/*
* Copyright (c) 2013, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
*
* 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 com.google.dart.engine.internal.element.member;
import com.google.dart.engine.element.Element;
import com.google.dart.engine.element.ElementVisitor;
import com.google.dart.engine.element.FieldElement;
import com.google.dart.engine.element.ParameterElement;
import com.google.dart.engine.element.PropertyAccessorElement;
import com.google.dart.engine.element.PropertyInducingElement;
import com.google.dart.engine.type.FunctionType;
import com.google.dart.engine.type.InterfaceType;
import com.google.dart.engine.type.Type;
/**
* Instances of the class {@code PropertyAccessorMember} represent a property accessor element
* defined in a parameterized type where the values of the type parameters are known.
*/
public class PropertyAccessorMember extends ExecutableMember implements PropertyAccessorElement {
/**
* If the given property accessor's type is different when any type parameters from the defining
* type's declaration are replaced with the actual type arguments from the defining type, create a
* property accessor member representing the given property accessor. Return the member that was
* created, or the base accessor if no member was created.
*
* @param baseAccessor the base property accessor for which a member might be created
* @param definingType the type defining the parameters and arguments to be used in the
* substitution
* @return the property accessor element that will return the correctly substituted types
*/
public static PropertyAccessorElement from(PropertyAccessorElement baseAccessor,
InterfaceType definingType) {
if (!isChangedByTypeSubstitution(baseAccessor, definingType)) {
return baseAccessor;
}
// TODO(brianwilkerson) Consider caching the substituted type in the instance. It would use more
// memory but speed up some operations. We need to see how often the type is being re-computed.
return new PropertyAccessorMember(baseAccessor, definingType);
}
/**
* Determine whether the given property accessor's type is changed when type parameters from the
* defining type's declaration are replaced with the actual type arguments from the defining type.
*
* @param baseAccessor the base property accessor
* @param definingType the type defining the parameters and arguments to be used in the
* substitution
* @return true if the type is changed by type substitution.
*/
private static boolean isChangedByTypeSubstitution(PropertyAccessorElement baseAccessor,
InterfaceType definingType) {
Type[] argumentTypes = definingType.getTypeArguments();
if (baseAccessor != null && argumentTypes.length != 0) {
FunctionType baseType = baseAccessor.getType();
Type[] parameterTypes = definingType.getElement().getType().getTypeArguments();
FunctionType substitutedType = baseType.substitute(argumentTypes, parameterTypes);
if (!baseType.equals(substitutedType)) {
return true;
}
// If this property accessor is based on a field, that field might have a propagated type.
// In which case we need to check whether the propagated type of the field needs substitution.
PropertyInducingElement field = baseAccessor.getVariable();
if (!field.isSynthetic()) {
Type baseFieldType = field.getPropagatedType();
if (baseFieldType != null) {
Type substitutedFieldType = baseFieldType.substitute(argumentTypes, parameterTypes);
if (!baseFieldType.equals(substitutedFieldType)) {
return true;
}
}
}
}
return false;
}
/**
* Initialize a newly created element to represent a property accessor of the given parameterized
* type.
*
* @param baseElement the element on which the parameterized element was created
* @param definingType the type in which the element is defined
*/
public PropertyAccessorMember(PropertyAccessorElement baseElement, InterfaceType definingType) {
super(baseElement, definingType);
}
@Override
public <R> R accept(ElementVisitor<R> visitor) {
return visitor.visitPropertyAccessorElement(this);
}
@Override
public PropertyAccessorElement getBaseElement() {
return (PropertyAccessorElement) super.getBaseElement();
}
@Override
public PropertyAccessorElement getCorrespondingGetter() {
return from(getBaseElement().getCorrespondingGetter(), getDefiningType());
}
@Override
public PropertyAccessorElement getCorrespondingSetter() {
return from(getBaseElement().getCorrespondingSetter(), getDefiningType());
}
@Override
public Element getEnclosingElement() {
return getBaseElement().getEnclosingElement();
}
@Override
public PropertyInducingElement getVariable() {
PropertyInducingElement variable = getBaseElement().getVariable();
if (variable instanceof FieldElement) {
return FieldMember.from(((FieldElement) variable), getDefiningType());
}
return variable;
}
@Override
public boolean isAbstract() {
return getBaseElement().isAbstract();
}
@Override
public boolean isGetter() {
return getBaseElement().isGetter();
}
@Override
public boolean isSetter() {
return getBaseElement().isSetter();
}
@Override
public String toString() {
PropertyAccessorElement baseElement = getBaseElement();
ParameterElement[] parameters = getParameters();
FunctionType type = getType();
StringBuilder builder = new StringBuilder();
if (isGetter()) {
builder.append("get ");
} else {
builder.append("set ");
}
builder.append(baseElement.getEnclosingElement().getDisplayName());
builder.append(".");
builder.append(baseElement.getDisplayName());
builder.append("(");
int parameterCount = parameters.length;
for (int i = 0; i < parameterCount; i++) {
if (i > 0) {
builder.append(", ");
}
builder.append(parameters[i]).toString();
}
builder.append(")");
if (type != null) {
builder.append(Element.RIGHT_ARROW);
builder.append(type.getReturnType());
}
return builder.toString();
}
@Override
protected InterfaceType getDefiningType() {
return (InterfaceType) super.getDefiningType();
}
}