1 /* 2 * Copyright (C) 2015 The Android Open Source Project 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 android.databinding.tool.expr; 18 19 import android.databinding.tool.reflection.ModelAnalyzer; 20 import android.databinding.tool.reflection.ModelClass; 21 import android.databinding.tool.reflection.ModelMethod; 22 import android.databinding.tool.writer.KCode; 23 import android.databinding.tool.writer.LayoutBinderWriterKt; 24 25 import java.util.ArrayList; 26 import java.util.List; 27 28 /** 29 * This wraps an expression, but makes it unique for a particular event listener type. 30 * This is used to differentiate listener methods. For example: 31 * <pre> 32 * public void onFoo(String str) {...} 33 * public void onFoo(int i) {...} 34 * </pre> 35 */ 36 public class ListenerExpr extends Expr { 37 private final String mName; 38 private final ModelClass mListenerType; 39 private final ModelMethod mMethod; 40 ListenerExpr(Expr expr, String name, ModelClass listenerType, ModelMethod method)41 ListenerExpr(Expr expr, String name, ModelClass listenerType, ModelMethod method) { 42 super(expr); 43 mName = name; 44 mListenerType = listenerType; 45 mMethod = method; 46 } 47 48 @Override resolveType(ModelAnalyzer modelAnalyzer)49 protected ModelClass resolveType(ModelAnalyzer modelAnalyzer) { 50 return mListenerType; 51 } 52 getMethod()53 public ModelMethod getMethod() { 54 return mMethod; 55 } 56 getChild()57 public Expr getChild() { 58 return getChildren().get(0); 59 } 60 getName()61 public String getName() { 62 return mName; 63 } 64 65 @Override isDynamic()66 public boolean isDynamic() { 67 return getChild().isDynamic(); 68 } 69 70 @Override constructDependencies()71 protected List<Dependency> constructDependencies() { 72 final List<Dependency> dependencies = new ArrayList<Dependency>(); 73 Dependency dependency = new Dependency(this, getChild()); 74 dependency.setMandatory(true); 75 dependencies.add(dependency); 76 return dependencies; 77 } 78 computeUniqueKey()79 protected String computeUniqueKey() { 80 return join(getResolvedType().getCanonicalName(), getChild().computeUniqueKey(), mName); 81 } 82 83 @Override generateCode(boolean expand)84 public KCode generateCode(boolean expand) { 85 KCode code = new KCode("("); 86 final int minApi = Math.max(mListenerType.getMinApi(), mMethod.getMinApi()); 87 if (minApi > 1) { 88 code.app("(getBuildSdkInt() < " + minApi + ") ? null : "); 89 } 90 final String fieldName = LayoutBinderWriterKt.getFieldName(this); 91 final String listenerClassName = LayoutBinderWriterKt.getListenerClassName(this); 92 final KCode value = getChild().toCode(); 93 code.app("((") 94 .app(fieldName) 95 .app(" == null) ? (") 96 .app(fieldName) 97 .app(" = new ") 98 .app(listenerClassName) 99 .app("()) : ") 100 .app(fieldName) 101 .app(")"); 102 if (getChild().isDynamic()) { 103 code.app(".setValue(", value) 104 .app(")"); 105 } 106 code.app(")"); 107 return code; 108 } 109 110 @Override getInvertibleError()111 public String getInvertibleError() { 112 return "Listeners cannot be the target of a two-way binding"; 113 } 114 } 115