feat(minimessage): use virtual components to preserve rainbow/gradien…

…t tags

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/MiniMessageSerializer.java

@@ -68,10 +68,13 @@ private MiniMessageSerializer() {
   private static void visit(final @NotNull Component component, final Collector emitter, final SerializableResolver resolver, final boolean lastChild) {
     // visit self
     resolver.handle(component, emitter);
-    emitter.flushClaims(component);
+    Component childSource = emitter.flushClaims(component);
+    if (childSource == null) {
+      childSource = component;
+    }
 
     // then children
-    for (final Iterator<Component> it = component.children().iterator(); it.hasNext();) {
+    for (final Iterator<Component> it = childSource.children().iterator(); it.hasNext();) {
       emitter.mark();
       visit(it.next(), emitter, resolver, lastChild && !it.hasNext());
     }
@@ -336,9 +339,11 @@ public boolean styleClaimed(final @NotNull String claimId) {
       return this.claimedStyleElements.contains(claimId);
     }
 
-    void flushClaims(final Component component) {
+    @Nullable Component flushClaims(final Component component) { // return: a substitute to provide children
+      Component ret = null;
       if (this.componentClaim != null) {
         this.componentClaim.emit(this);
+        ret = this.componentClaim.substitute();
         this.componentClaim = null;
       } else if (component instanceof TextComponent) {
         this.text(((TextComponent) component).content());
@@ -347,6 +352,7 @@ void flushClaims(final Component component) {
         throw new IllegalStateException("Unclaimed component " + component);
       }
       this.claimedStyleElements.clear();
+      return ret;
     }
   }
 

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/internal/serializer/Emitable.java

@@ -23,7 +23,9 @@
  */
 package net.kyori.adventure.text.minimessage.internal.serializer;
 
+import net.kyori.adventure.text.Component;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * Something that holds data representable as MiniMessage tags.
@@ -39,4 +41,16 @@ public interface Emitable {
    * @since 4.10.0
    */
   void emit(final @NotNull TokenEmitter emitter);
+
+  /**
+   * Provide a substitute for this component's actual children.
+   *
+   * <p>This allows modifying tags to output original data while still transforming the created components.</p>
+   *
+   * @return a potential substitute
+   * @since 4.13.0
+   */
+  default @Nullable Component substitute() { // TODO: maybe make this be only for component claims?
+    return null;
+  }
 }

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/tag/standard/AbstractColorChangingTag.java

@@ -25,14 +25,19 @@
 
 import java.util.Collections;
 import java.util.PrimitiveIterator;
+import java.util.function.Consumer;
 import java.util.stream.Stream;
 import net.kyori.adventure.internal.Internals;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.TextComponent;
+import net.kyori.adventure.text.VirtualComponent;
+import net.kyori.adventure.text.VirtualComponentHolder;
 import net.kyori.adventure.text.flattener.ComponentFlattener;
 import net.kyori.adventure.text.format.TextColor;
 import net.kyori.adventure.text.minimessage.internal.parser.node.TagNode;
 import net.kyori.adventure.text.minimessage.internal.parser.node.ValueNode;
+import net.kyori.adventure.text.minimessage.internal.serializer.Emitable;
+import net.kyori.adventure.text.minimessage.internal.serializer.TokenEmitter;
 import net.kyori.adventure.text.minimessage.tag.Inserting;
 import net.kyori.adventure.text.minimessage.tag.Modifying;
 import net.kyori.adventure.text.minimessage.tree.Node;
@@ -95,25 +100,31 @@ public final void postVisit() {
 
   @Override
   public final Component apply(final @NotNull Component current, final int depth) {
+    if (depth == 0) {
+      // capture state into a virtual component, no other logic is needed in normal MM handling
+      return Component.virtual(new TagInfoHolder(new ComponentData(this.preserveData(), current)));
+    }
+
     if ((this.disableApplyingColorDepth != -1 && depth > this.disableApplyingColorDepth) || current.style().color() != null) {
       if (this.disableApplyingColorDepth == -1 || depth < this.disableApplyingColorDepth) {
         this.disableApplyingColorDepth = depth;
       }
       // This component has its own color applied, which overrides ours
       // We still want to keep track of where we are though if this is text
       if (current instanceof TextComponent) {
-        final String content = ((TextComponent) current).content();
-        final int len = content.codePointCount(0, content.length());
-        for (int i = 0; i < len; i++) {
-          // increment our color index
-          this.advanceColor();
-        }
+        this.skipColorForLengthOf(((TextComponent) current).content());
       }
       return current.children(Collections.emptyList());
     }
 
     this.disableApplyingColorDepth = -1;
-    if (current instanceof TextComponent && ((TextComponent) current).content().length() > 0) {
+    if (current instanceof VirtualComponent) {
+      // this component has its own information, so we can't rainbowify direct content -- we can process children tho
+      // basically treat as if it's a non-text component
+      this.skipColorForLengthOf(((VirtualComponent) current).content());
+
+      return current.children(Collections.emptyList());
+    } else if (current instanceof TextComponent && ((TextComponent) current).content().length() > 0) {
       final TextComponent textComponent = (TextComponent) current;
       final String content = textComponent.content();
 
