api: Style#unmerge

api/src/main/java/net/kyori/adventure/text/ComponentCompaction.java

@@ -33,16 +33,14 @@
 import org.jetbrains.annotations.Nullable;
 
 final class ComponentCompaction {
-  private static final TextDecoration[] DECORATIONS = TextDecoration.values();
-
   private ComponentCompaction() {
   }
 
   static Component compact(final @NotNull Component self, final @Nullable Style parentStyle) {
     final List<Component> children = self.children();
     Component optimized = self.children(Collections.emptyList());
     if (parentStyle != null) {
-      optimized = optimized.style(simplifyStyle(self.style(), parentStyle));
+      optimized = optimized.style(self.style().unmerge(parentStyle));
     }
 
     final int childrenSize = children.size();
@@ -153,49 +151,6 @@ static Component compact(final @NotNull Component self, final @Nullable Style pa
     return optimized.children(childrenToAppend);
   }
 
-  /**
-   * Simplify the provided style to remove any information that is redundant.
-   *
-   * @param style style to simplify
-   * @param parentStyle parent to compare against
-   * @return a new, simplified style
-   */
-  private static @NotNull Style simplifyStyle(final @NotNull Style style, final @NotNull Style parentStyle) {
-    if (style.isEmpty()) {
-      // the target style is empty, so there is nothing to simplify
-      return style;
-    }
-
-    final Style.Builder builder = style.toBuilder();
-    if (Objects.equals(style.font(), parentStyle.font())) {
-      builder.font(null);
-    }
-
-    if (Objects.equals(style.color(), parentStyle.color())) {
-      builder.color(null);
-    }
-
-    for (final TextDecoration decoration : DECORATIONS) {
-      if (style.decoration(decoration) == parentStyle.decoration(decoration)) {
-        builder.decoration(decoration, TextDecoration.State.NOT_SET);
-      }
-    }
-
-    if (Objects.equals(style.clickEvent(), parentStyle.clickEvent())) {
-      builder.clickEvent(null);
-    }
-
-    if (Objects.equals(style.hoverEvent(), parentStyle.hoverEvent())) {
-      builder.hoverEvent(null);
-    }
-
-    if (Objects.equals(style.insertion(), parentStyle.insertion())) {
-      builder.insertion(null);
-    }
-
-    return builder.build();
-  }
-
   /**
   * Checks whether the Component is blank (a TextComponent containing only space characters).
   *

api/src/main/java/net/kyori/adventure/text/format/Style.java

@@ -529,6 +529,15 @@ default boolean hasDecoration(final @NotNull TextDecoration decoration) {
    */
   @NotNull Style merge(final @NotNull Style that, final Merge.@NotNull Strategy strategy, final @NotNull Set<Merge> merges);
 
+  /**
+   * Simplify this style to remove any information that is redundant.
+   *
+   * @param that parent to compare against
+   * @return a new, simplified style
+   * @since 4.12.0
+   */
+  @NotNull Style unmerge(final @NotNull Style that);
+
   /**
    * Tests if this style is empty.
    *

api/src/main/java/net/kyori/adventure/text/format/StyleImpl.java

@@ -183,6 +183,45 @@ final class StyleImpl implements Style {
     return builder.build();
   }
 
+  @Override
+  public @NotNull Style unmerge(final @NotNull Style that) {
+    if (this.isEmpty()) {
+      // the target style is empty, so there is nothing to simplify
+      return this;
+    }
+
+    final Style.Builder builder = new BuilderImpl(this);
+
+    if (Objects.equals(this.font(), that.font())) {
+      builder.font(null);
+    }
+
+    if (Objects.equals(this.color(), that.color())) {
+      builder.color(null);
+    }
+
+    for (int i = 0, length = DecorationMap.DECORATIONS.length; i < length; i++) {
+      final TextDecoration decoration = DecorationMap.DECORATIONS[i];
+      if (this.decoration(decoration) == that.decoration(decoration)) {
+        builder.decoration(decoration, TextDecoration.State.NOT_SET);
+      }
+    }
+
+    if (Objects.equals(this.clickEvent(), that.clickEvent())) {
+      builder.clickEvent(null);
+    }
+
+    if (Objects.equals(this.hoverEvent(), that.hoverEvent())) {
+      builder.hoverEvent(null);
+    }
+
+    if (Objects.equals(this.insertion(), that.insertion())) {
+      builder.insertion(null);
+    }
+
+    return builder.build();
+  }
+
   @SuppressWarnings("RedundantIfStatement")
   static boolean nothingToMerge(final @NotNull Style mergeFrom, final Merge.@NotNull Strategy strategy, final @NotNull Set<Merge> merges) {
     if (strategy == Merge.Strategy.NEVER) return true;

api/src/test/java/net/kyori/adventure/text/format/StyleTest.java

@@ -370,6 +370,32 @@ void testBuilderMerge_color() {
     );
   }
 
+  @Test
+  void testUnmergeEmpty() {
+    final Style s0 = Style.empty();
+    final Style s1 = Style.style(NamedTextColor.DARK_RED, TextDecoration.BOLD, TextDecoration.ITALIC);
+    final Style s2 = s1.unmerge(s0);
+    assertEquals(NamedTextColor.DARK_RED, s2.color());
+    assertDecorations(s2, ImmutableSet.of(TextDecoration.BOLD, TextDecoration.ITALIC), ImmutableSet.of());
+  }
+
+  @Test
+  void testUnmerge() {
+    final Style s0 = Style.style(NamedTextColor.DARK_RED, TextDecoration.BOLD);
+    final Style s1 = Style.style(NamedTextColor.DARK_RED, TextDecoration.BOLD, TextDecoration.ITALIC);
+    final Style s2 = s1.unmerge(s0);
+    assertNull(s2.color());
+    assertDecorations(s2, ImmutableSet.of(TextDecoration.ITALIC), ImmutableSet.of());
+  }
+
+  @Test
+  void testUnmergeWithEmptyChild() {
+    final Style s0 = Style.style(NamedTextColor.DARK_RED, TextDecoration.BOLD);
+    final Style s1 = Style.empty();
+    final Style s2 = s1.unmerge(s0);
+    assertSame(s1, s2);
+  }
+
   @Test
   void testEquals() {
     new EqualsTester()