clearresultsadapter.java

esri的ArcGIS Server超级学习模板程序（for java）

package com.esri.solutions.jitk.web.tasks.mapcomp;

import java.util.ArrayList;
import java.util.List;

import com.esri.adf.web.data.WebContext;
import com.esri.adf.web.data.query.QueryResult;
import com.esri.adf.web.data.results.ResultNode;
import com.esri.adf.web.data.results.WebResults;
import com.esri.solutions.jitk.web.tasks.IWebContextAware;

/**
 * Clears the Results when a Map Composition is created.  This object
 * will observe the <code>created</code> event that is fired by the
 * Map Composition tasks.  In order to clear the Results, the Graphics will
 * be cleared from the WebQuery, and WebResults object will be cleared.
 */
public class ClearResultsAdapter implements IMapCompositionEventObserver {

	/*
	 * (non-Javadoc)
	 * @see com.esri.solutions.jitk.web.tasks.mapcomp.IMapCompositionEventObserver#created(com.esri.solutions.jitk.web.tasks.mapcomp.MapCompositionEvent)
	 */
	public void created(MapCompositionEvent event) {
		if (event.getSource() instanceof IWebContextAware) {
			IWebContextAware ctxAware = (IWebContextAware) event.getSource();
			WebContext ctx = ctxAware.getContext();
			clearResults(ctx);
		}
	}

	/*
	 * (non-Javadoc)
	 * @see com.esri.solutions.jitk.web.tasks.mapcomp.IMapCompositionEventObserver#deleted(com.esri.solutions.jitk.web.tasks.mapcomp.MapCompositionEvent)
	 */
	public void deleted(MapCompositionEvent event) {
	}

	/*
	 * (non-Javadoc)
	 * @see com.esri.solutions.jitk.web.tasks.mapcomp.IMapCompositionEventObserver#opened(com.esri.solutions.jitk.web.tasks.mapcomp.MapCompositionEvent)
	 */
	public void opened(MapCompositionEvent event) {
	}

	/*
	 * (non-Javadoc)
	 * @see com.esri.solutions.jitk.web.tasks.mapcomp.IMapCompositionEventObserver#saved(com.esri.solutions.jitk.web.tasks.mapcomp.MapCompositionEvent)
	 */
	public void saved(MapCompositionEvent event) {
	}

	/**
	 * Clears the Results within the WebContext.  The Graphics in the
	 * WebQuery are cleared and the WebResults object is cleared.
	 * 
	 * @param ctx	Contains references to WebQuery and WebResults.
	 */
	private void clearResults (WebContext ctx) {
		ctx.getWebQuery().clearGraphics();
		WebResults results = ctx.getWebResults();
		
		if (results == null) {
			return;
		}
		
		List<ResultNode> resultNodes = new ArrayList<ResultNode>(results.getResultNodes());
		
		for (ResultNode node : resultNodes) {
			if (node == null) {
				continue;
			}
			clearResultNode(node);
			results.removeResultNode(node);
		}
	}
	
	/**
	 * Clears the specified Result Node and all of its children,
	 * recursively.  If a Result Node contains a Query Result,
	 * then {@link #clearQueryResult(QueryResult)}
	 * is invoked.
	 * 
	 * @param node	Result Node to clear.
	 */
	private void clearResultNode (ResultNode node) {
		assert(node != null);
		Object result = node.getResult();
		
		if (result instanceof QueryResult) {
			clearQueryResult((QueryResult) result);
		}
		
		for (ResultNode child : node.getChildren()) {
			if (child == null) {
				continue;
			}
			clearResultNode(child);
		}
	}
	
	/**
	 * Clears the specified Query Result.  The Graphics of the
	 * Result will be cleared via {@link QueryResult#clearGraphic()}.
	 * 
	 * @param result Query Result to clear.
	 */
	private void clearQueryResult (QueryResult result) {
		assert(result != null);
		result.clearGraphic();
	}
}