commit db9f41c03975654254cc10c7628ec8173dbc7f13
Author: Jean-Marc Lasgouttes <[email protected]>
Date: Fri Mar 31 16:56:06 2017 +0200
Work around bug in QTextLine::xToCursor
With RtL text, the method can be non-monotonic wrt x value (which is a
Qt bug). To work around this, we check whether positions adjacent to
those returned by xToCursor look better. Depending on whether the new
x position is too small or too large, we look backward or forward for
a better solution.
The performance is probably not great, but this is only needed for
user interactions, so the performance penalty should not be a problem.
Fixes part of #10569.
(cherry picked from commit da590925cd6749587b9f500ecdaa457e34bc0f4a)
---
src/frontends/qt4/GuiFontMetrics.cpp | 29 +++++++++++++++++++++++++++--
status.22x | 3 +++
2 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/src/frontends/qt4/GuiFontMetrics.cpp
b/src/frontends/qt4/GuiFontMetrics.cpp
index 80ff819..eb95401 100644
--- a/src/frontends/qt4/GuiFontMetrics.cpp
+++ b/src/frontends/qt4/GuiFontMetrics.cpp
@@ -265,9 +265,34 @@ int GuiFontMetrics::x2pos(docstring const & s, int & x,
bool const rtl,
double const wordspacing) const
{
shared_ptr<QTextLayout const> tl = getTextLayout(s, rtl, wordspacing);
- int const qpos = tl->lineForTextPosition(0).xToCursor(x);
+ QTextLine const & tline = tl->lineForTextPosition(0);
+ int qpos = tline.xToCursor(x);
+ int newx = static_cast<int>(tline.cursorToX(qpos));
+ // The value of qpos may be wrong in rtl text (see ticket #10569).
+ // To work around this, let's have a look at adjacent positions to
+ // see whether we find closer matches.
+ if (rtl && newx < x) {
+ while (qpos > 0) {
+ int const xm = static_cast<int>(tline.cursorToX(qpos -
1));
+ if (abs(xm - x) < abs(newx - x)) {
+ --qpos;
+ newx = xm;
+ } else
+ break;
+ }
+ } else if (rtl && newx > x) {
+ while (qpos < tline.textLength()) {
+ int const xp = static_cast<int>(tline.cursorToX(qpos +
1));
+ if (abs(xp - x) < abs(newx - x)) {
+ ++qpos;
+ newx = xp;
+ } else
+ break;
+ }
+ }
// correct x value to the actual cursor position.
- x = static_cast<int>(tl->lineForTextPosition(0).cursorToX(qpos));
+ x = newx;
+
/* Since QString is UTF-16 and docstring is UCS-4, the offsets may
* not be the same when there are high-plan unicode characters
* (bug #10443).
diff --git a/status.22x b/status.22x
index b0dfced..d3105f1 100644
--- a/status.22x
+++ b/status.22x
@@ -50,6 +50,9 @@ What's new
- Show correct color name for green in the status bar (bug 10656).
+- fixes to cursor positionning on mouse click for right-to-left text
+ (bug 10569).
+
* INTERNALS
