Add methods to convert between encoding and name to QStringConverter

Add static methods that allow converting between a name for an
encoding and the Encoding enum.

Change-Id: I12bc503cf757ea31d3ca8d5e1f1216efddcb16d4
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 24 insertions, 5 deletions

diff --git a/src/corelib/text/qstringconverter.cpp b/src/corelib/text/qstringconverter.cpp
index 9322fcd35e..4972bcde4f 100644
--- a/src/corelib/text/qstringconverter.cpp
+++ b/src/corelib/text/qstringconverter.cpp
@@ -1475,12 +1475,25 @@ static bool nameMatch(const char *a, const char *b)
 QStringConverter::QStringConverter(const char *name)
     : iface(nullptr)
 {
+    auto e = encodingForName(name);
+    if (e)
+        iface = encodingInterfaces + int(e.value());
+}
+
+std::optional<QStringConverter::Encoding> QStringConverter::encodingForName(const char *name)
+{
     for (int i = 0; i < LastEncoding + 1; ++i) {
-        if (nameMatch(encodingInterfaces[i].name, name)) {
-            iface = encodingInterfaces + i;
-            break;
-        }
+        if (nameMatch(encodingInterfaces[i].name, name))
+            return QStringConverter::Encoding(i);
     }
+    if (nameMatch(name, "latin1"))
+        return QStringConverter::Latin1;
+    return std::nullopt;
+}
+
+const char *QStringConverter::nameForEncoding(QStringConverter::Encoding e)
+{
+    return encodingInterfaces[int(e)].name;
 }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/text/qstringconverter.h b/src/corelib/text/qstringconverter.h
index 73f9f4f9ba..fe401ecc9e 100644
--- a/src/corelib/text/qstringconverter.h
+++ b/src/corelib/text/qstringconverter.h
@@ -45,6 +45,8 @@
 #include <QtCore/qstringbuilder.h>
 #endif
 
+#include <optional>
+
 QT_BEGIN_NAMESPACE
 
 // work around a compiler bug in GCC 7
@@ -148,7 +150,8 @@ protected:
     QSTRINGCONVERTER_CONSTEXPR QStringConverter(const Interface *i)
         : iface(i)
     {}
-    QStringConverter(const char *name);
+    Q_CORE_EXPORT QStringConverter(const char *name);
+
 
 public:
     bool isValid() const { return iface != nullptr; }
@@ -162,6 +165,9 @@ public:
     const char *name() const
     { return isValid() ? iface->name : nullptr; }
 
+    Q_CORE_EXPORT static std::optional<Encoding> encodingForName(const char *name);
+    Q_CORE_EXPORT static const char *nameForEncoding(Encoding e);
+
 protected:
     const Interface *iface;
     State state;