tools/processors/view_inspector/src/java/android/processor/view/inspector/InspectionCompanionGenerator.java - platform/frameworks/base - Gitiles

 /*
  * Copyright 2019 The Android Open Source Project
  *
  * 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 android.processor.view.inspector;


 import android.processor.view.inspector.InspectableClassModel.IntEnumEntry;
 import android.processor.view.inspector.InspectableClassModel.IntFlagEntry;
 import android.processor.view.inspector.InspectableClassModel.Property;

 import com.squareup.javapoet.ClassName;
 import com.squareup.javapoet.CodeBlock;
 import com.squareup.javapoet.FieldSpec;
 import com.squareup.javapoet.JavaFile;
 import com.squareup.javapoet.MethodSpec;
 import com.squareup.javapoet.NameAllocator;
 import com.squareup.javapoet.ParameterizedTypeName;
 import com.squareup.javapoet.TypeName;
 import com.squareup.javapoet.TypeSpec;

 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
 import java.util.NoSuchElementException;
 import java.util.Optional;

 import javax.annotation.processing.Filer;
 import javax.lang.model.element.Modifier;

 /**
  * Generates a source file defining a {@link android.view.inspector.InspectionCompanion}.
  */
 public final class InspectionCompanionGenerator {
     private final Filer mFiler;
     private final Class mRequestingClass;

     /**
      * The class name for {@code R.java}.
      */
     private static final ClassName R_CLASS_NAME = ClassName.get("android", "R");

     /**
      * The class name of {@link android.view.inspector.InspectionCompanion}.
      */
     private static final ClassName INSPECTION_COMPANION = ClassName.get(
             "android.view.inspector", "InspectionCompanion");

     /**
      * The class name of {@link android.view.inspector.PropertyMapper}.
      */
     private static final ClassName PROPERTY_MAPPER = ClassName.get(
             "android.view.inspector", "PropertyMapper");

     /**
      * The class name of {@link android.view.inspector.PropertyReader}.
      */
     private static final ClassName PROPERTY_READER = ClassName.get(
             "android.view.inspector", "PropertyReader");

     /**
      * The class name of {@link android.view.inspector.IntEnumMapping}.
      */
     private static final ClassName INT_ENUM_MAPPING = ClassName.get(
             "android.view.inspector", "IntEnumMapping");

     /**
      * The class name of {@link android.view.inspector.IntFlagMapping}.
      */
     private static final ClassName INT_FLAG_MAPPING = ClassName.get(
             "android.view.inspector", "IntFlagMapping");

     /**
      * The {@code mPropertiesMapped} field.
      */
     private static final FieldSpec M_PROPERTIES_MAPPED = FieldSpec
             .builder(TypeName.BOOLEAN, "mPropertiesMapped", Modifier.PRIVATE)
             .initializer("false")
             .addJavadoc(
                     "Set by {@link #mapProperties($T)} once properties have been mapped.\n",
                     PROPERTY_MAPPER)
             .build();

     /**
      * The suffix of the generated class name after the class's binary name.
      */
     private static final String GENERATED_CLASS_SUFFIX = "$InspectionCompanion";

     /**
      * The null resource ID, copied to avoid a host dependency on platform code.
      *
      * @see android.content.res.Resources#ID_NULL
      */
     private static final int ID_NULL = 0;

     /**
      * @param filer A filer to write the generated source to
      * @param requestingClass A class object representing the class that invoked the generator
      */
     public InspectionCompanionGenerator(Filer filer, Class requestingClass) {
         mFiler = filer;
         mRequestingClass = requestingClass;
     }

     /**
      * Generate and write an inspection companion.
      *
      * @param model The model to generated
      * @throws IOException From the Filer
      */
     public void generate(InspectableClassModel model) throws IOException {
         generateFile(model).writeTo(mFiler);
     }

