Fix Java 5 compatibility. Make applet removal opt-in. Update Fabric instructions

Author: Lassebq

doc/MultiMC.md

@@ -25,8 +25,7 @@ For this instance, perform the following steps:
 - Perform the same steps but instead of `org.mcphackers.launchwrapper.json` use the contents of [org.mcphackers.launchwrapper.fabric.json](org.mcphackers.launchwrapper.fabric.json)
 - Make sure it's the bottom-most component and is below the regular "LaunchWrapper" component
 
-## Forge
-To install LaunchWrapper with Forge follow instructions for Vanilla, then move "LaunchWrapper" component above Forge.
+Recent versions of Fabric loader will refuse to launch the game if multiple instances of asm libraries are present. You need to remove them.
 
 Edit "LaunchWrapper" component and modify `libraries` array:
 
@@ -50,8 +49,13 @@ Edit "LaunchWrapper" component and modify `libraries` array:
          }
      ],
 ```
+## Forge
+To install LaunchWrapper with Forge follow instructions for Vanilla, then move "LaunchWrapper" component above Forge.
+
+Remove asm libraries from LaunchWrapper component (refer to Fabric instructions)
 
 This only applies to versions where Forge isn't considered a jarmod. For versions where Forge is a jarmod, use Vanilla instructions.
+<!-- TODO: Determine version range -->
 
 ## Micromixin
 Micromixin is a lightweight alternative mixin implementation which can be used with standalone LaunchWrapper. Currently the implementation is barebones so many mixin annotations aren't supported. However, if the mod uses exclusively the annotations from base Mixin (Not MixinExtras) there's a high chance it'll work when recompiled with

doc/org.mcphackers.launchwrapper.fabric.json

@@ -9,5 +9,6 @@
             "url": "https://maven.glass-launcher.net/releases/"
         }
     ],
-    "mainClass": "org.mcphackers.launchwrapper.fabric.FabricBridge"
+    "mainClass": "org.mcphackers.launchwrapper.Launch",
+    "minecraftArguments": "--username ${auth_player_name} --session ${auth_session} --version ${version_name} --gameDir ${game_directory} --assetsDir ${assets_root} --assetIndex ${assets_index_name} --accessToken ${auth_access_token} --userType ${user_type} --versionType ${version_type} --tweakClass org.mcphackers.launchwrapper.tweak.FabricLoaderTweak"
 }

launchwrapper-fabric/src/main/java/org/mcphackers/launchwrapper/fabric/FabricBridge.java

@@ -33,7 +33,6 @@
 
 import org.mcphackers.launchwrapper.Launch;
 import org.mcphackers.launchwrapper.LaunchConfig;
-import org.mcphackers.launchwrapper.fabric.FabricBridge;
 import org.mcphackers.launchwrapper.target.MainLaunchTarget;
 import org.mcphackers.launchwrapper.tweak.FabricLoaderTweak;
 import org.mcphackers.launchwrapper.tweak.Tweak;
@@ -44,7 +43,8 @@ public class LWGameProvider implements GameProvider {
 	private static final Set<BuiltinTransform> TRANSFORM_WIDENALL_CLASSTWEAKS = EnumSet.of(BuiltinTransform.WIDEN_ALL_PACKAGE_ACCESS, BuiltinTransform.CLASS_TWEAKS);
 	private static final Set<BuiltinTransform> TRANSFORM_STRIPENV = EnumSet.of(BuiltinTransform.STRIP_ENVIRONMENT);
 
-	public LaunchConfig config = FabricBridge.getInstance().config;
+	public Launch launch = Launch.getInstance();
+	public LaunchConfig config = launch.config;
 	public MainLaunchTarget target = null;
 
 	private Arguments arguments;
@@ -58,10 +58,6 @@ public class LWGameProvider implements GameProvider {
 	private boolean hasModLoader;
 	private final GameTransformer transformer = new LWGameTransformer(this);
 
-	public Tweak getTweak(ClassNodeSource source) {
-		return new FabricLoaderTweak(Tweak.get(source, config), config);
-	}
-
 	@Override
 	public void launch(ClassLoader loader) {
 		String targetClass = target.targetClass;
@@ -169,7 +165,7 @@ public String getEntrypoint() {
 
 	@Override
 	public Path getLaunchDirectory() {
-		return FabricBridge.getInstance().config.gameDir.get().toPath();
+		return launch.config.gameDir.get().toPath();
 	}
 
 	@Override

launchwrapper-fabric/src/main/java/org/mcphackers/launchwrapper/inject/LWGameProvider.java

@@ -11,6 +11,16 @@
 import java.util.function.Function;
 import java.util.zip.ZipError;
 
