From: Stephan Witt <switt@lyx.org>
Date: Mon, 3 Aug 2020 12:15:09 +0000 (+0200)
Subject: #9376 prepare use of Length in lyxrc - move the class Length to support
X-Git-Tag: lyx-2.4.0dev-acb2ca7b~440
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=0fa4b7e736;p=lyx.git

#9376 prepare use of Length in lyxrc - move the class Length to support
---

diff --git a/src/BufferParams.cpp b/src/BufferParams.cpp
index f678e73a7f..6e0d9f91c6 100644
--- a/src/BufferParams.cpp
+++ b/src/BufferParams.cpp
@@ -32,7 +32,6 @@
 #include "Language.h"
 #include "LaTeXFeatures.h"
 #include "LaTeXFonts.h"
-#include "Length.h"
 #include "ModuleList.h"
 #include "Font.h"
 #include "Lexer.h"
@@ -54,6 +53,7 @@
 #include "support/FileName.h"
 #include "support/filetools.h"
 #include "support/gettext.h"
+#include "support/Length.h"
 #include "support/Messages.h"
 #include "support/mutex.h"
 #include "support/Package.h"
diff --git a/src/BufferView.cpp b/src/BufferView.cpp
index fe02be5019..e316aab02e 100644
--- a/src/BufferView.cpp
+++ b/src/BufferView.cpp
@@ -35,7 +35,6 @@
 #include "Language.h"
 #include "LaTeXFeatures.h"
 #include "LayoutFile.h"
-#include "Length.h"
 #include "Lexer.h"
 #include "LyX.h"
 #include "LyXAction.h"
@@ -81,6 +80,7 @@
 #include "support/filetools.h"
 #include "support/gettext.h"
 #include "support/lassert.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 #include "support/lyxlib.h"
 #include "support/Package.h"
diff --git a/src/Length.cpp b/src/Length.cpp
deleted file mode 100644
index d2868828b3..0000000000
--- a/src/Length.cpp
+++ /dev/null
@@ -1,463 +0,0 @@
-/**
- * \file Length.cpp
- * This file is part of LyX, the document processor.
- * Licence details can be found in the file COPYING.
- *
- * \author Matthias Ettrich
- * \author Lars Gullik Bjønnes
- * \author Jean-Marc Lasgouttes
- * \author Angus Leeming
- * \author John Levon
- * \author Dekel Tsur
- *
- * Full author contact details are available in file CREDITS.
- */
-
-#include <config.h>
-
-#include "Length.h"
-#include "LyXRC.h"
-
-#include "support/debug.h"
-#include "support/docstream.h"
-#include "support/lstrings.h"
-#include "support/lyxlib.h"
-
-#include <sstream>
-#include <iomanip>
-
-using namespace std;
-using namespace lyx::support;
-
-namespace lyx {
-
-
-/////////////////////////////////////////////////////////////////////
-//
-// Length
-//
-/////////////////////////////////////////////////////////////////////
-
-Length::Length()
-	: val_(0), unit_(Length::UNIT_NONE)
-{}
-
-
-Length::Length(double v, Length::UNIT u)
-	: val_(v), unit_(u)
-{}
-
-
-Length::Length(string const & data)
-	: val_(0), unit_(Length::UNIT_NONE)
-{
-	Length tmp;
-
-	if (!isValidLength(data, &tmp))
-		return; // should raise an exception
-
-	val_  = tmp.val_;
-	unit_ = tmp.unit_;
-}
-
-
-string const Length::asString() const
-{
-	ostringstream os;
-	if (unit_ != UNIT_NONE)
-		os << formatFPNumber(val_) << unit_name[unit_]; // setw?
-	return os.str();
-}
-
-
-docstring const Length::asDocstring() const
-{
-	odocstringstream os;
-	if (unit_ != UNIT_NONE)
-		os << from_ascii(formatFPNumber(val_))
-		   << from_ascii(unit_name[unit_]); // setw?
-	return os.str();
-}
-
-
-string const Length::asLatexString() const
-{
-	ostringstream os;
-	// Do not allow scientific notation (e.g. 1.2e+03), since this is not valid
-	// LaTeX (bug 9416)
-	switch (unit_) {
-	case PTW:
-		os << formatFPNumber(val_ / 100.0) << "\\textwidth";
-		break;
-	case PCW:
-		os << formatFPNumber(val_ / 100.0) << "\\columnwidth";
-		break;
-	case PPW:
-		os << formatFPNumber(val_ / 100.0) << "\\paperwidth";
-		break;
-	case PLW:
-		os << formatFPNumber(val_ / 100.0) << "\\linewidth";
-		break;
-	case PTH:
-		os << formatFPNumber(val_ / 100.0) << "\\textheight";
-		break;
-	case PPH:
-		os << formatFPNumber(val_ / 100.0) << "\\paperheight";
-		break;
-	case BLS:
-		os << formatFPNumber(val_ / 100.0) << "\\baselineskip";
-		break;
-	case UNIT_NONE:
-		break;
-	default:
-		os << formatFPNumber(val_) << unit_name[unit_];
-	  break;
-	}
-	return os.str();
-}
-
-
-string const Length::asHTMLString() const
-{
-	ostringstream os;
-	switch (unit_) {
-	case PT:
- 	case BP:
-	case DD:
-		// close enough
-		os << formatFPNumber(val_) << "pt";
-		break;
- 	case MM:
-	case CM:
-	case PC:
-	case IN:
-	case EX:
-	case EM:
-		os << formatFPNumber(val_) << unit_name[unit_];
-		break;
-	case CC:
-		os << formatFPNumber(val_ / 12.0) << "pt";
-		break;
- 	case MU:
-		os << formatFPNumber(val_ / 18.0) << "em";
-		break;
-	case PTW:
-	case PPW:
-	case PLW:
-	case PCW:
-	case PTH:
-	case PPH:
-	case BLS:
-		// what it's a percentage of probably won't make sense for HTML,
-		// so we'll assume people have chosen these appropriately
-		os << formatFPNumber(val_) << '%';
-		break;
-	case SP:
-	case UNIT_NONE:
-		break;
-	}
-	return os.str();
-}
-
-
-double Length::value() const
-{
-	return val_;
-}
-
-
-Length::UNIT Length::unit() const
-{
-	return unit_;
-}
-
-
-void Length::value(double v)
-{
-	val_ = v;
-}
-
-
-void Length::unit(Length::UNIT u)
-{
-	unit_ = u;
-}
-
-
-bool Length::zero() const
-{
-	return val_ == 0.0;
-}
-
-
-bool Length::empty() const
-{
-	return unit_ == Length::UNIT_NONE;
-}
-
-
-int Length::inPixels(int text_width, int em_width_base) const
-{
-	// Zoom factor specified by user in percent
-	double const zoom = lyxrc.currentZoom / 100.0; // [percent]
-
-	// DPI setting for monitor: pixels/inch
-	double const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
-
-	double const em_width_in = (em_width_base > 0)
-		? em_width_base / (zoom * dpi)
-		: 10.0/72.27;
-	// A different estimate for em_width is
-	// theFontMetrics(FontInfo(sane_font)).em()
-	// but this estimate might not be more accurate as the screen font
-	// is different then the latex font.
-
-	// Pixel values are scaled so that the ratio
-	// between lengths and font sizes on the screen
-	// is the same as on paper.
-
-	double const text_width_in = text_width / (zoom * dpi);
-	double const result = zoom * dpi * inInch(text_width_in, em_width_in);
-	return support::iround(result);
-}
-
-
-double Length::inInch(double text_width, double em_width) const
-{
-	double result = 0.0;
-
-	switch (unit_) {
-	case Length::SP:
-		// Scaled point: sp = 1/65536 pt
-		result = val_ / (72.27 * 65536); // 4736286.7
-		break;
-	case Length::PT:
-		// Point: 1 pt = 1/72.27 inch
-		result = val_ / 72.27; // 72.27
-		break;
-	case Length::BP:
-		// Big point: 1 bp = 1/72 inch
-		result = val_ / 72; // 72
-		break;
-	case Length::DD:
-		// Didot: 1157dd = 1238 pt?
-		result = val_ / (72.27 / (0.376 * 2.845)); // 67.559735
-		break;
-	case Length::MM:
-		// Millimeter: 1 mm = 1/25.4 inch
-		result = val_ / 25.4; // 25.4
-		break;
-	case Length::PC:
-		// Pica: 1 pc = 12 pt
-		result = val_ / (72.27 / 12); // 6.0225
-		break;
-	case Length::CC:
-		// Cicero: 1 cc = 12 dd
-		result = val_
-			/ (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
-		break;
-	case Length::CM:
-		// Centimeter: 1 cm = 1/2.54 inch
-		result = val_ / 2.54; // 2.54
-		break;
-	case Length::IN:
-		// Inch
-		result = val_;
-		break;
-	case Length::EX:
-		// Ex: The height of an "x"
-		// 0.4305 is the ration between 1ex and 1em in cmr10
-		result = val_ * em_width * 0.4305;
-		break;
-	case Length::EM:
-		// Em: The width of an "m"
-		result = val_ * em_width;
-		break;
-	case Length::MU:
-		// math unit = 1/18em
-		result = val_ * em_width / 18;
-		break;
-	case Length::PCW: // Always % of workarea
-	case Length::PTW:
-	case Length::PLW:
-		result = val_ * text_width / 100;
-		break;
-	case Length::PPW:
-		// paperwidth/textwidth is 1.7 for A4 paper with default margins
-		result = val_ * text_width * 1.7 / 100;
-		break;
-	case Length::PTH:
-		result = val_ * text_width * 1.787 / 100;
-		break;
-	case Length::PPH:
-		result = val_ * text_width * 2.2 / 100;
-		break;
-	case Length::BLS:
-		// baselineskip is approximately 1.2 times the font size for the cmr fonts
-		// The value actually depends on the current paragraph (see TextMetrics::setRowHeight),
-		// but we do not have this information here.
-		result = val_ * em_width * 1.2 / 100;
-		break;
-	case Length::UNIT_NONE:
-		result = 0;  // this cannot happen
-		break;
-	}
-	return result;
-}
-
-
-int Length::inBP() const
-{
-	// return any Length value as a one with
-	// the PostScript point, called bp (big points)
-
-	double const text_width_in = 210.0 / 2.54; // assume A4
-	double const em_width_in = 10.0 / 72.27;
-	double const result = 72.0 * inInch(text_width_in, em_width_in);
-	return support::iround(result);
-}
-
-
-Length::UNIT Length::defaultUnit()
-{
-	return lyxrc.default_length_unit;
-}
-
-
-
-bool operator==(Length const & l1, Length const & l2)
-{
-	return l1.value() == l2.value() && l1.unit() == l2.unit();
-}
-
-
-bool operator!=(Length const & l1, Length const & l2)
-{
-	return !(l1 == l2);
-}
-
-
-/////////////////////////////////////////////////////////////////////
