Optimise string operations a bit

- Use QString::arg(Args...) instead of .arg().arg()
- Use QLatin1String for string comparisons, should be faster
- Use QLatin1String::arg() for better readability

- Add the comment dfaure suggested in the MR, to explain why it's '2%'
  then '%1' in a QString().arg().arg()

NO_CHANGELOG

3 files changed, 12 insertions, 10 deletions

diff --git a/src/gui/kconfiggroupgui.cpp b/src/gui/kconfiggroupgui.cpp
index 09c31590..ab0c268f 100644
--- a/src/gui/kconfiggroupgui.cpp
+++ b/src/gui/kconfiggroupgui.cpp
@@ -54,8 +54,9 @@ static bool readEntryGui(const QByteArray &data, const char *key, const QVariant
             const int count = list.count();
 
             if (count != 3 && count != 4) {
-                const QString formatError = QStringLiteral(" (wrong format: expected '%1' items, read '%2')");
-                qCritical() << qPrintable(errString()) << qPrintable(formatError.arg(QStringLiteral("3' or '4")).arg(count));
+                qCritical() //
+                    << qPrintable(errString()) //
+                    << qPrintable(QStringLiteral(" (wrong format: expected '%1' items, read '%2')").arg(QStringLiteral("3' or '4")).arg(count));
                 return true; // return default
             }
 
@@ -70,9 +71,10 @@ static bool readEntryGui(const QByteArray &data, const char *key, const QVariant
                 }
                 if (j < 0 || j > 255) {
                     static const char *const components[] = {"red", "green", "blue", "alpha"};
-                    const QString boundsError = QStringLiteral(" (bounds error: %1 component %2)");
                     qCritical() << qPrintable(errString())
-                                << qPrintable(boundsError.arg(QLatin1String(components[i])).arg(j < 0 ? QStringLiteral("< 0") : QStringLiteral("> 255")));
+                                << qPrintable(QStringLiteral(" (bounds error: %1 component %2)")
+                                                  .arg(QLatin1String(components[i]), //
+                                                       j < 0 ? QStringLiteral("< 0") : QStringLiteral("> 255")));
                     return true; // return default
                 }
             }
diff --git a/src/gui/kconfiggui.cpp b/src/gui/kconfiggui.cpp
index 938fbd93..cafe061d 100644
--- a/src/gui/kconfiggui.cpp
+++ b/src/gui/kconfiggui.cpp
@@ -13,7 +13,7 @@
 
 static QString configName(const QString &id, const QString &key)
 {
-    return (QLatin1String("session/") + QGuiApplication::applicationName() + QLatin1Char('_') + id + QLatin1Char('_') + key);
+    return QLatin1String("session/%1_%2_%3").arg(QGuiApplication::applicationName(), id, key);
 }
 
 static KConfig *s_sessionConfig = nullptr;
diff --git a/src/gui/kwindowconfig.cpp b/src/gui/kwindowconfig.cpp
index a7697782..019e1aa2 100644
--- a/src/gui/kwindowconfig.cpp
+++ b/src/gui/kwindowconfig.cpp
@@ -37,7 +37,7 @@ static QString allConnectedScreens()
 static QString configFileString(const QRect &desk, const QString &key)
 {
     // We include resolution data to also save data on a per-resolution basis
-    const QString returnString = QStringLiteral("%1 %2 %3x%4").arg(allConnectedScreens()).arg(key).arg(desk.width()).arg(desk.height());
+    const QString returnString = QStringLiteral("%1 %2 %3x%4").arg(allConnectedScreens(), key, QString::number(desk.width()), QString::number(desk.height()));
     return returnString;
 }
 
@@ -136,7 +136,7 @@ void KWindowConfig::saveWindowPosition(const QWindow *window, KConfigGroup &conf
 {
     // On Wayland, the compositor is solely responsible for window positioning,
     // So this needs to be a no-op
-    if (!window || QGuiApplication::platformName() == QStringLiteral("wayland")) {
+    if (!window || QGuiApplication::platformName() == QLatin1String{"wayland"}) {
         return;
     }
 
@@ -149,7 +149,7 @@ void KWindowConfig::restoreWindowPosition(QWindow *window, const KConfigGroup &c
 {
     // On Wayland, the compositor is solely responsible for window positioning,
     // So this needs to be a no-op
-    if (!window || QGuiApplication::platformName() == QStringLiteral("wayland")) {
+    if (!window || QGuiApplication::platformName() == QLatin1String{"wayland"}) {
         return;
     }
 
@@ -166,8 +166,8 @@ void KWindowConfig::restoreWindowPosition(QWindow *window, const KConfigGroup &c
     // per-resolution information is not
     // TODO: Remove in KF6 or maybe even KF5.85 or something. It really only needs
     // to be here to transition existing users once they upgrade from 5.78 -> 5.79
-    const int fallbackXPosition = config.readEntry(QStringLiteral("%1 XPosition %2").arg(allConnectedScreens()).arg(desk.width()), -1);
-    const int fallbackYPosition = config.readEntry(QStringLiteral("%1 YPosition %2").arg(allConnectedScreens()).arg(desk.height()), -1);
+    const int fallbackXPosition = config.readEntry(QStringLiteral("%1 XPosition %2").arg(allConnectedScreens(), QString::number(desk.width())), -1);
+    const int fallbackYPosition = config.readEntry(QStringLiteral("%1 YPosition %2").arg(allConnectedScreens(), QString::number(desk.height())), -1);
     const int xPos = config.readEntry(windowXPositionString(desk), fallbackXPosition);
     const int yPos = config.readEntry(windowYPositionString(desk), fallbackYPosition);