cleargraphicsresourcesadapter.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 java.util.Map.Entry;

import com.esri.adf.web.data.GISResource;
import com.esri.adf.web.data.WebContext;
import com.esri.adf.web.data.graphics.GraphicsLayer;
import com.esri.adf.web.data.graphics.GraphicsResource;
import com.esri.solutions.jitk.web.tasks.IWebContextAware;

/**
 * Clears the Graphics on the map when a Map Composition is
 * opened or created.  This object will observe the <code>created</code>
 * and <code>opened</code> events that are fired by the Map
 * Composition tasks.
 */
public class ClearGraphicsResourcesAdapter implements
		IMapCompositionEventObserver {

	/**
	 * ID of the Graphics Resource within the WebContext
	 */
	private String m_resourceId;
	
	/*
	 * (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();
			removeGraphics(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) {
		if (event.getSource() instanceof IWebContextAware) {
			IWebContextAware ctxAware = (IWebContextAware) event.getSource();
			WebContext ctx = ctxAware.getContext();
			removeGraphics(ctx);
		}
	}

	/*
	 * (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) {
	}

	/**
	 * Sets the ID of the Graphics Resource within the Web Context.
	 * The Graphics Resource will be cleared of all graphics when this
	 * object is notified of a <code>created</code> or <code>opened</code>
	 * event.
	 * 
	 * @param resourceId	
	 */
	public void setGraphicsResourceId (String resourceId) {
		m_resourceId = resourceId;
	}
	
	/**
	 * Removes the Graphics from the Web Context.  The Graphics
	 * Resource ID will be used to find the Graphics Resource.  The
	 * Graphics Resource will then be cleared of all Graphics.
	 * 
	 * @param ctx	WebContext object to have its Graphics cleared.
	 */
	protected void removeGraphics (WebContext ctx) {
		
		List<GraphicsResource> graphics = new ArrayList<GraphicsResource>();
		
		if (m_resourceId == null) {
			for (Entry<String, GISResource> entry : ctx.getResources().entrySet()) {
				if (entry.getValue() instanceof GraphicsResource) {
					graphics.add((GraphicsResource) entry.getValue());
				}
			}
		} else {
			GISResource res = ctx.getResourceById(m_resourceId);
			
			if (res instanceof GraphicsResource) {
				graphics.add((GraphicsResource) res);
			}
		}
		
		if (graphics.isEmpty()) {
			return;
		}
		
		for (GraphicsResource graphicsRes : graphics) {
			List<GraphicsLayer> layers = graphicsRes.getLayers(true);
			
			for (GraphicsLayer layer : layers) {
				layer.removeAllGraphicFeatures();
			}
		}
		
		ctx.refresh();
	}
}