-//
-// GlueLength
-//
-/////////////////////////////////////////////////////////////////////
-
-
-GlueLength::GlueLength(Length const & len)
-	: len_(len)
-{}
-
-
-GlueLength::GlueLength(Length const & len, Length const & plus,
-		Length const & minus)
-	: len_(len), plus_(plus), minus_(minus)
-{}
-
-
-GlueLength::GlueLength(string const & data)
-{
-	if (!isValidGlueLength(data, this))
-		LYXERR0("Invalid glue length " + data);
-}
-
-
-string const GlueLength::asString() const
-{
-	if (len_.empty())
-		return string();
-
-	ostringstream buffer;
-
-	buffer << formatFPNumber(len_.value());
-
-	if (plus_.zero() && minus_.zero()) {
-		buffer << unit_name[len_.unit()];
-		return buffer.str();
-	}
-
-	// just len and plus
-	if (minus_.zero()) {
-		if (len_.unit() != plus_.unit())
-			buffer << unit_name[len_.unit()];
-		buffer << '+' << formatFPNumber(plus_.value());
-		buffer << unit_name[plus_.unit()];
-		return buffer.str();
-	}
-
-	// just len and minus
-	if (plus_.zero()) {
-		if (len_.unit() != minus_.unit())
-			buffer << unit_name[len_.unit()];
-		buffer << '-' << formatFPNumber(minus_.value());
-		buffer << unit_name[minus_.unit()];
-		return buffer.str();
-	}
-
-	// ok, len, plus AND minus
-
-	// len+-
-	if (minus_ == plus_) {
-		if (len_.unit() != minus_.unit())
-			buffer << unit_name[len_.unit()];
-		buffer << "+-" << formatFPNumber(minus_.value());
-		buffer << unit_name[minus_.unit()];
-		return buffer.str();
-	}
-
-	// this is so rare a case, why bother minimising units ?
-
-	buffer << unit_name[len_.unit()];
-	buffer << '+' << formatFPNumber(plus_.value()) << unit_name[plus_.unit()];
-	buffer << '-' << formatFPNumber(minus_.value()) << unit_name[minus_.unit()];
-
-	return buffer.str();
-}
-
-
-string const GlueLength::asLatexString() const
-{
-	ostringstream buffer;
-	// use Length::asLatexString() to handle also the percent lengths
-	buffer << len_.Length::asLatexString();
-	if (!plus_.zero())
-		buffer << " plus " << plus_.Length::asLatexString();
-	if (!minus_.zero())
-		buffer << " minus " << minus_.Length::asLatexString();
-	return buffer.str();
-}
-
-
-Length const & GlueLength::len() const
-{
-	return len_;
-}
-
-
-Length const & GlueLength::plus() const
-{
-	return plus_;
-}
-
-
-Length const & GlueLength::minus() const
-{
-	return minus_;
-}
-
-
-bool operator==(GlueLength const & l1, GlueLength const & l2)
-{
-	return l1.len() == l2.len()
-		 && l1.plus() == l2.plus()
-		 && l1.minus() == l2.minus();
-}
-
-
-bool operator!=(GlueLength const & l1, GlueLength const & l2)
-{
-	return !(l1 == l2);
-}
-
-
-} // namespace lyx
diff --git a/src/Length.h b/src/Length.h
deleted file mode 100644
index aaf19238e6..0000000000
--- a/src/Length.h
+++ /dev/null
@@ -1,211 +0,0 @@
-// -*- C++ -*-
-/**
- * \file Length.h
- * This file is part of LyX, the document processor.
- * Licence details can be found in the file COPYING.
- *
- * \author Matthias Ettrich
- * \author Lars Gullik Bjønnes
- * \author Jean-Marc Lasgouttes
- * \author John Levon
- *
- * Full author contact details are available in file CREDITS.
- */
-
-#ifndef LENGTH_H
-#define LENGTH_H
-
-#include "support/strfwd.h"
-
-
-namespace lyx {
-
-// Solaris/x86 version 9 and earlier define these
-#undef PC
-#undef SP
-
-/////////////////////////////////////////////////////////////////////
-//
-// Length
-//
-/////////////////////////////////////////////////////////////////////
-
-
-/**
- * Length - Represents latex length measurement
- */
-class Length {
-public:
-	/// length units
-	enum UNIT {
-		BP, ///< Big point (72bp = 1in), also PostScript point
-		CC, ///< Cicero = 12dd = 4.531mm
-		CM, ///< Centimeter = 10mm = 2.371pc
-		DD, ///< Didot point = 1/72 of a French inch, = 0.376mm
-		EM, ///< Width of capital "M" in current font.
-		EX, ///< Height of a small "x" for the current font.
-		IN, ///< Inch = 25.4mm = 72.27pt = 6.022pc
-		MM, ///< Millimeter = 2.845pt
-		MU, ///< Math unit (18mu = 1em) for positioning in math mode
-		PC, ///< Pica = 12pt = 4.218mm
-		PT, ///< Point = 1/72.27in = 0.351mm
-		SP, ///< Scaled point (65536sp = 1pt) TeX's smallest unit.
-		PTW, //< Percent of TextWidth
-		PCW, //< Percent of ColumnWidth
-		PPW, //< Percent of PageWidth
-		PLW, //< Percent of LineWidth
-		PTH, //< Percent of TextHeight          // Herbert 2002-05-16
-		PPH, //< Percent of PaperHeight         // Herbert 2002-05-16
-		BLS, //< Percent of BaselineSkip        // uwestoehr 2017-04-01
-		UNIT_NONE ///< no unit
-	};
-
-	///
-	Length();
-	///
-	Length(double v, Length::UNIT u);
-
-	/// "data" must be a decimal number, followed by a unit
-	explicit Length(std::string const & data);
-
-	///
-	double value() const;
-	///
-	Length::UNIT unit() const;
-	///
-	void value(double);
-	///
-	void unit(Length::UNIT unit);
-	///
-	bool zero() const;
-	///
-	bool empty() const;
-	/// return string representation
-	std::string const asString() const;
-	/// return string representation
-	docstring const asDocstring() const;
-	/// return string representation for LaTeX
-	std::string const asLatexString() const;
-	/// return string representation for HTML
-	std::string const asHTMLString() const;
-	/** return the on-screen size of this length.
-	 *
-	 *	If the second argument is not provided, then the unit EM will
-	 *	only be approximated. It is better if possible to use
-	 *	FontMetrics::em() to get this value.
-	 */
-	int inPixels(int text_width, int em_width = 0) const;
-
-	/// return the value in Big Postscript points.
-	/// Caution: Inaccurate for em, ex, mu and percent units.
-	int inBP() const;
-
-	/// return the default unit (centimeter or inch)
-	static UNIT defaultUnit();
-
-	friend bool isValidLength(std::string const & data, Length * result);
-
-private:
-	/// Convert value to inch for text width and em width given in inch
-	double inInch(double text_width, double em_width) const;
-	///
-	double val_;
-	///
-	Length::UNIT unit_;
-};
-
-///
-bool operator==(Length const & l1, Length const & l2);
-///
-bool operator!=(Length const & l1, Length const & l2);
-/** Test whether \p data represents a valid length.
- *
- * \returns whether \p data is a valid length
- * \param data Length in LyX format. Since the only difference between LyX
- * and LaTeX format is the representation of length variables as units (e.g.
- * \c text% vs. \c \\textwidth) you can actually use this function as well
- * for testing LaTeX lengths as long as they only contain real units like pt.
- * \param result Pointer to a Length variable. If \p result is not 0 and
- * \p data is valid, the length represented by it is stored into \p result.
- */
-bool isValidLength(std::string const & data, Length * result = 0);
-/// return the LyX name of the given unit number
-char const * stringFromUnit(int unit);
-
-
-/////////////////////////////////////////////////////////////////////
-//
-// GlueLength
-//
-/////////////////////////////////////////////////////////////////////
-
-class GlueLength {
-public:
-	///
-	GlueLength() {}
-	///
-	explicit GlueLength(Length const & len);
-	///
-	GlueLength(Length const & len,
-		      Length const & plus,
-		      Length const & minus);
-
-	/** "data" must be a decimal number, followed by a unit, and
-	  optional "glue" indicated by "+" and "-".  You may abbreviate
-	  reasonably.  Examples:
-	  1.2 cm  //  4mm +2pt  //  2cm -4mm +2mm  //  4+0.1-0.2cm
-	  The traditional Latex format is also accepted, like
-	  4cm plus 10pt minus 10pt */
-	explicit GlueLength(std::string const & data);
-
-	///
-	Length const & len() const;
-	///
-	Length const & plus() const;
-	///
-	Length const & minus() const;
-
-
-	/// conversion
-	std::string const asString() const;
-	///
-	std::string const asLatexString() const;
-
-	friend bool isValidGlueLength(std::string const & data,
-				      GlueLength* result);
-
-private:
-	/// the normal vlaue
-	Length len_;
-	/// extra stretch
-	Length plus_;
-	/// extra shrink
-	Length minus_;
-};
-
-///
-bool operator==(GlueLength const & l1, GlueLength const & l2);
-///
-bool operator!=(GlueLength const & l1, GlueLength const & l2);
-/** If "data" is valid, the length represented by it is
-    stored into "result", if that is not 0. */
-bool isValidGlueLength(std::string const & data, GlueLength * result = 0);
-
-/// the number of units possible
-extern int const num_units;
-
-/**
- * array of unit names
- *
- * FIXME: I am not sure if "mu" should be possible to select (Lgb)
- */
-extern char const * const unit_name[];
-extern char const * const unit_name_gui[];
-
-/// return the unit given a string representation such as "cm"
-Length::UNIT unitFromString(std::string const & data);
-
-
-} // namespace lyx
-
-#endif // LENGTH_H
diff --git a/src/LyXRC.h b/src/LyXRC.h
index ed7511a6d1..955826bcf6 100644
--- a/src/LyXRC.h
+++ b/src/LyXRC.h
@@ -18,9 +18,9 @@
 #ifndef LYXRC_H
 #define LYXRC_H
 
-#include "Length.h"
 #include "LyX.h"
 
