From 31471496fd53b20b684173da56ba59d0da7f90fc Mon Sep 17 00:00:00 2001 From: Jean-Marc Lasgouttes Date: Tue, 19 Jan 2016 12:02:43 +0100 Subject: [PATCH] Allow breaking a row element at a leading/trailing space When an inset is separated from the adjacent string by a space, it is reasonable to be able to break the string after the space. Unfortunately, QTextLayout does not do that. This patch reverts the workaround inserted in 71378268 and replaces it with a different trick: the string is enlosed between a pair of zero-width non breaking space characters, so that the leading/trailing spaces are now normal spaces, where QTextLayout will agree to break the string. Fixes bug #9921 for good. --- src/Row.cpp | 11 ----------- src/frontends/qt4/GuiFontMetrics.cpp | 14 ++++++++++++-- 2 files changed, 12 insertions(+), 13 deletions(-) diff --git a/src/Row.cpp b/src/Row.cpp index 2bfe55a1b8..6e51fb192b 100644 --- a/src/Row.cpp +++ b/src/Row.cpp @@ -129,17 +129,6 @@ bool Row::Element::breakAt(int w, bool force) return true; } - // Qt will not break at a leading space, and we need that sometimes, see - // http://www.lyx.org/trac/ticket/9921. - // It would be nice to fix this properly, but for now do it by hand. - // FIXME: figure out what to do for RtL text. - if (!isRTL() && !str.empty() && str[0] == ' ') { - dim.wid = 0; - str = ' '; - endpos = pos + 1; - return true; - } - return false; } diff --git a/src/frontends/qt4/GuiFontMetrics.cpp b/src/frontends/qt4/GuiFontMetrics.cpp index c58be2aee3..fdb8c73bc6 100644 --- a/src/frontends/qt4/GuiFontMetrics.cpp +++ b/src/frontends/qt4/GuiFontMetrics.cpp @@ -219,7 +219,16 @@ bool GuiFontMetrics::breakAt(docstring & s, int & x, bool const rtl, bool const if (s.empty()) return false; QTextLayout tl; - tl.setText(toqstr(s)); + /* Qt will not break at a leading or trailing space, and we need + * that sometimes, see http://www.lyx.org/trac/ticket/9921. + * + * To work around the problem, we enclose the string between + * zero-width characters so that the QTextLayout algorithm will + * agree to break the text at these extremal spaces. + */ + // Unicode character ZERO WIDTH NO-BREAK SPACE + QChar const zerow_nbsp(0xfeff); + tl.setText(zerow_nbsp + toqstr(s) + zerow_nbsp); tl.setFont(font_); // Note that both setFlags and the enums are undocumented tl.setFlags(rtl ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight); @@ -234,7 +243,8 @@ bool GuiFontMetrics::breakAt(docstring & s, int & x, bool const rtl, bool const if (int(line.naturalTextWidth()) > x) return false; x = int(line.naturalTextWidth()); - s = s.substr(0, line.textLength()); + // The -1 is here to account for the leading zerow_nbsp. + s = s.substr(0, line.textLength() - 1); return true; } -- 2.39.5