Let QTextLine decide its own x position in QPainter

So that it can take trailing space width into account when
doing right aligned text drawing.

Backported from master.

Task-number: QTBUG-18303
Reviewed-by: Eskil

4 files changed, 26 insertions, 22 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 0e279c9..3735e7c 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -8097,12 +8097,16 @@ start_lengthVariant:
             QTextLine line = textLayout.lineAt(i);
 
             qreal advance = line.horizontalAdvance();
-            if (tf & Qt::AlignRight)
-                xoff = r.width() - advance;
+            xoff = 0;
+            if (tf & Qt::AlignRight) {
+                QTextEngine *eng = textLayout.engine();
+                xoff = r.width() - advance -
+                    eng->leadingSpaceWidth(eng->lines[line.lineNumber()]).toReal();
+            }
             else if (tf & Qt::AlignHCenter)
-                xoff = (r.width() - advance)/2;
+                xoff = (r.width() - advance) / 2;
 
-            line.draw(painter, QPointF(r.x() + xoff + line.x(), r.y() + yoff));
+            line.draw(painter, QPointF(r.x() + xoff, r.y() + yoff));
         }
 
         if (restore) {
diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 4378c62..4f86cff 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -2681,6 +2681,22 @@ void QTextEngine::resolveAdditionalFormats() const
     specialData->resolvedFormatIndices = indices;
 }
 
+QFixed QTextEngine::leadingSpaceWidth(const QScriptLine &line)
+{
+    if (!line.hasTrailingSpaces
+        || (option.flags() & QTextOption::IncludeTrailingSpaces)
+        || !isRightToLeft())
+        return QFixed();
+
+    int pos = line.length;
+    const HB_CharAttributes *attributes = this->attributes();
+    if (!attributes)
+        return QFixed();
+    while (pos > 0 && attributes[line.from + pos - 1].whiteSpace)
+        --pos;
+    return width(line.from + pos, line.length - pos);
+}
+
 QStackTextEngine::QStackTextEngine(const QString &string, const QFont &f)
     : QTextEngine(string, f),
       _layoutData(string, _memory, MemSize)
diff --git a/src/gui/text/qtextengine_p.h b/src/gui/text/qtextengine_p.h
index 34723ab..67d7453 100644
--- a/src/gui/text/qtextengine_p.h
+++ b/src/gui/text/qtextengine_p.h
@@ -592,6 +592,7 @@ public:
     QString elidedText(Qt::TextElideMode mode, const QFixed &width, int flags = 0) const;
 
     void shapeLine(const QScriptLine &line);
+    QFixed leadingSpaceWidth(const QScriptLine &line);
 
 private:
     void setBoundary(int strPos) const;
diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index 905f81b..692620f 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -64,23 +64,6 @@ QT_BEGIN_NAMESPACE
 #define SuppressText 0x5012
 #define SuppressBackground 0x513
 
-static inline QFixed leadingSpaceWidth(QTextEngine *eng, const QScriptLine &line)
-{
-    if (!line.hasTrailingSpaces
-        || (eng->option.flags() & QTextOption::IncludeTrailingSpaces)
-        || !(eng->option.alignment() & Qt::AlignRight)
-        || !eng->isRightToLeft())
-        return QFixed();
-
-    int pos = line.length;
-    const HB_CharAttributes *attributes = eng->attributes();
-    if (!attributes)
-        return QFixed();
-    while (pos > 0 && attributes[line.from + pos - 1].whiteSpace)
-        --pos;
-    return eng->width(line.from + pos, line.length - pos);
-}
-
 static QFixed alignLine(QTextEngine *eng, const QScriptLine &line)
 {
     QFixed x = 0;
@@ -91,7 +74,7 @@ static QFixed alignLine(QTextEngine *eng, const QScriptLine &line)
         if (align & Qt::AlignJustify && eng->isRightToLeft())
             align = Qt::AlignRight;
         if (align & Qt::AlignRight)
-            x = line.width - (line.textAdvance + leadingSpaceWidth(eng, line));
+            x = line.width - (line.textAdvance + eng->leadingSpaceWidth(line));
         else if (align & Qt::AlignHCenter)
             x = (line.width - line.textAdvance)/2;
     }