The branch, str-metrics, has been updated.
- Log -----------------------------------------------------------------
commit 7b9b69f33c6d9bf0e6611e5fb8c406f3d3cefb80
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date: Wed May 14 17:46:43 2014 +0200
Fix positionning of cursor
The old implementation of Row::Element::pos2x and x2pos did not work
correctly with Arabic text, because characters can have shapes that
depend on context.
This new implementation leverages QTextLayout in a simplified way,
since only one word is added to the layout.
This allows to make Row::Element::x2pos more readable.
Fixes: #9115.
diff --git a/src/Row.cpp b/src/Row.cpp
index 48b4fff..50a47d3 100644
--- a/src/Row.cpp
+++ b/src/Row.cpp
@@ -36,78 +36,65 @@ using frontend::FontMetrics;
double Row::Element::pos2x(pos_type const i) const
{
- LASSERT(i >= pos && i <= endpos, return 0);
+ // This can happen with inline completion when clicking on the
+ // row after the completion.
+ if (i < pos || i > endpos)
+ return 0;
bool const rtl = font.isVisibleRightToLeft();
int w = 0;
//handle first the two bounds of the element
- if (i == pos)
- w = 0;
+ if (i == pos || type != STRING)
+ w = rtl ? width() : 0;
else if (i == endpos)
- w = width();
+ w = rtl ? 0 : width();
else {
- LASSERT(type == STRING, return 0);
FontMetrics const & fm = theFontMetrics(font);
- // FIXME Avoid caching of metrics there?
- w = fm.width(str.substr(0, i - pos));
+ w = fm.pos2x(str, i - pos, font.isVisibleRightToLeft());
}
- if (rtl)
- return width() - w;
- else
- return w;
+ return w;
}
-pos_type Row::Element::x2pos(double &x, bool const low) const
+pos_type Row::Element::x2pos(double &x) const
{
//lyxerr << "x2pos: x=" << x << " w=" << width() << " " << *this;
- // If element is rtl, flip x value
bool const rtl = font.isVisibleRightToLeft();
- double x2 = rtl ? (width() - x) : x;
+ size_t i;
- double last_w = 0;
- double w = 0;
- size_t i = 0;
switch (type) {
- case VIRTUAL:
- // those elements are actually empty (but they have a width)
- break;
case STRING: {
FontMetrics const & fm = theFontMetrics(font);
- // FIXME: implement dichotomy search?
- for ( ; i < str.size() ; ++i) {
- last_w = w;
- w = fm.width(str.substr(0, i + 1));
- if (w > x2)
- break;
- }
+ // FIXME: is it really necessary for x to be a double?
+ int xx = x;
+ i = fm.x2pos(str, xx, rtl);
+ x = xx;
break;
}
+ case VIRTUAL:
+ // those elements are actually empty (but they have a width)
+ i = 0;
+ x = rtl ? width() : 0;
+ break;
case SEPARATOR:
case INSET:
case SPACE:
- // those elements contain only one position
- w = width();
- }
-
- if (type == STRING && i == str.size())
- x2 = w;
- // round to the closest side. The !rtl is here to obtain the
- // same rounding as with the old code (this is cosmetic and
- // can be eventually removed).
- else if (type != VIRTUAL && !low && (x2 - last_w + !rtl > w - x2)) {
- x2 = w;
- ++i;
- } else
- x2 = last_w;
-
- // is element is rtl, flip values back
- x = rtl ? width() - x2 : x2;
+ // those elements contain only one position. Round to
+ // the closest side.
+ if (x > width()) {
+ x = width();
+ i = !rtl;
+ } else {
+ x = 0;
+ i = rtl;
+ }
+ }
//lyxerr << "=> p=" << pos + i << " x=" << x << endl;
return pos + i;
+
}
@@ -389,7 +376,8 @@ void Row::shorten_if_needed(pos_type const keep, int const
w)
// If there is a paragraph marker, it should be taken in account
if (elements_.size() == 2)
xstr -= back().width();
- pos_type new_pos = front.x2pos(xstr, true);
+ //FIXME: use FontMetrics::x2pos here?? handle rtl?
+ pos_type new_pos = front.x2pos(xstr);
front.str = front.str.substr(0, new_pos - pos_);
front.dim.wid = xstr;
front.endpos = new_pos;
diff --git a/src/Row.h b/src/Row.h
index 7725427..2aa09a6 100644
--- a/src/Row.h
+++ b/src/Row.h
@@ -71,11 +71,9 @@ public:
/** Return character position that is the closest to
* pixel position \param x. The value \param x is
- * rounded to the actual pixel position. If \param
- * short is true, the pixel value is rounded by
- * default.
+ * adjusted to the actual pixel position.
*/
- pos_type x2pos(double &x, bool low = false) const;
+ pos_type x2pos(double &x) const;
// Returns the position on left side of the element.
pos_type left_pos() const;
diff --git a/src/frontends/FontMetrics.h b/src/frontends/FontMetrics.h
index 59de630..56e47ea 100644
--- a/src/frontends/FontMetrics.h
+++ b/src/frontends/FontMetrics.h
@@ -77,6 +77,19 @@ public:
virtual int width(docstring const & s) const = 0;
/// FIXME ??
virtual int signedWidth(docstring const & s) const = 0;
+ /**
+ * return the x offset of a position in the string. The
+ * direction of the string is forced, and the returned value
+ * is from the left edge of the word, not from the start of the string.
