use the GeometryEngine to perform the simplify geometry operation on a polygon in esri - Java Geographic Information System

Description

use the GeometryEngine to perform the simplify geometry operation on a polygon in esri

Demo Code

  /*/*from  ww  w  . j  a v  a  2  s  .  c om*/
   * Copyright 2015 Esri.
   * 
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not
   * use this file except in compliance with the License. You may obtain a copy of
   * the License at
   * 
   * http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
   * License for the specific language governing permissions and limitations under
   * the License.
   */

  package com.esri.sampleviewer.samples.geometry;

  import javafx.application.Application;
  import javafx.application.Platform;
  import javafx.geometry.Insets;
  import javafx.geometry.Pos;
  import javafx.scene.Scene;
  import javafx.scene.control.Button;
  import javafx.scene.control.Label;
  import javafx.scene.control.TextArea;
  import javafx.scene.layout.StackPane;
  import javafx.scene.layout.VBox;
  import javafx.stage.Stage;

  import com.esri.arcgisruntime.geometry.Geometry;
  import com.esri.arcgisruntime.geometry.GeometryEngine;
  import com.esri.arcgisruntime.geometry.Part;
  import com.esri.arcgisruntime.geometry.PartCollection;
  import com.esri.arcgisruntime.geometry.Point;
  import com.esri.arcgisruntime.geometry.PointCollection;
  import com.esri.arcgisruntime.geometry.Polygon;
  import com.esri.arcgisruntime.geometry.SpatialReferences;
  import com.esri.arcgisruntime.mapping.Basemap;
  import com.esri.arcgisruntime.mapping.Map;
  import com.esri.arcgisruntime.mapping.view.Graphic;
  import com.esri.arcgisruntime.mapping.view.GraphicsOverlay;
  import com.esri.arcgisruntime.mapping.view.MapView;
  import com.esri.arcgisruntime.symbology.RgbColor;
  import com.esri.arcgisruntime.symbology.SimpleFillSymbol;
  import com.esri.arcgisruntime.symbology.SimpleLineSymbol;

  /**
   * This sample demonstrates how to use the {@link GeometryEngine} to perform the
   * simplify geometry operation on a polygon.
   * <h4>How it Works</h4>
   * 
   * First the {@link Graphic} polygon is created via {@link PointCollection} and
   * {@link PartCollection}. Next, the Simplify Geometry Engine operation is
   * performed and the {@link Geometry} result is displayed.
   * 
   * Note: Simplify geometry operation can also be perform on polylines.
   */
  public class GeometryEngineSimplify extends Application {

      private MapView mapView;
      private GraphicsOverlay geomLayer;
      private GraphicsOverlay resultGeomLayer;
      private Graphic polygon;

      // UI 
      private RgbColor red = new RgbColor(233, 31, 31, 255);
      private RgbColor black = new RgbColor(0, 0, 0, 255);
      private SimpleLineSymbol line = new SimpleLineSymbol(
              SimpleLineSymbol.Style.SOLID, black, 1, 1.0f);

      @Override
public void start(Stage stage) throws Exception {

  // create stack pane and application scene
  StackPane stackPane = new StackPane();
  Scene scene = new Scene(stackPane);
  scene.getStylesheets().add(getClass().getResource(
      "../resources/SamplesTheme.css").toExternalForm());

  // set title, size, and add scene to stage
  stage.setTitle("Geometry Engine Simplify");
  stage.setWidth(800);
  stage.setHeight(700);
  stage.setScene(scene);
  stage.show();

  // create a control panel
  VBox vBoxControl = new VBox(6);
  vBoxControl.setMaxSize(220, 220);
  vBoxControl.getStyleClass().add("panel-region");

  // create sample description
  Label descriptionLabel = new Label("Sample Description:");
  descriptionLabel.getStyleClass().add("panel-label");
  TextArea description = new TextArea(
      "Click the Simplify button to perform the geometry operation on the polygon. Press reset to start again.");
  description.setWrapText(true);
  description.autosize();
  description.setEditable(false);

  // create simplify button
  Button simplifyButton = new Button("Simplify");
  simplifyButton.setMaxWidth(Double.MAX_VALUE);
  simplifyButton.setDisable(true);

  // create reset button
  Button resetButton = new Button("Reset");
  resetButton.setMaxWidth(Double.MAX_VALUE);
  resetButton.setDisable(true);

  // perform the simplify geometry operation
  simplifyButton.setOnAction(e -> {
    Geometry resultPolygon = GeometryEngine.simplify(polygon.getGeometry());

