ProtocolLib/src/main/java/com/comphenix/protocol/wrappers/AbstractWrapper.java

package com.comphenix.protocol.wrappers;

import com.google.common.base.Preconditions;

/**
 * Represents a wrapper for an NMS object.
 * @author Kristian
 */
public abstract class AbstractWrapper {
    protected Object handle;
    protected Class<?> handleType;
    
    /**
     * Construct a new NMS wrapper.
     * @param handleType - the NMS handle type.
     */
    public AbstractWrapper(Class<?> handleType) {
        this.handleType = Preconditions.checkNotNull(handleType, "handleType cannot be NULL");
    }

    /**
     * Set the underlying NMS object.
     * @param handle - the NMS object.
     * @throws IllegalArgumentException If the handle is NULL.
     * @throws IllegalArgumentException If the handle is not assignable to {@link #getHandleType()}.
     */
    protected void setHandle(Object handle) {
        if (handle == null)
            throw new IllegalArgumentException("handle cannot be NULL.");
        if (!handleType.isAssignableFrom(handle.getClass()))
            throw new IllegalArgumentException("handle (" + handle + ") is not a " + handleType + ", but " + handle.getClass());
        this.handle = handle;
    }
    
    /**
     * Retrieves the underlying NMS object.
     * @return The underlying NMS object.
     */
    public Object getHandle() {
        return handle;
    }
    
    /**
     * Retrieve the type of the handle.
     * @return The type of the handle.
     */
    public Class<?> getHandleType() {
        return handleType;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == this) return true;

        if (obj instanceof AbstractWrapper) {
            AbstractWrapper that = (AbstractWrapper) obj;
            return this.handle.equals(that.handle);
        }

        return false;
    }

    @Override
    public int hashCode() {
        return handle.hashCode();
    }

    @Override
    public String toString() {
        return getClass().getName() + "[handle=" + handle + "]";
    }
}