+import org.mcphackers.launchwrapper.loader.SafeClassWriter;
+import org.mcphackers.launchwrapper.target.MainLaunchTarget;
+import org.mcphackers.launchwrapper.tweak.FabricLoaderTweak;
+import org.mcphackers.launchwrapper.tweak.Tweak;
+import org.mcphackers.launchwrapper.tweak.Tweaker;
+import org.mcphackers.launchwrapper.util.ClassNodeSource;
+import org.mcphackers.launchwrapper.util.asm.NodeHelper;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.tree.ClassNode;
+
 import net.fabricmc.loader.impl.game.patch.GameTransformer;
 import net.fabricmc.loader.impl.launch.FabricLauncher;
 import net.fabricmc.loader.impl.util.ExceptionUtil;
@@ -20,20 +30,14 @@
 import net.fabricmc.loader.impl.util.log.Log;
 import net.fabricmc.loader.impl.util.log.LogCategory;
 
-import org.mcphackers.launchwrapper.loader.SafeClassWriter;
-import org.mcphackers.launchwrapper.target.MainLaunchTarget;
-import org.mcphackers.launchwrapper.tweak.Tweak;
-import org.mcphackers.launchwrapper.util.ClassNodeSource;
-import org.mcphackers.launchwrapper.util.asm.NodeHelper;
-import org.objectweb.asm.ClassWriter;
-import org.objectweb.asm.tree.ClassNode;
-
 public class LWGameTransformer extends GameTransformer implements ClassNodeSource {
 	private final LWGameProvider gameProvider;
 	private FabricLauncher launcher;
 	private Map<String, ClassNode> modified;
 	private Function<String, ClassNode> classSource;
 	private boolean entrypointsLocated = false;
+	private FabricLoaderTweak tweak;
+	private List<Tweaker> tweakers;
 
 	public LWGameTransformer(LWGameProvider gameProvider) {
 		this.gameProvider = gameProvider;
@@ -62,7 +66,8 @@ public void locateEntrypoints(FabricLauncher launcher, List<Path> gameJars) {
 					}
 
 					try (InputStream is = entry.getInputStream()) {
-						return NodeHelper.readClass(is, 0);
+						node = NodeHelper.readClass(is, 0);
+						return node;
 					} catch (IOException | ZipError e) {
 						throw new RuntimeException(String.format("error reading %s in %s: %s", name, LoaderUtil.normalizePath(entry.getOrigin()), e), e);
 					}
@@ -71,9 +76,10 @@ public void locateEntrypoints(FabricLauncher launcher, List<Path> gameJars) {
 				}
 			};
 
-			Tweak tweak = gameProvider.getTweak(this);
-			tweak.transform(this);
-			gameProvider.target = (MainLaunchTarget)tweak.getLaunchTarget();
+			this.tweak = new FabricLoaderTweak(Tweak.getDefault(this, gameProvider.config), gameProvider.config);
+			this.tweakers = this.tweak.getTweakers();
+			this.tweak.transform(this);
+			gameProvider.target = (MainLaunchTarget)tweak.getBaseTweak().getLaunchTarget();
 
 		} catch (IOException e) {
 			throw ExceptionUtil.wrap(e);
@@ -88,19 +94,35 @@ public ClassNode getClass(String name) {
 		if (node == null) {
 			try {
 				node = NodeHelper.readClass(launcher.getResourceAsStream(LoaderUtil.getClassFileName(name)), 0);
+				return node;
 			} catch (IOException e) {
 				e.printStackTrace();
 			}
 		}
 		return node;
 	}
 
+	private void runTransformers(ClassNode node) {
+		if(tweakers == null || node == null) {
+			return;
+		}
+		boolean modified = false;
+		for (Tweaker tweak : tweakers) {
+			modified |= tweak.tweakClass(this, node.name);
+		}
+		if (modified) {
+			overrideClass(node);
+		}
+	}
+
+	@Override
 	public void overrideClass(ClassNode node) {
 		modified.put(node.name.replace("/", "."), node);
 	}
 
 	public byte[] transform(String className) {
 		ClassNode node = modified.get(className);
+				runTransformers(node);
 		if (node == null) {
 			return null;
 		}

launchwrapper-fabric/src/main/java/org/mcphackers/launchwrapper/inject/LWGameTransformer.java

@@ -1,15 +1,20 @@
 package org.mcphackers.launchwrapper.tweak;
 
+import java.security.CodeSource;
 import java.util.ArrayList;
 import java.util.List;
 
 import org.mcphackers.launchwrapper.LaunchConfig;
+import org.mcphackers.launchwrapper.loader.LaunchClassLoader;
 import org.mcphackers.launchwrapper.target.LaunchTarget;
+import org.mcphackers.launchwrapper.target.MainLaunchTarget;
 import org.mcphackers.launchwrapper.tweak.injection.Injection;
 import org.mcphackers.launchwrapper.tweak.injection.MinecraftGetter;
