1 /* 2 * Copyright (C) 2015 The Dagger Authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package dagger.internal.codegen.binding; 18 19 import static androidx.room.compiler.processing.compat.XConverters.toJavac; 20 import static dagger.internal.codegen.extension.Optionals.emptiesLast; 21 import static dagger.internal.codegen.xprocessing.XElements.getSimpleName; 22 import static java.util.Comparator.comparing; 23 24 import androidx.room.compiler.processing.XElement; 25 import androidx.room.compiler.processing.XTypeElement; 26 import dagger.internal.codegen.model.BindingKind; 27 import dagger.internal.codegen.model.Key; 28 import dagger.internal.codegen.xprocessing.XElements; 29 import java.util.Comparator; 30 import java.util.Optional; 31 32 /** An object that declares or specifies a binding. */ 33 public abstract class BindingDeclaration { 34 /** 35 * A comparator that compares binding declarations with elements. 36 * 37 * <p>Compares, in order: 38 * 39 * <ol> 40 * <li>Contributing module or enclosing type name 41 * <li>Binding element's simple name 42 * <li>Binding element's type 43 * </ol> 44 * 45 * Any binding declarations without elements are last. 46 */ 47 public static final Comparator<BindingDeclaration> COMPARATOR = 48 comparing( 49 (BindingDeclaration declaration) -> 50 declaration.contributingModule().isPresent() 51 ? declaration.contributingModule() 52 : declaration.bindingTypeElement(), 53 emptiesLast(comparing(XTypeElement::getQualifiedName))) 54 .thenComparing( 55 (BindingDeclaration declaration) -> declaration.bindingElement(), 56 emptiesLast( 57 comparing((XElement element) -> getSimpleName(element)) 58 .thenComparing((XElement element) -> toJavac(element).asType().toString()))); 59 60 /** The {@link Key} of this declaration. */ key()61 public abstract Key key(); 62 63 /** 64 * The {@link XElement} that declares this binding. Absent for {@linkplain BindingKind binding 65 * kinds} that are not always declared by exactly one element. 66 * 67 * <p>For example, consider {@link BindingKind#MULTIBOUND_SET}. A component with many 68 * {@code @IntoSet} bindings for the same key will have a synthetic binding that depends on all 69 * contributions, but with no identifiying binding element. A {@code @Multibinds} method will also 70 * contribute a synthetic binding, but since multiple {@code @Multibinds} methods can coexist in 71 * the same component (and contribute to one single binding), it has no binding element. 72 */ bindingElement()73 public abstract Optional<XElement> bindingElement(); 74 75 /** 76 * The type enclosing the {@link #bindingElement()}, or {@link Optional#empty()} if {@link 77 * #bindingElement()} is empty. 78 */ bindingTypeElement()79 public final Optional<XTypeElement> bindingTypeElement() { 80 return bindingElement().map(XElements::closestEnclosingTypeElement); 81 } 82 83 /** 84 * The installed module class that contributed the {@link #bindingElement()}. May be a subclass of 85 * the class that contains {@link #bindingElement()}. Absent if {@link #bindingElement()} is 86 * empty. 87 */ contributingModule()88 public abstract Optional<XTypeElement> contributingModule(); 89 } 90