+ */
+ virtual int pos2x(docstring const & s, int pos, bool rtl) const = 0;
+ /**
+ * return the position in the string for a given x offset. The
+ * direction of the string is forced, and the returned value
+ * is from the left edge of the word, not from the start of the string.
+ * the offset x is updated to match the closest position in the string.
+ */
+ virtual int x2pos(docstring const & s, int & x, bool rtl) const = 0;
/// return char dimension for the font.
virtual Dimension const dimension(char_type c) const = 0;
/**
diff --git a/src/frontends/qt4/GuiFontMetrics.cpp
b/src/frontends/qt4/GuiFontMetrics.cpp
index 27d4446..b6b2f5d 100644
--- a/src/frontends/qt4/GuiFontMetrics.cpp
+++ b/src/frontends/qt4/GuiFontMetrics.cpp
@@ -23,6 +23,8 @@
#include "support/lassert.h"
+#include <QTextLayout>
+
using namespace std;
namespace lyx {
@@ -50,7 +52,7 @@ inline QChar const ucs4_to_qchar(char_type const ucs4)
} // anon namespace
-GuiFontMetrics::GuiFontMetrics(QFont const & font) : metrics_(font, 0)
+GuiFontMetrics::GuiFontMetrics(QFont const & font) : font_(font),
metrics_(font, 0)
{
}
@@ -140,6 +142,53 @@ int GuiFontMetrics::signedWidth(docstring const & s) const
return width(s);
}
+namespace {
+void setTextLayout(QTextLayout & tl, docstring const & s, QFont const & font,
+ bool const rtl)
+{
+ QString qs;
+ /* In LyX, the character direction is forced by the language.
+ * Therefore, we have to signal that fact to Qt.
+ * Source: http://www.iamcal.com/understanding-bidirectional-text/
+ */
+ // Left-to-right override: forces to draw text left-to-right
+ char_type const LRO = 0x202D;
+ // Right-to-left override: forces to draw text right-to-left
+ char_type const RLO = 0x202E;
+ // Pop directional formatting: return to previous state
+ char_type const PDF = 0x202C;
+ if (rtl)
+ qs = toqstr(RLO + s + PDF);
+ else
+ qs = toqstr(LRO + s + PDF);
+
+ tl.setText(qs);
+ tl.setFont(font);
+ tl.beginLayout();
+ tl.createLine();
+ tl.endLayout();
+}
+}
+
+
+int GuiFontMetrics::pos2x(docstring const & s, int const pos, bool const rtl)
const
+{
+ QTextLayout tl;
+ setTextLayout(tl, s, font_, rtl);
+ return tl.lineForTextPosition(pos + 1).cursorToX(pos + 1);
+}
+
+
+int GuiFontMetrics::x2pos(docstring const & s, int & x, bool const rtl) const
+{
+ QTextLayout tl;
+ setTextLayout(tl, s, font_, rtl);
+ int const pos = tl.lineForTextPosition(0).xToCursor(x) - 1;
+ // correct x value to the actual cursor position.
+ x = tl.lineForTextPosition(0).cursorToX(pos + 1);
+ return pos;
+}
+
void GuiFontMetrics::rectText(docstring const & str,
int & w, int & ascent, int & descent) const
diff --git a/src/frontends/qt4/GuiFontMetrics.h
b/src/frontends/qt4/GuiFontMetrics.h
index a2c57ec..ac1e714 100644
--- a/src/frontends/qt4/GuiFontMetrics.h
+++ b/src/frontends/qt4/GuiFontMetrics.h
@@ -18,6 +18,7 @@
#include <map>
+#include <QFont>
#include <QFontMetrics>
#include <QHash>
@@ -41,6 +42,8 @@ public:
virtual int rbearing(char_type c) const;
virtual int width(docstring const & s) const;
virtual int signedWidth(docstring const & s) const;
+ virtual int pos2x(docstring const & s, int pos, bool rtl) const;
+ virtual int x2pos(docstring const & s, int & x, bool rtl) const;
virtual Dimension const dimension(char_type c) const;
virtual void rectText(docstring const & str,
@@ -55,6 +58,9 @@ public:
int width(QString const & str) const;
private:
+ /// The font
+ QFont font_;
+
/// Metrics on the font
QFontMetrics metrics_;
-----------------------------------------------------------------------
Summary of changes:
src/Row.cpp | 78 ++++++++++++++-------------------
src/Row.h | 6 +--
src/frontends/FontMetrics.h | 13 ++++++
src/frontends/qt4/GuiFontMetrics.cpp | 51 ++++++++++++++++++++++-
src/frontends/qt4/GuiFontMetrics.h | 6 +++
5 files changed, 104 insertions(+), 50 deletions(-)
hooks/post-receive
--
Repository for new features
