Improve support for completing constructor args

mickaelistria · Jan 29, 2025 · 994c755 · 994c755
1 parent c52dfb2
commit 994c755
Show file tree

Hide file tree

Showing 2 changed files with 49 additions and 14 deletions.
diff --git a/org.eclipse.jdt.core.javac/src/org/eclipse/jdt/internal/codeassist/DOMCompletionEngine.java b/org.eclipse.jdt.core.javac/src/org/eclipse/jdt/internal/codeassist/DOMCompletionEngine.java
@@ -94,7 +94,6 @@
 import org.eclipse.jdt.core.dom.MethodInvocation;
 import org.eclipse.jdt.core.dom.MethodRef;
 import org.eclipse.jdt.core.dom.Modifier;
-import org.eclipse.jdt.core.dom.Modifier.ModifierKeyword;
 import org.eclipse.jdt.core.dom.ModuleDeclaration;
 import org.eclipse.jdt.core.dom.Name;
 import org.eclipse.jdt.core.dom.NameQualifiedType;
@@ -127,6 +126,7 @@
 import org.eclipse.jdt.core.dom.VariableDeclarationExpression;
 import org.eclipse.jdt.core.dom.VariableDeclarationFragment;
 import org.eclipse.jdt.core.dom.VariableDeclarationStatement;
+import org.eclipse.jdt.core.dom.Modifier.ModifierKeyword;
 import org.eclipse.jdt.core.formatter.DefaultCodeFormatterConstants;
 import org.eclipse.jdt.core.search.IJavaSearchConstants;
 import org.eclipse.jdt.core.search.SearchEngine;
@@ -1033,9 +1033,22 @@ public void complete(org.eclipse.jdt.internal.compiler.env.ICompilationUnit sour
 					suggestDefaultCompletions = false;
 				}
 			}
-			if (context instanceof ClassInstanceCreation) {
-				if (this.expectedTypes.getExpectedTypes() != null && !this.expectedTypes.getExpectedTypes().isEmpty() && !this.expectedTypes.getExpectedTypes().get(0).isRecovered()) {
-					completeConstructor(this.expectedTypes.getExpectedTypes().get(0), context, this.javaProject);
+			if (context instanceof ClassInstanceCreation newObj) {
+				var newType = newObj.getType();
+				var binding = newType.resolveBinding();
+				if (this.offset > newType.getStartPosition() + newType.getLength() &&
+					binding != null &&
+					newObj.getType().resolveBinding().isEnum()) {
+					return; // don't complete illegal enum constructor
+				}
+				var visibleConstructors = Arrays.stream(binding.getDeclaredMethods())
+						.filter(IMethodBinding::isConstructor)
+						.filter(this::isVisible)
+						.toList();
+				if (visibleConstructors.size() == 1 && this.expectedTypes.getExpectedTypes() != null && !this.expectedTypes.getExpectedTypes().isEmpty() && !this.expectedTypes.getExpectedTypes().get(0).isRecovered()) {
+					completeConstructor(this.expectedTypes.getExpectedTypes().get(0), context, this.modelUnit.getJavaProject());
+				} else if (visibleConstructors.size() > 0) {
+					visibleConstructors.stream().map(this::toProposal).forEach(this.requestor::accept);
 				} else {
 					if (!this.requestor.isIgnored(CompletionProposal.TYPE_REF) && !this.requestor.isIgnored(CompletionProposal.CONSTRUCTOR_INVOCATION)) {
 						String packageName = "";//$NON-NLS-1$
@@ -2320,6 +2333,12 @@ private CompletionProposal toProposal(IBinding binding, String completion) {
 			} else {
 				kind = CompletionProposal.METHOD_REF;
 			}
+			if (this.toComplete instanceof ClassInstanceCreation newObj && newObj.getType() != null && this.offset > newObj.getType().getStartPosition() + newObj.getType().getLength()) {
+				// actually completing open arg list
+				completion = ""; //$NON-NLS-1$
+			} else {
+				completion += "()"; //$NON-NLS-1$
+			}
 		} else if (binding instanceof IVariableBinding variableBinding) {
 			if (variableBinding.isField()) {
 				kind = CompletionProposal.FIELD_REF;
@@ -2330,9 +2349,6 @@ private CompletionProposal toProposal(IBinding binding, String completion) {
 
 		DOMInternalCompletionProposal res = createProposal(kind);
 		res.setName(binding.getName().toCharArray());
-		if (kind == CompletionProposal.METHOD_REF) {
-			completion += "()"; //$NON-NLS-1$
-		}
 		res.setCompletion(completion.toCharArray());
 		res.setFlags(binding.getModifiers());
 

diff --git a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/ExpectedTypes.java b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/ExpectedTypes.java
@@ -88,7 +88,22 @@ private void computeExpectedTypes(){
 				return;
 			}
 			if (parent2 instanceof ClassInstanceCreation newObj && this.offset > newObj.getType().getStartPosition() + newObj.getType().getLength()) {
-				// TODO find params
+				int argIndexWip = 0;
+				var args = (List<Expression>)newObj.arguments();
+				for (argIndexWip = 0; argIndexWip < args.size(); argIndexWip++) {
+					var arg = args.get(argIndexWip);
+					if (this.offset < arg.getStartPosition() || this.offset > arg.getStartPosition() + arg.getLength()) {
+						break;
+					}
+				}
+				int argIndex = Math.max(0, argIndexWip - 1);
+				var binding = newObj.getType().resolveBinding();
+				Arrays.stream(binding.getDeclaredMethods())
+					.filter(IMethodBinding::isConstructor)
+					.map(IMethodBinding::getParameterTypes)
+					.filter(params -> params.length > argIndex)
+					.map(params -> params[argIndex])
+					.forEach(this.expectedTypes::add);
 				break;
 			}
 			if (parent2 instanceof CastExpression cast && this.offset > cast.getType().getStartPosition() + cast.getType().getLength()) {
@@ -237,12 +252,16 @@ private void computeExpectedTypes(){
 				}
 			}
 		} else if(parent instanceof ClassInstanceCreation allocationExpression) {
-			ITypeBinding binding = allocationExpression.resolveTypeBinding();
-			if(binding != null) {
-				computeExpectedTypesForAllocationExpression(
-					binding,
-					allocationExpression.arguments(),
-					allocationExpression);
+			if (this.offset <= allocationExpression.getType().getStartPosition() + allocationExpression.getType().getLength()) {
+				ITypeBinding binding = allocationExpression.resolveTypeBinding();
+				if(binding != null) {
+					computeExpectedTypesForAllocationExpression(
+						binding,
+						allocationExpression.arguments(),
+						allocationExpression);
+				}
+			} else {
+				//int itemIndexAtOffset =z
 			}
 		} else if(parent instanceof InstanceofExpression e) {
 			ITypeBinding binding = e.getLeftOperand().resolveTypeBinding();