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