    // update result as a red geometry 
    SimpleFillSymbol redSymbol = new SimpleFillSymbol(red,
        SimpleFillSymbol.Style.SOLID, line, 1.0f);
    resultGeomLayer.getGraphics().add(new Graphic(resultPolygon, redSymbol));

    resetButton.setDisable(false);
    simplifyButton.setDisable(true);
  });

  // clear result layer
  resetButton.setOnAction(e -> {
    resultGeomLayer.getGraphics().clear();
    simplifyButton.setDisable(false);
  });

  // add label, sample description, and buttons to the control panel
  vBoxControl.getChildren().addAll(descriptionLabel, description,
      simplifyButton, resetButton);

  try {

    Map map = new Map(Basemap.createLightGrayCanvas());

    // enable geometry operations when map is done loading
    map.addDoneLoadingListener(() -> {
      simplifyButton.setDisable(false);
    });

    mapView = new MapView();
    mapView.setMap(map);

    // set the map views's viewpoint centred on London and scaled
    Point viewPoint = new Point(-13500, 6710327, SpatialReferences
        .getWebMercator());
    mapView.setViewpointCenterWithScaleAsync(viewPoint, 25000);

    // create geometry layers
    geomLayer = new GraphicsOverlay();
    mapView.getGraphicsOverlays().add(geomLayer);

    resultGeomLayer = new GraphicsOverlay();
    mapView.getGraphicsOverlays().add(resultGeomLayer);

    // create sample polygon
    createPolygon();
    geomLayer.getGraphics().add(polygon);

    // add the map view and control panel to stack pane
    stackPane.getChildren().addAll(mapView, vBoxControl);
    StackPane.setAlignment(vBoxControl, Pos.TOP_LEFT);
    StackPane.setMargin(vBoxControl, new Insets(10, 0, 0, 10));

  } catch (Exception e) {
    // on any error, display the stack trace
    e.printStackTrace();
  }
}

      /**
       * Creates the polygon.
       * 
       */
      private void createPolygon() {

          // part one
          PointCollection partSegmentCollectionOne = new PointCollection(
                  SpatialReferences.getWebMercator());
          partSegmentCollectionOne.add(new Point(-13020, 6710130));
          partSegmentCollectionOne.add(new Point(-14160, 6710130));
          partSegmentCollectionOne.add(new Point(-14160, 6709300));
          partSegmentCollectionOne.add(new Point(-13020, 6709300));
          partSegmentCollectionOne.add(new Point(-13020, 6710130));
          Part partOne = new Part(partSegmentCollectionOne);

          // part two
          PointCollection partSegmentCollectionTwo = new PointCollection(
                  SpatialReferences.getWebMercator());
          partSegmentCollectionTwo.add(new Point(-12160, 6710730));
          partSegmentCollectionTwo.add(new Point(-13160, 6710730));
          partSegmentCollectionTwo.add(new Point(-13160, 6709100));
          partSegmentCollectionTwo.add(new Point(-12160, 6709100));
          partSegmentCollectionTwo.add(new Point(-12160, 6710730));
          Part partTwo = new Part(partSegmentCollectionTwo);

          // part three
          PointCollection partSegmentCollectionThree = new PointCollection(
                  SpatialReferences.getWebMercator());
          partSegmentCollectionThree.add(new Point(-12560, 6710030));
          partSegmentCollectionThree.add(new Point(-13520, 6710030));
          partSegmentCollectionThree.add(new Point(-13520, 6709000));
          partSegmentCollectionThree.add(new Point(-12560, 6709000));
          partSegmentCollectionThree.add(new Point(-12560, 6710030));
          Part partThree = new Part(partSegmentCollectionThree);

          PartCollection polygonParts = new PartCollection(partOne);
          polygonParts.add(partTwo);
          polygonParts.add(partThree);

          SimpleFillSymbol fillSymbol = new SimpleFillSymbol(red,
                  SimpleFillSymbol.Style.SOLID, line, 0.0f);
          polygon = new Graphic(new Polygon(polygonParts), fillSymbol);

      }

      /**
       * Stops and releases all resources used in application.
       *
       * @throws Exception if security manager doesn't allow JVM to exit with
       *           current status
       */
      @Override
      public void stop() throws Exception {

          if (mapView != null) {
              mapView.dispose();
          }
          Platform.exit();
          System.exit(0);
      }

      /**
       * Opens and runs application.
       *
       * @param args arguments passed to this application
       */
      public static void main(String[] args) {

          Application.launch(args);
      }
  }

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