feat: hide compiler-generated synthetic fields from autocomplete

Filter out class$0, class$1, etc. fields that Java compilers generate
for .class literal expressions when targeting pre-Java 5 bytecode.
These are internal compiler implementation details that should not
appear in completion results.

Added configurable hideSyntheticFields property (default: true) on
JavaLanguageSupport with getter/setter API, wired through to
SourceCompletionProvider.isAccessible().

Author: abanchev

RSTALanguageSupport/src/main/java/org/fife/rsta/ac/java/JavaCompletionProvider.java

@@ -123,6 +123,16 @@ public List<Completion> getCompletionsAt(JTextComponent tc, Point p) {
 	}
 
 
+	/**
+	 * Returns the source completion provider used internally.
+	 *
+	 * @return The source completion provider.
+	 */
+	SourceCompletionProvider getSourceProvider() {
+		return sourceProvider;
+	}
+
+
 	/**
 	 * Returns the jars on the "build path".
 	 *

RSTALanguageSupport/src/main/java/org/fife/rsta/ac/java/JavaLanguageSupport.java

@@ -62,6 +62,11 @@ public class JavaLanguageSupport extends AbstractLanguageSupport {
 	 */
 	private JarManager jarManager;
 
+	/**
+	 * Whether to hide compiler-generated synthetic fields from completions.
+	 */
+	private boolean hideSyntheticFields = true;
+
 	/**
 	 * Client property installed on text areas that points to a listener.
 	 */
@@ -109,6 +114,33 @@ public JarManager getJarManager() {
 	}
 
 
+	/**
+	 * Returns whether compiler-generated synthetic fields (e.g.
+	 * {@code class$0}) are hidden from completion results.  The default
+	 * value is {@code true}.
+	 *
+	 * @return Whether synthetic fields are hidden.
+	 * @see #setHideSyntheticFields(boolean)
+	 */
+	public boolean getHideSyntheticFields() {
+		return hideSyntheticFields;
+	}
+
+
+	/**
+	 * Sets whether compiler-generated synthetic fields (e.g. {@code class$0},
+	 * {@code class$1}) should be hidden from completion results.  These
+	 * fields are generated by compilers for {@code .class} literal
+	 * expressions when targeting pre-Java 5 bytecode.
+	 *
+	 * @param hide Whether to hide synthetic fields.
+	 * @see #getHideSyntheticFields()
+	 */
+	public void setHideSyntheticFields(boolean hide) {
+		this.hideSyntheticFields = hide;
+	}
+
+
 	/**
 	 * Returns the Java parser running on a text area with this Java language
 	 * support installed.
@@ -134,6 +166,7 @@ public JavaParser getParser(RSyntaxTextArea textArea) {
 	public void install(RSyntaxTextArea textArea) {
 
 		JavaCompletionProvider p = new JavaCompletionProvider(jarManager);
+		p.getSourceProvider().setHideSyntheticFields(hideSyntheticFields);
 		// Can't use createAutoCompletion(), as Java's is "special."
 		AutoCompletion ac = new JavaAutoCompletion(p, textArea);
 		ac.setListCellRenderer(new JavaCellRenderer());

RSTALanguageSupport/src/main/java/org/fife/rsta/ac/java/SourceCompletionProvider.java

@@ -89,6 +89,15 @@ class SourceCompletionProvider extends DefaultCompletionProvider {
 
 	//Shorthand completions (templates and comments)
 	private ShorthandCompletionCache shorthandCache;
+
+	/**
+	 * Whether to hide compiler-generated synthetic members (e.g.
+	 * {@code class$0} fields, {@code access$0} methods) from completion
+	 * results.  These are generated by compilers for {@code .class} literal
+	 * expressions and inner class private member access.  Defaults to
+	 * {@code true}.
+	 */
+	private boolean hideSyntheticFields = true;
 	/**
 	 * Constructor.
 	 */
@@ -113,6 +122,30 @@ class SourceCompletionProvider extends DefaultCompletionProvider {
 	}
 
 
+	/**
+	 * Returns whether compiler-generated synthetic fields are hidden from
+	 * completion results.
+	 *
+	 * @return Whether synthetic fields are hidden.
+	 * @see #setHideSyntheticFields(boolean)
+	 */
+	boolean isHideSyntheticFields() {
+		return hideSyntheticFields;
+	}
+
+
+	/**
+	 * Sets whether compiler-generated synthetic fields (e.g. {@code class$0})
+	 * should be hidden from completion results.
+	 *
+	 * @param hide Whether to hide synthetic fields.
+	 * @see #isHideSyntheticFields()
+	 */
+	void setHideSyntheticFields(boolean hide) {
+		this.hideSyntheticFields = hide;
+	}
+
+
 	private void addCompletionsForStaticMembers(Set<Completion> set,
 						CompilationUnit cu, ClassFile cf, String pkg) {
 
@@ -614,6 +647,16 @@ public SourceLocation getSourceLocForClass(String className) {
 	 */
 	private boolean isAccessible(MemberInfo info, String pkg) {
 
+		// Filter compiler-generated synthetic members from completion results:
+		// - class$N fields: generated for .class literal expressions (pre-Java 5)
+		// - access$N methods: generated for inner class private member access
+		if (hideSyntheticFields) {
+			String name = info.getName();
+			if (name != null && (name.startsWith("class$") || name.startsWith("access$"))) {
+				return false;
+			}
+		}
+
 		boolean accessible = false;
 		int access = info.getAccessFlags();