+#include "support/Length.h"
 #include "support/strfwd.h"
 #include "support/userinfo.h"
 
diff --git a/src/Makefile.am b/src/Makefile.am
index 4a74c6eef4..be8e478007 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -147,8 +147,6 @@ SOURCEFILESCORE = \
 	LaTeXPackages.cpp \
 	LayoutFile.cpp \
 	LayoutModuleList.cpp \
-	Length.cpp \
-	lengthcommon.cpp \
 	Lexer.cpp \
 	LyX.cpp \
 	LyXAction.cpp \
@@ -251,7 +249,6 @@ HEADERFILESCORE = \
 	LayoutEnums.h \
 	LayoutFile.h \
 	LayoutModuleList.h \
-	Length.h \
 	Lexer.h \
 	LyXAction.h \
 	lyxfind.h \
@@ -733,20 +730,15 @@ check_ExternalTransforms_SOURCES = \
 	tests/boost.cpp
 check_ExternalTransforms_LYX_OBJS = \
 	graphics/GraphicsParams.o \
-	insets/ExternalTransforms.o \
-	Length.o \
-	lengthcommon.o
+	insets/ExternalTransforms.o
 
 check_Length_CPPFLAGS = $(AM_CPPFLAGS)
-check_Length_LDADD = $(check_Length_LYX_OBJS) $(TESTS_LIBS)
+check_Length_LDADD = $(TESTS_LIBS)
 check_Length_LDFLAGS = $(QT_LDFLAGS) $(ADD_FRAMEWORKS)
 check_Length_SOURCES = \
 	tests/check_Length.cpp \
 	tests/dummy_functions.cpp \
 	tests/boost.cpp
-check_Length_LYX_OBJS = \
-	Length.o \
-	lengthcommon.o
 
 check_ListingsCaption_CPPFLAGS = $(AM_CPPFLAGS)
 check_ListingsCaption_LDADD = $(check_ListingsCaption_LYX_OBJS) $(TESTS_LIBS)
diff --git a/src/Paragraph.cpp b/src/Paragraph.cpp
index 1c8f03057a..133ddd15b8 100644
--- a/src/Paragraph.cpp
+++ b/src/Paragraph.cpp
@@ -30,7 +30,6 @@
 #include "Language.h"
 #include "LaTeXFeatures.h"
 #include "Layout.h"
-#include "Length.h"
 #include "Font.h"
 #include "FontList.h"
 #include "LyXRC.h"
@@ -62,6 +61,7 @@
 #include "support/ExceptionMessage.h"
 #include "support/gettext.h"
 #include "support/lassert.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 #include "support/textutils.h"
 #include "output_docbook.h"
diff --git a/src/ParagraphParameters.h b/src/ParagraphParameters.h
index ccb131c9c6..b4608e0b3b 100644
--- a/src/ParagraphParameters.h
+++ b/src/ParagraphParameters.h
@@ -15,12 +15,12 @@
 #define PARAGRAPHPARAMETERS_H
 
 #include "LayoutEnums.h"
-#include "Length.h"
 #include "Spacing.h"
 
 #include "support/debug.h"
 #include "support/types.h"
 #include "support/docstring.h"
+#include "support/Length.h"
 
 
 namespace lyx {
diff --git a/src/Text.cpp b/src/Text.cpp
index 60705c0b34..e03c2cb57c 100644
--- a/src/Text.cpp
+++ b/src/Text.cpp
@@ -37,7 +37,6 @@
 #include "InsetList.h"
 #include "Language.h"
 #include "Layout.h"
-#include "Length.h"
 #include "Lexer.h"
 #include "lyxfind.h"
 #include "LyXRC.h"
@@ -65,6 +64,7 @@
 #include "support/docstream.h"
 #include "support/gettext.h"
 #include "support/lassert.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 #include "support/lyxalgo.h"
 #include "support/lyxtime.h"
diff --git a/src/VSpace.cpp b/src/VSpace.cpp
index a2d4a3d398..d176850c87 100644
--- a/src/VSpace.cpp
+++ b/src/VSpace.cpp
@@ -16,11 +16,11 @@
 #include "BufferParams.h"
 #include "BufferView.h"
 #include "support/gettext.h"
-#include "Length.h"
 #include "Text.h"
 #include "TextMetrics.h" // for defaultRowHeight()
 
 #include "support/convert.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 
 #include "support/lassert.h"
diff --git a/src/VSpace.h b/src/VSpace.h
index 2bce154e33..7cd1a2b131 100644
--- a/src/VSpace.h
+++ b/src/VSpace.h
@@ -12,7 +12,7 @@
 #ifndef VSPACE_H
 #define VSPACE_H
 
-#include "Length.h"
+#include "support/Length.h"
 
 
 namespace lyx {
diff --git a/src/frontends/qt/GuiBox.cpp b/src/frontends/qt/GuiBox.cpp
index 67a1b0c52b..5b504ddbda 100644
--- a/src/frontends/qt/GuiBox.cpp
+++ b/src/frontends/qt/GuiBox.cpp
@@ -19,13 +19,13 @@
 #include "ColorCache.h"
 #include "ColorSet.h"
 #include "LengthCombo.h"
-#include "Length.h"
 #include "qt_helpers.h"
 #include "Validator.h"
 
 #include "insets/InsetBox.h"
 
 #include "support/gettext.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 
 #include <QComboBox>
diff --git a/src/frontends/qt/GuiExternal.cpp b/src/frontends/qt/GuiExternal.cpp
index d850c2d8a5..eb71aad4d1 100644
--- a/src/frontends/qt/GuiExternal.cpp
+++ b/src/frontends/qt/GuiExternal.cpp
@@ -17,7 +17,6 @@
 #include "Buffer.h"
 #include "FuncRequest.h"
 #include "support/gettext.h"
-#include "Length.h"
 #include "LyXRC.h"
 
 #include "insets/ExternalSupport.h"
@@ -31,6 +30,7 @@
 
 #include "support/convert.h"
 #include "support/filetools.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 #include "support/lyxlib.h"
 #include "support/os.h"
diff --git a/src/frontends/qt/GuiGraphics.cpp b/src/frontends/qt/GuiGraphics.cpp
index e0a1b20b32..142f433759 100644
--- a/src/frontends/qt/GuiGraphics.cpp
+++ b/src/frontends/qt/GuiGraphics.cpp
@@ -22,7 +22,6 @@
 #include "Buffer.h"
 #include "FuncRequest.h"
 #include "LengthCombo.h"
-#include "Length.h"
 #include "LyXRC.h"
 
 #include "graphics/epstools.h"
@@ -36,6 +35,7 @@
 #include "support/debug.h"
 #include "support/filetools.h"
 #include "support/gettext.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 #include "support/os.h"
 #include "support/Package.h"
diff --git a/src/frontends/qt/LengthCombo.h b/src/frontends/qt/LengthCombo.h
index 2545a96606..eb1a38769b 100644
--- a/src/frontends/qt/LengthCombo.h
+++ b/src/frontends/qt/LengthCombo.h
@@ -14,7 +14,7 @@
 
 #include <QComboBox>
 
-#include "Length.h"
+#include "support/Length.h"
 
 
 namespace lyx {
diff --git a/src/frontends/qt/Validator.h b/src/frontends/qt/Validator.h
index bf77795918..cce7cf5f75 100644
--- a/src/frontends/qt/Validator.h
+++ b/src/frontends/qt/Validator.h
@@ -25,9 +25,10 @@
 #ifndef VALIDATOR_H
 #define VALIDATOR_H
 
-#include "Length.h"
 #include "Dialog.h" // KernelDocType
 
+#include "support/Length.h"
+
 #include <QValidator>
 
 class QWidget;
diff --git a/src/frontends/qt/qt_helpers.cpp b/src/frontends/qt/qt_helpers.cpp
index 26c0df0ffc..d3da0ee7de 100644
--- a/src/frontends/qt/qt_helpers.cpp
+++ b/src/frontends/qt/qt_helpers.cpp
@@ -22,12 +22,12 @@
 #include "BufferParams.h"
 #include "FloatList.h"
 #include "Language.h"
-#include "Length.h"
 #include "TextClass.h"
 
 #include "support/convert.h"
 #include "support/debug.h"
 #include "support/gettext.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 #include "support/lyxalgo.h"
 #include "support/os.h"
diff --git a/src/frontends/qt/qt_helpers.h b/src/frontends/qt/qt_helpers.h
index 754b6bf913..92872e0808 100644
--- a/src/frontends/qt/qt_helpers.h
+++ b/src/frontends/qt/qt_helpers.h
@@ -14,7 +14,7 @@
 #define QTHELPERS_H
 
 #include "ColorSet.h"
-#include "Length.h"
+#include "support/Length.h"
 #include "support/qstring_helpers.h"
 #include "support/filetools.h"
 #include "qt_i18n.h"
diff --git a/src/graphics/GraphicsParams.h b/src/graphics/GraphicsParams.h
index 052b006bff..e05bb67c5a 100644
--- a/src/graphics/GraphicsParams.h
+++ b/src/graphics/GraphicsParams.h
@@ -14,9 +14,8 @@
 #ifndef GRAPHICSPARAMS_H
 #define GRAPHICSPARAMS_H
 
-#include "Length.h"
-
 #include "support/FileName.h"
+#include "support/Length.h"
 
 #include <string>
 #include <iosfwd>
diff --git a/src/insets/ExternalTransforms.h b/src/insets/ExternalTransforms.h
index d6735b60b5..6d0f9afedb 100644
--- a/src/insets/ExternalTransforms.h
+++ b/src/insets/ExternalTransforms.h
@@ -12,10 +12,9 @@
 #ifndef EXTERNALTRANSFORMS_H
 #define EXTERNALTRANSFORMS_H
 
-#include "Length.h"
-
 #include "graphics/GraphicsParams.h"
 
+#include "support/Length.h"
 #include "support/unique_ptr.h"
 
 #include <boost/any.hpp>
diff --git a/src/insets/InsetBox.h b/src/insets/InsetBox.h
index 418a242772..3398a52ed6 100644
--- a/src/insets/InsetBox.h
+++ b/src/insets/InsetBox.h
@@ -15,7 +15,8 @@
 #define INSETBOX_H
 
