From b6cf0418677729e91e5ccd866afdb22e11385d74 Mon Sep 17 00:00:00 2001
From: Anton Kudryavtsev <a.kudryavtsev@netris.ru>
Date: Fri, 13 May 2016 12:20:39 +0300
Subject: Widgets: use QStringRef to optimize memory allocation

Replace substring functions that return QString with
corresponding functions that return QStringRef where
it's possible.

Create QString from QStringRef only where necessary.

Change-Id: I728c4338135f83d9cdff4d1ee1aed77f95d453b8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
---
 src/widgets/widgets/qabstractspinbox.cpp | 4 ++--
 src/widgets/widgets/qtabbar.cpp          | 6 +++---
 src/widgets/widgets/qtextbrowser.cpp     | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

(limited to 'src')

diff --git a/src/widgets/widgets/qabstractspinbox.cpp b/src/widgets/widgets/qabstractspinbox.cpp
index b33984e6c6..774f5a708d 100644
--- a/src/widgets/widgets/qabstractspinbox.cpp
+++ b/src/widgets/widgets/qabstractspinbox.cpp
@@ -1418,7 +1418,7 @@ QStyle::SubControl QAbstractSpinBoxPrivate::newHoverControl(const QPoint &pos)
 
 QString QAbstractSpinBoxPrivate::stripped(const QString &t, int *pos) const
 {
-    QString text = t;
+    QStringRef text(&t);
     if (specialValueText.size() == 0 || text != specialValueText) {
         int from = 0;
         int size = text.size();
@@ -1440,7 +1440,7 @@ QString QAbstractSpinBoxPrivate::stripped(const QString &t, int *pos) const
     text = text.trimmed();
     if (pos)
         (*pos) -= (s - text.size());
-    return text;
+    return text.toString();
 
 }
 
diff --git a/src/widgets/widgets/qtabbar.cpp b/src/widgets/widgets/qtabbar.cpp
index 7a192193e4..09b7cb9d24 100644
--- a/src/widgets/widgets/qtabbar.cpp
+++ b/src/widgets/widgets/qtabbar.cpp
@@ -1413,13 +1413,13 @@ static QString computeElidedText(Qt::TextElideMode mode, const QString &text)
     QString ret;
     switch (mode) {
     case Qt::ElideRight:
-        ret = text.left(2) + Ellipses;
+        ret = text.leftRef(2) + Ellipses;
         break;
     case Qt::ElideMiddle:
-        ret = text.left(1) + Ellipses + text.right(1);
+        ret = text.leftRef(1) + Ellipses + text.rightRef(1);
         break;
     case Qt::ElideLeft:
-        ret = Ellipses + text.right(2);
+        ret = Ellipses + text.rightRef(2);
         break;
     case Qt::ElideNone:
         ret = text;
diff --git a/src/widgets/widgets/qtextbrowser.cpp b/src/widgets/widgets/qtextbrowser.cpp
index 45da34c383..df92fc0e1e 100644
--- a/src/widgets/widgets/qtextbrowser.cpp
+++ b/src/widgets/widgets/qtextbrowser.cpp
@@ -302,7 +302,7 @@ void QTextBrowserPrivate::setSource(const QUrl &url)
             qWarning("QTextBrowser: No document for %s", url.toString().toLatin1().constData());
 
         if (q->isVisible()) {
-            QString firstTag = txt.left(txt.indexOf(QLatin1Char('>')) + 1);
+            const QStringRef firstTag = txt.leftRef(txt.indexOf(QLatin1Char('>')) + 1);
             if (firstTag.startsWith(QLatin1String("<qt")) && firstTag.contains(QLatin1String("type")) && firstTag.contains(QLatin1String("detail"))) {
 #ifndef QT_NO_CURSOR
                 QApplication::restoreOverrideCursor();
-- 
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