Identify raster cell

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/*
 * Copyright 2020 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.identifyrastercell

import android.graphics.Color
import android.graphics.Point
import android.os.Bundle
import android.view.MotionEvent
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment
import com.esri.arcgisruntime.layers.RasterLayer
import com.esri.arcgisruntime.mapping.ArcGISMap
import com.esri.arcgisruntime.mapping.BasemapStyle
import com.esri.arcgisruntime.mapping.Viewpoint
import com.esri.arcgisruntime.mapping.view.DefaultMapViewOnTouchListener
import com.esri.arcgisruntime.mapping.view.MapView
import com.esri.arcgisruntime.raster.Raster
import com.esri.arcgisruntime.raster.RasterCell
import com.esri.arcgisruntime.sample.identifyrastercell.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

  private var rasterLayer: RasterLayer? = null

  private val activityMainBinding by lazy {
    ActivityMainBinding.inflate(layoutInflater)
  }

  private val mapView: MapView by lazy {
    activityMainBinding.mapView
  }

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(activityMainBinding.root)

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

    // load the raster file
    val rasterFile =
      Raster(getExternalFilesDir(null)?.path + "/SA_EVI_8Day_03May20.tif")

    // create the layer
    rasterLayer = RasterLayer(rasterFile)

    // define a new map
    val rasterMap = ArcGISMap(BasemapStyle.ARCGIS_OCEANS).apply {
      // add the raster layer
      operationalLayers.add(rasterLayer)
    }

    mapView.apply {
      // add the map to the map view
      map = rasterMap
      setViewpoint(Viewpoint( -33.9, 18.6, 1000000.0))

      // set behavior for double touch drag and on single tap gestures
      onTouchListener = object : DefaultMapViewOnTouchListener(this@MainActivity, mapView) {
        override fun onDoubleTouchDrag(e: MotionEvent): Boolean {
          // identify the pixel at the given screen point
          identifyPixel(Point(e.x.toInt(), e.y.toInt()))
          return true
        }

        override fun onSingleTapConfirmed(e: MotionEvent): Boolean {
          // identify the pixel at the given screen point
          identifyPixel(Point(e.x.toInt(), e.y.toInt()))
          return true
        }
      }
    }
  }

  /**
   * Identify the pixel at the given screen point and report raster cell attributes in a callout.
   *
   * @param screenPoint from motion event, for use in identify
   */
  private fun identifyPixel(screenPoint: Point) {
    rasterLayer?.let { rasterLayer ->
      // identify at the tapped screen point
      val identifyResultFuture =
        mapView.identifyLayerAsync(rasterLayer, screenPoint, 1.0, false, 10)

      identifyResultFuture.addDoneListener {
        // get the identify result
        val identifyResult = identifyResultFuture.get()

        // create a string builder
        val stringBuilder = StringBuilder()

        // get the a list of geoelements as raster cells from the identify result
        identifyResult.elements.filterIsInstance<RasterCell>().forEach { cell ->
          // get each attribute for the cell
          cell.attributes.forEach {
            // add the key/value pair to the string builder
            stringBuilder.append(it.key + ": " + it.value)
            stringBuilder.append("\n")
          }

          // format the X & Y coordinate values of the raster cell to a human readable string
          val xyString =
            "X: ${String.format("%.4f", cell.geometry.extent.xMin)} " + "\n" +
                "Y: ${String.format("%.4f", cell.geometry.extent.yMin)}"
          // add the coordinate string to the string builder
          stringBuilder.append(xyString)

          // create a textview for the callout
          val calloutContent = TextView(applicationContext).apply {
            setTextColor(Color.BLACK)
            // format coordinates to 4 decimal places and display lat long read out
            text = stringBuilder.toString()
          }
          // display the callout in the map view
          mapView.callout.apply {
            location = mapView.screenToLocation(screenPoint)
            content = calloutContent
            style.leaderLength = 64
          }.show()
        }
      }
    }
  }

  override fun onPause() {
    mapView.pause()
    super.onPause()
  }

  override fun onResume() {
    super.onResume()
    mapView.resume()
  }

  override fun onDestroy() {
    mapView.dispose()
    super.onDestroy()
  }
}