 #include "InsetCollapsible.h"
-#include "Length.h"
+
+#include "support/Length.h"
 
 
 namespace lyx {
diff --git a/src/insets/InsetGraphics.cpp b/src/insets/InsetGraphics.cpp
index 62efa84dc0..99fcf3d6fc 100644
--- a/src/insets/InsetGraphics.cpp
+++ b/src/insets/InsetGraphics.cpp
@@ -62,7 +62,6 @@ TODO
 #include "FuncStatus.h"
 #include "InsetIterator.h"
 #include "LaTeXFeatures.h"
-#include "Length.h"
 #include "Lexer.h"
 #include "MetricsInfo.h"
 #include "Mover.h"
@@ -86,6 +85,7 @@ TODO
 #include "support/ExceptionMessage.h"
 #include "support/filetools.h"
 #include "support/gettext.h"
+#include "support/Length.h"
 #include "support/lyxlib.h"
 #include "support/lstrings.h"
 #include "support/os.h"
diff --git a/src/insets/InsetInfo.cpp b/src/insets/InsetInfo.cpp
index 699d878bb1..4edf0eb1e0 100644
--- a/src/insets/InsetInfo.cpp
+++ b/src/insets/InsetInfo.cpp
@@ -25,7 +25,6 @@
 #include "LaTeXFeatures.h"
 #include "Language.h"
 #include "LayoutFile.h"
-#include "Length.h"
 #include "LyXAction.h"
 #include "LyXRC.h"
 #include "LyXVC.h"
@@ -45,6 +44,7 @@
 #include "support/FileName.h"
 #include "support/filetools.h"
 #include "support/gettext.h"
+#include "support/Length.h"
 #include "support/Messages.h"
 #include "support/lstrings.h"
 #include "support/qstring_helpers.h"
diff --git a/src/insets/InsetLine.cpp b/src/insets/InsetLine.cpp
index e6964aad79..8d6a4ada2f 100644
--- a/src/insets/InsetLine.cpp
+++ b/src/insets/InsetLine.cpp
@@ -21,7 +21,6 @@
 #include "FuncRequest.h"
 #include "FuncStatus.h"
 #include "LaTeXFeatures.h"
-#include "Length.h"
 #include "MetricsInfo.h"
 #include "OutputParams.h"
 #include "output_docbook.h"
@@ -35,6 +34,7 @@
 #include "support/debug.h"
 #include "support/docstream.h"
 #include "support/gettext.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 
 #include <cstdlib>
diff --git a/src/insets/InsetListingsParams.cpp b/src/insets/InsetListingsParams.cpp
index 2e2f4c6e53..9c87a58c77 100644
--- a/src/insets/InsetListingsParams.cpp
+++ b/src/insets/InsetListingsParams.cpp
@@ -13,7 +13,7 @@
 
 #include "InsetListingsParams.h"
 
-#include "Length.h"
+#include "support/Length.h"
 #include "Lexer.h"
 
 #include "support/convert.h"
diff --git a/src/insets/InsetNomencl.cpp b/src/insets/InsetNomencl.cpp
index e7fc8a7d98..c762e33d67 100644
--- a/src/insets/InsetNomencl.cpp
+++ b/src/insets/InsetNomencl.cpp
@@ -26,7 +26,6 @@
 #include "InsetList.h"
 #include "Language.h"
 #include "LaTeXFeatures.h"
-#include "Length.h"
 #include "LyX.h"
 #include "OutputParams.h"
 #include "xml.h"
@@ -38,6 +37,7 @@
 #include "support/debug.h"
 #include "support/docstream.h"
 #include "support/gettext.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 
 using namespace std;
diff --git a/src/insets/InsetSpace.cpp b/src/insets/InsetSpace.cpp
index 04b515cdcc..5a4f46801a 100644
--- a/src/insets/InsetSpace.cpp
+++ b/src/insets/InsetSpace.cpp
@@ -22,7 +22,6 @@
 #include "FuncStatus.h"
 #include "Language.h"
 #include "LaTeXFeatures.h"
-#include "Length.h"
 #include "Lexer.h"
 #include "MetricsInfo.h"
 #include "OutputParams.h"
@@ -33,6 +32,7 @@
 #include "support/docstream.h"
 #include "support/gettext.h"
 #include "support/lassert.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 
 #include "frontends/Application.h"
diff --git a/src/insets/InsetSpace.h b/src/insets/InsetSpace.h
index 1111aa1e82..0ebcec1f54 100644
--- a/src/insets/InsetSpace.h
+++ b/src/insets/InsetSpace.h
@@ -16,7 +16,8 @@
 #define INSET_SPACE_H
 
 #include "Inset.h"
-#include "Length.h"
+
+#include "support/Length.h"
 
 
 namespace lyx {
diff --git a/src/insets/InsetTabular.h b/src/insets/InsetTabular.h
index d917ab8370..028da97969 100644
--- a/src/insets/InsetTabular.h
+++ b/src/insets/InsetTabular.h
@@ -25,7 +25,8 @@
 #define INSET_TABULAR_H
 
 #include "InsetText.h"
-#include "Length.h"
+
+#include "support/Length.h"
 
 #include <climits>
 #include <iosfwd>
diff --git a/src/insets/InsetWrap.h b/src/insets/InsetWrap.h
index 934e3bd101..5619dc042b 100644
--- a/src/insets/InsetWrap.h
+++ b/src/insets/InsetWrap.h
@@ -13,7 +13,8 @@
 #define INSETWRAP_H
 
 #include "InsetCaptionable.h"
-#include "Length.h"
+
+#include "support/Length.h"
 
