Apply raster rendering rule

/* Copyright 2025 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.arcgismaps.sample.applyrasterrenderingrule

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.runtime.Composable
import com.arcgismaps.ApiKey
import com.arcgismaps.ArcGISEnvironment
import com.esri.arcgismaps.sample.sampleslib.theme.SampleAppTheme
import com.esri.arcgismaps.sample.applyrasterrenderingrule.screens.ApplyRasterRenderingRuleScreen

class MainActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // authentication with an API key or named user is
        // required to access basemaps and other location services
        ArcGISEnvironment.apiKey = ApiKey.create(BuildConfig.ACCESS_TOKEN)

        enableEdgeToEdge()
        setContent {
            SampleAppTheme {
                ApplyRasterRenderingRuleApp()
            }
        }
    }

    @Composable
    private fun ApplyRasterRenderingRuleApp() {
        Surface(color = MaterialTheme.colorScheme.background) {
            ApplyRasterRenderingRuleScreen(
                sampleName = getString(R.string.apply_raster_rendering_rule_app_name)
            )
        }
    }
}

/* Copyright 2025 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.arcgismaps.sample.applyrasterrenderingrule.components

import android.app.Application
import androidx.lifecycle.AndroidViewModel
import androidx.lifecycle.viewModelScope
import com.arcgismaps.mapping.ArcGISMap
import com.arcgismaps.mapping.BasemapStyle
import com.arcgismaps.mapping.Viewpoint
import com.arcgismaps.mapping.layers.RasterLayer
import com.arcgismaps.raster.ImageServiceRaster
import com.arcgismaps.raster.RenderingRule
import com.arcgismaps.toolkit.geoviewcompose.MapViewProxy
import com.esri.arcgismaps.sample.sampleslib.components.MessageDialogViewModel
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.asStateFlow
import kotlinx.coroutines.launch

private const val IMAGE_SERVICE_URL = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/CharlotteLAS/ImageServer"

class ApplyRasterRenderingRuleViewModel(app: Application) : AndroidViewModel(app) {

    val mapViewProxy = MapViewProxy()

    var arcGISMap = ArcGISMap(BasemapStyle.ArcGISStreets)

    // List of raster layers, each with a different rendering rule
    private val rasterLayers: MutableList<RasterLayer> = mutableListOf()

    // List of rendering rule names for the dropdown
    private val _renderingRuleNames = MutableStateFlow<List<String>>(emptyList())
    val renderingRuleNames = _renderingRuleNames.asStateFlow()

    // Currently selected rendering rule name
    private val _selectedRenderingRuleName = MutableStateFlow("")
    val selectedRenderingRuleName = _selectedRenderingRuleName.asStateFlow()

    // Message dialog for error handling
    val messageDialogVM = MessageDialogViewModel()

    init {
        viewModelScope.launch(Dispatchers.IO) {
            createRasterLayers()
        }
    }

    /**
     * Loads the image service raster, gets all rendering rule infos, and creates a raster layer for each rule.
     */
    private suspend fun createRasterLayers() {
        // Create and load the base image service raster
        val imageServiceRaster = ImageServiceRaster(IMAGE_SERVICE_URL)
        imageServiceRaster.load().onFailure {
            messageDialogVM.showMessageDialog(
                title = "Failed to load image service raster",
                description = it.message.toString()
            )
            return
        }
        val serviceInfo = imageServiceRaster.serviceInfo
        // Check availability of rendering rule infos
        val renderingRuleInfos = serviceInfo?.renderingRuleInfos ?: emptyList()
        if (renderingRuleInfos.isEmpty()) {
            messageDialogVM.showMessageDialog("No rendering rules found for this image service.")
            return
        }
        val ruleNames = mutableListOf<String>()
        // 'None' option: no rendering rule
        val baseRaster = ImageServiceRaster(IMAGE_SERVICE_URL)
        val baseLayer = RasterLayer(baseRaster).apply { name = "None" }
        rasterLayers.add(baseLayer)
        // For each rendering rule info, create a new raster layer
        for (ruleInfo in renderingRuleInfos) {
            val raster = ImageServiceRaster(IMAGE_SERVICE_URL)
            raster.renderingRule = RenderingRule(ruleInfo)
            val rasterLayer = RasterLayer(raster).apply { name = ruleInfo.name }
            rasterLayers.add(rasterLayer)
            ruleNames.add(ruleInfo.name)
        }
        // Load all raster layers
        rasterLayers.forEach { layer ->
            layer.load().onFailure {
                messageDialogVM.showMessageDialog(
                    title = "Failed to load raster layer",
                    description = it.message.toString()
                )
            }
        }
        _renderingRuleNames.value = ruleNames
        // Set initial selection to 'None'
        _selectedRenderingRuleName.value = "None"
        // Set the initial layer on the map
        setRasterLayer("None")
    }

