Configure basemap style parameters

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
/* Copyright 2024 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.configurebasemapstyleparameters.components

import android.app.Application
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.setValue
import androidx.lifecycle.AndroidViewModel
import com.arcgismaps.geometry.Point
import com.arcgismaps.mapping.ArcGISMap
import com.arcgismaps.mapping.Basemap
import com.arcgismaps.mapping.BasemapStyle
import com.arcgismaps.mapping.BasemapStyleLanguageStrategy
import com.arcgismaps.mapping.BasemapStyleParameters
import com.arcgismaps.mapping.Viewpoint
import java.util.Locale


class MapViewModel(application: Application) : AndroidViewModel(application) {

    val map = ArcGISMap(BasemapStyle.OsmLightGrayBase).apply {
        //  Focus the viewpoint on an area where the different languages are best showcased:
        //  Bulgaria / Greece / Turkey, as they use three different alphabets: Cyrillic, Greek, and
        //  Latin, respectively.
        initialViewpoint = Viewpoint(
            center = Point(3144804.0, 4904598.0),
            scale = 1e7
        )
    }

    // a list of language strategies options
    val languageStrategyOptions = listOf("Global", "Local")

    // keep track of selected language strategy state
    var languageStrategy by mutableStateOf(languageStrategyOptions[1])
        private set

    // set language strategy and call createNewBasemapStyleParameters
    fun updateLanguageStrategy(strategy: String) {
        languageStrategy = strategy
        createNewBasemapStyleParameters(languageStrategy, specificLanguage)
    }

    // a list of sample language options
    val specificLanguageOptions = listOf("None", "Bulgarian", "Greek", "Turkish")

    // keep track of selected specific language state
    var specificLanguage by mutableStateOf(specificLanguageOptions[0])
        private set

    // set specific language and call createNewBasemapStyleParameters
    fun updateSpecificStrategy(language: String) {
        specificLanguage = language
        createNewBasemapStyleParameters(languageStrategy, specificLanguage)
    }

    init {
        // initialize the app with a local basemap style strategy
        createNewBasemapStyleParameters(languageStrategy, specificLanguage)
    }

    /**
     * Basemap is immutable so we need to create a new one to set new parameters. Uses an
     * OpenStreetMap basemap style, because they support localization.
     */
    private fun createNewBasemapStyleParameters(
        languageStrategy: String,
        specificLanguage: String
    ) {
        val basemapStyleParameters = BasemapStyleParameters().apply {
            // A SpecificLanguage setting overrides the BasemapStyleLanguageStrategy settings when
            // the BasemapStyleParameters.Specific(Locale.forLanguageTag("...") is a non-empty string.
            // Setting the specific language back to an empty string allows the strategy to be used.
            this.languageStrategy = when (specificLanguage) {
                "None" -> {
                    BasemapStyleLanguageStrategy.Specific(Locale.forLanguageTag(""))
                    when (languageStrategy) {
                        // set the language strategy based on the selected radio buttons
                        "Global" -> BasemapStyleLanguageStrategy.Global
                        "Local" -> BasemapStyleLanguageStrategy.Local
                        else -> throw IllegalArgumentException("Invalid language strategy")
                    }
                }
                // set the specific language based on the selected drop down option
                "Bulgarian" -> BasemapStyleLanguageStrategy.Specific(Locale.forLanguageTag("bg"))
                "Greek" -> BasemapStyleLanguageStrategy.Specific(Locale.forLanguageTag("el"))
                "Turkish" -> BasemapStyleLanguageStrategy.Specific(Locale.forLanguageTag("tr"))
                else -> throw IllegalArgumentException("Invalid specific language")
            }
        }
        // set a new basemap with the chosen style parameters
        map.setBasemap(Basemap(BasemapStyle.OsmLightGray, basemapStyleParameters))
    }
}