@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 static boolean isIndexedListLoopStatement(PsiForStatement forStatement, boolean ignoreUntypedCollections) {
final PsiStatement initialization = forStatement.getInitialization();
if (!(initialization instanceof PsiDeclarationStatement)) {
return false;
}
final PsiDeclarationStatement declaration = (PsiDeclarationStatement)initialization;
final PsiElement[] declaredElements = declaration.getDeclaredElements();
final PsiElement secondDeclaredElement;
if (declaredElements.length == 1) {
secondDeclaredElement = null;
}
else if (declaredElements.length == 2) {
secondDeclaredElement = declaredElements[1];
}
else {
return false;
}
final PsiElement declaredElement = declaredElements[0];
if (!(declaredElement instanceof PsiVariable)) {
return false;
}
final PsiVariable indexVariable = (PsiVariable)declaredElement;
final PsiExpression initialValue = indexVariable.getInitializer();
if (initialValue == null) {
return false;
}
final Object constant = ExpressionUtils.computeConstantExpression(initialValue);
if (!(constant instanceof Number)) {
return false;
}
final Number number = (Number)constant;
if (number.intValue() != 0) {
return false;
}
final PsiExpression condition = forStatement.getCondition();
final Holder collectionHolder = getCollectionFromSizeComparison(condition, indexVariable, secondDeclaredElement);
if (collectionHolder == null) {
return false;
}
final PsiStatement update = forStatement.getUpdate();
if (!VariableAccessUtils.variableIsIncremented(indexVariable, update)) {
return false;
}
final PsiStatement body = forStatement.getBody();
if (!isIndexVariableOnlyUsedAsListIndex(collectionHolder, indexVariable, body)) {
return false;
}
if (collectionHolder != Holder.DUMMY) {
final PsiVariable collection = collectionHolder.getVariable();
final PsiClassType collectionType = (PsiClassType)collection.getType();
final PsiType[] parameters = collectionType.getParameters();
if (ignoreUntypedCollections && parameters.length == 0) {
return false;
}
return !VariableAccessUtils.variableIsAssigned(collection, body);
}
return true;
}