1 /* 2 * Copyright (C) 2017 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.javapoet; 18 19 import com.google.auto.common.MoreTypes; 20 import com.squareup.javapoet.CodeBlock; 21 import dagger.internal.codegen.langmodel.DaggerTypes; 22 import javax.lang.model.type.TypeMirror; 23 24 /** 25 * Encapsulates a {@link CodeBlock} for an <a 26 * href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-15.html">expression</a> and the 27 * {@link TypeMirror} that it represents from the perspective of the compiler. Consider the 28 * following example: 29 * 30 * <pre><code> 31 * {@literal @SuppressWarnings("rawtypes")} 32 * private Provider fooImplProvider = DoubleCheck.provider(FooImpl_Factory.create()); 33 * </code></pre> 34 * 35 * <p>An {@code Expression} for {@code fooImplProvider.get()} would have a {@link #type()} of {@code 36 * java.lang.Object} and not {@code FooImpl}. 37 */ 38 public final class Expression { 39 private final TypeMirror type; 40 private final CodeBlock codeBlock; 41 Expression(TypeMirror type, CodeBlock codeBlock)42 private Expression(TypeMirror type, CodeBlock codeBlock) { 43 this.type = type; 44 this.codeBlock = codeBlock; 45 } 46 47 /** Creates a new {@link Expression} with a {@link TypeMirror} and {@link CodeBlock}. */ create(TypeMirror type, CodeBlock expression)48 public static Expression create(TypeMirror type, CodeBlock expression) { 49 return new Expression(type, expression); 50 } 51 52 /** 53 * Creates a new {@link Expression} with a {@link TypeMirror}, {@linkplain CodeBlock#of(String, 54 * Object[]) format, and arguments}. 55 */ create(TypeMirror type, String format, Object... args)56 public static Expression create(TypeMirror type, String format, Object... args) { 57 return create(type, CodeBlock.of(format, args)); 58 } 59 60 /** Returns a new expression that casts the current expression to {@code newType}. */ 61 // TODO(ronshapiro): consider overloads that take a Types and Elements and only cast if necessary, 62 // or just embedding a Types/Elements instance in an Expression. castTo(TypeMirror newType)63 public Expression castTo(TypeMirror newType) { 64 return create(newType, "($T) $L", newType, codeBlock); 65 } 66 67 /** 68 * Returns a new expression that {@link #castTo(TypeMirror)} casts the current expression to its 69 * boxed type if this expression has a primitive type. 70 */ box(DaggerTypes types)71 public Expression box(DaggerTypes types) { 72 return type.getKind().isPrimitive() 73 ? castTo(types.boxedClass(MoreTypes.asPrimitiveType(type)).asType()) 74 : this; 75 } 76 77 /** The {@link TypeMirror type} to which the expression evaluates. */ type()78 public TypeMirror type() { 79 return type; 80 } 81 82 /** The code of the expression. */ codeBlock()83 public CodeBlock codeBlock() { 84 return codeBlock; 85 } 86 87 @Override toString()88 public String toString() { 89 return String.format("[%s] %s", type, codeBlock); 90 } 91 } 92