SMapJs.java

package org.swellrt.beta.model.js;

import java.util.ArrayList;

import org.swellrt.beta.model.IllegalCastException;
import org.swellrt.beta.model.SMap;
import org.swellrt.beta.model.SNode;
import org.swellrt.beta.model.SUtils;
import org.waveprotocol.wave.client.common.util.JsoView;

import com.google.gwt.core.client.JavaScriptObject;

public class SMapJs implements SMap {
	
	public interface Func {
		public void apply(String key, Object value);
	}

	private static native boolean isObject(JavaScriptObject jso) /*-{
		return typeof jso == "object";
	}-*/;
	
	private static native boolean isArray(JavaScriptObject jso) /*-{
	    return Array.isArray(jso);
	}-*/;

	private static native boolean isPrimitive(JavaScriptObject jso) /*-{
		
		if (typeof jso == "number" ||
			typeof jso == "boolean" ||
			typeof jso == "string") {
			
			return true;
		
			}
			
		return false;
	
	}-*/;

	private static native void iterateObject(JavaScriptObject jso, Func f) /*-{

	    for (var property in jso) {
	      if (jso.hasOwnProperty(property)) {
	       f.@org.swellrt.beta.model.js.SMapJs.Func::apply(Ljava/lang/String;Ljava/lang/Object;)(property, jso[property]);
	      }
	    }
	
	}-*/;

	private static native void iterateArray(JavaScriptObject jso, Func f) /*-{
	
	    for (var i = 0; i < jso.lenght; i++) {
	      f.@org.swellrt.beta.model.js.SMapJs.Func::apply(Ljava/lang/String;Ljava/lang/Object;)(i+"", jso[i]);
	    }

	}-*/;
	 

	
	

	private static SNode castToSNode(JavaScriptObject object) throws IllegalCastException {
		if (object == null)
			throw new IllegalCastException("Error casting a null javascript object");
		
		if (isPrimitive(object)) {			
			// We assume primite JS values are transparently converted to Java primitives
			return SUtils.castToSNode(object);			
		} else if (isObject(object)) {
			return new SMapJs(object);		
		} else if (isArray(object)) {			
			// TBC
			throw new IllegalCastException("Error casting from javascript to SNode");
		}

		throw new IllegalCastException("Error casting from javascript to SNode");
	}
	
	
	
	
	private static Object castToValue(JavaScriptObject object) throws IllegalCastException {		
		if (object == null)
			throw new IllegalCastException("Error casting a null javascript object");
		
		if (isPrimitive(object)) {			
			return object;
		} else if (isObject(object)) {
			return new SMapJs(object);		
		} else if (isArray(object)) {			
			// TBC
			throw new IllegalCastException("Error casting from javascript to value");
		}
		
		throw new IllegalCastException("Error casting from javascript to value");
	}
	 
	public static SMapJs create(JavaScriptObject jso) throws IllegalCastException {
		if (jso == null || !isObject(jso)) {
			throw new IllegalCastException("JavaScript type is not an object or it is null");
		}		
		return new SMapJs(jso);
		
	}
	
	private final JavaScriptObject jso;
	private final JsoView jsv;
	
	protected SMapJs(JavaScriptObject jso) {
		this.jso = jso;
		this.jsv = JsoView.as(jso);
	}

	@Override
	public Object get(String key) {
		
		if (key == null)
			return null;
		
		try {
			return castToValue(jsv.getJso(key));		
		} catch (IllegalCastException e) {
			return null;
		}
	}

	@Override
	public SNode getNode(String key) {
		
		if (key == null)
			return null;
		
		try {
			return castToSNode(jsv.getJso(key));		
		} catch (IllegalCastException e) {
			return null;
		}
	}

	@Override
	public SMap put(String key, SNode value) {
		throw new IllegalStateException("Wrapped Javascript SNode's can't be mutated");
	}

	@Override
	public SMap put(String key, Object object) throws IllegalCastException {
		throw new IllegalStateException("Wrapped Javascript SNode's can't be mutated");
	}

	@Override
	public void remove(String key) {
		throw new IllegalStateException("Wrapped Javascript SNode's can't be mutated");	
	}

	@Override
	public boolean has(String key) {
		return jsv.containsKey(key);
	}

	@Override
	public String[] keys() {
		
		ArrayList<String> keyList = new ArrayList<String>();
		
		iterateObject(this.jso, new Func() {
			@Override
			public void apply(String key, Object value) {
				keyList.add(key);
			}			
		});
		
		return keyList.toArray(new String[keyList.size()]);
	}

	@Override
	public void clear() {
		throw new IllegalStateException("Wrapped Javascript SNode's can't be mutated");			
	}

	@Override
	public boolean isEmpty() {
		return keys().length == 0;
	}

	@Override
	public int size() {
		return keys().length;
	}

	@Override
	public Object asNative() {
		return jso;
	}
}