src/com/android/settings/DisplaySettings.java

/*
 * Copyright (C) 2010 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;

import com.android.settings.search.BaseSearchIndexProvider;
import com.android.settings.search.Indexable;

import static android.provider.Settings.System.SCREEN_BRIGHTNESS_MODE;
import static android.provider.Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
import static android.provider.Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL;
import static android.provider.Settings.System.SCREEN_OFF_TIMEOUT;

import android.app.ActivityManagerNative;
import android.app.Dialog;
import android.app.admin.DevicePolicyManager;
import android.content.ContentResolver;
import android.content.Context;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Bundle;
import android.os.Handler;
import android.os.RemoteException;
import android.preference.CheckBoxPreference;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.Preference.OnPreferenceClickListener;
import android.preference.PreferenceScreen;
import android.provider.SearchIndexableResource;
import android.provider.Settings;
import android.util.Log;

import java.util.ArrayList;
import java.util.List;

public class DisplaySettings extends SettingsPreferenceFragment implements
        Preference.OnPreferenceChangeListener, OnPreferenceClickListener, Indexable {
    private static final String TAG = "DisplaySettings";

    /** If there is no setting in the provider, use this. */
    private static final int FALLBACK_SCREEN_TIMEOUT_VALUE = 30000;

    private static final String KEY_SCREEN_TIMEOUT = "screen_timeout";
    private static final String KEY_FONT_SIZE = "font_size";
    private static final String KEY_SCREEN_SAVER = "screensaver";
    private static final String KEY_AUTO_BRIGHTNESS = "auto_brightness";

    private static final int DLG_GLOBAL_CHANGE_WARNING = 1;

    private WarnedListPreference mFontSizePref;

    private final Configuration mCurConfig = new Configuration();
    private final Handler mHandler = new Handler();

    private ListPreference mScreenTimeoutPreference;
    private Preference mScreenSaverPreference;
    private CheckBoxPreference mAutoBrightnessPreference;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        final ContentResolver resolver = getActivity().getContentResolver();

        addPreferencesFromResource(R.xml.display_settings);

        mScreenSaverPreference = findPreference(KEY_SCREEN_SAVER);
        if (mScreenSaverPreference != null
                && getResources().getBoolean(
                        com.android.internal.R.bool.config_dreamsSupported) == false) {
            getPreferenceScreen().removePreference(mScreenSaverPreference);
        }

        mScreenTimeoutPreference = (ListPreference) findPreference(KEY_SCREEN_TIMEOUT);
        final long currentTimeout = Settings.System.getLong(resolver, SCREEN_OFF_TIMEOUT,
                FALLBACK_SCREEN_TIMEOUT_VALUE);
        mScreenTimeoutPreference.setValue(String.valueOf(currentTimeout));
        mScreenTimeoutPreference.setOnPreferenceChangeListener(this);
        disableUnusableTimeouts(mScreenTimeoutPreference);
        updateTimeoutPreferenceDescription(currentTimeout);

        mFontSizePref = (WarnedListPreference) findPreference(KEY_FONT_SIZE);
        mFontSizePref.setOnPreferenceChangeListener(this);
        mFontSizePref.setOnPreferenceClickListener(this);

        if (isAutomaticBrightnessAvailable(getResources())) {
            mAutoBrightnessPreference = (CheckBoxPreference) findPreference(KEY_AUTO_BRIGHTNESS);
            mAutoBrightnessPreference.setOnPreferenceChangeListener(this);
        } else {
            removePreference(KEY_AUTO_BRIGHTNESS);
        }
    }

    private static boolean isAutomaticBrightnessAvailable(Resources res) {
        return res.getBoolean(com.android.internal.R.bool.config_automatic_brightness_available);
    }

    private void updateTimeoutPreferenceDescription(long currentTimeout) {
        ListPreference preference = mScreenTimeoutPreference;
        String summary;
        if (currentTimeout < 0) {
            // Unsupported value
            summary = "";
        } else {
            final CharSequence[] entries = preference.getEntries();
            final CharSequence[] values = preference.getEntryValues();
            if (entries == null || entries.length == 0) {
                summary = "";
            } else {
                int best = 0;
                for (int i = 0; i < values.length; i++) {
                    long timeout = Long.parseLong(values[i].toString());
                    if (currentTimeout >= timeout) {
                        best = i;
                    }
                }
                summary = preference.getContext().getString(R.string.screen_timeout_summary,
                        entries[best]);
            }
        }
        preference.setSummary(summary);
    }