     /**
      * Generate a {@link JavaFile} from a model.
      *
      * This is package-public for testing.
      *
      * @param model The model to generate from
      * @return A generated file of an {@link android.view.inspector.InspectionCompanion}
      */
     JavaFile generateFile(InspectableClassModel model) {
         return JavaFile
                 .builder(model.getClassName().packageName(), generateTypeSpec(model))
                 .indent("    ")
                 .build();
     }

     /**
      * Generate a {@link TypeSpec} for the {@link android.view.inspector.InspectionCompanion}
      * for the supplied model.
      *
      * @param model The model to generate from
      * @return A TypeSpec of the inspection companion
      */
     private TypeSpec generateTypeSpec(InspectableClassModel model) {
         final List<PropertyIdField> propertyIdFields = generatePropertyIdFields(model);

         TypeSpec.Builder builder = TypeSpec
                 .classBuilder(generateClassName(model))
                 .addModifiers(Modifier.PUBLIC, Modifier.FINAL)
                 .addSuperinterface(ParameterizedTypeName.get(
                         INSPECTION_COMPANION, model.getClassName()))
                 .addJavadoc("Inspection companion for {@link $T}.\n\n", model.getClassName())
                 .addJavadoc("Generated by {@link $T}\n", getClass())
                 .addJavadoc("on behalf of {@link $T}.\n", mRequestingClass)
                 .addField(M_PROPERTIES_MAPPED);

         for (PropertyIdField propertyIdField : propertyIdFields) {
             builder.addField(propertyIdField.mFieldSpec);
         }

         builder.addMethod(generateMapProperties(propertyIdFields))
                 .addMethod(generateReadProperties(model, propertyIdFields));

         generateGetNodeName(model).ifPresent(builder::addMethod);

         return builder.build();
     }

     /**
      * Build a list of {@link PropertyIdField}'s for a model.
      *
      * To insure idempotency of the generated code, this method sorts the list of properties
      * alphabetically by name.
      *
      * A {@link NameAllocator} is used to ensure that the field names are valid Java identifiers,
      * and it prevents overlaps in names by suffixing them as needed.
      *
      * @param model The model to get properties from
      * @return A list of properties and fields
      */
     private List<PropertyIdField> generatePropertyIdFields(InspectableClassModel model) {
         final NameAllocator nameAllocator = new NameAllocator();
         final List<Property> sortedProperties = new ArrayList<>(model.getAllProperties());
         final List<PropertyIdField> propertyIdFields = new ArrayList<>(sortedProperties.size());

         sortedProperties.sort(Comparator.comparing(Property::getName));

         for (Property property : sortedProperties) {
             // Format a property to a member field name like "someProperty" -> "mSomePropertyId"
             final String memberName = String.format(
                     "m%s%sId",
                     property.getName().substring(0, 1).toUpperCase(),
                     property.getName().substring(1));
             final FieldSpec fieldSpec = FieldSpec
                     .builder(TypeName.INT, nameAllocator.newName(memberName), Modifier.PRIVATE)
                     .addJavadoc("Property ID of {@code $L}.\n", property.getName())
                     .build();

             propertyIdFields.add(new PropertyIdField(fieldSpec, property));
         }

         return propertyIdFields;
     }

     /**
      * Generate a method definition for
      * {@link android.view.inspector.InspectionCompanion#getNodeName()}, if needed.
      *
      * If {@link InspectableClassModel#getNodeName()} is empty, This method returns an empty
      * optional, otherwise, it generates a simple method that returns the string value of the
      * node name.
      *
      * @param model The model to generate from
      * @return The method definition or an empty Optional
      */
     private Optional<MethodSpec> generateGetNodeName(InspectableClassModel model) {
         return model.getNodeName().map(nodeName -> MethodSpec.methodBuilder("getNodeName")
                 .addAnnotation(Override.class)
                 .addModifiers(Modifier.PUBLIC)
                 .returns(String.class)
                 .addStatement("return $S", nodeName)
                 .build());
     }