 
 namespace lyx {
diff --git a/src/lengthcommon.cpp b/src/lengthcommon.cpp
deleted file mode 100644
index 4478d84ae5..0000000000
--- a/src/lengthcommon.cpp
+++ /dev/null
@@ -1,367 +0,0 @@
-/**
- * \file lengthcommon.cpp
- * This file is part of LyX, the document processor.
- * Licence details can be found in the file COPYING.
- *
- * \author Lars Gullik Bjønnes
- * \author Matthias Ettrich
- * \author John Levon
- *
- * Full author contact details are available in file CREDITS.
- */
-
-#include <config.h>
-
-#include "Length.h"
-
-#include "support/convert.h"
-#include "support/gettext.h"
-#include "support/lassert.h"
-#include "support/lstrings.h"
-
-using namespace std;
-using namespace lyx::support;
-
-
-namespace lyx {
-
-// I am not sure if "mu" should be possible to select (Lgb)
-
-// the latex units
-char const * const unit_name[] = {
-	"bp", "cc", "cm", "dd", "em", "ex", "in", "mm", "mu",
-	"pc", "pt", "sp",
-	"text%",  "col%", "page%", "line%",
-	"theight%", "pheight%", "baselineskip%", "" };
-
-int const num_units = int(sizeof(unit_name) / sizeof(unit_name[0]) - 1);
-
-// the LyX gui units
-char const * const unit_name_gui[] = {
-	N_("bp"), N_("cc[[unit of measure]]"), N_("cm"), N_("dd"), N_("em"),
-	N_("ex"), N_("in[[unit of measure]]"), N_("mm"), N_("mu[[unit of measure]]"), N_("pc"),
-	N_("pt"), N_("sp"), N_("Text Width %"),
-	N_("Column Width %"), N_("Page Width %"), N_("Line Width %"),
-	N_("Text Height %"), N_("Page Height %"), N_("Line Distance %"), "" };
-
-
-Length::UNIT unitFromString(string const & data)
-{
-	int i = 0;
-	while (i < num_units && data != unit_name[i])
-		++i;
-	return static_cast<Length::UNIT>(i);
-}
-
-
-namespace {
-
-/// skip n characters of input
-inline void lyx_advance(string & data, size_t n)
-{
-	data.erase(0, n);
-}
-
-
-/// return true when the input is at the end
-inline bool isEndOfData(string const & data)
-{
-	return ltrim(data).empty();
-}
-
-
-/**
- * nextToken -  return the next token in the input
- * @param data input string
- * @param number_index the current position in the number array
- * @param unit_index the current position in the unit array
- * @return a char representing the type of token returned
- *
- * The possible return values are :
- *	+	stretch indicator for glue length
- *	-	shrink indicator for glue length
- *	n	a numeric value (stored in number array)
- *	u	a unit type (stored in unit array)
- *	E	parse error
- */
-char nextToken(string & data, double * number, int & number_index,
-               Length::UNIT * unit, int & unit_index)
-{
-	data = ltrim(data);
-
-	if (data.empty())
-		return '\0';
-
-	if (data[0] == '+') {
-		lyx_advance(data, 1);
-		return '+';
-	}
-
-	if (prefixIs(data, "plus")) {
-		lyx_advance(data, 4);
-		return '+';
-	}
-
-	if (data[0] == '-') {
-		lyx_advance(data, 1);
-		return '-';
-	}
-
-	if (prefixIs(data, "minus")) {
-		lyx_advance(data, 5);
-		return '-';
-	}
-
-	size_t i = data.find_first_not_of("0123456789.");
-
-	if (i != 0) {
-		if (number_index > 3)
-			return 'E';
-
-		string buffer;
-
-		// we have found some number
-		if (i == string::npos) {
-			buffer = data;
-			i = data.size() + 1;
-		} else {
-			buffer = data.substr(0, i);
-		}
-
-		lyx_advance(data, i);
-
-		if (isStrDbl(buffer)) {
-			number[number_index] = convert<double>(buffer);
-			++number_index;
-			return 'n';
-		}
-		return 'E';
-	}
-
-	i = data.find_first_not_of("abcdefghijklmnopqrstuvwxyz%");
-	if (i != 0) {
-		if (unit_index > 3)
-			return 'E';
-
-		string buffer;
-
-		// we have found some alphabetical string
-		if (i == string::npos) {
-			buffer = data;
-			i = data.size() + 1;
-		} else {
-			buffer = data.substr(0, i);
-		}
-
-		// possibly we have "mmplus" string or similar
-		if (buffer.size() > 5 &&
-				(buffer.substr(2, 4) == string("plus") ||
-				 buffer.substr(2, 5) == string("minus")))
-		{
-			lyx_advance(data, 2);
-			unit[unit_index] = unitFromString(buffer.substr(0, 2));
-		} else {
-			lyx_advance(data, i);
-			unit[unit_index] = unitFromString(buffer);
-		}
-
-		if (unit[unit_index] != Length::UNIT_NONE) {
-			++unit_index;
-			return 'u';
-		}
-		return 'E';  // Error
-	}
-	return 'E';  // Error
-}
-
-
-/// latex representation of a vspace
-struct LaTeXLength {
-	char const * pattern;
-	int  plus_val_index;
-	int  minus_val_index;
-	int  plus_uni_index;
-	int  minus_uni_index;
-};
-
-
-/// the possible formats for a vspace string
-LaTeXLength table[] = {
-	{ "nu",       0, 0, 0, 0 },
-	{ "nu+nu",    2, 0, 2, 0 },
-	{ "nu+nu-nu", 2, 3, 2, 3 },
-	{ "nu+-nu",   2, 2, 2, 2 },
-	{ "nu-nu",    0, 2, 0, 2 },
-	{ "nu-nu+nu", 3, 2, 3, 2 },
-	{ "nu-+nu",   2, 2, 2, 2 },
-	{ "n+nu",     2, 0, 1, 0 },
-	{ "n+n-nu",   2, 3, 1, 1 },
-	{ "n+-nu",    2, 2, 1, 1 },
-	{ "n-nu",     0, 2, 0, 1 },
-	{ "n-n+nu",   3, 2, 1, 1 },
-	{ "n-+nu",    2, 2, 1, 1 },
-	{ "",         0, 0, 0, 0 }   // sentinel, must be empty
-};
-
-
-} // namespace
-
-
-const char * stringFromUnit(int unit)
-{
-	if (unit < 0 || unit > num_units)
-		return nullptr;
-	return unit_name[unit];
-}
-
-
-bool isValidGlueLength(string const & data, GlueLength * result)
-{
-	// This parser is table-driven.  First, it constructs a "pattern"
-	// that describes the sequence of tokens in "data".  For example,
-	// "n-nu" means: number, minus sign, number, unit.  As we go along,
-	// numbers and units are stored into static arrays.  Then, "pattern"
-	// is searched in the "table".  If it is found, the associated
-	// table entries tell us which number and unit should go where
-	// in the Length structure.  Example: if "data" has the "pattern"
-	// "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
-	// That means, "plus_val" is the second number that was seen
-	// in the input, "minus_val" is the third number, and "plus_uni"
-	// and "minus_uni" are the second and third units, respectively.
-	// ("val" and "uni" are always the first items seen in "data".)
-	// This is the most elegant solution I could find -- a straight-
-	// forward approach leads to very long, tedious code that would be
-	// much harder to understand and maintain. (AS)
-
-	if (data.empty()) {
-		if (result)
-			*result = GlueLength();
-		return true;
-	}
-	string buffer = ltrim(data);
-
-	// To make isValidGlueLength recognize negative values as
-	// the first number this little hack is needed:
-	int val_sign = 1; // positive as default
-	switch (buffer[0]) {
-	case '-':
-		lyx_advance(buffer, 1);
-		val_sign = -1;
-		break;
-	case '+':
-		lyx_advance(buffer, 1);
-		break;
-	default:
-		break;
-	}
-	// end of hack
-
-	// used to return numeric values in parsing vspace
-	double number[4] = { 0, 0, 0, 0 };
-	// used to return unit types in parsing vspace
-	Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
-	                        Length::UNIT_NONE, Length::UNIT_NONE};
-	int number_index = 1; // entries at index 0 are sentinels
-	int unit_index = 1;   // entries at index 0 are sentinels
-
-	// construct "pattern" from "data"
-	size_t const pattern_max_size = 20;
-	string pattern;
-	while (!isEndOfData(buffer)) {
-		if (pattern.size() > pattern_max_size)
-			return false;
-		char const c = nextToken(buffer, number, number_index, unit,
-				unit_index);
-		if (c == 'E')
-			return false;
-		pattern.push_back(c);
-	}
-
-	// search "pattern" in "table"
-	size_t table_index = 0;
-	while (pattern != table[table_index].pattern) {
-		++table_index;
-		if (!*table[table_index].pattern)
-			return false;
-	}
-
-	// Get the values from the appropriate places.  If an index
-	// is zero, the corresponding array value is zero or UNIT_NONE,
-	// so we needn't check this.
-	if (result) {
-		result->len_.value  (number[1] * val_sign);
-		result->len_.unit   (unit[1]);
-		result->plus_.value (number[table[table_index].plus_val_index]);
-		result->plus_.unit  (unit  [table[table_index].plus_uni_index]);
-		result->minus_.value(number[table[table_index].minus_val_index]);
-		result->minus_.unit (unit  [table[table_index].minus_uni_index]);
-	}
-	return true;
-}
-
-
-bool isValidLength(string const & data, Length * result)
-{
-	// This is a trimmed down version of isValidGlueLength.
-	// The parser may seem overkill for lengths without
-	// glue, but since we already have it, using it is
-	// easier than writing something from scratch.
-	if (data.empty()) {
-		if (result)
-			*result = Length();
-		return true;
-	}
-
-	string buffer = data;
-
-	// To make isValidLength recognize negative values
-	// this little hack is needed:
-	int val_sign = 1; // positive as default
-	switch (buffer[0]) {
-	case '-':
-		lyx_advance(buffer, 1);
-		val_sign = -1;
-		break;
-	case '+':
-		lyx_advance(buffer, 1);
-		// fall through
-	default:
-		// no action
-		break;
-	}
-	// end of hack
-
-	// used to return numeric values in parsing vspace
-	double number[4] = { 0, 0, 0, 0 };
-	// used to return unit types in parsing vspace
-	Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
-	                        Length::UNIT_NONE, Length::UNIT_NONE};
-	int number_index = 1; // entries at index 0 are sentinels
-	int unit_index = 1;   // entries at index 0 are sentinels
-
-	// construct "pattern" from "data"
-	string pattern;
-	while (!isEndOfData(buffer)) {
-		if (pattern.size() > 2)
-			return false;
-		char const token = nextToken(buffer, number,
-				number_index, unit, unit_index);
-		if (token == 'E')
-			return false;
-		pattern += token;
-	}
-
-	// only the most basic pattern is accepted here
-	if (pattern != "nu")
-		return false;
-
-	// It _was_ a correct length string.
-	// Store away the values we found.
-	if (result) {
-		result->val_  = number[1] * val_sign;
-		result->unit_ = unit[1];
-	}
-	return true;
-}
-
-} // namespace lyx
diff --git a/src/mathed/InsetMathGrid.h b/src/mathed/InsetMathGrid.h
index 1c8efd1814..fa7c2f2691 100644
--- a/src/mathed/InsetMathGrid.h
+++ b/src/mathed/InsetMathGrid.h
@@ -13,7 +13,8 @@
 #define MATH_GRID_H
 
 #include "InsetMathNest.h"
-#include "Length.h"
+
+#include "support/Length.h"
 
 #include <map>
 
diff --git a/src/mathed/InsetMathKern.h b/src/mathed/InsetMathKern.h
index e985ad4dc3..58d540d1fc 100644
--- a/src/mathed/InsetMathKern.h
+++ b/src/mathed/InsetMathKern.h
@@ -13,7 +13,8 @@
 #define MATH_CHEATINSET_H
 
 #include "InsetMath.h"
-#include "Length.h"
+
+#include "support/Length.h"
 
 
 namespace lyx {
diff --git a/src/mathed/InsetMathSpace.h b/src/mathed/InsetMathSpace.h
index 4f16f1640b..32147dbe25 100644
--- a/src/mathed/InsetMathSpace.h
+++ b/src/mathed/InsetMathSpace.h
@@ -13,7 +13,8 @@
 #define MATH_SPACEINSET_H
 
 #include "InsetMath.h"
-#include "Length.h"
+
+#include "support/Length.h"
 
 
 namespace lyx {
diff --git a/src/mathed/InsetMathXYMatrix.h b/src/mathed/InsetMathXYMatrix.h
index a5be7c0af3..68de02813a 100644
--- a/src/mathed/InsetMathXYMatrix.h
+++ b/src/mathed/InsetMathXYMatrix.h
@@ -12,9 +12,10 @@
 #ifndef MATH_XYMATRIX_H
 #define MATH_XYMATRIX_H
 
-#include "Length.h"
 #include "InsetMathGrid.h"
 
+#include "support/Length.h"
+
 
 namespace lyx {
 
diff --git a/src/mathed/MathSupport.cpp b/src/mathed/MathSupport.cpp
index 45ca429681..ef93cb0bf1 100644
--- a/src/mathed/MathSupport.cpp
+++ b/src/mathed/MathSupport.cpp
@@ -15,7 +15,6 @@
 
 #include "InsetMathFont.h"
 #include "InsetMathSymbol.h"
-#include "Length.h"
 #include "MathData.h"
 #include "MathFactory.h"
 #include "MathParser.h"
@@ -31,6 +30,7 @@
 #include "support/debug.h"
 #include "support/docstream.h"
 #include "support/lassert.h"
+#include "support/Length.h"
 #include "support/lyxlib.h"
 
