Implement the main switch of notifications on lock screen

    xmlns:settings="http://schemas.android.com/apk/res-auto"

    xmlns:app="http://schemas.android.com/apk/res-auto">

    <com.android.settingslib.widget.MainSwitchPreference

        android:key="lock_screen_notification_global_pref"

        android:title="@string/switch_on_text"

        settings:controller="com.android.settings.notification.LockScreenNotificationsGlobalPreferenceController"/>

</PreferenceScreen>

/*

 * Copyright (C) 2024 The Android Open Source Project

 *

 * 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.android.settings.notification;

import android.content.ContentResolver;

import android.content.Context;

import android.database.ContentObserver;

import android.net.Uri;

import android.os.Handler;

import android.os.Looper;

import android.provider.Settings;

import androidx.annotation.NonNull;

import androidx.annotation.Nullable;

import androidx.lifecycle.Lifecycle;

import androidx.lifecycle.LifecycleEventObserver;

import androidx.lifecycle.LifecycleOwner;

import androidx.preference.Preference;

import androidx.preference.PreferenceScreen;

import com.android.server.notification.Flags;

import com.android.settings.widget.SettingsMainSwitchPreferenceController;

public class LockScreenNotificationsGlobalPreferenceController

        extends SettingsMainSwitchPreferenceController

        implements LifecycleEventObserver {

    public static final int ON = 1;

    public static final int OFF = 0;

    private final ContentResolver mContentResolver;

    private final ContentObserver mContentObserver;

    @Nullable private Preference mPreference;

    public LockScreenNotificationsGlobalPreferenceController(

            @NonNull Context context,

            @NonNull String preferenceKey

    ) {

        super(context, preferenceKey);

        mContentResolver = context.getContentResolver();

        mContentObserver = new ContentObserver(new Handler(Looper.getMainLooper())) {

            @Override

            public void onChange(boolean selfChange, @Nullable Uri uri) {

                if (mPreference == null) return;

                updateState(mPreference);

            }

        };

    }

    @Override

    public void displayPreference(@NonNull PreferenceScreen screen) {

        super.displayPreference(screen);

        mPreference = screen.findPreference(getPreferenceKey());

    }

    @Override

    public void updateState(@NonNull Preference preference) {

        super.updateState(preference);

        setChecked(lockScreenShowNotifications());

    }

    @Override

    public int getAvailabilityStatus() {

        // TODO: b/367455695 - remove this when the feature flag is removed!

        return Flags.notificationLockScreenSettings() ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;

    }

    @Override

    public boolean isChecked() {

        return lockScreenShowNotifications();

    }

    private boolean lockScreenShowNotifications() {

        return Settings.Secure.getInt(mContext.getContentResolver(),

                Settings.Secure.LOCK_SCREEN_SHOW_NOTIFICATIONS, OFF) == ON;

    }

    @Override

    public boolean setChecked(boolean isChecked) {

        return Settings.Secure.putInt(mContext.getContentResolver(),

                Settings.Secure.LOCK_SCREEN_SHOW_NOTIFICATIONS, (isChecked ? ON : OFF));

    }

    @Override

    public int getSliceHighlightMenuRes() {

        // not needed since it's not sliceable

        return NO_RES;

    }

    @Override

    public void onStateChanged(@NonNull LifecycleOwner lifecycleOwner,

            @NonNull Lifecycle.Event event) {

        if (event == Lifecycle.Event.ON_RESUME) {

            mContentResolver.registerContentObserver(

                    Settings.Secure.getUriFor(Settings.Secure.LOCK_SCREEN_SHOW_NOTIFICATIONS),

                    /* notifyForDescendants= */ false,

                    mContentObserver

            );

        } else {

            mContentResolver.unregisterContentObserver(mContentObserver);

        }

    }

}