     /**
      * Generate a method definition for
      * {@link android.view.inspector.InspectionCompanion#mapProperties(
      * android.view.inspector.PropertyMapper)}.
      *
      * @param propertyIdFields A list of properties to map to ID fields
      * @return The method definition
      */
     private MethodSpec generateMapProperties(List<PropertyIdField> propertyIdFields) {
         final MethodSpec.Builder builder = MethodSpec.methodBuilder("mapProperties")
                 .addAnnotation(Override.class)
                 .addModifiers(Modifier.PUBLIC)
                 .addParameter(PROPERTY_MAPPER, "propertyMapper");

         propertyIdFields.forEach(p -> builder.addStatement(generatePropertyMapperInvocation(p)));
         builder.addStatement("$N = true", M_PROPERTIES_MAPPED);

         return builder.build();
     }

     /**
      * Generate a method definition for
      * {@link android.view.inspector.InspectionCompanion#readProperties(
      * Object, android.view.inspector.PropertyReader)}.
      *
      * @param model The model to generate from
      * @param propertyIdFields A list of properties and ID fields to read from
      * @return The method definition
      */
     private MethodSpec generateReadProperties(
             InspectableClassModel model,
             List<PropertyIdField> propertyIdFields) {
         final MethodSpec.Builder builder =  MethodSpec.methodBuilder("readProperties")
                 .addAnnotation(Override.class)
                 .addModifiers(Modifier.PUBLIC)
                 .addParameter(model.getClassName(), "node")
                 .addParameter(PROPERTY_READER, "propertyReader")
                 .addCode(generatePropertyMapInitializationCheck());

         for (PropertyIdField propertyIdField : propertyIdFields) {
             builder.addStatement(
                     "propertyReader.read$L($N, node.$L)",
                     methodSuffixForPropertyType(propertyIdField.mProperty.getType()),
                     propertyIdField.mFieldSpec,
                     propertyIdField.mProperty.getAccessor().invocation());
         }

         return builder.build();
     }

     /**
      * Generate a statement maps a property with a {@link android.view.inspector.PropertyMapper}.
      *
      * @param propertyIdField The property model and ID field to generate from
      * @return A statement that invokes property mapper method
      */
     private CodeBlock generatePropertyMapperInvocation(PropertyIdField propertyIdField) {
         final CodeBlock.Builder builder = CodeBlock.builder();
         final Property property = propertyIdField.mProperty;
         final FieldSpec fieldSpec = propertyIdField.mFieldSpec;

         builder.add(
                 "$N = propertyMapper.map$L($S,$W",
                 fieldSpec,
                 methodSuffixForPropertyType(property.getType()),
                 property.getName());

         if (property.isAttributeIdInferrableFromR()) {
             builder.add("$T.attr.$L", R_CLASS_NAME, property.getName());
         } else {
             if (property.getAttributeId() == ID_NULL) {
                 builder.add("$L", ID_NULL);
             } else {
                 builder.add("$L", hexLiteral(property.getAttributeId()));
             }
         }

         switch (property.getType()) {
             case INT_ENUM:
                 builder.add(",$W");
                 builder.add(generateIntEnumMappingBuilder(property.getIntEnumEntries()));
                 break;
             case INT_FLAG:
                 builder.add(",$W");
                 builder.add(generateIntFlagMappingBuilder(property.getIntFlagEntries()));
                 break;
         }

         return builder.add(")").build();
     }

     /**
      * Generate a check that throws
      * {@link android.view.inspector.InspectionCompanion.UninitializedPropertyMapException}
      * if the properties haven't been initialized.
      *
      * <pre>
      *     if (!mPropertiesMapped) {
      *         throw new InspectionCompanion.UninitializedPropertyMapException();
      *     }
      * </pre>
      *
      * @return A codeblock containing the property map initialization check
      */
     private CodeBlock generatePropertyMapInitializationCheck() {
         return CodeBlock.builder()
                 .beginControlFlow("if (!$N)", M_PROPERTIES_MAPPED)
                 .addStatement(
                         "throw new $T()",
                         INSPECTION_COMPANION.nestedClass("UninitializedPropertyMapException"))
                 .endControlFlow()
                 .build();
     }

