app_Settings/src/com/android/settings/accessibility/MagnificationOneFingerPanningPreferenceController.java

/*
 * 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.accessibility;

import static com.android.settings.accessibility.AccessibilityUtil.State.OFF;
import static com.android.settings.accessibility.AccessibilityUtil.State.ON;

import android.content.Context;
import android.content.res.Resources;
import android.database.ContentObserver;
import android.net.Uri;
import android.os.Handler;
import android.os.Looper;
import android.provider.Settings;

import androidx.annotation.Nullable;
import androidx.annotation.VisibleForTesting;
import androidx.preference.Preference;
import androidx.preference.PreferenceScreen;
import androidx.preference.TwoStatePreference;

import com.android.settings.R;
import com.android.settings.accessibility.MagnificationCapabilities.MagnificationMode;
import com.android.settings.core.TogglePreferenceController;
import com.android.settingslib.core.lifecycle.LifecycleObserver;
import com.android.settingslib.core.lifecycle.events.OnPause;
import com.android.settingslib.core.lifecycle.events.OnResume;

public class MagnificationOneFingerPanningPreferenceController
        extends TogglePreferenceController implements LifecycleObserver, OnResume, OnPause {
    static final String PREF_KEY = Settings.Secure.ACCESSIBILITY_SINGLE_FINGER_PANNING_ENABLED;

    private TwoStatePreference mSwitchPreference;

    @VisibleForTesting
    final boolean mDefaultValue;

    @VisibleForTesting
    final ContentObserver mContentObserver = new ContentObserver(
            new Handler(Looper.getMainLooper())) {
        @Override
        public void onChange(boolean selfChange, @Nullable Uri uri) {
            updateState(mSwitchPreference);
        }
    };

    public MagnificationOneFingerPanningPreferenceController(Context context) {
        super(context, PREF_KEY);
        boolean defaultValue;
        try {
            defaultValue = context.getResources().getBoolean(
                    com.android.internal.R.bool.config_enable_a11y_magnification_single_panning);
        } catch (Resources.NotFoundException e) {
            defaultValue = false;
        }
        mDefaultValue = defaultValue;
    }

    @Override
    public void onResume() {
        MagnificationCapabilities.registerObserver(mContext, mContentObserver);
    }

    @Override
    public void onPause() {
        MagnificationCapabilities.unregisterObserver(mContext, mContentObserver);
    }

    @Override
    public int getAvailabilityStatus() {
        return AVAILABLE;
    }

    @Override
    public boolean isChecked() {
        return Settings.Secure.getInt(
                mContext.getContentResolver(),
                PREF_KEY,
                (mDefaultValue) ? ON : OFF) == ON;
    }

    @Override
    public boolean setChecked(boolean isChecked) {
        var toReturn = Settings.Secure.putInt(mContext.getContentResolver(),
                PREF_KEY,
                (isChecked ? ON : OFF));
        refreshSummary(mSwitchPreference);
        return toReturn;
    }

    @Override
    public CharSequence getSummary() {
        if (!mSwitchPreference.isEnabled()) {
            return mContext.getString(
                    R.string.accessibility_magnification_one_finger_panning_summary_unavailable);
        }

        return (isChecked())
                ? mContext.getString(
                        R.string.accessibility_magnification_one_finger_panning_summary_on)
                : mContext.getString(
                        R.string.accessibility_magnification_one_finger_panning_summary_off);
    }

    @Override
    public int getSliceHighlightMenuRes() {
        return R.string.menu_key_accessibility;
    }

    @Override
    public void displayPreference(PreferenceScreen screen) {
        super.displayPreference(screen);
        mSwitchPreference = screen.findPreference(getPreferenceKey());
        updateState(mSwitchPreference);
    }

    @Override
    public void updateState(Preference preference) {
        super.updateState(preference);

        if (preference == null) {
            return;
        }
        @MagnificationMode int mode =
                MagnificationCapabilities.getCapabilities(mContext);
        preference.setEnabled(
                mode == MagnificationMode.FULLSCREEN || mode == MagnificationMode.ALL);
        refreshSummary(preference);
    }
}