Add new enum value VisualTabCharacter into QChar

With this enumeration value, users can get the width of
the current font TAB character more conveniently

In addition, added some documentation about where
users may use this enumeration.

Fixes: QTBUG-92205
Done-with: Volker Hilsheimer <volker.hilsheimer@qt.io>
Done-with: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Change-Id: I9794b7553e9299e351f9182de02866d07a1393fc
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

5 files changed, 16 insertions, 2 deletions

diff --git a/src/corelib/text/qchar.cpp b/src/corelib/text/qchar.cpp
index dcc36d18ce..7aff25fb4a 100644
--- a/src/corelib/text/qchar.cpp
+++ b/src/corelib/text/qchar.cpp
@@ -595,6 +595,7 @@ QT_BEGIN_NAMESPACE
     \value ByteOrderSwapped
     \value ParagraphSeparator
     \value LineSeparator
+    \value VisualTabCharacter Used to represent a tabulation as a horizontal arrow. Since 6.2.
     \value LastValidCodePoint
 */
 
diff --git a/src/corelib/text/qchar.h b/src/corelib/text/qchar.h
index 78d95e39fa..2a899abf6b 100644
--- a/src/corelib/text/qchar.h
+++ b/src/corelib/text/qchar.h
@@ -98,6 +98,7 @@ public:
         ByteOrderSwapped = 0xfffe,
         ParagraphSeparator = 0x2029,
         LineSeparator = 0x2028,
+        VisualTabCharacter = 0x2192,
         LastValidCodePoint = 0x10ffff
     };
 
diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index b2b87fb92e..381c1d20ce 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -2617,7 +2617,7 @@ void QTextLine::draw_internal(QPainter *p, const QPointF &pos,
                     gf.width = iterator.itemWidth;
                     QPainterPrivate::get(p)->drawTextItem(QPointF(iterator.x.toReal(), y.toReal()), gf, eng);
                     if (eng->option.flags() & QTextOption::ShowTabsAndSpaces) {
-                        const QChar visualTab = u'\x2192';
+                        const QChar visualTab = QChar(QChar::VisualTabCharacter);
                         int w = QFontMetrics(f).horizontalAdvance(visualTab);
                         qreal x = iterator.itemWidth.toReal() - w; // Right-aligned
                         if (x < 0)
diff --git a/src/widgets/widgets/qplaintextedit.cpp b/src/widgets/widgets/qplaintextedit.cpp
index 20fdbcd6a8..71aecc4275 100644
--- a/src/widgets/widgets/qplaintextedit.cpp
+++ b/src/widgets/widgets/qplaintextedit.cpp
@@ -2497,7 +2497,13 @@ void QPlainTextEdit::setOverwriteMode(bool overwrite)
     \brief the tab stop distance in pixels
     \since 5.10
 
-    By default, this property contains a value of 80.
+    By default, this property contains a value of 80 pixels.
+
+    Do not set a value less than the \l {QFontMetrics::}{horizontalAdvance()}
+    of the QChar::VisualTabCharacter character, otherwise the tab-character
+    will be drawn incompletely.
+
+    \sa QTextOption::ShowTabsAndSpaces, QTextDocument::defaultTextOption
 */
 
 qreal QPlainTextEdit::tabStopDistance() const
diff --git a/src/widgets/widgets/qtextedit.cpp b/src/widgets/widgets/qtextedit.cpp
index 2d3f98b4b9..55fb8adc5d 100644
--- a/src/widgets/widgets/qtextedit.cpp
+++ b/src/widgets/widgets/qtextedit.cpp
@@ -2066,6 +2066,12 @@ void QTextEdit::setOverwriteMode(bool overwrite)
     \since 5.10
 
     By default, this property contains a value of 80 pixels.
+
+    Do not set a value less than the \l {QFontMetrics::}{horizontalAdvance()}
+    of the QChar::VisualTabCharacter character, otherwise the tab-character
+    will be drawn incompletely.
+
+    \sa QTextOption::ShowTabsAndSpaces, QTextDocument::defaultTextOption
 */
 
 qreal QTextEdit::tabStopDistance() const