     /**
      * Generate an invocation of {@link android.view.inspector.IntEnumMapping.Builder}.
      *
      * <pre>
      *      new IntEnumMapping.Builder()
      *          .addValue("ONE", 1)
      *          .build()
      * </pre>
      *
      * @return A codeblock containing the an int enum mapping builder
      */
     private CodeBlock generateIntEnumMappingBuilder(List<IntEnumEntry> intEnumEntries) {
         final ArrayList<IntEnumEntry> sortedEntries = new ArrayList<>(intEnumEntries);
         sortedEntries.sort(Comparator.comparing(IntEnumEntry::getValue));

         final CodeBlock.Builder builder = CodeBlock.builder()
                 .add("new $T()$>", INT_ENUM_MAPPING.nestedClass("Builder"));

         for (IntEnumEntry entry : sortedEntries) {
             builder.add("\n.addValue($S, $L)", entry.getName(), entry.getValue());
         }

         return builder.add("\n.build()$<").build();
     }

     private CodeBlock generateIntFlagMappingBuilder(List<IntFlagEntry> intFlagEntries) {
         final ArrayList<IntFlagEntry> sortedEntries = new ArrayList<>(intFlagEntries);
         sortedEntries.sort(Comparator.comparing(IntFlagEntry::getName));

         final CodeBlock.Builder builder = CodeBlock.builder()
                 .add("new $T()$>", INT_FLAG_MAPPING.nestedClass("Builder"));

         for (IntFlagEntry entry : sortedEntries) {
             if (entry.hasMask()) {
                 builder.add(
                         "\n.addFlag($S, $L, $L)",
                         entry.getName(),
                         hexLiteral(entry.getTarget()),
                         hexLiteral(entry.getMask()));
             } else {
                 builder.add(
                         "\n.addFlag($S, $L)",
                         entry.getName(),
                         hexLiteral(entry.getTarget()));
             }
         }

         return builder.add("\n.build()$<").build();
     }

     /**
      * Generate the final class name for the inspection companion from the model's class name.
      *
      * The generated class is added to the same package as the source class. If the class in the
      * model is a nested class, the nested class names are joined with {@code "$"}. The suffix
      * {@code "$$InspectionCompanion"} is always added the the generated name. E.g.: For modeled
      * class {@code com.example.Outer.Inner}, the generated class name will be
      * {@code com.example.Outer$Inner$$InspectionCompanion}.
      *
      * @param model The model to generate from
      * @return A class name for the generated inspection companion class
      */
     private static ClassName generateClassName(InspectableClassModel model) {
         final ClassName className = model.getClassName();

         return ClassName.get(
                 className.packageName(),
                 String.join("$", className.simpleNames()) + GENERATED_CLASS_SUFFIX);
     }

     /**
      * Get the suffix for a {@code map} or {@code read} method for a property type.
      *
      * @param type The requested property type
      * @return A method suffix
      */
     private static String methodSuffixForPropertyType(Property.Type type) {
         switch (type) {
             case BOOLEAN:
                 return "Boolean";
             case BYTE:
                 return "Byte";
             case CHAR:
                 return "Char";
             case DOUBLE:
                 return "Double";
             case FLOAT:
                 return "Float";
             case INT:
                 return "Int";
             case LONG:
                 return "Long";
             case SHORT:
                 return "Short";
             case OBJECT:
                 return "Object";
             case COLOR:
                 return "Color";
             case GRAVITY:
                 return "Gravity";
             case INT_ENUM:
                 return "IntEnum";
             case INT_FLAG:
                 return "IntFlag";
             case RESOURCE_ID:
                 return "ResourceId";
             default:
                 throw new NoSuchElementException(String.format("No such property type, %s", type));
         }
     }

     private static String hexLiteral(int value) {
         return String.format("0x%08x", value);
     }

