// This code prints the column title for all columns.
// It also prints the values that appear in all columns.

Main {

  traversal allColumns (ColumnTitleVisitor) {
    // columns and sub-parts
    bypassing Expr
    to *;
  }
  traversal allColumns (ColumnValueVisitor) {
    // just columns
    to Column;
  }

  void printColumnTitle() =
    allColumns(ColumnTitleVisitor);

  void printColumnValue(String names) =
    allColumns(ColumnValueVisitor);
}


Column {
  {{
    static int min_width = 7;
    static int max_width = 30;
    int real_width;  // the actual width that will be used
  }}
}



// This visitor prints the titles of the columns and sets the
// real width that will be used to print the values.

ColumnTitleVisitor {
  // Column = "column" <title> Title [Width] "is" <expr> Expr.

  {{
    String theTitle;
    String line1;
    String line2;
    String dashes = "===================================================";
    Column col;
  }}

  init {{
    line1 = "";
    line2 = "";
  }}

  before Column {{
    col = host;
    col.real_width = 0;
  }}

  after Main {{
    System.out.println (line1 + "Events");
    System.out.println (line2 + "======");
  }}

  after Column {{
    if (col.real_width == 0) {
      col.real_width = theTitle.length();
    }
    if (col.real_width < Column.min_width) {
      col.real_width = Column.min_width;
    } else if (host.real_width > Column.max_width) {
      col.real_width = Column.max_width;
    }

    String paddedString = "                          " + theTitle;
    int paddedLen = paddedString.length();
    line1 = line1 + paddedString.substring(paddedLen - col.real_width) + " ";
    int dashLen = dashes.length();
    line2 = line2 + dashes.substring(dashLen - col.real_width) + " ";
  }}

  before Title {{
    theTitle = host.get_string();
  }}

  before Width {{
    col.real_width = host.get_width().intValue();
  }}
}


// This visitor prints the values of the columns.

ColumnValueVisitor {
  {{
    String line = "";
  }}

  after Main {{
    System.out.println (line + names);
  }}

  after Column {{
    Double value = host.get_expr().evaluate();
    Long longValue = new Long(value.longValue()); // don't print decimal point
    String paddedString = "                          " + longValue;

    int paddedLen = paddedString.length();
    line = line + paddedString.substring(paddedLen - host.real_width) + " ";
  }}
}