbstractWriter

        protected AbstractWriter​(Writer w,
                         Document doc,
                         int pos,
                         int len)
        Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in.
        Parameters:
        w - a Writer
        doc - an Element
        pos - The location in the document to fetch the content.
        len - The amount to write out.

      • AbstractWriter

        protected AbstractWriter​(Writer w,
                         Element root)
        Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in.
        Parameters:
        w - a Writer
        root - an Element

      • AbstractWriter

        protected AbstractWriter​(Writer w,
                         Element root,
                         int pos,
                         int len)
        Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in.
        Parameters:
        w - a Writer
        root - an Element
        pos - The location in the document to fetch the content.
        len - The amount to write out.

    • Method Detail

      • getStartOffset

        public int getStartOffset()
        Returns the first offset to be output.
        Returns:
        the first offset to be output
        Since:
        1.3

      • getEndOffset

        public int getEndOffset()
        Returns the last offset to be output.
        Returns:
        the last offset to be output
        Since:
        1.3

      • getElementIterator

        protected ElementIterator getElementIterator()
        Fetches the ElementIterator.
        Returns:
        the ElementIterator.

      • getWriter

        protected Writer getWriter()
        Returns the Writer that is used to output the content.
        Returns:
        the Writer that is used to output the content
        Since:
        1.3

      • getDocument

        protected Document getDocument()
        Fetches the document.
        Returns:
        the Document.

      • inRange

        protected boolean inRange​(Element next)
        This method determines whether the current element is in the range specified. When no range is specified, the range is initialized to be the entire document. inRange() returns true if the range specified intersects with the element's range.
        Parameters:
        next - an Element.
        Returns:
        boolean that indicates whether the element is in the range.

      • write

        protected abstract void write()
                       throws IOException,
                              BadLocationException
        This abstract method needs to be implemented by subclasses. Its responsibility is to iterate over the elements and use the write() methods to generate output in the desired format.
        Throws:
        IOException - if an I/O problem has occurred
        BadLocationException - for an invalid location within the document

      • getText

        protected String getText​(Element elem)
                  throws BadLocationException
        Returns the text associated with the element. The assumption here is that the element is a leaf element. Throws a BadLocationException when encountered.
        Parameters:
        elem - an Element
        Returns:
        the text as a String
        Throws:
        BadLocationException - if pos represents an invalid location within the document

      • text

        protected void text​(Element elem)
             throws BadLocationException,
                    IOException
        Writes out text. If a range is specified when the constructor is invoked, then only the appropriate range of text is written out.
        Parameters:
        elem - an Element.
        Throws:
        IOException - on any I/O error
        BadLocationException - if pos represents an invalid location within the document.

      • setLineLength

        protected void setLineLength​(int l)
        Enables subclasses to set the number of characters they want written per line. The default is 100.
        Parameters:
        l - the maximum line length.

      • getLineLength

        protected int getLineLength()
        Returns the maximum line length.
        Returns:
        the maximum line length
        Since:
        1.3

      • setCurrentLineLength

        protected void setCurrentLineLength​(int length)
        Sets the current line length.
        Parameters:
        length - the new line length
        Since:
        1.3

      • getCurrentLineLength

        protected int getCurrentLineLength()
        Returns the current line length.
        Returns:
        the current line length
        Since:
        1.3

      • isLineEmpty

        protected boolean isLineEmpty()
        Returns true if the current line should be considered empty. This is true when getCurrentLineLength == 0 || indent has been invoked on an empty line.
        Returns:
        true if the current line should be considered empty
        Since:
        1.3

      • setCanWrapLines

        protected void setCanWrapLines​(boolean newValue)
        Sets whether or not lines can be wrapped. This can be toggled during the writing of lines. For example, outputting HTML might set this to false when outputting a quoted string.
        Parameters:
        newValue - new value for line wrapping
        Since:
        1.3

      • getCanWrapLines

        protected boolean getCanWrapLines()
        Returns whether or not the lines can be wrapped. If this is false no lineSeparator's will be output.
        Returns:
        whether or not the lines can be wrapped
        Since:
        1.3

      • setIndentSpace

        protected void setIndentSpace​(int space)
        Enables subclasses to specify how many spaces an indent maps to. When indentation takes place, the indent level is multiplied by this mapping. The default is 2.
        Parameters:
        space - an int representing the space to indent mapping.

      • getIndentSpace

        protected int getIndentSpace()
        Returns the amount of space to indent.
        Returns:
        the amount of space to indent
        Since:
        1.3

      • setLineSeparator

        public void setLineSeparator​(String value)
        Sets the String used to represent newlines. This is initialized in the constructor from either the Document, or the System property line.separator.
        Parameters:
        value - the new line separator
        Since:
        1.3

      • getLineSeparator

        public String getLineSeparator()
        Returns the string used to represent newlines.
        Returns:
        the string used to represent newlines
        Since:
        1.3

      • incrIndent

        protected void incrIndent()
        Increments the indent level. If indenting would cause getIndentSpace() *getIndentLevel() to be > than getLineLength() this will not cause an indent.

      • decrIndent

        protected void decrIndent()
        Decrements the indent level.

      • getIndentLevel

        protected int getIndentLevel()
        Returns the current indentation level. That is, the number of times incrIndent has been invoked minus the number of times decrIndent has been invoked.
        Returns:
        the current indentation level
        Since:
        1.3

      • indent

        protected void indent()
               throws IOException
        Does indentation. The number of spaces written out is indent level times the space to map mapping. If the current line is empty, this will not make it so that the current line is still considered empty.
        Throws:
        IOException - on any I/O error

      • write

        protected void write​(char ch)
              throws IOException
        Writes out a character. This is implemented to invoke the write method that takes a char[].
        Parameters:
        ch - a char.
        Throws:
        IOException - on any I/O error

      • write

        protected void write​(String content)
              throws IOException
        Writes out a string. This is implemented to invoke the write method that takes a char[].
        Parameters:
        content - a String.
        Throws:
        IOException - on any I/O error

      • writeLineSeparator

        protected void writeLineSeparator()
                           throws IOException
        Writes the line separator. This invokes output directly as well as setting the lineLength to 0.
        Throws:
        IOException - on any I/O error
        Since:
        1.3

      • write

        protected void write​(char[] chars,
                     int startIndex,
                     int length)
              throws IOException
        All write methods call into this one. If getCanWrapLines() returns false, this will call output with each sequence of chars that doesn't contain a NEWLINE, followed by a call to writeLineSeparator. On the other hand, if getCanWrapLines() returns true, this will split the string, as necessary, so getLineLength is honored. The only exception is if the current string contains no whitespace, and won't fit in which case the line length will exceed getLineLength.
        Parameters:
        chars - characters to output
        startIndex - starting index
        length - length of output
        Throws:
        IOException - on any I/O error
        Since:
        1.3

      • writeAttributes

        protected void writeAttributes​(AttributeSet attr)
                        throws IOException
        Writes out the set of attributes as " <name>=<value>" pairs. It throws an IOException when encountered.
        Parameters:
        attr - an AttributeSet.
        Throws:
        IOException - on any I/O error

      • output

        protected void output​(char[] content,
                      int start,
                      int length)
               throws IOException
        The last stop in writing out content. All the write methods eventually make it to this method, which invokes write on the Writer.

        This method also updates the line length based on length. If this is invoked to output a newline, the current line length will need to be reset as will no longer be valid. If it is up to the caller to do this. Use writeLineSeparator to write out a newline, which will property update the current line length.

        Parameters:
        content - characters to output
        start - starting index
        length - length of output
        Throws:
        IOException - on any I/O error
        Since:
        1.3