public static boolean isReceiverType(
PsiType functionalInterfaceType,
PsiClass containingClass,
@Nullable PsiMethod referencedMethod) {
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(functionalInterfaceType);
final MethodSignature function = LambdaUtil.getFunction(resolveResult.getElement());
if (function != null) {
final int interfaceMethodParamsLength = function.getParameterTypes().length;
if (interfaceMethodParamsLength > 0) {
final PsiType firstParamType =
resolveResult.getSubstitutor().substitute(function.getParameterTypes()[0]);
boolean isReceiver =
isReceiverType(
firstParamType,
containingClass,
PsiUtil.resolveGenericsClassInType(firstParamType).getSubstitutor());
if (isReceiver) {
if (referencedMethod == null) {
if (interfaceMethodParamsLength == 1) return true;
return false;
}
if (referencedMethod.getParameterList().getParametersCount()
!= interfaceMethodParamsLength - 1) {
return false;
}
return true;
}
}
}
return false;
}
private static boolean hasReceiver(
@NotNull PsiMethodReferenceExpression methodRef,
@NotNull PsiMethod method,
PsiType functionalInterfaceType) {
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(functionalInterfaceType);
final PsiMethod interfaceMethod = LambdaUtil.getFunctionalInterfaceMethod(resolveResult);
final MethodSignature signature =
interfaceMethod != null
? interfaceMethod.getSignature(
LambdaUtil.getSubstitutor(interfaceMethod, resolveResult))
: null;
if (signature == null) {
return false;
}
final PsiType[] parameterTypes = signature.getParameterTypes();
final QualifierResolveResult qualifierResolveResult = getQualifierResolveResult(methodRef);
return (method.getParameterList().getParametersCount() + 1 == parameterTypes.length
|| method.isVarArgs()
&& parameterTypes.length > 0
&& !method.hasModifierProperty(PsiModifier.STATIC))
&& hasReceiver(parameterTypes, qualifierResolveResult, methodRef);
}
public static boolean isAcceptable(
PsiLambdaExpression lambdaExpression, final PsiType leftType, boolean checkReturnType) {
if (leftType instanceof PsiIntersectionType) {
for (PsiType conjunctType : ((PsiIntersectionType) leftType).getConjuncts()) {
if (isAcceptable(lambdaExpression, conjunctType, checkReturnType)) return true;
}
return false;
}
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(GenericsUtil.eliminateWildcards(leftType));
final PsiClass psiClass = resolveResult.getElement();
if (psiClass instanceof PsiAnonymousClass) {
return isAcceptable(
lambdaExpression, ((PsiAnonymousClass) psiClass).getBaseClassType(), checkReturnType);
}
final MethodSignature methodSignature = getFunction(psiClass);
if (methodSignature == null) return false;
final PsiParameter[] lambdaParameters = lambdaExpression.getParameterList().getParameters();
final PsiType[] parameterTypes = methodSignature.getParameterTypes();
if (lambdaParameters.length != parameterTypes.length) return false;
for (int lambdaParamIdx = 0, length = lambdaParameters.length;
lambdaParamIdx < length;
lambdaParamIdx++) {
PsiParameter parameter = lambdaParameters[lambdaParamIdx];
final PsiTypeElement typeElement = parameter.getTypeElement();
if (typeElement != null) {
final PsiType lambdaFormalType = typeElement.getType();
final PsiType methodParameterType = parameterTypes[lambdaParamIdx];
if (lambdaFormalType instanceof PsiPrimitiveType) {
if (methodParameterType instanceof PsiPrimitiveType)
return methodParameterType.equals(lambdaFormalType);
return false;
}
if (!TypeConversionUtil.erasure(lambdaFormalType)
.isAssignableFrom(
TypeConversionUtil.erasure(
GenericsUtil.eliminateWildcards(
resolveResult
.getSubstitutor()
.substitute(
methodSignature
.getSubstitutor()
.substitute(methodParameterType)))))) {
return false;
}
}
}
if (checkReturnType) {
final String uniqueVarName =
JavaCodeStyleManager.getInstance(lambdaExpression.getProject())
.suggestUniqueVariableName("l", lambdaExpression, true);
String canonicalText = leftType.getCanonicalText();
if (leftType instanceof PsiEllipsisType) {
canonicalText = ((PsiEllipsisType) leftType).toArrayType().getCanonicalText();
}
final PsiStatement assignmentFromText =
JavaPsiFacade.getElementFactory(lambdaExpression.getProject())
.createStatementFromText(
canonicalText + " " + uniqueVarName + " = " + lambdaExpression.getText(),
lambdaExpression);
final PsiLocalVariable localVariable =
(PsiLocalVariable)
((PsiDeclarationStatement) assignmentFromText).getDeclaredElements()[0];
LOG.assertTrue(psiClass != null);
PsiType methodReturnType = getReturnType(psiClass, methodSignature);
if (methodReturnType != null) {
methodReturnType =
resolveResult
.getSubstitutor()
.substitute(methodSignature.getSubstitutor().substitute(methodReturnType));
return LambdaHighlightingUtil.checkReturnTypeCompatible(
(PsiLambdaExpression) localVariable.getInitializer(), methodReturnType)
== null;
}
}
return true;
}