MapBox Android版开发 4 国际化功能v11

前言
遇到的问题
国际化功能
- 原文给出的方案(V10版)
- migrate-to-v11
- 适用于V11版的代码
示例
- MapStyle类
- 运行效果图

前言

在前文MapBox地图样式v11中，使用Style的localizeLabels方法本地化地图语言。但Mapbox Standard样式和Mapbox Standard Satellite样式仍显示英文。本文将介绍MapBox国际化功能的使用方法。

遇到的问题

在前文本地化样式时，使用了localizeLabels方法，源码如下：

fun MapboxStyleManager.localizeLabels(locale: Locale, layerIds: List<String>? = null) {
  if (styleURI == "mapbox://styles/mapbox/standard") {
    throw RuntimeException(
      "Mapbox Standard style does not support client-side runtime localization." +
        " Consider using Mapbox internationalization capability instead: https://www.mapbox.com/blog/maps-internationalization-34-languages"
    )
  }
  setMapLanguage(locale, this, layerIds)
}

通过源码可以看出，若尝试切换Mapbox Standard地图语言时，SDK会抛出异常，并给出提示：不支持客户端运行时本地化，考虑使用Mapbox 国际化功能……

Mapbox Standard style does not support client-side runtime localization.

Consider using Mapbox internationalization capability …

那么MapBox推荐的国际化功能是什么？又如何实现Mapbox Standard样式地图语言的切换？从异常给出的链接可以找到答案。

国际化功能

Dynamically Localize Your Maps with Our New Internationalization Capability(2022)，摘取部分原文：

Mapbox Internationalization Makes Localizing Maps Easy.
No more building and maintaining hundreds of styles.
With a more finite number of styles, the map loads dynamically and more quickly based on the users device or browser.
Rendering is dynamic and fast based on preferences in the device or browser, so users do not need to manually select a language display on the map.

原文给出的方案(V10版)

// Create a settings service instance as PERSISTENT, the 
// language set will be persisted across the application lifecycle.
private val settingsService: SettingsServiceInterface by lazy {
    SettingsServiceFactory.getInstance(SettingsServiceStorageType.PERSISTENT)
}

val locale = context.getResources().getConfiguration().locale
// set language in bcp-47 tag
val language = locale.language().toLanguageTag();
settingsService.set(MapboxCommonSettings.LANGUAGE, Value(language))

// set worldview
val worldView = "US"
settingsService.set(MapboxCommonSettings.WORLDVIEW, Value(worldView))

migrate-to-v11

在V11版中SettingsServiceInterface没有定义，参考官网migrate-to-v11中的说明：

The interface SettingsServiceInterface has been removed in favor of class SettingsService. SettingsServiceFactory.getInstance(...) now returns the SettingsService class.

适用于V11版的代码

// Create a settings service instance as PERSISTENT,
// the language set will be persisted across the application lifecycle.
private val settingsService: SettingsService by lazy {
    SettingsServiceFactory.getInstance(SettingsServiceStorageType.PERSISTENT)
}

val locale = context.resources.configuration.locales[0]
// set language in bcp-47 tag
val language = locale.toLanguageTag()
settingsService.set(MapboxCommonSettings.LANGUAGE, Value(language))

// set worldview
val worldView = "CN"
settingsService.set(MapboxCommonSettings.WORLDVIEW, Value(worldView))

// worldview: CN (China), IN (India), JP (Japan), US (United States)

示例

MapStyle类

修改Style的本地化示例代码

package com.example.mapdemo

import android.content.Context
import com.mapbox.bindgen.Value
import com.mapbox.common.MapboxCommonSettings
import com.mapbox.common.SettingsService
import com.mapbox.common.SettingsServiceFactory
import com.mapbox.common.SettingsServiceStorageType
import com.mapbox.maps.MapboxMap
import com.mapbox.maps.Style
import com.mapbox.maps.extension.localization.localizeLabels
import java.util.Locale

class MapStyle(map: MapboxMap) {
    private var map = map

    // Create a settings service instance as PERSISTENT,
    // the language set will be persisted across the application lifecycle.
    private val settingsService: SettingsService by lazy {
        SettingsServiceFactory.getInstance(SettingsServiceStorageType.PERSISTENT)
    }

    fun changeStyle(context: Context, style: String) {
        map.loadStyle(style) {
            if (style != Style.STANDARD && style != Style.STANDARD_SATELLITE) {
                it.localizeLabels(Locale.CHINESE)
            } else {
                val locale = context.resources.configuration.locales[0]
                // set language in bcp-47 tag
                val language = locale.toLanguageTag()
                settingsService.set(MapboxCommonSettings.LANGUAGE, Value(language))

                val worldView = "CN"
                settingsService.set(MapboxCommonSettings.WORLDVIEW, Value(worldView))
            }
        }
    }
}