paperparcel.AdapterNameGenerator.java Source code

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Here is the source code for paperparcel.AdapterNameGenerator.java

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/*
 * Copyright (C) 2016 Bradley Campbell.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package paperparcel;

import com.google.common.base.CaseFormat;
import com.google.common.base.Joiner;
import com.google.common.collect.Maps;
import com.squareup.javapoet.ArrayTypeName;
import com.squareup.javapoet.ClassName;
import com.squareup.javapoet.ParameterizedTypeName;
import com.squareup.javapoet.TypeName;
import com.squareup.javapoet.WildcardTypeName;
import java.util.Map;

/**
 * Generates a human readable field name to use for an adapter instance in a class. Adapters
 * are added as constant fields, so generated names are formatted with uppercase characters and
 * words are separated by underscores as per java convention.
 */
final class AdapterNameGenerator {
    private final Map<TypeName, String> typeToNames = Maps.newLinkedHashMap();
    private final UniqueNameSet adapterNames = new UniqueNameSet("_");

    /**
     * Creates a name based on the given {@link TypeName}. Names are constants, so will use
     * {@link CaseFormat#UPPER_UNDERSCORE} formatting.
     */
    String getName(TypeName typeName) {
        String name = typeToNames.get(typeName);
        if (name != null) {
            return name;
        }
        name = getNameInternal(typeName);
        name = CaseFormat.UPPER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, name);
        name = adapterNames.getUniqueName(name);
        typeToNames.put(typeName, name);
        return name;
    }

    private String getNameInternal(TypeName typeName) {
        String adapterName = null;
        if (typeName instanceof WildcardTypeName) {
            WildcardTypeName wildcardTypeName = (WildcardTypeName) typeName;
            String upperBoundsPart = "";
            String lowerBoundsPart = "";
            for (TypeName upperBound : wildcardTypeName.upperBounds) {
                upperBoundsPart += getNameInternal(upperBound);
            }
            for (TypeName lowerBound : wildcardTypeName.lowerBounds) {
                lowerBoundsPart += getNameInternal(lowerBound);
            }
            adapterName = upperBoundsPart + lowerBoundsPart;
        }
        if (typeName instanceof ArrayTypeName) {
            ArrayTypeName arrayTypeName = (ArrayTypeName) typeName;
            adapterName = getNameInternal(arrayTypeName.componentType) + "Array";
        }
        if (typeName instanceof ParameterizedTypeName) {
            ParameterizedTypeName parameterizedTypeName = (ParameterizedTypeName) typeName;
            String paramPart = "";
            for (TypeName param : parameterizedTypeName.typeArguments) {
                paramPart += getNameInternal(param);
            }
            adapterName = paramPart + parameterizedTypeName.rawType.simpleName();
        }
        if (typeName instanceof ClassName) {
            ClassName className = (ClassName) typeName;
            adapterName = Joiner.on("_").join(className.simpleNames());
        }
        if (typeName.isPrimitive()) {
            adapterName = typeName.toString();
        }
        if (adapterName == null) {
            throw new AssertionError();
        }
        return adapterName;
    }
}