ConsoleUtils Class Reference

Singleton helper for terminal-width-aware string wrapping in TOPP-tool console output. More...

#include <OpenMS/APPLICATIONS/ConsoleUtils.h>

Collaboration diagram for ConsoleUtils:

Public Member Functions
	ConsoleUtils (const ConsoleUtils &)=delete
	Copy constructor deleted (singleton)
void	operator= (ConsoleUtils const &)=delete
	Assignment operator deleted (singleton)
int	getConsoleWidth () const
	Cached console width (or std::numeric_limits<int>::max() when detection failed and wrapping is effectively disabled)

Static Public Member Functions
static const ConsoleUtils &	getInstance ()
	Return the singleton instance (constructed on first call; thread-safe per Meyers-singleton rules)
static StringList	breakStringList (const std::string &input, const Size indentation, const Size max_lines, const Size first_line_prefill=0)
	Wrap input to the current console width and return one element per output line.
static std::string	breakString (const std::string &input, const Size indentation, const Size max_lines, const Size first_line_prefill=0)
	Convenience wrapper around breakStringList that joins the result with "\\n".

Private Member Functions
	ConsoleUtils ()
	Private ctor — caches the console width once; use getInstance to access.
int	readConsoleSize_ ()
	Probe the host environment / terminal to determine the console width (also honours the COLUMNS env var)
StringList	breakString_ (const std::string &input, const Size indentation, const Size max_lines, Size first_line_prefill) const
	Non-static implementation used by the public static wrappers; receives the cached console_width_.

Private Attributes
int	console_width_ = std::numeric_limits<int>::max()
	Cached console width; numeric_limits<int>::max() means "could not detect → no wrapping".

Friends
struct	ConsoleWidthTest
	Test hook: lets unit tests pin console_width_ to a deterministic value.

Detailed Description

Singleton helper for terminal-width-aware string wrapping in TOPP-tool console output.

Detects the current console width on construction (so it reflects the terminal the program was launched in) and exposes helpers that wrap long strings to that width with hanging indentation — the typical pattern used by TOPP tools to format --help output, parameter descriptions, and CLI error messages.

The detected width can be overridden at run time by setting the COLUMNS environment variable before launching the program. If the width cannot be determined (e.g. when stdout is not a terminal), it falls back to std::numeric_limits<int>::max(), which effectively disables wrapping.

Construction is private; access via getInstance(). The class is non-copyable and the cached console width is read once per process — long-running tools that resize their terminal mid-run will continue to use the original width.

Constructor & Destructor Documentation

ConsoleUtils() [1/2]

ConsoleUtils ( )

private

Private ctor — caches the console width once; use getInstance to access.

ConsoleUtils() [2/2]

ConsoleUtils ( const ConsoleUtils &  )

delete

Copy constructor deleted (singleton)

Member Function Documentation

breakString()

static std::string breakString ( const std::string &  input, const Size  indentation, const Size  max_lines, const Size  first_line_prefill = 0  )

static

Convenience wrapper around breakStringList that joins the result with "\\n".

breakString_()

StringList breakString_ ( const std::string &  input, const Size  indentation, const Size  max_lines, Size  first_line_prefill  ) const

private

Non-static implementation used by the public static wrappers; receives the cached console_width_.

breakStringList()

static StringList breakStringList ( const std::string &  input, const Size  indentation, const Size  max_lines, const Size  first_line_prefill = 0  )

static

Wrap input to the current console width and return one element per output line.

Behaviour:

• Lines 2..N are prefixed by indentation spaces, giving a left-aligned hanging block; lines wider than the console get broken at the console width.
• indentation == 0 falls back to the native console behaviour (raw line break at the right edge with no prefix on the next line).
• If the wrapped output would exceed max_lines, excess lines are dropped and a "..." marker is inserted; the final line is always preserved so the tail of the message stays visible.
• first_line_prefill lets the caller advertise how many characters are already present on the current console line (e.g. when this string is being appended after a label), so the first wrap point is calculated correctly.

Parameters

[in]	input	String to wrap.
[in]	indentation	Spaces to prepend to lines 2..N (must not exceed console width).
[in]	max_lines	Maximum output lines; excess lines collapse into "..." with the last line kept.
[in]	first_line_prefill	Number of characters already written on the current line (must not exceed console width).

Returns

One element per wrapped output line.

getConsoleWidth()

int getConsoleWidth ( ) const

inline

Cached console width (or std::numeric_limits<int>::max() when detection failed and wrapping is effectively disabled)

getInstance()

static const ConsoleUtils & getInstance ( )

static

Return the singleton instance (constructed on first call; thread-safe per Meyers-singleton rules)

operator=()

void operator= ( ConsoleUtils const &  )

delete

Assignment operator deleted (singleton)

readConsoleSize_()

int readConsoleSize_ ( )

private

Probe the host environment / terminal to determine the console width (also honours the COLUMNS env var)

Friends And Related Symbol Documentation

ConsoleWidthTest

friend struct ConsoleWidthTest

friend

Test hook: lets unit tests pin console_width_ to a deterministic value.

Member Data Documentation

console_width_

int console_width_ = std::numeric_limits<int>::max()

private

Cached console width; numeric_limits<int>::max() means "could not detect → no wrapping".