001    /*
002     * Copyright 2010-2013 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.jet.lang.descriptors;
018    
019    import com.google.common.collect.Maps;
020    import com.google.common.collect.Sets;
021    import org.jetbrains.annotations.NotNull;
022    import org.jetbrains.annotations.Nullable;
023    import org.jetbrains.jet.lang.resolve.DescriptorUtils;
024    
025    import java.util.Map;
026    import java.util.Set;
027    
028    public class Visibilities {
029        public static final Visibility PRIVATE = new Visibility("private", false) {
030            @Override
031            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
032                DeclarationDescriptor parent = what;
033                while (parent != null) {
034                    parent = parent.getContainingDeclaration();
035                    if ((parent instanceof ClassDescriptor && !DescriptorUtils.isClassObject(parent)) ||
036                        parent instanceof PackageFragmentDescriptor) {
037                        break;
038                    }
039                }
040                if (parent == null) {
041                    return false;
042                }
043                DeclarationDescriptor fromParent = from;
044                while (fromParent != null) {
045                    if (parent == fromParent) {
046                        return true;
047                    }
048                    if (fromParent instanceof PackageFragmentDescriptor) {
049                        return parent instanceof PackageFragmentDescriptor && ((PackageFragmentDescriptor) parent).getFqName()
050                                .isAncestorOf(((PackageFragmentDescriptor) fromParent).getFqName());
051                    }
052                    fromParent = fromParent.getContainingDeclaration();
053                }
054                return false;
055            }
056        };
057    
058        public static final Visibility PROTECTED = new Visibility("protected", true) {
059            @Override
060            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
061                ClassDescriptor classDescriptor = DescriptorUtils.getParentOfType(what, ClassDescriptor.class);
062                if (classDescriptor == null) return false;
063    
064                ClassDescriptor fromClass = DescriptorUtils.getParentOfType(from, ClassDescriptor.class, false);
065                if (fromClass == null) return false;
066                if (DescriptorUtils.isSubclass(fromClass, classDescriptor)) {
067                    return true;
068                }
069                return isVisible(what, fromClass.getContainingDeclaration());
070            }
071        };
072    
073        public static final Visibility INTERNAL = new Visibility("internal", false) {
074            @Override
075            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
076                DeclarationDescriptor fromOrModule = from instanceof PackageViewDescriptor ? ((PackageViewDescriptor) from).getModule() : from;
077                return DescriptorUtils.areInSameModule(what, fromOrModule);
078            }
079        };
080    
081        public static final Visibility PUBLIC = new Visibility("public", true) {
082            @Override
083            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
084                return true;
085            }
086        };
087    
088        public static final Visibility LOCAL = new Visibility("local", false) {
089            @Override
090            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
091                throw new IllegalStateException(); //This method shouldn't be invoked for LOCAL visibility
092            }
093        };
094    
095        public static final Visibility INHERITED = new Visibility("inherited", false) {
096            @Override
097            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
098                throw new IllegalStateException("Visibility is unknown yet"); //This method shouldn't be invoked for INHERITED visibility
099            }
100        };
101    
102        /* Visibility for fake override invisible members (they are created for better error reporting) */
103        public static final Visibility INVISIBLE_FAKE = new Visibility("invisible_fake", false) {
104            @Override
105            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
106                return false;
107            }
108        };
109    
110        public static final Set<Visibility> INVISIBLE_FROM_OTHER_MODULES = Sets.newHashSet(PRIVATE, INTERNAL, LOCAL);
111    
112        private Visibilities() {
113        }
114    
115        public static boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
116            return findInvisibleMember(what, from) == null;
117        }
118    
119        @Nullable
120        public static DeclarationDescriptorWithVisibility findInvisibleMember(
121                @NotNull DeclarationDescriptorWithVisibility what,
122                @NotNull DeclarationDescriptor from
123        ) {
124            DeclarationDescriptorWithVisibility parent = what;
125            while (parent != null && parent.getVisibility() != LOCAL) {
126                if (!parent.getVisibility().isVisible(parent, from)) {
127                    return parent;
128                }
129                parent = DescriptorUtils.getParentOfType(parent, DeclarationDescriptorWithVisibility.class);
130            }
131            return null;
132        }
133    
134        private static final Map<Visibility, Integer> ORDERED_VISIBILITIES = Maps.newHashMap();
135    
136        static {
137            ORDERED_VISIBILITIES.put(PRIVATE, 0);
138            ORDERED_VISIBILITIES.put(INTERNAL, 1);
139            ORDERED_VISIBILITIES.put(PROTECTED, 1);
140            ORDERED_VISIBILITIES.put(PUBLIC, 2);
141        }
142    
143        /*package*/
144        @Nullable
145        static Integer compareLocal(@NotNull Visibility first, @NotNull Visibility second) {
146            if (first == second) return 0;
147            Integer firstIndex = ORDERED_VISIBILITIES.get(first);
148            Integer secondIndex = ORDERED_VISIBILITIES.get(second);
149            if (firstIndex == null || secondIndex == null || firstIndex.equals(secondIndex)) {
150                return null;
151            }
152            return firstIndex - secondIndex;
153        }
154    
155        @Nullable
156        public static Integer compare(@NotNull Visibility first, @NotNull Visibility second) {
157            Integer result = first.compareTo(second);
158            if (result != null) {
159                return result;
160            }
161            Integer oppositeResult = second.compareTo(first);
162            if (oppositeResult != null) {
163                return -oppositeResult;
164            }
165            return null;
166        }
167    }