     /**
      * Value class that holds a {@link Property} and a {@link FieldSpec} for that property.
      */
     private static final class PropertyIdField {
         private final FieldSpec mFieldSpec;
         private final Property mProperty;

         private PropertyIdField(FieldSpec fieldSpec, Property property) {
             mFieldSpec = fieldSpec;
             mProperty = property;
         }
     }
 }
	/*
	* Copyright 2019 The Android Open Source Project
	*
	* 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 android.processor.view.inspector;


	import android.processor.view.inspector.InspectableClassModel.IntEnumEntry;
	import android.processor.view.inspector.InspectableClassModel.IntFlagEntry;
	import android.processor.view.inspector.InspectableClassModel.Property;

	import com.squareup.javapoet.ClassName;
	import com.squareup.javapoet.CodeBlock;
	import com.squareup.javapoet.FieldSpec;
	import com.squareup.javapoet.JavaFile;
	import com.squareup.javapoet.MethodSpec;
	import com.squareup.javapoet.NameAllocator;
	import com.squareup.javapoet.ParameterizedTypeName;
	import com.squareup.javapoet.TypeName;
	import com.squareup.javapoet.TypeSpec;

	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.Comparator;
	import java.util.List;
	import java.util.NoSuchElementException;
	import java.util.Optional;

	import javax.annotation.processing.Filer;
	import javax.lang.model.element.Modifier;

	/**
	* Generates a source file defining a {@link android.view.inspector.InspectionCompanion}.
	*/
	public final class InspectionCompanionGenerator {
	private final Filer mFiler;
	private final Class mRequestingClass;

	/**
	* The class name for {@code R.java}.
	*/
	private static final ClassName R_CLASS_NAME = ClassName.get("android", "R");

	/**
	* The class name of {@link android.view.inspector.InspectionCompanion}.
	*/
	private static final ClassName INSPECTION_COMPANION = ClassName.get(
	"android.view.inspector", "InspectionCompanion");

	/**
	* The class name of {@link android.view.inspector.PropertyMapper}.
	*/
	private static final ClassName PROPERTY_MAPPER = ClassName.get(
	"android.view.inspector", "PropertyMapper");

	/**
	* The class name of {@link android.view.inspector.PropertyReader}.
	*/
	private static final ClassName PROPERTY_READER = ClassName.get(
	"android.view.inspector", "PropertyReader");

	/**
	* The class name of {@link android.view.inspector.IntEnumMapping}.
	*/
	private static final ClassName INT_ENUM_MAPPING = ClassName.get(
	"android.view.inspector", "IntEnumMapping");

	/**
	* The class name of {@link android.view.inspector.IntFlagMapping}.
	*/
	private static final ClassName INT_FLAG_MAPPING = ClassName.get(
	"android.view.inspector", "IntFlagMapping");

	/**
	* The {@code mPropertiesMapped} field.
	*/
	private static final FieldSpec M_PROPERTIES_MAPPED = FieldSpec
	.builder(TypeName.BOOLEAN, "mPropertiesMapped", Modifier.PRIVATE)
	.initializer("false")
	.addJavadoc(
	"Set by {@link #mapProperties($T)} once properties have been mapped.\n",
	PROPERTY_MAPPER)
	.build();

	/**
	* The suffix of the generated class name after the class's binary name.
	*/
	private static final String GENERATED_CLASS_SUFFIX = "$InspectionCompanion";

	/**
	* The null resource ID, copied to avoid a host dependency on platform code.
	*
	* @see android.content.res.Resources#ID_NULL
	*/
	private static final int ID_NULL = 0;

	/**
	* @param filer A filer to write the generated source to
	* @param requestingClass A class object representing the class that invoked the generator
	*/
	public InspectionCompanionGenerator(Filer filer, Class requestingClass) {
	mFiler = filer;
	mRequestingClass = requestingClass;
	}

	/**
	* Generate and write an inspection companion.
	*
	* @param model The model to generated
	* @throws IOException From the Filer
	*/
	public void generate(InspectableClassModel model) throws IOException {
	generateFile(model).writeTo(mFiler);
	}

