Module org.apache.sis.util
Package org.apache.sis.util.collection

Class TreeTableFormat

Object
Format
CompoundFormat<TreeTable>
TabularFormat<TreeTable>
TreeTableFormat
All Implemented Interfaces:
Serializable, Cloneable, Localized
public class TreeTableFormat extends TabularFormat<TreeTable>
A parser and formatter for Tree­Table instances. This formatter is given an arbitrary number of Table­Columns to use during the formatting. The first column is taken as the node label. If a Tree­Table is formatted with only that column, then the String result is like the following example: 
   Node #1
     ├─Node #2
     │   └─Node #4
     └─Node #3
If the same Tree­Table is formatted with two columns, then the String result is like the following example: 
   Node #1……………………… More #1
     ├─Node #2…………… More #2
     │   └─Node #4… More #4
     └─Node #3…………… More #3
This representation can be printed to the console output (for example) if the stream uses a monospaced font and supports Unicode characters.

Customization

Some formatting characteristics (indentation width, column where to draw the vertical line below nodes) can be modified by calls to the setter methods defined in this formatter. In particular, the dots joining the node labels to their values can be specified by the column separator pattern. The default pattern is "?……[…] ", which means "If the next value is non-null, then insert the "……" string, repeat the '…' character as many time as needed (may be zero), and finally insert a space".

Safety against infinite recursivity

Some Tree­Table implementations generate the nodes dynamically as wrappers around Java objects. Such Java objects may contain cyclic associations (A contains B contains C contains A), which result in a tree of infinite depth. Some examples can be found in ISO 19115 metadata. This Tree­Table­Format class contains a safety against such cycles. The algorithm is based on the assumption that for each node, the values and children are fully determined by the user object, if non-null. Consequently, for each node C to be formatted, if the user object of that node is the same instance (in the sense of the == operator) than the user object of a parent node A, then the children of the C node will not be formatted.
Since:
0.3
See Also:

  • Constructor Details

    • TreeTableFormat

      public TreeTableFormat(Locale locale, TimeZone timezone)
      Creates a new tree table format.
      Parameters:
      locale - the locale to use for numbers, dates and angles formatting, or null for the root locale.
      timezone - the timezone, or null for UTC.

  • Method Details

    • getValueType

      public final Class<TreeTable> getValueType()
      Returns the type of objects formatted by this class.
      Specified by:
      get­Value­Type in class Compound­Format<Tree­Table>
      Returns:
      Tree­Table​.class

    • getColumns

      public TableColumn<?>[] getColumns()
      Returns the table columns to parse and format, or null for the default list of columns. The default is:
      Returns:
      the table columns to parse and format, or null for the default.

    • setColumns

      public void setColumns(TableColumn<?>... columns) throws IllegalArgumentException
      Sets the table columns to parse and format. A null value means to use the default list of columns, as defined in the get­Columns() method.
      Parameters:
      columns - the table columns to parse and format, or null for the default.
      Throws:
      Illegal­Argument­Exception - if the given array is empty, contains a null element or a duplicated value.

    • getIndentation

      public int getIndentation()
      Returns the number of spaces to add on the left margin for each indentation level. The default value is 4.
      Returns:
      the current indentation.

    • setIndentation

      public void setIndentation(int indentation) throws IllegalArgumentException
      Sets the number of spaces to add on the left margin for each indentation level. If the new indentation is smaller than the vertical line position, then the latter is also set to the given indentation value.
      Parameters:
      indentation - the new indentation.
      Throws:
      Illegal­Argument­Exception - if the given value is negative.

    • getVerticalLinePosition

      public int getVerticalLinePosition()
      Returns the position of the vertical line, relative to the position of the root label. The default value is 2, which means that the vertical line is drawn below the third letter of the root label.
      Returns:
      the current vertical line position.

    • setVerticalLinePosition

      public void setVerticalLinePosition(int verticalLinePosition) throws IllegalArgumentException
      Sets the position of the vertical line, relative to the position of the root label. The given value cannot be greater than the indentation.
      Parameters:
      vertical­Line­Position - the new vertical line position.
      Throws:
      Illegal­Argument­Exception - if the given value is negative or greater than the indentation.

