InverseBinding.java revision d3f2b9229472c9dae9bf4ae8b3e2d653b5653b01 
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
17package android.databinding.tool;
18
19import android.databinding.tool.expr.Expr;
20import android.databinding.tool.expr.ExprModel;
21import android.databinding.tool.expr.FieldAccessExpr;
22import android.databinding.tool.processing.ErrorMessages;
23import android.databinding.tool.processing.Scope;
24import android.databinding.tool.processing.scopes.LocationScopeProvider;
25import android.databinding.tool.reflection.ModelAnalyzer;
26import android.databinding.tool.reflection.ModelClass;
27import android.databinding.tool.store.Location;
28import android.databinding.tool.store.SetterStore;
29import android.databinding.tool.store.SetterStore.BindingGetterCall;
30import android.databinding.tool.store.SetterStore.BindingSetterCall;
31import android.databinding.tool.util.L;
32import android.databinding.tool.util.Preconditions;
33import android.databinding.tool.writer.FlagSet;
34import android.databinding.tool.writer.KCode;
35import android.databinding.tool.writer.LayoutBinderWriterKt;
36
37import kotlin.jvm.functions.Function2;
38
39import java.util.ArrayList;
40import java.util.List;
41
42public class InverseBinding implements LocationScopeProvider {
43
44    private final String mName;
45    private final Expr mExpr;
46    private final BindingTarget mTarget;
47    private BindingGetterCall mGetterCall;
48    private final ArrayList<FieldAccessExpr> mChainedExpressions = new ArrayList<FieldAccessExpr>();
49
50    public InverseBinding(BindingTarget target, String name, Expr expr) {
51        mTarget = target;
52        mName = name;
53        mExpr = expr;
54    }
55
56    @Override
57    public List<Location> provideScopeLocation() {
58        if (mExpr != null) {
59            return mExpr.getLocations();
60        } else {
61            return mChainedExpressions.get(0).getLocations();
62        }
63    }
64
65    void setGetterCall(BindingGetterCall getterCall) {
66        mGetterCall = getterCall;
67    }
68
69    public void addChainedExpression(FieldAccessExpr expr) {
70        mChainedExpressions.add(expr);
71    }
72
73    public boolean isOnBinder() {
74        return mTarget.getResolvedType().isViewDataBinding();
75    }
76
77    private SetterStore.BindingGetterCall getGetterCall() {
78        if (mGetterCall == null) {
79            if (mExpr != null) {
80                mExpr.getResolvedType(); // force resolve of ObservableFields
81            }
82            try {
83                Scope.enter(mTarget);
84                Scope.enter(this);
85                resolveGetterCall();
86                if (mGetterCall == null) {
87                    L.e(ErrorMessages.CANNOT_FIND_GETTER_CALL, mName,
88                            mExpr == null ? "Unknown" : mExpr.getResolvedType(),
89                            mTarget.getResolvedType());
90                }
91            } finally {
92                Scope.exit();
93                Scope.exit();
94            }
95        }
96        return mGetterCall;
97    }
98
99    private void resolveGetterCall() {
100        ModelClass viewType = mTarget.getResolvedType();
101        final SetterStore setterStore = SetterStore.get(ModelAnalyzer.getInstance());
102        final ModelClass resolvedType = mExpr == null ? null : mExpr.getResolvedType();
103        mGetterCall = setterStore.getGetterCall(mName, viewType, resolvedType,
104                getModel().getImports());
105    }
106
107    public BindingTarget getTarget() {
108        return mTarget;
109    }
110
111    public KCode toJavaCode(String bindingComponent, final FlagSet flagField) {
112        final String targetViewName = LayoutBinderWriterKt.getFieldName(getTarget());
113        KCode code = new KCode();
114        // A chained expression will have substituted its chained value for the expression
115        // unless the attribute has no expression. Therefore, chaining and expressions are
116        // mutually exclusive.
117        Preconditions.check((mExpr == null) != mChainedExpressions.isEmpty(),
118                "Chained expressions are only against unbound attributes.");
119        if (mExpr != null) {
120            code.app("", mExpr.toInverseCode(new KCode(getGetterCall().toJava(bindingComponent,
121                    targetViewName))));
122        } else { // !mChainedExpressions.isEmpty())
123            final String fieldName = flagField.getLocalName();
124            FlagSet flagSet = new FlagSet();
125            for (FieldAccessExpr expr : mChainedExpressions) {
126                flagSet = flagSet.or(new FlagSet(expr.getId()));
127            }
128            final FlagSet allFlags = flagSet;
129            code.nl(new KCode("synchronized(this) {"));
130            code.tab(LayoutBinderWriterKt
131                    .mapOr(flagField, flagSet, new Function2<String, Integer, KCode>() {
132                        @Override
133                        public KCode invoke(String suffix, Integer index) {
134                            return new KCode(fieldName)
135                                    .app(suffix)
136                                    .app(" |= ")
137                                    .app(LayoutBinderWriterKt.binaryCode(allFlags, index))
138                                    .app(";");
139                        }
140                    }));
141            code.nl(new KCode("}"));
142            code.nl(new KCode("requestRebind()"));
143        }
144        return code;
145    }
146
147    public String getBindingAdapterInstanceClass() {
148        return getGetterCall().getBindingAdapterInstanceClass();
149    }
150
151    /**
152     * The min api level in which this binding should be executed.
153     * <p>
154     * This should be the minimum value among the dependencies of this binding.
155     */
156    public int getMinApi() {
157        final BindingGetterCall getterCall = getGetterCall();
158        return Math.max(getterCall.getMinApi(), getterCall.getEvent().getMinApi());
159    }
160
161    public BindingSetterCall getEventSetter() {
162        final BindingGetterCall getterCall = getGetterCall();
163        return getterCall.getEvent();
164    }
165
166    public String getName() {
167        return mName;
168    }
169
170    public String getEventAttribute() {
171        return getGetterCall().getEventAttribute();
172    }
173
174    public ExprModel getModel() {
175        if (mExpr != null) {
176            return mExpr.getModel();
177        }
178        return mChainedExpressions.get(0).getModel();
179    }
180}
181