FBB::Table(3bobcat)

Table-formatter
(libbobcat-dev_6.02.02)

2005-2022

NAME

SYNOPSIS

DESCRIPTION

FBB::Table objects can be used to create tables. Tables are filled either column- or row-wise. Many of the table's characteristics may be fine-tuned using a separate FBB::TableSupport object (cf. tablesupport(3bobcat)). When no FBB::TableSupport object is used, a plain table, filled row-wise or column-wise, is constructed which can be inserted into a std::ostream.

Tables defined by Table consist of rows and a fixed number of columns. The number of columns is specified at construction time, the number of rows also depends on the number of inserted elements. Columns and rows are addressed using indices (starting at 0). Before the leftmost column, between the columns and beyond the last column separators are defined. By default these separators are empty, but each separator may be given a (fixed) width or content. The separator before column col is addressed as separator col, the rightmost separator is addressed as separator nColummns.

Rows can also be separated from each other using separators. These separating rows are empty by default. The row-separator before row row is addressed as row-separator row. The row-separator following the final row is addressed as row-separator nRows, where nRows is the value returned by the nRows member function.

Non-default (i.e., non-empty) separators are defined using FBB::TableSupport objects (cf. tablesupport(3bobcat)).

Table objects look a lot like ostream objects, using a simple way to define new elements: each new insertion defines another table element, and it is difficult to end a row before it has received its nColumn number of elements. Table's sister-class, TableBuf, is a std::streambuf type of class, offering additional control through the use of a wrapping ostream class object.

NAMESPACE

INHERITS FROM

std::ostringstream - Table inherits from std::ostringstream, allowing insertions into a Table object. Each separate insertion adds another element to the Table object.

FBB::TableBase - This class implements common elements of the table implementation. The TableBase class is not intended to be used by itself, and no separate man-page is provided. Facilities provided by Table which were inherited from TableBase are described in this man-page.

ENUMERATIONS

• ROWWISE:
  When this value is specified at construction time, elements are added row-wise to the table. I.e., the second element inserted into the Table will be found in the second column of the first row;
• COLUMNWISE:
  When this value is specified at construction time, elements are added column-wise to the table. I.e., the second element is found in the second row of the first column.

enum WidthType
This enumeration defines two values:

• COLUMNWIDTH:
  Specify this value when the columns may have variable widths. In this case each column will be as wide as its widest element. This is the default WidthType used by Table objects.
• EQUALWIDTH:
  Specify this value when all of the table's columns must have equal widths (i.e., equal to the width of the widest table element),

CONSTRUCTORS

• Table(size_t nColumns, Table::FillDirection direction, Table::WidthType widthType = Table::COLUMNWIDTH):
  The table's number of columns, the fill directions and the column width-type must be provided. The number of rows is implied by the combination of this parameter and the number of elements that is actually inserted into the Table object. The direction parameter specifies the way new elements are added to the Table object: row-wise or column-wise. Finally, the widthType parameter is used to specify the way the width of the table's columns is determined. Each column either defines its own width or all columns have equal widths.
• Table(TableSupport &tableSupport, size_t nColumns, Table::FillDirection direction, Table::WidthType widthType = Table::COLUMNWIDTH):
  This constructor operates identically to the previous constructor, but expects an additional reference to a TableSupport object. A TableSupport object offers additional formatting features used by the table defining elements like horizontal lines between rows, additional separators, etc, etc. The TableSupport object is passed as a non-const reference as the Table object must be able to manipulate its data. See tablesuppport(3bobcat) for more information about TableSupport.

Copy and move constructors (and assignment operators) are not available.

OVERLOADED OPERATORS

• std::ostream &operator<<(std::ostream &str, Table &table):
  This operator inserts a Table into a std::ostream object. This operator requires a non-const table as it may have to complete the table by adding empty elements (i.e., empty strings) to obtain a completely filled rectangular table;
• Table &operator<<(Table &obj, Align const &align):
  This operator changes the default alignment of either a column or an element. It is a wrapper around the member setAlign (see below for its description). By default, all elements are right-aligned (see also align(3bobcat));
• Table &operator<<(Table &obj, Type const &item):
  This operator is defined as a function template: Type is a template type parameter instantiated to a type for which std::ostringstream insertions are possible. It inserts the value/object item into the Table's std::ostringstream base class object as the table's next element.

MEMBER FUNCTIONS

• Table &append(std::string const &text char const *sep = " \t", bool addEmpty = false):
  Fields in text separated by one of the characters in sep are added as elements to the Table object. Empty fields are ignored unless the parameter addEmpty is true;
• void clear():
  The content of the table is erased;
• void clearStr():
  The content of its std::ostringstream base class buffer is erased;
• Table &def():
  After inserting elements into a Table object its number of elements may or may not be an integral multiple of the number of columns specified at construction time. To `complete' a Table object to a rectangular object, for which all column widths and alignments have been determined def can be called. It is automatically called by operator<<(ostream, Table). In other situations it may be called explicitly to force the insertion of another row in a table using ROWWISE insertions. With COLUMNWISE insertions its working is complex, since new elements added to a COLUMNWISE filled table will reshuffle its elements over the table's columns;
• void fill(InputIterator begin, InputIterator end):
  This member is defined as a member template; InputIterator is a template type parameter representing any input iterator. It can also be, e.g., a pointer to an insertable type. The iterators must point to data elements which can be inserted into an std::ostream. The range of values implied by the member's iterator pair are inserted into the table as new elements;
• void push_back(std::string const &element):
  New elements can be added to the table using push_back. It could e.g., be called from a back_inserter adaptor

tab << Align(2, FBB::center)

tab << Align(2, 3, FBB::center)

#include <iostream>

#include <bobcat/table>
#include <bobcat/tablelines>

using namespace std;
using namespace FBB;

int main(int argc, char **argv)
{
    TableLines tablelines;
                                // width/separators of cols 0, 1 and 2
    tablelines << 0 << " | " << " | ";

                                // hline over cols 1 and 2 of row 1
    tablelines << TableLines::HLine(1, 1, 3);

    Table tab(tablelines, 3, Table::ROWWISE, Table::EQUALWIDTH);
    // or: Table tab(tablelines, 3, Table::ROWWISE);

    tab << Align(0, std::left);     // set column non-default alignment
    tab.fill(argv + 1, argv + argc);// fill range of values

    cout << tab << '\n';            // complete the table and insert

    tab << "hello" << "" << "wo";   // add additional elements.
    if (tab.nRows() > 2)
        tab << Align(2, 2, center); // set the layout of a specific element

    cout << tab << '\n';
}