Merge "[PreferenceGraph] Introduce PreferenceScreenProvider" into main

package {

    default_applicable_licenses: ["frameworks_base_license"],

}

filegroup {

    name: "SettingsLibGraph-srcs",

    srcs: ["src/**/*"],

}

android_library {

    name: "SettingsLibGraph",

    defaults: [

        "SettingsLintDefaults",

    ],

    srcs: [":SettingsLibGraph-srcs"],

    static_libs: [

        "androidx.annotation_annotation",

        "androidx.preference_preference",

    ],

    kotlincflags: ["-Xjvm-default=all"],

}

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.android.settingslib.graph">

  <uses-sdk android:minSdkVersion="21" />

</manifest>

package com.android.settingslib.graph

import androidx.annotation.StringRes

import androidx.annotation.XmlRes

import androidx.preference.Preference

import androidx.preference.PreferenceManager

import androidx.preference.PreferenceScreen

/** Manager to create and initialize preference screen. */

class PreferenceScreenManager(private val preferenceManager: PreferenceManager) {

    private val context = preferenceManager.context

    // the map will preserve order

    private val updaters = mutableMapOf<String, PreferenceUpdater>()

    private val screenUpdaters = mutableListOf<PreferenceScreenUpdater>()

    /** Creates an empty [PreferenceScreen]. */

    fun createPreferenceScreen(): PreferenceScreen =

        preferenceManager.createPreferenceScreen(context)

    /** Creates [PreferenceScreen] from resource. */

    fun createPreferenceScreen(@XmlRes xmlRes: Int): PreferenceScreen =

        preferenceManager.inflateFromResource(context, xmlRes, null)

    /** Adds updater for given preference. */

    fun addPreferenceUpdater(@StringRes key: Int, updater: PreferenceUpdater) =

        addPreferenceUpdater(context.getString(key), updater)

    /** Adds updater for given preference. */

    fun addPreferenceUpdater(

        key: String,

        updater: PreferenceUpdater,

    ): PreferenceScreenManager {

        updaters.put(key, updater)?.let { if (it != updater) throw IllegalArgumentException() }

        return this

    }

    /** Adds updater for preference screen. */

    fun addPreferenceScreenUpdater(updater: PreferenceScreenUpdater): PreferenceScreenManager {

        screenUpdaters.add(updater)

        return this

    }

    /** Adds a list of updaters for preference screen. */

    fun addPreferenceScreenUpdater(

        vararg updaters: PreferenceScreenUpdater,

    ): PreferenceScreenManager {

        screenUpdaters.addAll(updaters)

        return this

    }

    /** Updates preference screen with registered updaters. */

    fun updatePreferenceScreen(preferenceScreen: PreferenceScreen) {

        for ((key, updater) in updaters) {

            preferenceScreen.findPreference<Preference>(key)?.let { updater.updatePreference(it) }

        }

        for (updater in screenUpdaters) {

            updater.updatePreferenceScreen(preferenceScreen)

        }

    }

}

/** Updater of [Preference]. */

interface PreferenceUpdater {

    fun updatePreference(preference: Preference)

}

/** Updater of [PreferenceScreen]. */

interface PreferenceScreenUpdater {

    fun updatePreferenceScreen(preferenceScreen: PreferenceScreen)

}

package com.android.settingslib.graph

import android.content.Context

import androidx.preference.PreferenceScreen

/**

 * Interface to provide [PreferenceScreen].

 *

 * It is expected to be implemented by Activity/Fragment and the implementation needs to use

 * [Context] APIs (e.g. `getContext()`, `getActivity()`) with caution: preference screen creation

 * could happen in background service, where the Activity/Fragment lifecycle callbacks (`onCreate`,

 * `onDestroy`, etc.) are not invoked.

 */

interface PreferenceScreenProvider {

    /**

     * Creates [PreferenceScreen].

     *

     * Preference screen creation could happen in background service. The implementation MUST use

     * given [context] instead of APIs like `getContext()`, `getActivity()`, etc.

     */

    fun createPreferenceScreen(

        context: Context,

        preferenceScreenManager: PreferenceScreenManager,

    ): PreferenceScreen?

}