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tutorial:mixin_examples [2022/08/07 21:51] – Added examples salvopeluxtutorial:mixin_examples [2024/01/13 15:02] (current) – arkosammy12
Line 13: Line 13:
 </code> </code>
  
-===== Access `this` instance of the class your mixin is targeting =====+===== Access the this instance of the class your mixin is targeting ===== 
 +Note: Double casting ''this'' should be avoided when possible. If you intend to use a method or field from the target class, use ''@Shadow''. If the method or field is from a parent of the target class, have your mixin extend the direct parent of the target class. 
 Mixin: Mixin:
 <code java> <code java>
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   @Inject(method = "foo()V", at = @At("HEAD"))   @Inject(method = "foo()V", at = @At("HEAD"))
   private void injected(CallbackInfo ci) {   private void injected(CallbackInfo ci) {
-    ((TargetClass)(Object)this).methodOfTheTargetClass();+    TargetClass thisObject = (TargetClass)(Object)this;
   }   }
 } }
Line 145: Line 147:
 </code> </code>
  
-===== Injecting into the point before a method call with shift amount =====+===== Injecting into the point with shift amount =====
 Mixin: Mixin:
 <code java> <code java>
Line 246: Line 248:
  
 ===== Capturing local values ===== ===== Capturing local values =====
 +==== Capture locals without MixinExtras ====
  
 Mixin: Mixin:
 <code java> <code java>
-@Inject(method = "foo()V", at = @At(value = "TAIL"), locals = LocalCapture.CAPTURE_FAILEXCEPTION)+@Inject(method = "foo()V", at = @At(value = "TAIL"), locals = LocalCapture.CAPTURE_FAILHARD)
 private void injected(CallbackInfo ci, TypeArg1 arg1) { private void injected(CallbackInfo ci, TypeArg1 arg1) {
-  arg1.doSomethingWithArg1();+  //CAPTURE_FAILHARD: If the calculated locals are different from the expected values, throws an error. 
 +  arg1.doSomething4();
 } }
 </code> </code>
Line 259: Line 263:
   public void foo() {   public void foo() {
     TypeArg1 arg1 = getArg1();     TypeArg1 arg1 = getArg1();
-    arg1.doSomwthing1(); +    arg1.doSomething1(); 
-    arg1.doSomwthing2();+    arg1.doSomething2();
     TypeArg2 arg2 = getArg2();     TypeArg2 arg2 = getArg2();
     arg2.doSomething3();     arg2.doSomething3();
Line 267: Line 271:
 </code> </code>
  
 +==== Capture locals with MixinExtras ====
 +:!: See the oficial MixinExtra's [[https://github.com/LlamaLad7/MixinExtras/wiki/Local|Wiki]].
 +
 +:!: MixinExtras required Fabric Loader 0.15 or above, or you have to manually specify it in ''build.gradle''.
 +
 +:!: If there are multiple locals with that type, you have to specify ''ordinal'' or it will throw an error.
 +
 +Mixin:
 +<code java>
 +@Inject(method = "foo()V", at = @At(value = "TAIL"))
 +private void injected(CallbackInfo ci, @Local TypeArg2 arg2) {
 +  arg1.doSomething4();
 +}
 +</code>
 +
 +Result:
 +<code diff>
 +  public void foo() {
 +    TypeArg1 arg1 = getArg1();
 +    arg1.doSomething1();
 +    arg1.doSomething2();
 +    TypeArg2 arg2 = getArg2();
 +    arg2.doSomething3();
 ++   injected(new CallbackInfo("foo", false), arg2);
 +  }
 +</code>
 +
 +==== Capturing one of multiple locals of a type ====
 +Mixin:
 +<code java>
 +@Inject(method = "foo()V", at = @At(value = "TAIL"))
 +private void injected(CallbackInfo ci, @Local(ordinal = 2) TypeArg arg) {
 +  arg1.doSomething4();
 +}
 +</code>
 +
 +Result:
 +<code diff>
 +  public void foo() {
 +    TypeArg arg1 = getArg1();
 +    TypeArg arg2 = getArg2();
 +    TypeArg arg3 = getArg3();
 +    TypeArg arg4 = getArg4();
 +    doSomething();
 ++   injected(new CallbackInfo("foo", false), arg3);
 +  }
 +</code>
 +
 +===== Modifying locals =====
 +This requires MixinExtras.
 +
 +Mixin:
 +<code java>
 +  @Inject(method = "foo()V", at = @At(value = "INVOKE", target = "doSomething()V", shift = At.Shift.AFTER))
 +  private static void injected(CallbackInfo ci, @Local LocalRef<String> localRef) {
 +    localRef.set(localRef.get() + " - modified")
 +  }
 +</code>
 +
 +Result:
 +<code diff>
 +  public void foo() {
 +    String s = "example string";
 +    doSomething();
 ++   s = s + " - modified";
 +    doSomething2(s);
 +  }
 +</code>
 ===== Modifying a return value ===== ===== Modifying a return value =====
 Mixin: Mixin:
tutorial/mixin_examples.1659909087.txt.gz · Last modified: 2022/08/07 21:51 by salvopelux