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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

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package org.netbeans.html.json.spi;

import java.lang.ref.Reference;

import java.lang.ref.WeakReference;

import net.java.html.BrwsrCtx;

import net.java.html.json.ComputedProperty;

import org.netbeans.html.json.impl.Bindings;

import org.netbeans.html.json.impl.JSON;

import org.netbeans.html.json.impl.PropertyBindingAccessor;

import org.netbeans.html.json.impl.RcvrJSON;

/** Describes a property when one is asked to

 * bind it

 *

 * @author Jaroslav Tulach

 */

public abstract class PropertyBinding {

    PropertyBinding() {

    }

    static {

        new PropertyBindingAccessor() {

            @Override

            protected JSONCall newCall(BrwsrCtx ctx, RcvrJSON callback, String headers, String urlBefore, String urlAfter, String method, Object data) {

                return new JSONCall(ctx, callback, headers, urlBefore, urlAfter, method, data);

            }

            @Override

            protected Bindings bindings(Proto proto, boolean initialize, Object copyFrom) {

                return initialize ? proto.initBindings(copyFrom) : proto.getBindings();

            }

            @Override

            protected void notifyChange(Proto proto, int propIndex) {

                proto.onChange(propIndex);

            }

            @Override

            protected Proto findProto(Proto.Type<?> type, Object object) {

                return type.protoFor(object);

            }

            @Override

            protected <Model> Model cloneTo(Proto.Type<Model> type, Model model, BrwsrCtx c) {

                return type.cloneTo(model, c);

            }

            @Override

            protected Object read(Proto.Type<?> from, BrwsrCtx c, Object data) {

                return from.read(c, data);

            }

            @Override

            protected <M> PropertyBinding newBinding(

                Proto.Type<M> access, Bindings<?> bindings, String name, int index, M model, byte propertyType) {

                return new Impl(model, bindings, name, index, access, propertyType);

            }

        };

    }

    /** Name of the property this binding represents.

     * @return name of the property

     */

    public abstract String getPropertyName();

    /** Changes value of the property. Can be called only on dedicated

     * thread. See {@link Technology#runSafe(java.lang.Runnable)}.

     *

     * @param v new value of the property

     */

    public abstract void setValue(Object v);

    /** Obtains current value of the property this binding represents.

     * Can be called only on dedicated

     * thread. See {@link Technology#runSafe(java.lang.Runnable)}.

     *

     * @return the value or <code>null</code>

     */

    public abstract Object getValue();

    /** Is this property read only?. Or can one call {@link #setValue(java.lang.Object)}?

     * The property can still change, but only as a result of other

     * properties being changed, just like {@link ComputedProperty} can.

     *

     * @return true, if this property is read only

     */

    public abstract boolean isReadOnly();

    /** Is this property constant?. If a property is constant, than its

     * value cannot changed after it is read.

     *

     * @return true, if this property is constant

     * @since 1.3

     */

    public abstract boolean isConstant();

    /** Returns identical version of the binding, but one that holds on the

     * original model object via weak reference.

     *

     * @return binding that uses weak reference

     * @since 1.1

     */

    public abstract PropertyBinding weak();

    private static abstract class AImpl<M> extends PropertyBinding {

        public final String name;

        public final byte propertyType;

        final Proto.Type<M> access;

        final Bindings<?> bindings;

        final int index;

        public AImpl(Bindings<?> bindings, String name, int index, Proto.Type<M> access, byte propertyType) {

            this.bindings = bindings;

            this.name = name;

            this.index = index;

            this.access = access;

            this.propertyType = propertyType;

        }

        protected abstract M model();

        @Override

        public void setValue(Object v) {

            M model = model();

            if (model == null) {

                return;

            }

            access.setValue(model, index, v);

        }

        @Override

        public Object getValue() {

            M model = model();

            if (model == null) {

                return null;

            }

            Object v = access.getValue(model, index);

            Object r = JSON.find(v, bindings);

            return r == null ? v : r;

        }

        @Override

        public boolean isReadOnly() {

            return (propertyType & 1) != 0;

        }

        @Override

        public boolean isConstant() {

            return (propertyType & 2) != 0;

        }

        @Override

        public String getPropertyName() {

            return name;

        }

    } // end of PBData

    private static final class Impl<M> extends AImpl<M> {

        private final M model;

        public Impl(M model, Bindings<?> bindings, String name, int index, Proto.Type<M> access, byte propertyType) {

            super(bindings, name, index, access, propertyType);

            this.model = model;

        }

        @Override

        protected M model() {

            return model;

        }

        @Override

        public PropertyBinding weak() {

            return new Weak(model, bindings, name, index, access, propertyType);

        }

    }

    private static final class Weak<M> extends AImpl<M> {

        private final Reference<M> ref;

        public Weak(M model, Bindings<?> bindings, String name, int index, Proto.Type<M> access, byte propertyType) {

            super(bindings, name, index, access, propertyType);

            this.ref = new WeakReference<M>(model);

        }

        @Override

        protected M model() {

            return ref.get();

        }

        @Override

        public PropertyBinding weak() {

            return this;

        }

    }

}