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
050                               && ((PackageFragmentDescriptor) parent).getFqName().isAncestorOf(((PackageFragmentDescriptor) fromParent).getFqName())
051                               && DescriptorUtils.areInSameModule(fromParent, parent);
052                    }
053                    fromParent = fromParent.getContainingDeclaration();
054                }
055                return false;
056            }
057        };
058    
059        public static final Visibility PROTECTED = new Visibility("protected", true) {
060            @Override
061            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
062                ClassDescriptor classDescriptor = DescriptorUtils.getParentOfType(what, ClassDescriptor.class);
063                if (classDescriptor == null) return false;
064    
065                ClassDescriptor fromClass = DescriptorUtils.getParentOfType(from, ClassDescriptor.class, false);
066                if (fromClass == null) return false;
067                if (DescriptorUtils.isSubclass(fromClass, classDescriptor)) {
068                    return true;
069                }
070                return isVisible(what, fromClass.getContainingDeclaration());
071            }
072        };
073    
074        public static final Visibility INTERNAL = new Visibility("internal", false) {
075            @Override
076            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
077                DeclarationDescriptor fromOrModule = from instanceof PackageViewDescriptor ? ((PackageViewDescriptor) from).getModule() : from;
078                return DescriptorUtils.areInSameModule(what, fromOrModule);
079            }
080        };
081    
082        public static final Visibility PUBLIC = new Visibility("public", true) {
083            @Override
084            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
085                return true;
086            }
087        };
088    
089        public static final Visibility LOCAL = new Visibility("local", false) {
090            @Override
091            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
092                throw new IllegalStateException(); //This method shouldn't be invoked for LOCAL visibility
093            }
094        };
095    
096        public static final Visibility INHERITED = new Visibility("inherited", false) {
097            @Override
098            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
099                throw new IllegalStateException("Visibility is unknown yet"); //This method shouldn't be invoked for INHERITED visibility
100            }
101        };
102    
103        /* Visibility for fake override invisible members (they are created for better error reporting) */
104        public static final Visibility INVISIBLE_FAKE = new Visibility("invisible_fake", false) {
105            @Override
106            protected boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
107                return false;
108            }
109        };
110    
111        public static final Set<Visibility> INVISIBLE_FROM_OTHER_MODULES = Sets.newHashSet(PRIVATE, INTERNAL, LOCAL);
112    
113        private Visibilities() {
114        }
115    
116        public static boolean isVisible(@NotNull DeclarationDescriptorWithVisibility what, @NotNull DeclarationDescriptor from) {
117            return findInvisibleMember(what, from) == null;
118        }
119    
120        @Nullable
121        public static DeclarationDescriptorWithVisibility findInvisibleMember(
122                @NotNull DeclarationDescriptorWithVisibility what,
123                @NotNull DeclarationDescriptor from
124        ) {
125            DeclarationDescriptorWithVisibility parent = what;
126            while (parent != null && parent.getVisibility() != LOCAL) {
127                if (!parent.getVisibility().isVisible(parent, from)) {
128                    return parent;
129                }
130                parent = DescriptorUtils.getParentOfType(parent, DeclarationDescriptorWithVisibility.class);
131            }
132            return null;
133        }
134    
135        private static final Map<Visibility, Integer> ORDERED_VISIBILITIES = Maps.newHashMap();
136    
137        static {
138            ORDERED_VISIBILITIES.put(PRIVATE, 0);
139            ORDERED_VISIBILITIES.put(INTERNAL, 1);
140            ORDERED_VISIBILITIES.put(PROTECTED, 1);
141            ORDERED_VISIBILITIES.put(PUBLIC, 2);
142        }
143    
144        /*package*/
145        @Nullable
146        static Integer compareLocal(@NotNull Visibility first, @NotNull Visibility second) {
147            if (first == second) return 0;
148            Integer firstIndex = ORDERED_VISIBILITIES.get(first);
149            Integer secondIndex = ORDERED_VISIBILITIES.get(second);
150            if (firstIndex == null || secondIndex == null || firstIndex.equals(secondIndex)) {
151                return null;
152            }
153            return firstIndex - secondIndex;
154        }
155    
156        @Nullable
157        public static Integer compare(@NotNull Visibility first, @NotNull Visibility second) {
158            Integer result = first.compareTo(second);
159            if (result != null) {
160                return result;
161            }
162            Integer oppositeResult = second.compareTo(first);
163            if (oppositeResult != null) {
164                return -oppositeResult;
165            }
166            return null;
167        }
168    }