@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;
}
private PsiType addBounds(PsiType substituted, final PsiTypeParameter typeParameter) {
PsiElement captureContext = null;
if (substituted instanceof PsiCapturedWildcardType) {
final PsiCapturedWildcardType captured = (PsiCapturedWildcardType) substituted;
substituted = captured.getWildcard();
captureContext = captured.getContext();
}
if (substituted instanceof PsiWildcardType && !((PsiWildcardType) substituted).isSuper()) {
PsiType originalBound = ((PsiWildcardType) substituted).getBound();
PsiManager manager = typeParameter.getManager();
final PsiType[] boundTypes = typeParameter.getExtendsListTypes();
for (PsiType boundType : boundTypes) {
PsiType substitutedBoundType = boundType.accept(mySimpleSubstitutionVisitor);
PsiWildcardType wildcardType = (PsiWildcardType) substituted;
if (substitutedBoundType != null
&& !(substitutedBoundType instanceof PsiWildcardType)
&& !substitutedBoundType.equalsToText("java.lang.Object")) {
if (originalBound == null
|| (!TypeConversionUtil.erasure(substitutedBoundType)
.isAssignableFrom(TypeConversionUtil.erasure(originalBound))
&& !TypeConversionUtil.erasure(substitutedBoundType)
.isAssignableFrom(
originalBound))) { // erasure is essential to avoid infinite recursion
if (wildcardType.isExtends()) {
final PsiType glb =
GenericsUtil.getGreatestLowerBound(wildcardType.getBound(), substitutedBoundType);
if (glb != null) {
substituted = PsiWildcardType.createExtends(manager, glb);
}
} else {
// unbounded
substituted = PsiWildcardType.createExtends(manager, substitutedBoundType);
}
}
}
}
}
if (captureContext != null) {
LOG.assertTrue(substituted instanceof PsiWildcardType);
substituted = PsiCapturedWildcardType.create((PsiWildcardType) substituted, captureContext);
}
return substituted;
}