	/**
	* Generate a {@link JavaFile} from a model.
	*
	* This is package-public for testing.
	*
	* @param model The model to generate from
	* @return A generated file of an {@link android.view.inspector.InspectionCompanion}
	*/
	JavaFile generateFile(InspectableClassModel model) {
	return JavaFile
	.builder(model.getClassName().packageName(), generateTypeSpec(model))
	.indent(" ")
	.build();
	}

	/**
	* Generate a {@link TypeSpec} for the {@link android.view.inspector.InspectionCompanion}
	* for the supplied model.
	*
	* @param model The model to generate from
	* @return A TypeSpec of the inspection companion
	*/
	private TypeSpec generateTypeSpec(InspectableClassModel model) {
	final List<PropertyIdField> propertyIdFields = generatePropertyIdFields(model);

	TypeSpec.Builder builder = TypeSpec
	.classBuilder(generateClassName(model))
	.addModifiers(Modifier.PUBLIC, Modifier.FINAL)
	.addSuperinterface(ParameterizedTypeName.get(
	INSPECTION_COMPANION, model.getClassName()))
	.addJavadoc("Inspection companion for {@link $T}.\n\n", model.getClassName())
	.addJavadoc("Generated by {@link $T}\n", getClass())
	.addJavadoc("on behalf of {@link $T}.\n", mRequestingClass)
	.addField(M_PROPERTIES_MAPPED);

	for (PropertyIdField propertyIdField : propertyIdFields) {
	builder.addField(propertyIdField.mFieldSpec);
	}

	builder.addMethod(generateMapProperties(propertyIdFields))
	.addMethod(generateReadProperties(model, propertyIdFields));

	generateGetNodeName(model).ifPresent(builder::addMethod);

	return builder.build();
	}

	/**
	* Build a list of {@link PropertyIdField}'s for a model.
	*
	* To insure idempotency of the generated code, this method sorts the list of properties
	* alphabetically by name.
	*
	* A {@link NameAllocator} is used to ensure that the field names are valid Java identifiers,
	* and it prevents overlaps in names by suffixing them as needed.
	*
	* @param model The model to get properties from
	* @return A list of properties and fields
	*/
	private List<PropertyIdField> generatePropertyIdFields(InspectableClassModel model) {
	final NameAllocator nameAllocator = new NameAllocator();
	final List<Property> sortedProperties = new ArrayList<>(model.getAllProperties());
	final List<PropertyIdField> propertyIdFields = new ArrayList<>(sortedProperties.size());

	sortedProperties.sort(Comparator.comparing(Property::getName));

	for (Property property : sortedProperties) {
	// Format a property to a member field name like "someProperty" -> "mSomePropertyId"
	final String memberName = String.format(
	"m%s%sId",
	property.getName().substring(0, 1).toUpperCase(),
	property.getName().substring(1));
	final FieldSpec fieldSpec = FieldSpec
	.builder(TypeName.INT, nameAllocator.newName(memberName), Modifier.PRIVATE)
	.addJavadoc("Property ID of {@code $L}.\n", property.getName())
	.build();

	propertyIdFields.add(new PropertyIdField(fieldSpec, property));
	}

	return propertyIdFields;
	}

	/**
	* Generate a method definition for
	* {@link android.view.inspector.InspectionCompanion#getNodeName()}, if needed.
	*
	* If {@link InspectableClassModel#getNodeName()} is empty, This method returns an empty
	* optional, otherwise, it generates a simple method that returns the string value of the
	* node name.
	*
	* @param model The model to generate from
	* @return The method definition or an empty Optional
	*/
	private Optional<MethodSpec> generateGetNodeName(InspectableClassModel model) {
	return model.getNodeName().map(nodeName -> MethodSpec.methodBuilder("getNodeName")
	.addAnnotation(Override.class)
	.addModifiers(Modifier.PUBLIC)
	.returns(String.class)
	.addStatement("return $S", nodeName)
	.build());
	}

