zoomtoscaletask.java

esri的ArcGIS Server超级学习模板程序（for java）

package com.esri.solutions.jitk.web.tasks.navigation.scale;

import com.esri.adf.web.data.WebContext;
import com.esri.adf.web.data.WebMap;
import com.esri.adf.web.data.geometry.GeometryUtil;
import com.esri.adf.web.data.geometry.WebExtent;
import com.esri.adf.web.data.tasks.TaskInfo;
import com.esri.adf.web.faces.event.TaskEvent;

import com.esri.solutions.jitk.web.tasks.RenderControlledTask;

import org.apache.log4j.Logger;

import java.util.Map;


public class ZoomToScaleTask extends RenderControlledTask {
    private static final long serialVersionUID = 652269790014907948L;
    private static Logger _logger = Logger.getLogger(ZoomToScaleTask.class.getName());
    private static final String SCALE_MAP_TASK = "SCALE_MAP_TASK";
    private String _taskName = null;
    private String _mapScaleTxt = "";
    private Map<String, String> _mapScales = null;
    private String _mapScaleSel = "";
    private String _errMessage = "";
    private String footerNote = null;
    private boolean _errOccurred;
    private ZoomToScaleTaskInfo _taskInfo = null;

    public ZoomToScaleTask() {
        super();
        setTaskInfo(new ZoomToScaleTaskInfo(this));
        this._taskName = SCALE_MAP_TASK;
    }

    public TaskInfo getTaskInfo() {
        if (this._context == null) {
            _taskInfo.getTaskDescriptor().setDisabled(true);
        }

        return this._taskInfo;
    }

    public void setTaskInfo(TaskInfo taskInfo) {
        this._taskInfo = (ZoomToScaleTaskInfo) taskInfo;
        super.setTaskInfo(this._taskInfo);
    }

    public String getTaskName() {
        return _taskName;
    }

    public void setTaskName(String taskName) {
        this._taskName = taskName;
    }

    public String getMapScaleTxt() {
        return _mapScaleTxt;
    }

    public void setMapScaleTxt(String mapScaleTxt) {
        this._mapScaleTxt = mapScaleTxt;
    }

    public String getMapScaleSel() {
        return this._mapScaleSel;
    }

    public void setMapScaleSel(String mapScaleSel) {
        this._mapScaleSel = mapScaleSel;
    }

    public void scale(TaskEvent event) {
        try {
            _logger.debug("Scale task invoked");
            requestTaskRender();

            WebContext webContext = event.getWebContext();

            if (getContext() == null) {
                setContext(event.getWebContext());
            }

            //Get WebMap
            WebMap webMap = webContext.getWebMap();

            //Get, expand and set map's extent					
            WebExtent webExtent = webMap.getCurrentExtent();
            WebExtent fullExtent = webMap.getFullExtent();
            double currentMapScale = webMap.getMapScale();
            double mapScale;

            String mapScaleTextVal = getMapScaleTxt();

            if ((mapScaleTextVal == null) || (mapScaleTextVal.length() <= 0)) {
                this.renderResourceMessage(ResourceProps.MSG_MISSING_SCALE);

                return;
            }

            mapScaleTextVal = mapScaleTextVal.replace(",", "");
            mapScale = Double.parseDouble(mapScaleTextVal);

            _logger.info("Scaling map to 1:" + mapScaleTextVal);

            double scaleFactor = mapScale / currentMapScale;

            com.esri.solutions.jitk.web.data.geometry.WebExtent newExtent = new com.esri.solutions.jitk.web.data.geometry.WebExtent(webExtent);
            newExtent.expand(scaleFactor);

            if (GeometryUtil.inside(newExtent, fullExtent)) {
                _logger.debug("Next extent " + newExtent +
                    " within full extent " + fullExtent + ", scaling");

                //Refresh context to update all controls
                webExtent.expand(scaleFactor);
                webContext.refresh();
                webMap.setMapScale(mapScale);
            } else {
                _logger.debug("Next extent " + newExtent +
                    " NOT within full extent " + fullExtent + ", NOT scaling");
                renderResourceMessage(ResourceProps.MSG_SCALEBEYONDFULLEXTENT);
            }
        } catch (Exception ex) {
            renderExceptionMessage(ex);
        }
    }

    public String getErrMessage() {
        return _errMessage;
    }

    public void setErrMessage(String errMessage) {
        this._errMessage = errMessage;
    }

    /**
     * Get footer note
     */
    public String getFooterNote() {
        return this.footerNote;
    }

    /**
     * Set footer note
     */
    public void setFooterNote(String footerNote) {
        this.footerNote = footerNote;
    }

    public boolean isErrOccurred() {
        return _errOccurred;
    }

    public void setErrOccurred(boolean errOccurred) {
        this._errOccurred = errOccurred;
    }

    public Map<String, String> getMapScales() {
        return _mapScales;
    }

    public void setMapScales(Map<String, String> mapScales) {
        this._mapScales = mapScales;
    }
}