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/*
* Copyright 2003-2013 Dave Griffith, Bas Leijdekkers
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.siyeh.ig.performance;
import com.intellij.psi.*;
import com.intellij.psi.util.InheritanceUtil;
import com.intellij.psi.util.PsiTreeUtil;
import com.siyeh.ig.psiutils.ClassUtils;
import org.jetbrains.annotations.NotNull;
public class InnerClassReferenceVisitor extends JavaRecursiveElementVisitor {
private final PsiClass innerClass;
private boolean referencesStaticallyAccessible = true;
public InnerClassReferenceVisitor(PsiClass innerClass) {
this.innerClass = innerClass;
}
public boolean canInnerClassBeStatic() {
return referencesStaticallyAccessible;
}
private boolean isClassStaticallyAccessible(PsiClass aClass) {
if (PsiTreeUtil.isAncestor(innerClass, aClass, false)) {
return true;
}
if (aClass.getContainingClass() != null) {
return aClass.hasModifierProperty(PsiModifier.STATIC);
}
if (InheritanceUtil.isInheritorOrSelf(innerClass, aClass, true)) {
return true;
}
PsiClass classScope = aClass;
final PsiClass outerClass = ClassUtils.getContainingClass(innerClass);
while (classScope != null) {
if (InheritanceUtil.isInheritorOrSelf(outerClass, classScope, true)) {
return false;
}
final PsiElement scope = classScope.getScope();
if (scope instanceof PsiClass) {
classScope = (PsiClass)scope;
}
else {
classScope = null;
}
}
return true;
}
@Override
public void visitThisExpression(@NotNull PsiThisExpression expression) {
if (!referencesStaticallyAccessible) {
return;
}
super.visitThisExpression(expression);
if (hasContainingClassQualifier(expression)) {
referencesStaticallyAccessible = false;
}
}
@Override
public void visitSuperExpression(@NotNull PsiSuperExpression expression) {
if (!referencesStaticallyAccessible) {
return;
}
super.visitSuperExpression(expression);
if (hasContainingClassQualifier(expression)) {
referencesStaticallyAccessible = false;
}
}
private boolean hasContainingClassQualifier(PsiQualifiedExpression expression) {
final PsiJavaCodeReferenceElement qualifier = expression.getQualifier();
if (qualifier == null) {
return false;
}
final PsiElement element = qualifier.resolve();
if (!(element instanceof PsiClass)) {
return false;
}
final PsiClass aClass = (PsiClass)element;
return !aClass.equals(innerClass);
}
@Override
public void visitReferenceElement(@NotNull PsiJavaCodeReferenceElement reference) {
if (!referencesStaticallyAccessible) {
return;
}
final PsiElement parent = reference.getParent();
if (parent instanceof PsiThisExpression || parent instanceof PsiSuperExpression) {
return;
}
super.visitReferenceElement(reference);
final PsiElement qualifier = reference.getQualifier();
if (qualifier instanceof PsiSuperExpression) {
return;
}
if (qualifier instanceof PsiReferenceExpression) {
final PsiReferenceExpression referenceExpression = (PsiReferenceExpression)qualifier;
final PsiElement resolvedExpression = referenceExpression.resolve();
if (!(resolvedExpression instanceof PsiField) && !(resolvedExpression instanceof PsiMethod)) {
return;
}
}
final PsiElement element = reference.resolve();
if (element instanceof PsiMethod || element instanceof PsiField) {
final PsiMember member = (PsiMember)element;
if (member.hasModifierProperty(PsiModifier.STATIC)) {
return;
}
final PsiClass containingClass = member.getContainingClass();
if (innerClass.equals(containingClass)) {
return;
}
if (member.hasModifierProperty(PsiModifier.PRIVATE)) {
referencesStaticallyAccessible = false;
return;
}
referencesStaticallyAccessible &= isClassStaticallyAccessible(containingClass);
}
else if (element instanceof PsiLocalVariable || element instanceof PsiParameter) {
final PsiElement containingMethod = PsiTreeUtil.getParentOfType(reference, PsiMethod.class);
final PsiElement referencedMethod = PsiTreeUtil.getParentOfType(element, PsiMethod.class);
if (containingMethod != null && referencedMethod != null && !containingMethod.equals(referencedMethod)) {
referencesStaticallyAccessible = false;
}
}
else if (element instanceof PsiClass) {
final PsiClass aClass = (PsiClass)element;
referencesStaticallyAccessible &= isClassStaticallyAccessible(aClass);
}
}
}
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