MethodBaseExpr.java revision c0c1dab0b6254e4d27f18c37a72a9e7952e958a0 
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 */
16
17package android.databinding.tool.expr;
18
19import android.databinding.tool.processing.Scope;
20import android.databinding.tool.reflection.ModelAnalyzer;
21import android.databinding.tool.reflection.ModelClass;
22import android.databinding.tool.reflection.ModelMethod;
23import android.databinding.tool.solver.ExecutionPath;
24
25import java.util.ArrayList;
26import java.util.List;
27
28public abstract class MethodBaseExpr extends Expr {
29    String mName;
30
31    MethodBaseExpr(Expr parent, String name) {
32        super(parent);
33        mName = name;
34    }
35
36    public Expr getTarget() {
37        return getChildren().get(0);
38    }
39
40    @Override
41    public List<ExecutionPath> toExecutionPath(List<ExecutionPath> paths) {
42        final List<ExecutionPath> targetPaths = getTarget().toExecutionPath(paths);
43        // after this, we need a null check.
44        List<ExecutionPath> result = new ArrayList<ExecutionPath>();
45        if (getTarget() instanceof StaticIdentifierExpr) {
46            result.addAll(toExecutionPathInOrder(paths, getTarget()));
47        } else {
48            for (ExecutionPath path : targetPaths) {
49                final ComparisonExpr cmp = getModel()
50                        .comparison("!=", getTarget(), getModel().symbol("null", Object.class));
51                path.addPath(cmp);
52                final ExecutionPath subPath = path.addBranch(cmp, true);
53                if (subPath != null) {
54                    subPath.addPath(this);
55                    result.add(subPath);
56                }
57            }
58        }
59        return result;
60    }
61
62    protected Expr resolveListenersAsMethodReference(ModelClass listener, Expr parent) {
63        final Expr target = getTarget();
64        final ModelClass childType = target.getResolvedType();
65        if (listener == null) {
66            throw new IllegalStateException(
67                    String.format("Could not resolve %s as a listener.", this));
68        }
69
70        List<ModelMethod> abstractMethods = listener.getAbstractMethods();
71        int numberOfAbstractMethods = abstractMethods == null ? 0 : abstractMethods.size();
72        if (numberOfAbstractMethods != 1) {
73            throw new IllegalStateException(String.format(
74                    "Could not find accessor %s.%s and %s has %d abstract methods, so is" +
75                            " not resolved as a listener",
76                    childType.getCanonicalName(), mName,
77                    listener.getCanonicalName(), numberOfAbstractMethods));
78        }
79
80        // Look for a signature matching the abstract method
81        final ModelMethod listenerMethod = abstractMethods.get(0);
82        final ModelClass[] listenerParameters = listenerMethod.getParameterTypes();
83        boolean isStatic = getTarget() instanceof StaticIdentifierExpr;
84        List<ModelMethod> methods = childType.findMethods(mName, isStatic);
85        for (ModelMethod method : methods) {
86            if (acceptsParameters(method, listenerParameters) &&
87                    method.getReturnType(null).equals(listenerMethod.getReturnType(null))) {
88                target.getParents().remove(this);
89                resetResolvedType();
90                // replace this with ListenerExpr in parent
91                Expr listenerExpr = getModel().listenerExpr(getTarget(), mName, listener,
92                        listenerMethod);
93                if (parent != null) {
94                    int index;
95                    while ((index = parent.getChildren().indexOf(this)) != -1) {
96                        parent.getChildren().set(index, listenerExpr);
97                    }
98                }
99                if (getModel().mBindingExpressions.contains(this)) {
100                    getModel().bindingExpr(listenerExpr);
101                }
102                getParents().remove(parent);
103                if (getParents().isEmpty()) {
104                    getModel().removeExpr(this);
105                }
106                return listenerExpr;
107            }
108        }
109
110        throw new IllegalStateException(String.format(
111                "Listener class %s with method %s did not match signature of any method %s",
112                listener.getCanonicalName(), listenerMethod.getName(), this));
113    }
114
115    private boolean acceptsParameters(ModelMethod method, ModelClass[] listenerParameters) {
116        ModelClass[] parameters = method.getParameterTypes();
117        if (parameters.length != listenerParameters.length) {
118            return false;
119        }
120        for (int i = 0; i < parameters.length; i++) {
121            if (!parameters[i].isAssignableFrom(listenerParameters[i])) {
122                return false;
123            }
124        }
125        return true;
126    }
127
128    @Override
129    protected List<Dependency> constructDependencies() {
130        final List<Dependency> dependencies = constructDynamicChildrenDependencies();
131        for (Dependency dependency : dependencies) {
132            if (dependency.getOther() == getTarget()) {
133                dependency.setMandatory(true);
134            }
135        }
136        return dependencies;
137    }
138
139    public String getName() {
140        return mName;
141    }
142
143    @Override
144    public void updateExpr(ModelAnalyzer modelAnalyzer) {
145        try {
146            Scope.enter(this);
147            resolveType(modelAnalyzer);
148            super.updateExpr(modelAnalyzer);
149        } finally {
150            Scope.exit();
151        }
152    }
153}
154