1/* 2 * Copyright (C) 2016 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 */ 16package android.databinding.tool.expr; 17 18import android.databinding.tool.CallbackWrapper; 19import android.databinding.tool.processing.ErrorMessages; 20import android.databinding.tool.reflection.ModelAnalyzer; 21import android.databinding.tool.reflection.ModelClass; 22import android.databinding.tool.util.Preconditions; 23import android.databinding.tool.writer.KCode; 24 25import java.util.Collections; 26import java.util.List; 27 28/** 29 * This expressions that are used to reference arguments in callbacks. 30 * <p 31 * While the callback is being parsed, they get whatever the variable user defined in the lambda. 32 * When the code is being generated, they get simple enumarated names so that multiple callbacks 33 * can be handled in the same method. 34 */ 35public class CallbackArgExpr extends IdentifierExpr { 36 37 private int mArgIndex; 38 39 private String mName; 40 41 private ModelClass mClassFromCallback; 42 43 public CallbackArgExpr(int argIndex, String name) { 44 super(name); 45 mArgIndex = argIndex; 46 mName = name; 47 } 48 49 @Override 50 public boolean isDynamic() { 51 return false; 52 } 53 54 public void setClassFromCallback(ModelClass modelClass) { 55 mClassFromCallback = modelClass; 56 } 57 58 @Override 59 protected ModelClass resolveType(ModelAnalyzer modelAnalyzer) { 60 Preconditions 61 .checkNotNull(mClassFromCallback, ErrorMessages.UNDEFINED_CALLBACK_ARGUMENT, mName); 62 return mClassFromCallback; 63 } 64 65 @Override 66 protected List<Dependency> constructDependencies() { 67 return Collections.emptyList(); 68 } 69 70 @Override 71 protected KCode generateCode() { 72 return new KCode(CallbackWrapper.ARG_PREFIX + mArgIndex); 73 } 74 75 @Override 76 protected String computeUniqueKey() { 77 return CallbackWrapper.ARG_PREFIX + mArgIndex; 78 } 79 80 @Override 81 public String getInvertibleError() { 82 return "Callback arguments cannot be inverted"; 83 } 84 85 public String getName() { 86 return mName; 87 } 88 89 @Override 90 public Expr cloneToModel(ExprModel model) { 91 return new CallbackArgExpr(mArgIndex, mName); 92 } 93} 94