	/**
	* Generate a method definition for
	* {@link android.view.inspector.InspectionCompanion#mapProperties(
	* android.view.inspector.PropertyMapper)}.
	*
	* @param propertyIdFields A list of properties to map to ID fields
	* @return The method definition
	*/
	private MethodSpec generateMapProperties(List<PropertyIdField> propertyIdFields) {
	final MethodSpec.Builder builder = MethodSpec.methodBuilder("mapProperties")
	.addAnnotation(Override.class)
	.addModifiers(Modifier.PUBLIC)
	.addParameter(PROPERTY_MAPPER, "propertyMapper");

	propertyIdFields.forEach(p -> builder.addStatement(generatePropertyMapperInvocation(p)));
	builder.addStatement("$N = true", M_PROPERTIES_MAPPED);

	return builder.build();
	}

	/**
	* Generate a method definition for
	* {@link android.view.inspector.InspectionCompanion#readProperties(
	* Object, android.view.inspector.PropertyReader)}.
	*
	* @param model The model to generate from
	* @param propertyIdFields A list of properties and ID fields to read from
	* @return The method definition
	*/
	private MethodSpec generateReadProperties(
	InspectableClassModel model,
	List<PropertyIdField> propertyIdFields) {
	final MethodSpec.Builder builder = MethodSpec.methodBuilder("readProperties")
	.addAnnotation(Override.class)
	.addModifiers(Modifier.PUBLIC)
	.addParameter(model.getClassName(), "node")
	.addParameter(PROPERTY_READER, "propertyReader")
	.addCode(generatePropertyMapInitializationCheck());

	for (PropertyIdField propertyIdField : propertyIdFields) {
	builder.addStatement(
	"propertyReader.read$L($N, node.$L)",
	methodSuffixForPropertyType(propertyIdField.mProperty.getType()),
	propertyIdField.mFieldSpec,
	propertyIdField.mProperty.getAccessor().invocation());
	}

	return builder.build();
	}

	/**
	* Generate a statement maps a property with a {@link android.view.inspector.PropertyMapper}.
	*
	* @param propertyIdField The property model and ID field to generate from
	* @return A statement that invokes property mapper method
	*/
	private CodeBlock generatePropertyMapperInvocation(PropertyIdField propertyIdField) {
	final CodeBlock.Builder builder = CodeBlock.builder();
	final Property property = propertyIdField.mProperty;
	final FieldSpec fieldSpec = propertyIdField.mFieldSpec;

	builder.add(
	"$N = propertyMapper.map$L($S,$W",
	fieldSpec,
	methodSuffixForPropertyType(property.getType()),
	property.getName());

	if (property.isAttributeIdInferrableFromR()) {
	builder.add("$T.attr.$L", R_CLASS_NAME, property.getName());
	} else {
	if (property.getAttributeId() == ID_NULL) {
	builder.add("$L", ID_NULL);
	} else {
	builder.add("$L", hexLiteral(property.getAttributeId()));
	}
	}

	switch (property.getType()) {
	case INT_ENUM:
	builder.add(",$W");
	builder.add(generateIntEnumMappingBuilder(property.getIntEnumEntries()));
	break;
	case INT_FLAG:
	builder.add(",$W");
	builder.add(generateIntFlagMappingBuilder(property.getIntFlagEntries()));
	break;
	}

	return builder.add(")").build();
	}

	/**
	* Generate a check that throws
	* {@link android.view.inspector.InspectionCompanion.UninitializedPropertyMapException}
	* if the properties haven't been initialized.
	*
	* <pre>
	* if (!mPropertiesMapped) {
	* throw new InspectionCompanion.UninitializedPropertyMapException();
	* }
	* </pre>
	*
	* @return A codeblock containing the property map initialization check
	*/
	private CodeBlock generatePropertyMapInitializationCheck() {
	return CodeBlock.builder()
	.beginControlFlow("if (!$N)", M_PROPERTIES_MAPPED)
	.addStatement(
	"throw new $T()",
	INSPECTION_COMPANION.nestedClass("UninitializedPropertyMapException"))
	.endControlFlow()
	.build();
	}