 #include <map>
diff --git a/src/support/Length.cpp b/src/support/Length.cpp
new file mode 100644
index 0000000000..d23ea9bf98
--- /dev/null
+++ b/src/support/Length.cpp
@@ -0,0 +1,463 @@
+/**
+ * \file Length.cpp
+ * This file is part of LyX, the document processor.
+ * Licence details can be found in the file COPYING.
+ *
+ * \author Matthias Ettrich
+ * \author Lars Gullik Bjønnes
+ * \author Jean-Marc Lasgouttes
+ * \author Angus Leeming
+ * \author John Levon
+ * \author Dekel Tsur
+ *
+ * Full author contact details are available in file CREDITS.
+ */
+
+#include <config.h>
+
+#include "LyXRC.h"
+
+#include "support/debug.h"
+#include "support/docstream.h"
+#include "support/Length.h"
+#include "support/lstrings.h"
+#include "support/lyxlib.h"
+
+#include <sstream>
+#include <iomanip>
+
+using namespace std;
+using namespace lyx::support;
+
+namespace lyx {
+
+
+/////////////////////////////////////////////////////////////////////
+//
+// Length
+//
+/////////////////////////////////////////////////////////////////////
+
+Length::Length()
+	: val_(0), unit_(Length::UNIT_NONE)
+{}
+
+
+Length::Length(double v, Length::UNIT u)
+	: val_(v), unit_(u)
+{}
+
+
+Length::Length(string const & data)
+	: val_(0), unit_(Length::UNIT_NONE)
+{
+	Length tmp;
+
+	if (!isValidLength(data, &tmp))
+		return; // should raise an exception
+
+	val_  = tmp.val_;
+	unit_ = tmp.unit_;
+}
+
+
+string const Length::asString() const
+{
+	ostringstream os;
+	if (unit_ != UNIT_NONE)
+		os << formatFPNumber(val_) << unit_name[unit_]; // setw?
+	return os.str();
+}
+
+
+docstring const Length::asDocstring() const
+{
+	odocstringstream os;
+	if (unit_ != UNIT_NONE)
+		os << from_ascii(formatFPNumber(val_))
+		   << from_ascii(unit_name[unit_]); // setw?
+	return os.str();
+}
+
+
+string const Length::asLatexString() const
+{
+	ostringstream os;
+	// Do not allow scientific notation (e.g. 1.2e+03), since this is not valid
+	// LaTeX (bug 9416)
+	switch (unit_) {
+	case PTW:
+		os << formatFPNumber(val_ / 100.0) << "\\textwidth";
+		break;
+	case PCW:
+		os << formatFPNumber(val_ / 100.0) << "\\columnwidth";
+		break;
+	case PPW:
+		os << formatFPNumber(val_ / 100.0) << "\\paperwidth";
+		break;
+	case PLW:
+		os << formatFPNumber(val_ / 100.0) << "\\linewidth";
+		break;
+	case PTH:
+		os << formatFPNumber(val_ / 100.0) << "\\textheight";
+		break;
+	case PPH:
+		os << formatFPNumber(val_ / 100.0) << "\\paperheight";
+		break;
+	case BLS:
+		os << formatFPNumber(val_ / 100.0) << "\\baselineskip";
+		break;
+	case UNIT_NONE:
+		break;
+	default:
+		os << formatFPNumber(val_) << unit_name[unit_];
+	  break;
+	}
+	return os.str();
+}
+
+
+string const Length::asHTMLString() const
+{
+	ostringstream os;
+	switch (unit_) {
+	case PT:
+ 	case BP:
+	case DD:
+		// close enough
+		os << formatFPNumber(val_) << "pt";
+		break;
+ 	case MM:
+	case CM:
+	case PC:
+	case IN:
+	case EX:
+	case EM:
+		os << formatFPNumber(val_) << unit_name[unit_];
+		break;
+	case CC:
+		os << formatFPNumber(val_ / 12.0) << "pt";
+		break;
+ 	case MU:
+		os << formatFPNumber(val_ / 18.0) << "em";
+		break;
+	case PTW:
+	case PPW:
+	case PLW:
+	case PCW:
+	case PTH:
+	case PPH:
+	case BLS:
+		// what it's a percentage of probably won't make sense for HTML,
+		// so we'll assume people have chosen these appropriately
+		os << formatFPNumber(val_) << '%';
+		break;
+	case SP:
+	case UNIT_NONE:
+		break;
+	}
+	return os.str();
+}
+
+
+double Length::value() const
+{
+	return val_;
+}
+
+
+Length::UNIT Length::unit() const
+{
+	return unit_;
+}
+
+
+void Length::value(double v)
+{
+	val_ = v;
+}
+
+
+void Length::unit(Length::UNIT u)
+{
+	unit_ = u;
+}
+
+
+bool Length::zero() const
+{
+	return val_ == 0.0;
+}
+
+
+bool Length::empty() const
+{
+	return unit_ == Length::UNIT_NONE;
+}
+
+
+int Length::inPixels(int text_width, int em_width_base) const
+{
+	// Zoom factor specified by user in percent
+	double const zoom = lyxrc.currentZoom / 100.0; // [percent]
+
+	// DPI setting for monitor: pixels/inch
+	double const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
+
+	double const em_width_in = (em_width_base > 0)
+		? em_width_base / (zoom * dpi)
+		: 10.0/72.27;
+	// A different estimate for em_width is
+	// theFontMetrics(FontInfo(sane_font)).em()
+	// but this estimate might not be more accurate as the screen font
+	// is different then the latex font.
+
+	// Pixel values are scaled so that the ratio
+	// between lengths and font sizes on the screen
+	// is the same as on paper.
+
+	double const text_width_in = text_width / (zoom * dpi);
+	double const result = zoom * dpi * inInch(text_width_in, em_width_in);
+	return support::iround(result);
+}
+
+
+double Length::inInch(double text_width, double em_width) const
+{
+	double result = 0.0;
+
+	switch (unit_) {
+	case Length::SP:
+		// Scaled point: sp = 1/65536 pt
+		result = val_ / (72.27 * 65536); // 4736286.7
+		break;
+	case Length::PT:
+		// Point: 1 pt = 1/72.27 inch
+		result = val_ / 72.27; // 72.27
+		break;
+	case Length::BP:
+		// Big point: 1 bp = 1/72 inch
+		result = val_ / 72; // 72
+		break;
+	case Length::DD:
+		// Didot: 1157dd = 1238 pt?
+		result = val_ / (72.27 / (0.376 * 2.845)); // 67.559735
+		break;
+	case Length::MM:
+		// Millimeter: 1 mm = 1/25.4 inch
+		result = val_ / 25.4; // 25.4
+		break;
+	case Length::PC:
+		// Pica: 1 pc = 12 pt
+		result = val_ / (72.27 / 12); // 6.0225
+		break;
+	case Length::CC:
+		// Cicero: 1 cc = 12 dd
+		result = val_
+			/ (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
+		break;
+	case Length::CM:
+		// Centimeter: 1 cm = 1/2.54 inch
+		result = val_ / 2.54; // 2.54
+		break;
+	case Length::IN:
+		// Inch
+		result = val_;
+		break;
+	case Length::EX:
+		// Ex: The height of an "x"
+		// 0.4305 is the ration between 1ex and 1em in cmr10
+		result = val_ * em_width * 0.4305;
+		break;
+	case Length::EM:
+		// Em: The width of an "m"
+		result = val_ * em_width;
+		break;
+	case Length::MU:
+		// math unit = 1/18em
+		result = val_ * em_width / 18;
+		break;
+	case Length::PCW: // Always % of workarea
+	case Length::PTW:
+	case Length::PLW:
+		result = val_ * text_width / 100;
+		break;
+	case Length::PPW:
+		// paperwidth/textwidth is 1.7 for A4 paper with default margins
+		result = val_ * text_width * 1.7 / 100;
+		break;
+	case Length::PTH:
+		result = val_ * text_width * 1.787 / 100;
+		break;
+	case Length::PPH:
+		result = val_ * text_width * 2.2 / 100;
+		break;
+	case Length::BLS:
+		// baselineskip is approximately 1.2 times the font size for the cmr fonts
+		// The value actually depends on the current paragraph (see TextMetrics::setRowHeight),
+		// but we do not have this information here.
+		result = val_ * em_width * 1.2 / 100;
+		break;
+	case Length::UNIT_NONE:
+		result = 0;  // this cannot happen
+		break;
+	}
+	return result;
+}
+
+
+int Length::inBP() const
+{
+	// return any Length value as a one with
+	// the PostScript point, called bp (big points)
+
+	double const text_width_in = 210.0 / 2.54; // assume A4
+	double const em_width_in = 10.0 / 72.27;
+	double const result = 72.0 * inInch(text_width_in, em_width_in);
+	return support::iround(result);
+}
+
+
+Length::UNIT Length::defaultUnit()
+{
+	return lyxrc.default_length_unit;
+}
+
+
+
+bool operator==(Length const & l1, Length const & l2)
+{
+	return l1.value() == l2.value() && l1.unit() == l2.unit();
+}
+
+
+bool operator!=(Length const & l1, Length const & l2)
+{
+	return !(l1 == l2);
+}
+
+
+/////////////////////////////////////////////////////////////////////
+//
+// GlueLength
+//
+/////////////////////////////////////////////////////////////////////
+
+
+GlueLength::GlueLength(Length const & len)
+	: len_(len)
+{}
+
+
+GlueLength::GlueLength(Length const & len, Length const & plus,
+		Length const & minus)
+	: len_(len), plus_(plus), minus_(minus)
+{}
+
+
+GlueLength::GlueLength(string const & data)
+{
+	if (!isValidGlueLength(data, this))
+		LYXERR0("Invalid glue length " + data);
+}
+
+
+string const GlueLength::asString() const
+{
+	if (len_.empty())
+		return string();
+
+	ostringstream buffer;
+
+	buffer << formatFPNumber(len_.value());
+
+	if (plus_.zero() && minus_.zero()) {
+		buffer << unit_name[len_.unit()];
+		return buffer.str();
+	}
+
+	// just len and plus
+	if (minus_.zero()) {
+		if (len_.unit() != plus_.unit())
+			buffer << unit_name[len_.unit()];
+		buffer << '+' << formatFPNumber(plus_.value());
+		buffer << unit_name[plus_.unit()];
+		return buffer.str();
+	}
+
+	// just len and minus
+	if (plus_.zero()) {
+		if (len_.unit() != minus_.unit())
+			buffer << unit_name[len_.unit()];
+		buffer << '-' << formatFPNumber(minus_.value());
+		buffer << unit_name[minus_.unit()];
+		return buffer.str();
+	}
+
+	// ok, len, plus AND minus
+
+	// len+-
+	if (minus_ == plus_) {
+		if (len_.unit() != minus_.unit())
+			buffer << unit_name[len_.unit()];
+		buffer << "+-" << formatFPNumber(minus_.value());
+		buffer << unit_name[minus_.unit()];
+		return buffer.str();
+	}
+
+	// this is so rare a case, why bother minimising units ?
+
+	buffer << unit_name[len_.unit()];
+	buffer << '+' << formatFPNumber(plus_.value()) << unit_name[plus_.unit()];
+	buffer << '-' << formatFPNumber(minus_.value()) << unit_name[minus_.unit()];
+
+	return buffer.str();
+}
+
+
+string const GlueLength::asLatexString() const
+{
+	ostringstream buffer;
+	// use Length::asLatexString() to handle also the percent lengths
+	buffer << len_.Length::asLatexString();
+	if (!plus_.zero())
+		buffer << " plus " << plus_.Length::asLatexString();
+	if (!minus_.zero())
+		buffer << " minus " << minus_.Length::asLatexString();
+	return buffer.str();
+}
+
+
+Length const & GlueLength::len() const
+{
+	return len_;
+}
+
+
+Length const & GlueLength::plus() const
+{
+	return plus_;
+}
+
+
+Length const & GlueLength::minus() const
+{
+	return minus_;
+}
+
+
+bool operator==(GlueLength const & l1, GlueLength const & l2)
+{
+	return l1.len() == l2.len()
+		 && l1.plus() == l2.plus()
+		 && l1.minus() == l2.minus();
+}
+
+
+bool operator!=(GlueLength const & l1, GlueLength const & l2)
+{
+	return !(l1 == l2);
+}
+
+
+} // namespace lyx
diff --git a/src/support/Length.h b/src/support/Length.h
new file mode 100644
index 0000000000..aaf19238e6
--- /dev/null
+++ b/src/support/Length.h
@@ -0,0 +1,211 @@
+// -*- C++ -*-
+/**
+ * \file Length.h
+ * This file is part of LyX, the document processor.
+ * Licence details can be found in the file COPYING.
+ *
+ * \author Matthias Ettrich
+ * \author Lars Gullik Bjønnes
+ * \author Jean-Marc Lasgouttes
+ * \author John Levon
+ *
+ * Full author contact details are available in file CREDITS.
+ */
+
+#ifndef LENGTH_H
+#define LENGTH_H
+
+#include "support/strfwd.h"
+
+
+namespace lyx {
+
+// Solaris/x86 version 9 and earlier define these
+#undef PC
+#undef SP
+
+/////////////////////////////////////////////////////////////////////
+//
+// Length
+//
+/////////////////////////////////////////////////////////////////////
+
+
+/**
+ * Length - Represents latex length measurement
+ */
+class Length {
+public:
+	/// length units
+	enum UNIT {
+		BP, ///< Big point (72bp = 1in), also PostScript point
+		CC, ///< Cicero = 12dd = 4.531mm
+		CM, ///< Centimeter = 10mm = 2.371pc
+		DD, ///< Didot point = 1/72 of a French inch, = 0.376mm
+		EM, ///< Width of capital "M" in current font.
+		EX, ///< Height of a small "x" for the current font.
+		IN, ///< Inch = 25.4mm = 72.27pt = 6.022pc
+		MM, ///< Millimeter = 2.845pt
+		MU, ///< Math unit (18mu = 1em) for positioning in math mode
+		PC, ///< Pica = 12pt = 4.218mm
+		PT, ///< Point = 1/72.27in = 0.351mm
+		SP, ///< Scaled point (65536sp = 1pt) TeX's smallest unit.
+		PTW, //< Percent of TextWidth
+		PCW, //< Percent of ColumnWidth
+		PPW, //< Percent of PageWidth
+		PLW, //< Percent of LineWidth
+		PTH, //< Percent of TextHeight          // Herbert 2002-05-16
+		PPH, //< Percent of PaperHeight         // Herbert 2002-05-16
+		BLS, //< Percent of BaselineSkip        // uwestoehr 2017-04-01
+		UNIT_NONE ///< no unit
+	};
+
+	///
+	Length();
+	///
+	Length(double v, Length::UNIT u);
+
+	/// "data" must be a decimal number, followed by a unit
+	explicit Length(std::string const & data);
+
+	///
+	double value() const;
+	///
+	Length::UNIT unit() const;
+	///
+	void value(double);
+	///
+	void unit(Length::UNIT unit);
+	///
+	bool zero() const;
+	///
+	bool empty() const;
+	/// return string representation
+	std::string const asString() const;
+	/// return string representation
+	docstring const asDocstring() const;
+	/// return string representation for LaTeX
+	std::string const asLatexString() const;
+	/// return string representation for HTML
+	std::string const asHTMLString() const;
+	/** return the on-screen size of this length.
+	 *
+	 *	If the second argument is not provided, then the unit EM will
+	 *	only be approximated. It is better if possible to use
+	 *	FontMetrics::em() to get this value.
+	 */
+	int inPixels(int text_width, int em_width = 0) const;
+
+	/// return the value in Big Postscript points.
+	/// Caution: Inaccurate for em, ex, mu and percent units.
+	int inBP() const;
+
+	/// return the default unit (centimeter or inch)
+	static UNIT defaultUnit();
+