    /**
     * Sets the raster layer with the given name as the only operational layer on the map.
     * Zooms to the layer's extent if available.
     */
    fun setRasterLayer(ruleName: String) {
        val rasterLayer = rasterLayers.firstOrNull { it.name == ruleName }
        if (rasterLayer != null) {
            arcGISMap.operationalLayers.clear()
            arcGISMap.operationalLayers.add(rasterLayer)
            _selectedRenderingRuleName.value = ruleName
            // Zoom to the raster layer's extent if available
            viewModelScope.launch {
                rasterLayer.fullExtent?.let { extent ->
                    mapViewProxy.setViewpoint(Viewpoint(extent))
                }
            }
        }
    }
}

/* Copyright 2025 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.arcgismaps.sample.applyrasterrenderingrule.screens

import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.Scaffold
import androidx.compose.runtime.Composable
import androidx.compose.runtime.collectAsState
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import androidx.lifecycle.viewmodel.compose.viewModel
import com.arcgismaps.toolkit.geoviewcompose.MapView
import com.esri.arcgismaps.sample.applyrasterrenderingrule.components.ApplyRasterRenderingRuleViewModel
import com.esri.arcgismaps.sample.sampleslib.components.DropDownMenuBox
import com.esri.arcgismaps.sample.sampleslib.components.MessageDialog
import com.esri.arcgismaps.sample.sampleslib.components.SampleTopAppBar

/**
 * Main screen layout for the sample app
 */
@Composable
fun ApplyRasterRenderingRuleScreen(sampleName: String) {
    val mapViewModel: ApplyRasterRenderingRuleViewModel = viewModel()

    val renderingRuleNames by mapViewModel.renderingRuleNames.collectAsState()
    val selectedRenderingRuleName by mapViewModel.selectedRenderingRuleName.collectAsState()

    // Used to trigger dropdown selection
    var selectedIndex by remember(selectedRenderingRuleName, renderingRuleNames) {
        mutableIntStateOf(renderingRuleNames.indexOf(selectedRenderingRuleName).coerceAtLeast(0))
    }

    Scaffold(
        topBar = { SampleTopAppBar(title = sampleName) },
        content = { padding ->
            Column(
                modifier = Modifier
                    .fillMaxSize()
                    .padding(padding),
            ) {
                MapView(
                    modifier = Modifier
                        .fillMaxSize()
                        .weight(1f),
                    arcGISMap = mapViewModel.arcGISMap,
                    mapViewProxy = mapViewModel.mapViewProxy
                )
                Row(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(16.dp),
                    horizontalArrangement = Arrangement.Center
                ) {
                    if (renderingRuleNames.isNotEmpty()) {
                        DropDownMenuBox(
                            textFieldValue = renderingRuleNames.getOrElse(selectedIndex) { "" },
                            textFieldLabel = "Rendering Rule",
                            dropDownItemList = renderingRuleNames,
                            onIndexSelected = { index ->
                                selectedIndex = index
                                val ruleName = renderingRuleNames.getOrNull(index) ?: return@DropDownMenuBox
                                mapViewModel.setRasterLayer(ruleName)
                            }
                        )
                    }
                }
            }

            mapViewModel.messageDialogVM.apply {
                if (dialogStatus) {
                    MessageDialog(
                        title = messageTitle,
                        description = messageDescription,
                        onDismissRequest = ::dismissDialog
                    )
                }
            }
        }
    )
}