Clip geometry

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Sample viewer app

Clip a geometry with another geometry.

Image of clip geometry

Use case

Create a new set of geometries for analysis (e.g. displaying buffer zones around abandoned coal mine shafts in an area of planned urban development) by clipping intersecting geometries.

How to use the sample

Tap the "Clip" button to clip the blue graphic with the red dashed envelopes.

How it works

  1. Use the static method GeometryEngine.clip() to generate a clipped Geometry, passing in an existing Geometry and an Envelope as parameters. The existing geometry will be clipped where it intersects an envelope.
  2. Create a new Graphic from the clipped geometry and add it to a GraphicsOverlay on the MapView.

Relevant API

  • Envelope
  • Geometry
  • GeometryEngine.clip
  • Graphic
  • GraphicsOverlay

Additional information

Note: the resulting geometry may be null if the envelope does not intersect the geometry being clipped.

Tags

analysis, clip, geometry

Sample Code

MainActivity.java
                                                                                                                                    
/*
 *  Copyright 2019 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.arcgisruntime.sample.clipgeometry;

import android.graphics.Color;
import android.os.Bundle;
import android.widget.Button;

import androidx.appcompat.app.AppCompatActivity;
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.geometry.Envelope;
import com.esri.arcgisruntime.geometry.Geometry;
import com.esri.arcgisruntime.geometry.GeometryEngine;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.Viewpoint;
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.SimpleFillSymbol;
import com.esri.arcgisruntime.symbology.SimpleLineSymbol;

public class MainActivity extends AppCompatActivity {

  private MapView mMapView;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // authentication with an API key or named user is required to access basemaps and other
    // location services
    ArcGISRuntimeEnvironment.setApiKey(BuildConfig.API_KEY);

    // get a reference to the map view and set a topographic map to it,
    mMapView = findViewById(R.id.mapView);
    ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_TOPOGRAPHIC);
    mMapView.setMap(map);
    mMapView.setViewpoint(new Viewpoint(40, -106, 10000000));

    // create a graphics overlay to contain the geometry to clip
    GraphicsOverlay graphicsOverlay = new GraphicsOverlay();
    mMapView.getGraphicsOverlays().add(graphicsOverlay);

    // create a blue graphic of Colorado
    Envelope colorado = new Envelope(new Point(-11362327.128340, 5012861.290274),
        new Point(-12138232.018408, 4441198.773776));
    SimpleFillSymbol fillSymbol = new SimpleFillSymbol(SimpleFillSymbol.Style.SOLID,
        getColor(R.color.transparentDarkBlue), new SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, Color.BLUE, 2));
    Graphic coloradoGraphic = new Graphic(colorado, fillSymbol);
    graphicsOverlay.getGraphics().add(coloradoGraphic);

    // create a graphics overlay to contain the clipping envelopes
    GraphicsOverlay envelopesOverlay = new GraphicsOverlay();
    mMapView.getGraphicsOverlays().add(envelopesOverlay);

    // create a dotted red outline symbol
    SimpleLineSymbol redOutline = new SimpleLineSymbol(SimpleLineSymbol.Style.DOT, Color.RED, 3);

    // create a envelope outside Colorado
    Envelope outsideEnvelope = new Envelope(new Point(-11858344.321294, 5147942.225174),
        new Point(-12201990.219681, 5297071.577304));
    Graphic outside = new Graphic(outsideEnvelope, redOutline);
    envelopesOverlay.getGraphics().add(outside);

    // create a envelope intersecting Colorado
    Envelope intersectingEnvelope = new Envelope(new Point(-11962086.479298, 4566553.881363),
        new Point(-12260345.183558, 4332053.378376));
    Graphic intersecting = new Graphic(intersectingEnvelope, redOutline);
    envelopesOverlay.getGraphics().add(intersecting);

    // create a envelope inside Colorado
    Envelope containedEnvelope = new Envelope(new Point(-11655182.595204, 4741618.772994),
        new Point(-11431488.567009, 4593570.068343));
    Graphic contained = new Graphic(containedEnvelope, redOutline);
    envelopesOverlay.getGraphics().add(contained);

    // create a graphics overlay to contain the clipped areas
    GraphicsOverlay clipAreasOverlay = new GraphicsOverlay();
    mMapView.getGraphicsOverlays().add(clipAreasOverlay);

    // create a button to perform the clip operation
    Button clipButton = findViewById(R.id.clipButton);
    clipButton.setOnClickListener(v -> {
      // disable button
      clipButton.setEnabled(false);
      // for each envelope, clip the Colorado geometry and show the result, replacing the original Colorado graphic
      coloradoGraphic.setVisible(false);
      for (Graphic graphic : envelopesOverlay.getGraphics()) {
        Geometry geometry = GeometryEngine.clip(coloradoGraphic.getGeometry(), (Envelope) graphic.getGeometry());
        if (geometry != null) {
          Graphic clippedGraphic = new Graphic(geometry, fillSymbol);
          clipAreasOverlay.getGraphics().add(clippedGraphic);
        }
      }
    });
  }

  @Override
  protected void onPause() {
    mMapView.pause();
    super.onPause();
  }

  @Override
  protected void onResume() {
    super.onResume();
    mMapView.resume();
  }

  @Override
  protected void onDestroy() {
    mMapView.dispose();
    super.onDestroy();
  }
}