    • getNodeFilter

      public Predicate<TreeTable.Node> getNodeFilter()
      Returns the filter that specify whether a node should be formatted or ignored. This is the predicate specified in the last call to set­Node­Filter(Predicate). If no filter has been set, then this method returns null.
      Returns:
      a filter for specifying whether a node should be formatted, or null if no filtering is applied.
      Since:
      1.0

    • setNodeFilter

      public void setNodeFilter(Predicate<TreeTable.Node> filter)
      Sets a filter specifying whether a node should be formatted or ignored. Filters are tested at formatting time for all children of the root node (but not for the root node itself). Filters are ignored at parsing time.
      Parameters:
      filter - filter for specifying whether a node should be formatted, or null for no filtering.
      Since:
      1.0

    • parse

      public TreeTable parse(CharSequence text, ParsePosition pos) throws ParseException
      Creates a tree from the given character sequence, or returns null if the given text does not look like a tree for this method. This method can parse the trees created by the format(…) methods defined in this class.

      Parsing rules

      • Each node shall be represented by a single line made of two parts, in that order:
        1. white spaces and tree drawing characters ('│', '├', '└' or '─');
        2. string representations of node values, separated by the colunm separator.
      • The number of spaces and drawing characters before the node values determines the node indentation. This indentation does not need to be a factor of the get­Indentation() value, but must be consistent across all the parsed tree.
      • The indentation determines the parent of each node.
      • Parsing stops at first empty line (ignoring whitespaces), or at the end of the given text.

      Error index

      If the given text does not seem to be a tree table, then this method returns null. Otherwise if parsing started but failed, then:
      Specified by:
      parse in class Compound­Format<Tree­Table>
      Parameters:
      text - the character sequence for the tree to parse.
      pos - the position where to start the parsing.
      Returns:
      the parsed tree, or null if the given character sequence cannot be parsed.
      Throws:
      Parse­Exception - if an error occurred while parsing a node value.

    • format

      public void format(TreeTable tree, Appendable toAppendTo) throws IOException
      Writes a graphical representation of the specified tree table in the given stream or buffer. This method iterates recursively over all children. For each column to format in each node, this method gets a textual representation of the value in that column using the formatter obtained by a call to Compound­Format​.get­Format(Class).
      Specified by:
      format in class Compound­Format<Tree­Table>
      Parameters:
      tree - the tree to format.
      to­Append­To - where to format the tree.
      Throws:
      IOException - if an error occurred while writing to the given appendable.
      See Also:

    • createFormat

      protected Format createFormat(Class<?> valueType)
      Creates a new format to use for parsing and formatting values of the given type. This method is invoked the first time that a format is needed for the given type. Subclasses can override this method if they want to configure the way dates, numbers or other objects are formatted. See parent class documentation for more information.

      The implementation in Tree­Table­Format differs from the default implementation in the following aspects:

      Overrides:
      create­Format in class Compound­Format<Tree­Table>
      Parameters:
      value­Type - the base type of values to parse or format.
      Returns:
      the format to use for parsing of formatting values of the given type, or null if none.

    • writeColumnSeparator

      protected void writeColumnSeparator(int nextColumn, TableAppender out)
      Writes characters between columns. The default implementation applies the configuration specified by Tabular­Format​.set­Column­Separator­Pattern(String) as below:
      out​.append(before­Fill); out​.next­Column(fill­Character); out​.append(column­Separator);
      The output with default values is like below: 
         root
     └─column0…… column1…… column2…… column3
      Subclasses can override this method if different column separators are desired. Note however that doing so may prevent the parse(…) method to work.
      Parameters:
      next­Column - zero-based index of the column to be written after the separator.
      out - where to write the column separator.
      Since:
      1.0
      See Also:

    • clone

      public TreeTableFormat clone()
      Returns a clone of this format.
      Overrides:
      clone in class Tabular­Format<Tree­Table>
      Returns:
      a clone of this format.