add setting for quickplay singleplayer

Signed-off-by: Trial97 <alexandru.tripon97@gmail.com>

launcher/minecraft/launch/MinecraftTarget.cpp

@@ -0,0 +1,65 @@
+/* Copyright 2013-2021 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MinecraftTarget.h"
+
+#include <QStringList>
+
+// FIXME: the way this is written, it can't ever do any sort of validation and can accept total junk
+MinecraftTarget MinecraftTarget::parse(const QString& fullAddress, bool useWorld)
+{
+    if (useWorld) {
+        MinecraftTarget target;
+        target.world = fullAddress;
+        return target;
+    }
+    QStringList split = fullAddress.split(":");
+
+    // The logic below replicates the exact logic minecraft uses for parsing server addresses.
+    // While the conversion is not lossless and eats errors, it ensures the same behavior
+    // within Minecraft and Prism Launcher when entering server addresses.
+    if (fullAddress.startsWith("[")) {
+        int bracket = fullAddress.indexOf("]");
+        if (bracket > 0) {
+            QString ipv6 = fullAddress.mid(1, bracket - 1);
+            QString port = fullAddress.mid(bracket + 1).trimmed();
+
+            if (port.startsWith(":") && !ipv6.isEmpty()) {
+                port = port.mid(1);
+                split = QStringList({ ipv6, port });
+            } else {
+                split = QStringList({ ipv6 });
+            }
+        }
+    }
+
+    if (split.size() > 2) {
+        split = QStringList({ fullAddress });
+    }
+
+    QString realAddress = split[0];
+
+    quint16 realPort = 25565;
+    if (split.size() > 1) {
+        bool ok;
+        realPort = split[1].toUInt(&ok);
+
+        if (!ok) {
+            realPort = 25565;
+        }
+    }
+
+    return MinecraftTarget{ realAddress, realPort };
+}