+	friend bool isValidLength(std::string const & data, Length * result);
+
+private:
+	/// Convert value to inch for text width and em width given in inch
+	double inInch(double text_width, double em_width) const;
+	///
+	double val_;
+	///
+	Length::UNIT unit_;
+};
+
+///
+bool operator==(Length const & l1, Length const & l2);
+///
+bool operator!=(Length const & l1, Length const & l2);
+/** Test whether \p data represents a valid length.
+ *
+ * \returns whether \p data is a valid length
+ * \param data Length in LyX format. Since the only difference between LyX
+ * and LaTeX format is the representation of length variables as units (e.g.
+ * \c text% vs. \c \\textwidth) you can actually use this function as well
+ * for testing LaTeX lengths as long as they only contain real units like pt.
+ * \param result Pointer to a Length variable. If \p result is not 0 and
+ * \p data is valid, the length represented by it is stored into \p result.
+ */
+bool isValidLength(std::string const & data, Length * result = 0);
+/// return the LyX name of the given unit number
+char const * stringFromUnit(int unit);
+
+
+/////////////////////////////////////////////////////////////////////
+//
+// GlueLength
+//
+/////////////////////////////////////////////////////////////////////
+
+class GlueLength {
+public:
+	///
+	GlueLength() {}
+	///
+	explicit GlueLength(Length const & len);
+	///
+	GlueLength(Length const & len,
+		      Length const & plus,
+		      Length const & minus);
+
+	/** "data" must be a decimal number, followed by a unit, and
+	  optional "glue" indicated by "+" and "-".  You may abbreviate
+	  reasonably.  Examples:
+	  1.2 cm  //  4mm +2pt  //  2cm -4mm +2mm  //  4+0.1-0.2cm
+	  The traditional Latex format is also accepted, like
+	  4cm plus 10pt minus 10pt */
+	explicit GlueLength(std::string const & data);
+
+	///
+	Length const & len() const;
+	///
+	Length const & plus() const;
+	///
+	Length const & minus() const;
+
+
+	/// conversion
+	std::string const asString() const;
+	///
+	std::string const asLatexString() const;
+
+	friend bool isValidGlueLength(std::string const & data,
+				      GlueLength* result);
+
+private:
+	/// the normal vlaue
+	Length len_;
+	/// extra stretch
+	Length plus_;
+	/// extra shrink
+	Length minus_;
+};
+
+///
+bool operator==(GlueLength const & l1, GlueLength const & l2);
+///
+bool operator!=(GlueLength const & l1, GlueLength const & l2);
+/** If "data" is valid, the length represented by it is
+    stored into "result", if that is not 0. */
+bool isValidGlueLength(std::string const & data, GlueLength * result = 0);
+
+/// the number of units possible
+extern int const num_units;
+
+/**
+ * array of unit names
+ *
+ * FIXME: I am not sure if "mu" should be possible to select (Lgb)
+ */
+extern char const * const unit_name[];
+extern char const * const unit_name_gui[];
+
+/// return the unit given a string representation such as "cm"
+Length::UNIT unitFromString(std::string const & data);
+
+
+} // namespace lyx
+
+#endif // LENGTH_H
diff --git a/src/support/Makefile.am b/src/support/Makefile.am
index 3d92b62db0..8b7d211fa0 100644
--- a/src/support/Makefile.am
+++ b/src/support/Makefile.am
@@ -71,6 +71,9 @@ liblyxsupport_a_SOURCES = \
 	kill.cpp \
 	lassert.h \
 	lassert.cpp \
+	Length.cpp \
+	Length.h \
+	lengthcommon.cpp \
 	limited_stack.h \
 	lstrings.cpp \
 	lstrings.h \
diff --git a/src/support/lengthcommon.cpp b/src/support/lengthcommon.cpp
new file mode 100644
index 0000000000..303dbcbc1f
--- /dev/null
+++ b/src/support/lengthcommon.cpp
@@ -0,0 +1,366 @@
+/**
+ * \file lengthcommon.cpp
+ * This file is part of LyX, the document processor.
+ * Licence details can be found in the file COPYING.
+ *
+ * \author Lars Gullik Bjønnes
+ * \author Matthias Ettrich
+ * \author John Levon
+ *
+ * Full author contact details are available in file CREDITS.
+ */
+
+#include <config.h>
+
+#include "support/convert.h"
+#include "support/gettext.h"
+#include "support/lassert.h"
+#include "support/Length.h"
+#include "support/lstrings.h"
+
+using namespace std;
+using namespace lyx::support;
+
+
+namespace lyx {
+
+// I am not sure if "mu" should be possible to select (Lgb)
+
+// the latex units
+char const * const unit_name[] = {
+	"bp", "cc", "cm", "dd", "em", "ex", "in", "mm", "mu",
+	"pc", "pt", "sp",
+	"text%",  "col%", "page%", "line%",
+	"theight%", "pheight%", "baselineskip%", "" };
+
+int const num_units = int(sizeof(unit_name) / sizeof(unit_name[0]) - 1);
+
+// the LyX gui units
+char const * const unit_name_gui[] = {
+	N_("bp"), N_("cc[[unit of measure]]"), N_("cm"), N_("dd"), N_("em"),
+	N_("ex"), N_("in[[unit of measure]]"), N_("mm"), N_("mu[[unit of measure]]"), N_("pc"),
+	N_("pt"), N_("sp"), N_("Text Width %"),
+	N_("Column Width %"), N_("Page Width %"), N_("Line Width %"),
+	N_("Text Height %"), N_("Page Height %"), N_("Line Distance %"), "" };
+
+
+Length::UNIT unitFromString(string const & data)
+{
+	int i = 0;
+	while (i < num_units && data != unit_name[i])
+		++i;
+	return static_cast<Length::UNIT>(i);
+}
+
+
+namespace {
+
+/// skip n characters of input
+inline void lyx_advance(string & data, size_t n)
+{
+	data.erase(0, n);
+}
+
+
+/// return true when the input is at the end
+inline bool isEndOfData(string const & data)
+{
+	return ltrim(data).empty();
+}
+
+
+/**
+ * nextToken -  return the next token in the input
+ * @param data input string
+ * @param number_index the current position in the number array
+ * @param unit_index the current position in the unit array
+ * @return a char representing the type of token returned
+ *
+ * The possible return values are :
+ *	+	stretch indicator for glue length
+ *	-	shrink indicator for glue length
+ *	n	a numeric value (stored in number array)
+ *	u	a unit type (stored in unit array)
+ *	E	parse error
+ */
+char nextToken(string & data, double * number, int & number_index,
+               Length::UNIT * unit, int & unit_index)
+{
+	data = ltrim(data);
+
+	if (data.empty())
+		return '\0';
+
+	if (data[0] == '+') {
+		lyx_advance(data, 1);
+		return '+';
+	}
+
+	if (prefixIs(data, "plus")) {
+		lyx_advance(data, 4);
+		return '+';
+	}
+
+	if (data[0] == '-') {
+		lyx_advance(data, 1);
+		return '-';
+	}
+
+	if (prefixIs(data, "minus")) {
+		lyx_advance(data, 5);
+		return '-';
+	}
+
+	size_t i = data.find_first_not_of("0123456789.");
+
+	if (i != 0) {
+		if (number_index > 3)
+			return 'E';
+
+		string buffer;
+
+		// we have found some number
+		if (i == string::npos) {
+			buffer = data;
+			i = data.size() + 1;
+		} else {
+			buffer = data.substr(0, i);
+		}
+
+		lyx_advance(data, i);
+
+		if (isStrDbl(buffer)) {
+			number[number_index] = convert<double>(buffer);
+			++number_index;
+			return 'n';
+		}
+		return 'E';
+	}
+
+	i = data.find_first_not_of("abcdefghijklmnopqrstuvwxyz%");
+	if (i != 0) {
+		if (unit_index > 3)
+			return 'E';
+
+		string buffer;
+
+		// we have found some alphabetical string
+		if (i == string::npos) {
+			buffer = data;
+			i = data.size() + 1;
+		} else {
+			buffer = data.substr(0, i);
+		}
+
+		// possibly we have "mmplus" string or similar
+		if (buffer.size() > 5 &&
+				(buffer.substr(2, 4) == string("plus") ||
+				 buffer.substr(2, 5) == string("minus")))
+		{
+			lyx_advance(data, 2);
+			unit[unit_index] = unitFromString(buffer.substr(0, 2));
+		} else {
+			lyx_advance(data, i);
+			unit[unit_index] = unitFromString(buffer);
+		}
+
+		if (unit[unit_index] != Length::UNIT_NONE) {
+			++unit_index;
+			return 'u';
+		}
+		return 'E';  // Error
+	}
+	return 'E';  // Error
+}
+
+
+/// latex representation of a vspace
+struct LaTeXLength {
+	char const * pattern;
+	int  plus_val_index;
+	int  minus_val_index;
+	int  plus_uni_index;
+	int  minus_uni_index;
+};
+
+
+/// the possible formats for a vspace string
+LaTeXLength table[] = {
+	{ "nu",       0, 0, 0, 0 },
+	{ "nu+nu",    2, 0, 2, 0 },
+	{ "nu+nu-nu", 2, 3, 2, 3 },
+	{ "nu+-nu",   2, 2, 2, 2 },
+	{ "nu-nu",    0, 2, 0, 2 },
+	{ "nu-nu+nu", 3, 2, 3, 2 },
+	{ "nu-+nu",   2, 2, 2, 2 },
+	{ "n+nu",     2, 0, 1, 0 },
+	{ "n+n-nu",   2, 3, 1, 1 },
+	{ "n+-nu",    2, 2, 1, 1 },
+	{ "n-nu",     0, 2, 0, 1 },
+	{ "n-n+nu",   3, 2, 1, 1 },
+	{ "n-+nu",    2, 2, 1, 1 },
+	{ "",         0, 0, 0, 0 }   // sentinel, must be empty
+};
+
+
+} // namespace
+
+
+const char * stringFromUnit(int unit)
+{
+	if (unit < 0 || unit > num_units)
+		return nullptr;
+	return unit_name[unit];
+}
+
+
+bool isValidGlueLength(string const & data, GlueLength * result)
+{
+	// This parser is table-driven.  First, it constructs a "pattern"
+	// that describes the sequence of tokens in "data".  For example,
+	// "n-nu" means: number, minus sign, number, unit.  As we go along,
+	// numbers and units are stored into static arrays.  Then, "pattern"
+	// is searched in the "table".  If it is found, the associated
+	// table entries tell us which number and unit should go where
+	// in the Length structure.  Example: if "data" has the "pattern"
+	// "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
+	// That means, "plus_val" is the second number that was seen
+	// in the input, "minus_val" is the third number, and "plus_uni"
+	// and "minus_uni" are the second and third units, respectively.
+	// ("val" and "uni" are always the first items seen in "data".)
+	// This is the most elegant solution I could find -- a straight-
+	// forward approach leads to very long, tedious code that would be
+	// much harder to understand and maintain. (AS)
+
+	if (data.empty()) {
+		if (result)
+			*result = GlueLength();
+		return true;
+	}
+	string buffer = ltrim(data);
+
+	// To make isValidGlueLength recognize negative values as
+	// the first number this little hack is needed:
+	int val_sign = 1; // positive as default
+	switch (buffer[0]) {
+	case '-':
+		lyx_advance(buffer, 1);
+		val_sign = -1;
+		break;
+	case '+':
+		lyx_advance(buffer, 1);
+		break;
+	default:
+		break;
+	}
+	// end of hack
+
+	// used to return numeric values in parsing vspace
+	double number[4] = { 0, 0, 0, 0 };
+	// used to return unit types in parsing vspace
+	Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
+	                        Length::UNIT_NONE, Length::UNIT_NONE};
+	int number_index = 1; // entries at index 0 are sentinels
+	int unit_index = 1;   // entries at index 0 are sentinels
+
+	// construct "pattern" from "data"
+	size_t const pattern_max_size = 20;
+	string pattern;
+	while (!isEndOfData(buffer)) {
+		if (pattern.size() > pattern_max_size)
+			return false;
+		char const c = nextToken(buffer, number, number_index, unit,
+				unit_index);
+		if (c == 'E')
+			return false;
+		pattern.push_back(c);
+	}
+
+	// search "pattern" in "table"
+	size_t table_index = 0;
+	while (pattern != table[table_index].pattern) {
+		++table_index;
+		if (!*table[table_index].pattern)
+			return false;
+	}
+
+	// Get the values from the appropriate places.  If an index
+	// is zero, the corresponding array value is zero or UNIT_NONE,
+	// so we needn't check this.
+	if (result) {
+		result->len_.value  (number[1] * val_sign);
+		result->len_.unit   (unit[1]);
+		result->plus_.value (number[table[table_index].plus_val_index]);
+		result->plus_.unit  (unit  [table[table_index].plus_uni_index]);
+		result->minus_.value(number[table[table_index].minus_val_index]);
+		result->minus_.unit (unit  [table[table_index].minus_uni_index]);
+	}
+	return true;
+}
+
+
+bool isValidLength(string const & data, Length * result)
+{
+	// This is a trimmed down version of isValidGlueLength.
+	// The parser may seem overkill for lengths without
+	// glue, but since we already have it, using it is
+	// easier than writing something from scratch.
+	if (data.empty()) {
+		if (result)
+			*result = Length();
+		return true;
+	}
+
+	string buffer = data;
+
+	// To make isValidLength recognize negative values
+	// this little hack is needed:
+	int val_sign = 1; // positive as default
+	switch (buffer[0]) {
+	case '-':
+		lyx_advance(buffer, 1);
+		val_sign = -1;
+		break;
+	case '+':
+		lyx_advance(buffer, 1);
+		// fall through
+	default:
+		// no action
+		break;
+	}
+	// end of hack
+
+	// used to return numeric values in parsing vspace
+	double number[4] = { 0, 0, 0, 0 };
+	// used to return unit types in parsing vspace
+	Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
+	                        Length::UNIT_NONE, Length::UNIT_NONE};
+	int number_index = 1; // entries at index 0 are sentinels
+	int unit_index = 1;   // entries at index 0 are sentinels
+
+	// construct "pattern" from "data"
+	string pattern;
+	while (!isEndOfData(buffer)) {
+		if (pattern.size() > 2)
+			return false;
+		char const token = nextToken(buffer, number,
+				number_index, unit, unit_index);
+		if (token == 'E')
+			return false;
+		pattern += token;
+	}
+
+	// only the most basic pattern is accepted here
+	if (pattern != "nu")
+		return false;
+
+	// It _was_ a correct length string.
+	// Store away the values we found.
+	if (result) {
+		result->val_  = number[1] * val_sign;
+		result->unit_ = unit[1];
+	}
+	return true;
+}
+
+} // namespace lyx
diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index df83d0441b..957e4c0cd7 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -66,7 +66,7 @@ endforeach()
 
