@Nullable
private PsiType extractContentTypeFromType(PsiType collectionType) {
if (!(collectionType instanceof PsiClassType)) {
return null;
}
final PsiClassType classType = (PsiClassType) collectionType;
final PsiType[] parameterTypes = classType.getParameters();
if (parameterTypes.length == 0) {
return null;
}
final PsiType parameterType = parameterTypes[0];
if (parameterType == null) {
return null;
}
if (parameterType instanceof PsiWildcardType) {
final PsiWildcardType wildcardType = (PsiWildcardType) parameterType;
return wildcardType.getExtendsBound();
} else if (parameterType instanceof PsiCapturedWildcardType) {
final PsiCapturedWildcardType capturedWildcardType =
(PsiCapturedWildcardType) parameterType;
final PsiWildcardType wildcardType = capturedWildcardType.getWildcard();
return wildcardType.getExtendsBound();
}
return parameterType;
}
public static boolean provablyDistinct(PsiWildcardType type1, PsiWildcardType type2) {
if (type1.isSuper() && type2.isSuper()) return false;
if (type1.isExtends() && type2.isExtends()) {
final PsiType extendsBound1 = type1.getExtendsBound();
final PsiType extendsBound2 = type2.getExtendsBound();
if (extendsBound1 instanceof PsiArrayType
&& proveArrayTypeDistinct(
type1.getManager().getProject(), (PsiArrayType) extendsBound1, extendsBound2)
|| extendsBound2 instanceof PsiArrayType
&& proveArrayTypeDistinct(
type1.getManager().getProject(), (PsiArrayType) extendsBound2, extendsBound1))
return true;
final PsiClass boundClass1 = PsiUtil.resolveClassInType(extendsBound1);
final PsiClass boundClass2 = PsiUtil.resolveClassInType(extendsBound2);
if (boundClass1 != null && boundClass2 != null) {
return proveExtendsBoundsDistinct(type1, type2, boundClass1, boundClass2);
}
return provablyDistinct(extendsBound1, extendsBound2, 1);
}
if (type2.isExtends()) return provablyDistinct(type2, type1);
if (type1.isExtends() && type2.isSuper()) {
final PsiType extendsBound = type1.getExtendsBound();
final PsiType superBound = type2.getSuperBound();
if (extendsBound instanceof PsiArrayType
&& proveArrayTypeDistinct(
type1.getManager().getProject(), (PsiArrayType) extendsBound, superBound)
|| superBound instanceof PsiArrayType
&& proveArrayTypeDistinct(
type1.getManager().getProject(), (PsiArrayType) superBound, extendsBound))
return true;
final PsiClass extendsBoundClass = PsiUtil.resolveClassInType(extendsBound);
final PsiClass superBoundClass = PsiUtil.resolveClassInType(superBound);
if (extendsBoundClass != null && superBoundClass != null) {
if (extendsBoundClass instanceof PsiTypeParameter) {
return try2ProveTypeParameterDistinct(type2, extendsBoundClass);
}
if (superBoundClass instanceof PsiTypeParameter) return false;
return !InheritanceUtil.isInheritorOrSelf(superBoundClass, extendsBoundClass, true);
}
return true;
}
if (!type1.isBounded() || !type2.isBounded()) {
return false;
}
return !type1.equals(type2);
}
