webattributeselection.java

esri的ArcGIS Server超级学习模板程序（for java）

package com.esri.solutions.jitk.web.tasks.query.location;

import java.util.ArrayList;
import java.util.List;
import org.apache.log4j.Logger;
import com.esri.adf.web.data.WebContext;
import com.esri.adf.web.data.WebContextInitialize;
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.adf.web.data.results.WebResultsObserver;

/**
  # Use the WebQuery methods addDisplayGeometry/containsDisplayGeometry/clearGraphic to handle the display of selected features 
  
  # Clear selection should basically call WebQuery.clearGraphics. 
  	There is, however, a complication: I’d like to see the same selection behavior as in ArcMap where 
  	the tabular results and the map share the same selection set. Clearing the map selection should 
  	therefore also clear the (WebResults) selection displayed in the results table and vice versa. This needs 
  	some form of observer/observable patter or eventing mechanism. A WebSelection container paired 
  	with a WebSelectionbObserver interface could be a good idea. 
  	
  # Finally, there should be some interaction between the WebResults and the WebSelection. 
  	In detail, 
  	>> members of WebSelection should always be in WebResults, while the opposite is not necessarily true. <<
  	That implies that if a selected feature is removed from the WebResults, it 
  	should be automatically removed from the WebSelection as well. 
  	
  	This class is tied to WebResults as an observer because it needs to be aware of results added/removed etc actions.

 */

public class WebAttributeSelection implements WebResultsObserver, WebContextInitialize {
	private static final Logger logger = Logger.getLogger(WebAttributeSelection.class);
	
	private List<WebAttributeSelectionObserver> observers = new ArrayList<WebAttributeSelectionObserver>();
	private List<QueryResult> results = new ArrayList<QueryResult>();
	private WebContext webContext;

	//members of WebSelection should always be in WebResults, while the opposite is not necessarily true.
	public void addResults(String groupHeader, List<QueryResult> results) {
		this.results.addAll(results);
		notifyObservers(WebAttributeSelectionObserver.added, null);
		//TODO
		webContext.getWebResults().addResults(groupHeader, results);
	}
	
	public void removeResults(List<QueryResult> results) {
		this.results.retainAll(results);
		notifyObservers(WebAttributeSelectionObserver.removed, null);
	}
	
	public void clearAll() {
		this.results.clear();
		notifyObservers(WebAttributeSelectionObserver.cleared_all, null);		
	}
	
	public void replaceResults() {
		//TODO
	}

	public void notifyObservers(int updateType, Object arbitrary) {
		for(WebAttributeSelectionObserver observer: observers) {
			observer.update(this, updateType, arbitrary);
		}
	}
	
	public void addObserver(WebAttributeSelectionObserver observer) {
		if (!observers.contains(observer))
			observers.add(observer);
	}

	public boolean removeObserver(WebAttributeSelectionObserver observer) {
		return observers.remove(observer);
	}
	
	//TODO
	public void webResultsUpdate(WebResults results, int updateType, ResultNode resultNode, Object arbitrary) {
		switch (updateType) {
		case (WebResultsObserver.ALL_RESULTS_CLEARED): 
			break;
		case (WebResultsObserver.RESULT_ADDED):
			break;
		case (WebResultsObserver.RESULT_MODIFIED):
			break;
		case (WebResultsObserver.RESULT_REMOVED):
			//That implies that if a selected feature is removed from the WebResults, it should be automatically removed from the WebSelection as well. 	
			//TODO remove results contained in the affected ResultNode from WebSelection
			break;
		case(WebResultsObserver.RESULT_REPLACED):
			break;
		default:
			logger.warn("Invalid updateType received: " + updateType);
			break;
		}		
	}
	
	public void destroy() {
	}

	//NOTE: adding this class as an observer to WebResults can also be done declaratively
	public void init(WebContext webContext) {
		this.webContext = webContext;
		this.webContext.getWebResults().addObserver(this);
	}
}