QTextLayout: replace a use of an inefficient QList with QVector

The QTextLayout::FormatRange is larger than void* and thus should not be held in
QList. Use a QVector instead.

Other parts of Qt already hold FormatRanges in QVectors, so this also makes
handling FormatRanges more consistent.

To avoid ugly names for the getter which doesn't overload on return type alone),
rename the set of function to format (from additionalFormats).

[ChangeLog][QtGui][QTextLayout] Added QVector-based alternatives setFormat(),
format(), and clearFormat() to setAdditionalFormats(), additionalFormats(),
and clearAdditionalFormats(), resp.

Change-Id: Ie04a561b43c91c3b2befb3cac2981821f84d5f77
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

4 files changed, 50 insertions, 11 deletions

diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 67a19804a3..187ffa5be7 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -2571,7 +2571,7 @@ void QTextEngine::setPreeditArea(int position, const QString &preeditText)
     clearLineData();
 }
 
-void QTextEngine::setFormats(const QList<QTextLayout::FormatRange> &formats)
+void QTextEngine::setFormats(const QVector<QTextLayout::FormatRange> &formats)
 {
     if (formats.isEmpty()) {
         if (!specialData)
@@ -2946,17 +2946,17 @@ QFixed QTextEngine::calculateTabWidth(int item, QFixed x) const
 
 namespace {
 class FormatRangeComparatorByStart {
-    const QList<QTextLayout::FormatRange> &list;
+    const QVector<QTextLayout::FormatRange> &list;
 public:
-    FormatRangeComparatorByStart(const QList<QTextLayout::FormatRange> &list) : list(list) { }
+    FormatRangeComparatorByStart(const QVector<QTextLayout::FormatRange> &list) : list(list) { }
     bool operator()(int a, int b) {
         return list.at(a).start < list.at(b).start;
     }
 };
 class FormatRangeComparatorByEnd {
-    const QList<QTextLayout::FormatRange> &list;
+    const QVector<QTextLayout::FormatRange> &list;
 public:
-    FormatRangeComparatorByEnd(const QList<QTextLayout::FormatRange> &list) : list(list) { }
+    FormatRangeComparatorByEnd(const QVector<QTextLayout::FormatRange> &list) : list(list) { }
     bool operator()(int a, int b) {
         return list.at(a).start + list.at(a).length < list.at(b).start + list.at(b).length;
     }
diff --git a/src/gui/text/qtextengine_p.h b/src/gui/text/qtextengine_p.h
index 39b9e0cb5a..3590c6da07 100644
--- a/src/gui/text/qtextengine_p.h
+++ b/src/gui/text/qtextengine_p.h
@@ -570,9 +570,9 @@ public:
 
     inline bool hasFormats() const
     { return block.docHandle() || (specialData && !specialData->formats.isEmpty()); }
-    inline QList<QTextLayout::FormatRange> formats() const
-    { return specialData ? specialData->formats : QList<QTextLayout::FormatRange>(); }
-    void setFormats(const QList<QTextLayout::FormatRange> &formats);
+    inline QVector<QTextLayout::FormatRange> formats() const
+    { return specialData ? specialData->formats : QVector<QTextLayout::FormatRange>(); }
+    void setFormats(const QVector<QTextLayout::FormatRange> &formats);
 
 private:
     static void init(QTextEngine *e);
@@ -580,7 +580,7 @@ private:
     struct SpecialData {
         int preeditPosition;
         QString preeditText;
-        QList<QTextLayout::FormatRange> formats;
+        QVector<QTextLayout::FormatRange> formats;
         QVector<QTextCharFormat> resolvedFormats;
         // only used when no docHandle is available
         QScopedPointer<QTextFormatCollection> formatCollection;
diff --git a/src/gui/text/qtextlayout.cpp b/src/gui/text/qtextlayout.cpp
index 7da3e84041..dabe06fa88 100644
--- a/src/gui/text/qtextlayout.cpp
+++ b/src/gui/text/qtextlayout.cpp
@@ -485,7 +485,6 @@ QString QTextLayout::preeditAreaText() const
     return d->preeditAreaText();
 }
 
-
 /*!
     Sets the additional formats supported by the text layout to \a formatList.
     The formats are applied with preedit area text in place.
@@ -494,7 +493,20 @@ QString QTextLayout::preeditAreaText() const
 */
 void QTextLayout::setAdditionalFormats(const QList<FormatRange> &formatList)
 {
-    d->setFormats(formatList);
+    setFormats(formatList.toVector());
+}
+
+/*!
+    \since 5.6
+
+    Sets the additional formats supported by the text layout to \a formats.
+    The formats are applied with preedit area text in place.
+
+    \sa formats(), clearFormats()
+*/
+void QTextLayout::setFormats(const QVector<FormatRange> &formats)
+{
+    d->setFormats(formats);
 
     if (d->block.docHandle())
         d->block.docHandle()->documentChange(d->block.position(), d->block.length());
@@ -507,6 +519,18 @@ void QTextLayout::setAdditionalFormats(const QList<FormatRange> &formatList)
 */
 QList<QTextLayout::FormatRange> QTextLayout::additionalFormats() const
 {
+    return formats().toList();
+}
+
+/*!
+    \since 5.6
+
+    Returns the list of additional formats supported by the text layout.
+
+    \sa setFormats(), clearFormats()
+*/
+QVector<QTextLayout::FormatRange> QTextLayout::formats() const
+{
     return d->formats();
 }
 
@@ -521,6 +545,18 @@ void QTextLayout::clearAdditionalFormats()
 }
 
 /*!
+    \since 5.6
+
+    Clears the list of additional formats supported by the text layout.
+
+    \sa formats(), setFormats()
+*/
+void QTextLayout::clearFormats()
+{
+    setFormats(QVector<FormatRange>());
+}
+
+/*!
     Enables caching of the complete layout information if \a enable is
     true; otherwise disables layout caching. Usually
     QTextLayout throws most of the layouting information away after a
diff --git a/src/gui/text/qtextlayout.h b/src/gui/text/qtextlayout.h
index 47dcd388e2..ce092e0928 100644
--- a/src/gui/text/qtextlayout.h
+++ b/src/gui/text/qtextlayout.h
@@ -129,6 +129,9 @@ public:
     void setAdditionalFormats(const QList<FormatRange> &overrides);
     QList<FormatRange> additionalFormats() const;
     void clearAdditionalFormats();
+    void setFormats(const QVector<FormatRange> &overrides);
+    QVector<FormatRange> formats() const;
+    void clearFormats();
 
     void setCacheEnabled(bool enable);
     bool cacheEnabled() const;