	/**
	* Generate an invocation of {@link android.view.inspector.IntEnumMapping.Builder}.
	*
	* <pre>
	* new IntEnumMapping.Builder()
	* .addValue("ONE", 1)
	* .build()
	* </pre>
	*
	* @return A codeblock containing the an int enum mapping builder
	*/
	private CodeBlock generateIntEnumMappingBuilder(List<IntEnumEntry> intEnumEntries) {
	final ArrayList<IntEnumEntry> sortedEntries = new ArrayList<>(intEnumEntries);
	sortedEntries.sort(Comparator.comparing(IntEnumEntry::getValue));

	final CodeBlock.Builder builder = CodeBlock.builder()
	.add("new $T()$>", INT_ENUM_MAPPING.nestedClass("Builder"));

	for (IntEnumEntry entry : sortedEntries) {
	builder.add("\n.addValue($S, $L)", entry.getName(), entry.getValue());
	}

	return builder.add("\n.build()$<").build();
	}

	private CodeBlock generateIntFlagMappingBuilder(List<IntFlagEntry> intFlagEntries) {
	final ArrayList<IntFlagEntry> sortedEntries = new ArrayList<>(intFlagEntries);
	sortedEntries.sort(Comparator.comparing(IntFlagEntry::getName));

	final CodeBlock.Builder builder = CodeBlock.builder()
	.add("new $T()$>", INT_FLAG_MAPPING.nestedClass("Builder"));

	for (IntFlagEntry entry : sortedEntries) {
	if (entry.hasMask()) {
	builder.add(
	"\n.addFlag($S, $L, $L)",
	entry.getName(),
	hexLiteral(entry.getTarget()),
	hexLiteral(entry.getMask()));
	} else {
	builder.add(
	"\n.addFlag($S, $L)",
	entry.getName(),
	hexLiteral(entry.getTarget()));
	}
	}

	return builder.add("\n.build()$<").build();
	}

	/**
	* Generate the final class name for the inspection companion from the model's class name.
	*
	* The generated class is added to the same package as the source class. If the class in the
	* model is a nested class, the nested class names are joined with {@code "$"}. The suffix
	* {@code "$$InspectionCompanion"} is always added the the generated name. E.g.: For modeled
	* class {@code com.example.Outer.Inner}, the generated class name will be
	* {@code com.example.Outer$Inner$$InspectionCompanion}.
	*
	* @param model The model to generate from
	* @return A class name for the generated inspection companion class
	*/
	private static ClassName generateClassName(InspectableClassModel model) {
	final ClassName className = model.getClassName();

	return ClassName.get(
	className.packageName(),
	String.join("$", className.simpleNames()) + GENERATED_CLASS_SUFFIX);
	}

	/**
	* Get the suffix for a {@code map} or {@code read} method for a property type.
	*
	* @param type The requested property type
	* @return A method suffix
	*/
	private static String methodSuffixForPropertyType(Property.Type type) {
	switch (type) {
	case BOOLEAN:
	return "Boolean";
	case BYTE:
	return "Byte";
	case CHAR:
	return "Char";
	case DOUBLE:
	return "Double";
	case FLOAT:
	return "Float";
	case INT:
	return "Int";
	case LONG:
	return "Long";
	case SHORT:
	return "Short";
	case OBJECT:
	return "Object";
	case COLOR:
	return "Color";
	case GRAVITY:
	return "Gravity";
	case INT_ENUM:
	return "IntEnum";
	case INT_FLAG:
	return "IntFlag";
	case RESOURCE_ID:
	return "ResourceId";
	default:
	throw new NoSuchElementException(String.format("No such property type, %s", type));
	}
	}

	private static String hexLiteral(int value) {
	return String.format("0x%08x", value);
	}

	/**
	* Value class that holds a {@link Property} and a {@link FieldSpec} for that property.
	*/
	private static final class PropertyIdField {
	private final FieldSpec mFieldSpec;
	private final Property mProperty;

	private PropertyIdField(FieldSpec fieldSpec, Property property) {
	mFieldSpec = fieldSpec;
	mProperty = property;
	}
	}
	}