 set(check_ExternalTransforms_SOURCES)
 foreach(_f graphics/GraphicsParams.cpp insets/ExternalTransforms.cpp
-	Length.cpp lengthcommon.cpp tests/check_ExternalTransforms.cpp
+	tests/check_ExternalTransforms.cpp
 	tests/boost.cpp tests/dummy_functions.cpp)
     list(APPEND check_ExternalTransforms_SOURCES ${TOP_SRC_DIR}/src/${_f})
 endforeach()
@@ -90,7 +90,7 @@ add_test(NAME "check_ExternalTransforms"
 add_dependencies(lyx_run_tests check_ExternalTransforms)
 
 set(check_Length_SOURCES)
-foreach(_f Length.cpp lengthcommon.cpp tests/check_Length.cpp tests/boost.cpp tests/dummy_functions.cpp)
+foreach(_f tests/check_Length.cpp tests/boost.cpp tests/dummy_functions.cpp)
   list(APPEND check_Length_SOURCES ${TOP_SRC_DIR}/src/${_f})
 endforeach()
 add_executable(check_Length ${check_Length_SOURCES})
diff --git a/src/tex2lyx/CMakeLists.txt b/src/tex2lyx/CMakeLists.txt
index cb129af158..2a68e71150 100644
--- a/src/tex2lyx/CMakeLists.txt
+++ b/src/tex2lyx/CMakeLists.txt
@@ -7,14 +7,13 @@
 
 project(${_tex2lyx})
 
-# There is no header file lengthcommon.h
-set(LINKED_sources ${TOP_SRC_DIR}/src/lengthcommon.cpp)
+set(LINKED_sources)
 set(LINKED_headers)
 
 foreach(_src graphics/GraphicsParams insets/ExternalTemplate
 	insets/ExternalTransforms insets/InsetLayout Author CiteEnginesList Color Counters
 	Encoding FloatList Floating FontInfo LaTeXPackages Layout
-	LayoutFile LayoutModuleList Length Lexer ModuleList TextClass
+	LayoutFile LayoutModuleList Lexer ModuleList TextClass
 	Spacing version)
 	list(APPEND LINKED_sources ${TOP_SRC_DIR}/src/${_src}.cpp)
 	list(APPEND LINKED_headers ${TOP_SRC_DIR}/src/${_src}.h)
diff --git a/src/tex2lyx/Makefile.am b/src/tex2lyx/Makefile.am
index 87bb3355e0..05a3efc55a 100644
--- a/src/tex2lyx/Makefile.am
+++ b/src/tex2lyx/Makefile.am
@@ -102,8 +102,6 @@ LYX_OBJS = \
 	../Layout.o \
 	../LayoutFile.o \
 	../LayoutModuleList.o \
-	../Length.o \
-	../lengthcommon.o \
 	../Lexer.o \
 	../ModuleList.o \
 	../Spacing.o \
diff --git a/src/tex2lyx/text.cpp b/src/tex2lyx/text.cpp
index fdcab6333f..6744d78157 100644
--- a/src/tex2lyx/text.cpp
+++ b/src/tex2lyx/text.cpp
@@ -21,7 +21,6 @@
 #include "FloatList.h"
 #include "LaTeXPackages.h"
 #include "Layout.h"
-#include "Length.h"
 #include "Preamble.h"
 
 #include "insets/ExternalTemplate.h"
@@ -30,6 +29,7 @@
 #include "support/convert.h"
 #include "support/FileName.h"
 #include "support/filetools.h"
+#include "support/Length.h"
 #include "support/lstrings.h"
 #include "support/lyxtime.h"