Various tweaks to the Java component of the launcher

Signed-off-by: TheKodeToad <TheKodeToad@proton.me>

1 files changed, 104 insertions, 0 deletions

diff --git a/libraries/launcher/org/prismlauncher/impl/LegacyLauncher.java b/libraries/launcher/org/prismlauncher/impl/LegacyLauncher.java
new file mode 100644
index 00000000..30a4dba7
--- /dev/null
+++ b/libraries/launcher/org/prismlauncher/impl/LegacyLauncher.java
@@ -0,0 +1,104 @@
+/* Copyright 2012-2021 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.
+ */
+
+package org.prismlauncher.impl;
+
+import java.applet.Applet;
+import java.io.File;
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+import java.lang.reflect.Field;
+import java.util.Collections;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import org.prismlauncher.applet.LegacyFrame;
+import org.prismlauncher.utils.Parameters;
+import org.prismlauncher.utils.Utils;
+
+@SuppressWarnings("removal")
+public final class LegacyLauncher extends AbstractLauncher {
+
+    private static final Logger LOGGER = Logger.getLogger("LegacyLauncher");
+
+    private final String user, session;
+    private final String title;
+    private final String appletClass;
+
+    private final boolean noApplet;
+    private final String cwd;
+
+    public LegacyLauncher(Parameters params) {
+        super(params);
+
+        user = params.first("userName");
+        session = params.first("sessionId");
+        title = params.firstSafe("windowTitle", "Minecraft");
+        appletClass = params.firstSafe("appletClass", "net.minecraft.client.MinecraftApplet");
+
+        List<String> traits = params.allSafe("traits", Collections.<String>emptyList());
+        noApplet = traits.contains("noapplet");
+
+        cwd = System.getProperty("user.dir");
+    }
+
+    @Override
+    public void launch() throws Throwable {
+        Class<?> main = loadMain();
+        Field gameDirField = Utils.getMinecraftGameDirField(main);
+
+        if (gameDirField == null) {
+            LOGGER.warning("Could not find Mineraft path field.");
+        } else {
+            gameDirField.setAccessible(true);
+            gameDirField.set(null, new File(cwd));
+        }
+
+        if (!noApplet) {
+            LOGGER.info("Launching with applet wrapper...");
+
+            try {
+                Class<?> appletClass = classLoader.loadClass(this.appletClass);
+
+                MethodHandle constructor = MethodHandles.lookup().findConstructor(appletClass, MethodType.methodType(void.class));
+                Applet applet = (Applet) constructor.invoke();
+
+                LegacyFrame window = new LegacyFrame(title, applet);
+
+                window.start(
+                        user,
+                        session,
+                        width,
+                        height,
+                        maximize,
+                        serverAddress,
+                        serverPort,
+                        mcParams.contains("--demo")
+                );
+
+                return;
+            } catch (Throwable e) {
+                LOGGER.log(Level.SEVERE, "Applet wrapper failed:", e);
+
+                LOGGER.warning("Falling back to using main class.");
+            }
+        }
+
+        invokeMain(main);
+    }
+
+}