 import org.mcphackers.launchwrapper.tweak.injection.fabric.FabricHook;
 
 public class FabricLoaderTweak extends Tweak {
+	private static final String FABRIC_KNOT_CLIENT = "net/fabricmc/loader/impl/launch/knot/KnotClient";
+	private static final String FABRIC_KNOT = "net/fabricmc/loader/impl/launch/knot/Knot";
 
 	protected Tweak baseTweak;
 
@@ -37,8 +42,30 @@ public List<Tweaker> getTweakers() {
 		return baseTweak.getTweakers();
 	}
 
+	private static String gameProdiverSource() {
+		// Location of META-INF/services/net.fabricmc.loader.impl.game.GameProvider
+		CodeSource resource = FabricLoaderTweak.class.getProtectionDomain().getCodeSource();
+		if (resource == null) {
+			return null;
+		}
+		return resource.getLocation().getPath();
+	}
+
+	public Tweak getBaseTweak() {
+		return baseTweak;
+	}
+
 	@Override
 	public LaunchTarget getLaunchTarget() {
-		return baseTweak.getLaunchTarget();
+		MainLaunchTarget target = new MainLaunchTarget(FABRIC_KNOT_CLIENT, new String[0]) {
+			@Override
+			public void launch(LaunchClassLoader loader) {
+				System.setProperty("fabric.skipMcProvider", "true");
+				loader.overrideClassSource(FABRIC_KNOT, gameProdiverSource());
+				loader.overrideClassSource(FABRIC_KNOT_CLIENT, gameProdiverSource());
+				loader.invokeMain(FABRIC_KNOT_CLIENT.replace('/', '.'), config.getArgs());
+			}
+		};
+		return target;
 	}
 }

launchwrapper-fabric/src/main/java/org/mcphackers/launchwrapper/tweak/FabricLoaderTweak.java

@@ -65,11 +65,11 @@ public class LaunchConfig {
 	public final LaunchParameterEnum<SkinType> skinProxy	= new LaunchParameterEnum<SkinType>("skinProxy", SkinType.DEFAULT, true);
 	public final LaunchParameterSkinOptions skinOptions		= new LaunchParameterSkinOptions("skinOptions");
 	public final LaunchParameterFile levelsDir				= new LaunchParameterFile("levelsDir", null, true);
+	public final LaunchParameterSwitch useFakeApplet		= new LaunchParameterSwitch("useFakeApplet", false, true);
 	public final LaunchParameterSwitch isom					= new LaunchParameterSwitch("isom", false, true);
 	public final LaunchParameterFileList icon				= new LaunchParameterFileList("icon", null, true);
 	public final LaunchParameterString title				= new LaunchParameterString("title", null, true);
 	public final LaunchParameterSwitch vsync				= new LaunchParameterSwitch("vsync", false, true);
-	public final LaunchParameterSwitch resizable			= new LaunchParameterSwitch("resizable", false, true);
 	public final LaunchParameterSwitch applet 				= new LaunchParameterSwitch("applet", false);
 	public final LaunchParameterSwitch oneSixFlag			= new LaunchParameterSwitch("oneSixFlag", false, true);
 	public final LaunchParameterSwitch unlicensedCopy		= new LaunchParameterSwitchReverse("unlicensedCopy", haspaid);

src/main/java/org/mcphackers/launchwrapper/LaunchConfig.java

@@ -99,7 +99,7 @@ private static ClassLoader getParentClassLoader() {
 			return (ClassLoader)ClassLoader.class.getMethod("getPlatformClassLoader").invoke(null); // Java 9+ only
 		} catch (NoSuchMethodException e) {
 			return null; // fall back to boot cl
-		} catch (ReflectiveOperationException e) {
+		} catch (Exception e) {
 			throw new RuntimeException(e);
 		}
 	}

src/main/java/org/mcphackers/launchwrapper/loader/LaunchClassLoader.java

@@ -29,7 +29,7 @@ public Skin getSkin(String name, SkinTexture type) {
 
 			URL texturesURL = new URL("http://skinsystem.ely.by/textures/" + name);
 			String response = new String(Util.readStream(openDirectConnection(texturesURL).getInputStream()), "UTF-8");
-			if (response.isEmpty()) {
+			if (response.length() == 0) {
 				return null;
 			}
 			JSONObject texturesJson = new JSONObject(response);

src/main/java/org/mcphackers/launchwrapper/protocol/skin/ElyBySkinProvider.java

@@ -119,7 +119,7 @@ public static Profile getProfile(String uuid) {
 				return null;
 			}
 			String response = new String(Util.readStream(connection.getInputStream()), "UTF-8");
-			if (response.isEmpty()) {
+			if (response.length() == 0) {
 				return null;
 			}
 			JSONObject profileJson = new JSONObject(response);