@@ -138,6 +149,14 @@ public final Component apply(final @NotNull Component current, final int depth)
     return Component.empty().mergeStyle(current);
   }
 
+  private void skipColorForLengthOf(final String content) {
+    final int len = content.codePointCount(0, content.length());
+    for (int i = 0; i < len; i++) {
+      // increment our color index
+      this.advanceColor();
+    }
+  }
+
   // The lifecycle
 
   protected abstract void init();
@@ -155,6 +174,14 @@ public final Component apply(final @NotNull Component current, final int depth)
    */
   protected abstract TextColor color();
 
+  /**
+   * Return an emitable that will accurately reserialize the provided input data.
+   *
+   * @return the emitable for this tag
+   * @since 4.13.0
+   */
+  protected abstract @NotNull Consumer<TokenEmitter> preserveData();
+
   // misc
 
   @Override
@@ -170,4 +197,55 @@ public final Component apply(final @NotNull Component current, final int depth)
 
   @Override
   public abstract int hashCode();
+
+  static final class ComponentData implements Emitable {
+    final Consumer<TokenEmitter> output;
+    final Component originalComp;
+
+    ComponentData(final Consumer<TokenEmitter> output, final Component originalComp) {
+      this.output = output;
+      this.originalComp = originalComp;
+    }
+
+    @Override
+    public void emit(final @NotNull TokenEmitter emitter) {
+      this.output.accept(emitter);
+    }
+
+    @Override
+    public Component substitute() {
+      return this.originalComp;
+    }
+  }
+
+  static final class TagInfoHolder implements VirtualComponentHolder<ComponentData> {
+    private final ComponentData data;
+
+    TagInfoHolder(final ComponentData data) {
+      this.data = data;
+    }
+
+    @Override
+    public @NotNull ComponentData unbox() {
+      return this.data;
+    }
+
+    @Override
+    public @NotNull String fallbackString() {
+      return ""; // only holds data for reserialization, not for display
+    }
+  }
+
+  static @Nullable Emitable claimComponent(final Component comp) {
+    if (!(comp instanceof VirtualComponent)) {
+      return null;
+    }
+
+    final VirtualComponentHolder<?> holder = ((VirtualComponent) comp).holder();
+    if (!(holder instanceof TagInfoHolder)) {
+      return null;
+    }
+
+    return ((TagInfoHolder) holder).unbox();
+  }
 }

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/tag/standard/GradientTag.java

@@ -29,9 +29,13 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.OptionalDouble;
+import java.util.function.Consumer;
 import java.util.stream.Stream;
+import net.kyori.adventure.text.format.NamedTextColor;
 import net.kyori.adventure.text.format.TextColor;
 import net.kyori.adventure.text.minimessage.Context;
+import net.kyori.adventure.text.minimessage.internal.serializer.SerializableResolver;
+import net.kyori.adventure.text.minimessage.internal.serializer.TokenEmitter;
 import net.kyori.adventure.text.minimessage.tag.Tag;
 import net.kyori.adventure.text.minimessage.tag.resolver.ArgumentQueue;
 import net.kyori.adventure.text.minimessage.tag.resolver.TagResolver;
@@ -47,8 +51,10 @@
  */
 final class GradientTag extends AbstractColorChangingTag {
   private static final String GRADIENT = "gradient";
+  private static final TextColor DEFAULT_WHITE = TextColor.color(0xffffff);
+  private static final TextColor DEFAULT_BLACK = TextColor.color(0x000000);
 
