lib/src/model/typedef.dart

// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:analyzer/dart/element/element.dart';
import 'package:analyzer/dart/element/type.dart';
import 'package:dartdoc/src/element_type.dart';
import 'package:dartdoc/src/model/comment_referable.dart';
import 'package:dartdoc/src/model/model.dart';
import 'package:dartdoc/src/render/typedef_renderer.dart';

abstract class Typedef extends ModelElement
    with TypeParameters, Categorization
    implements EnclosedElement {
  Typedef(TypeAliasElement element, Library library, PackageGraph packageGraph)
      : super(element, library, packageGraph);

  DartType get aliasedType => element.aliasedType;

  @override
  TypeAliasElement get element => super.element;

  ElementType _modelType;
  ElementType get modelType =>
      _modelType ??= modelBuilder.typeFrom(element.aliasedType, library);

  @override
  Library get enclosingElement => library;

  @override
  String get nameWithGenerics => '$name${super.genericParameters}';

  @override
  String get genericParameters => _renderer.renderGenericParameters(this);

  @override
  String get linkedGenericParameters =>
      _renderer.renderLinkedGenericParameters(this);

  @override
  String get filePath => '${library.dirName}/$fileName';

  /// Helper for mustache templates, which can't do casting themselves
  /// without this.
  FunctionTypedef get asCallable => this as FunctionTypedef;

  @override
  String get href {
    if (!identical(canonicalModelElement, this)) {
      return canonicalModelElement?.href;
    }
    assert(canonicalLibrary != null);
    assert(canonicalLibrary == library);
    return '${package.baseHref}$filePath';
  }

  // Food for mustache.
  bool get isInherited => false;

  @override
  String get kind => 'typedef';

  @override
  List<TypeParameter> get typeParameters => element.typeParameters.map((f) {
        return modelBuilder.from(f, library) as TypeParameter;
      }).toList();

  TypedefRenderer get _renderer => packageGraph.rendererFactory.typedefRenderer;

  @override
  Iterable<CommentReferable> get referenceParents => [definingLibrary];

  Map<String, CommentReferable> _referenceChildren;
  @override
  Map<String, CommentReferable> get referenceChildren {
    if (_referenceChildren == null) {
      _referenceChildren = {};
      _referenceChildren
          .addEntriesIfAbsent(typeParameters.explicitOnCollisionWith(this));
    }
    return _referenceChildren;
  }
}

/// A typedef referring to a non-function typedef that is nevertheless not
/// referring to a defined class.  An example is a typedef alias for `void` or
/// for `Function` itself.
class GeneralizedTypedef extends Typedef {
  GeneralizedTypedef(
      TypeAliasElement element, Library library, PackageGraph packageGraph)
      : super(element, library, packageGraph) {
    assert(!isCallable);
  }
}

/// A typedef referring to a non-function, defined type.
class ClassTypedef extends Typedef {
  ClassTypedef(
      TypeAliasElement element, Library library, PackageGraph packageGraph)
      : super(element, library, packageGraph) {
    assert(!isCallable);
    assert(modelType.modelElement is Class);
  }

  @override
  DefinedElementType get modelType => super.modelType;

  @override
  Map<String, CommentReferable> get referenceChildren {
    if (_referenceChildren == null) {
      _referenceChildren = super.referenceChildren;
      _referenceChildren
          .addEntriesIfAbsent(modelType.modelElement.referenceChildren.entries);
    }
    return _referenceChildren;
  }
}

/// A typedef referring to a function type.
class FunctionTypedef extends Typedef {
  FunctionTypedef(
      TypeAliasElement element, Library library, PackageGraph packageGraph)
      : super(element, library, packageGraph) {
    assert(isCallable);
  }

  @override
  Callable get modelType => super.modelType;

  @override
  Map<String, CommentReferable> get referenceChildren {
    if (_referenceChildren == null) {
      _referenceChildren = super.referenceChildren;
      _referenceChildren
          .addEntriesIfAbsent(parameters.explicitOnCollisionWith(this));
    }
    return _referenceChildren;
  }
}