-  static final TagResolver RESOLVER = TagResolver.resolver(GRADIENT, GradientTag::create);
+  static final TagResolver RESOLVER = SerializableResolver.claimingComponent(GRADIENT, GradientTag::create, AbstractColorChangingTag::claimComponent);
 
   private int index = 0;
   private int colorIndex = 0;
@@ -102,7 +108,7 @@ private GradientTag(final float phase, final List<TextColor> colors) {
     }
 
     if (colors.isEmpty()) {
-      this.colors = new TextColor[]{TextColor.color(0xffffff), TextColor.color(0x000000)};
+      this.colors = new TextColor[]{DEFAULT_WHITE, DEFAULT_BLACK};
     } else {
       this.colors = colors.toArray(new TextColor[0]);
     }
@@ -145,6 +151,38 @@ protected TextColor color() {
     }
   }
 
+  @Override
+  protected @NotNull Consumer<TokenEmitter> preserveData() {
+    final TextColor[] colors;
+    final float phase;
+
+    if (this.negativePhase) {
+      colors = Arrays.copyOf(this.colors, this.colors.length);
+      Collections.reverse(Arrays.asList(colors));
+      phase = this.phase - 1;
+    } else {
+      colors = this.colors;
+      phase = this.phase;
+    }
+
+    return emit -> {
+      emit.tag(GRADIENT);
+      if (colors.length != 2 || !colors[0].equals(DEFAULT_WHITE) || !colors[1].equals(DEFAULT_BLACK)) { // non-default params
+        for (final TextColor color : colors) {
+          if (color instanceof NamedTextColor) {
+            emit.argument(NamedTextColor.NAMES.keyOrThrow((NamedTextColor) color));
+          } else {
+            emit.argument(color.asHexString());
+          }
+        }
+      }
+
+      if (phase != 0) {
+        emit.argument(Float.toString(phase));
+      }
+    };
+  }
+
   @Override
   public @NotNull Stream<? extends ExaminableProperty> examinableProperties() {
     return Stream.of(

text-minimessage/src/main/java/net/kyori/adventure/text/minimessage/tag/standard/RainbowTag.java

@@ -24,9 +24,12 @@
 package net.kyori.adventure.text.minimessage.tag.standard;
 
 import java.util.Objects;
+import java.util.function.Consumer;
 import java.util.stream.Stream;
 import net.kyori.adventure.text.format.TextColor;
 import net.kyori.adventure.text.minimessage.Context;
+import net.kyori.adventure.text.minimessage.internal.serializer.SerializableResolver;
+import net.kyori.adventure.text.minimessage.internal.serializer.TokenEmitter;
 import net.kyori.adventure.text.minimessage.tag.Tag;
 import net.kyori.adventure.text.minimessage.tag.resolver.ArgumentQueue;
 import net.kyori.adventure.text.minimessage.tag.resolver.TagResolver;
@@ -44,7 +47,7 @@ final class RainbowTag extends AbstractColorChangingTag {
   private static final String REVERSE = "!";
   private static final String RAINBOW = "rainbow";
 
-  static final TagResolver RESOLVER = TagResolver.resolver(RAINBOW, RainbowTag::create);
+  static final TagResolver RESOLVER = SerializableResolver.claimingComponent(RAINBOW, RainbowTag::create, AbstractColorChangingTag::claimComponent);
 
   private final boolean reversed;
   private final int phase;
@@ -105,6 +108,22 @@ protected TextColor color() {
     return TextColor.color(HSVLike.hsvLike(hue, 1f, 1f));
   }
 
+  @Override
+  protected @NotNull Consumer<TokenEmitter> preserveData() {
+    final boolean reversed = this.reversed;
+    final int phase = this.phase;
+    return emit -> {
+      emit.tag(RAINBOW);
+      if (reversed && phase != 0) {
+        emit.argument(REVERSE + phase);
+      } else if (reversed) {
+        emit.argument(REVERSE);
+      } else if (phase != 0) {
+        emit.argument(Integer.toString(phase));
+      }
+    };
+  }
+
   @Override
   public @NotNull Stream<? extends ExaminableProperty> examinableProperties() {
     return Stream.of(ExaminableProperty.of("phase", this.phase));

text-minimessage/src/test/java/net/kyori/adventure/text/minimessage/AbstractTest.java

@@ -23,6 +23,7 @@
  */
 package net.kyori.adventure.text.minimessage;
 
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.function.UnaryOperator;
 import java.util.stream.Collectors;
@@ -75,4 +76,9 @@ public static Context dummyContext(final String originalMessage) {
   public static ArgumentQueue emptyArgumentQueue(final Context context) {
     return new ArgumentQueueImpl<>(context, Collections.<Tag.Argument>emptyList());
   }
+
+  public static Component virtualOfChildren(final ComponentLike... children) {
+    return Component.virtual(() -> "") // not part of equality... should it be?
+      .children(Arrays.asList(children));
+  }
 }