    private void disableUnusableTimeouts(ListPreference screenTimeoutPreference) {
        final DevicePolicyManager dpm =
                (DevicePolicyManager) getActivity().getSystemService(
                Context.DEVICE_POLICY_SERVICE);
        final long maxTimeout = dpm != null ? dpm.getMaximumTimeToLock(null) : 0;
        if (maxTimeout == 0) {
            return; // policy not enforced
        }
        final CharSequence[] entries = screenTimeoutPreference.getEntries();
        final CharSequence[] values = screenTimeoutPreference.getEntryValues();
        ArrayList<CharSequence> revisedEntries = new ArrayList<CharSequence>();
        ArrayList<CharSequence> revisedValues = new ArrayList<CharSequence>();
        for (int i = 0; i < values.length; i++) {
            long timeout = Long.parseLong(values[i].toString());
            if (timeout <= maxTimeout) {
                revisedEntries.add(entries[i]);
                revisedValues.add(values[i]);
            }
        }
        if (revisedEntries.size() != entries.length || revisedValues.size() != values.length) {
            final int userPreference = Integer.parseInt(screenTimeoutPreference.getValue());
            screenTimeoutPreference.setEntries(
                    revisedEntries.toArray(new CharSequence[revisedEntries.size()]));
            screenTimeoutPreference.setEntryValues(
                    revisedValues.toArray(new CharSequence[revisedValues.size()]));
            if (userPreference <= maxTimeout) {
                screenTimeoutPreference.setValue(String.valueOf(userPreference));
            } else if (revisedValues.size() > 0
                    && Long.parseLong(revisedValues.get(revisedValues.size() - 1).toString())
                    == maxTimeout) {
                // If the last one happens to be the same as the max timeout, select that
                screenTimeoutPreference.setValue(String.valueOf(maxTimeout));
            } else {
                // There will be no highlighted selection since nothing in the list matches
                // maxTimeout. The user can still select anything less than maxTimeout.
                // TODO: maybe append maxTimeout to the list and mark selected.
            }
        }
        screenTimeoutPreference.setEnabled(revisedEntries.size() > 0);
    }

    int floatToIndex(float val) {
        String[] indices = getResources().getStringArray(R.array.entryvalues_font_size);
        float lastVal = Float.parseFloat(indices[0]);
        for (int i=1; i<indices.length; i++) {
            float thisVal = Float.parseFloat(indices[i]);
            if (val < (lastVal + (thisVal-lastVal)*.5f)) {
                return i-1;
            }
            lastVal = thisVal;
        }
        return indices.length-1;
    }

    public void readFontSizePreference(ListPreference pref) {
        try {
            mCurConfig.updateFrom(ActivityManagerNative.getDefault().getConfiguration());
        } catch (RemoteException e) {
            Log.w(TAG, "Unable to retrieve font size");
        }

        // mark the appropriate item in the preferences list
        int index = floatToIndex(mCurConfig.fontScale);
        pref.setValueIndex(index);

        // report the current size in the summary text
        final Resources res = getResources();
        String[] fontSizeNames = res.getStringArray(R.array.entries_font_size);
        pref.setSummary(String.format(res.getString(R.string.summary_font_size),
                fontSizeNames[index]));
    }

    @Override
    public void onResume() {
        super.onResume();
        updateState();
    }

    @Override
    public Dialog onCreateDialog(int dialogId) {
        if (dialogId == DLG_GLOBAL_CHANGE_WARNING) {
            return Utils.buildGlobalChangeWarningDialog(getActivity(),
                    R.string.global_font_change_title,
                    new Runnable() {
                        public void run() {
                            mFontSizePref.click();
                        }
                    });
        }
        return null;
    }

    private void updateState() {
        readFontSizePreference(mFontSizePref);
        updateScreenSaverSummary();

        // Update auto brightness if it is available.
        if (mAutoBrightnessPreference != null) {
            int brightnessMode = Settings.System.getInt(getContentResolver(),
                    SCREEN_BRIGHTNESS_MODE, SCREEN_BRIGHTNESS_MODE_MANUAL);
            mAutoBrightnessPreference.setChecked(brightnessMode != SCREEN_BRIGHTNESS_MODE_MANUAL);
        }
    }

    private void updateScreenSaverSummary() {
        if (mScreenSaverPreference != null) {
            mScreenSaverPreference.setSummary(
                    DreamSettings.getSummaryTextWithDreamName(getActivity()));
        }
    }

    public void writeFontSizePreference(Object objValue) {
        try {
            mCurConfig.fontScale = Float.parseFloat(objValue.toString());
            ActivityManagerNative.getDefault().updatePersistentConfiguration(mCurConfig);
        } catch (RemoteException e) {
            Log.w(TAG, "Unable to save font size");
        }
    }

    @Override
    public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
        return super.onPreferenceTreeClick(preferenceScreen, preference);
    }

    @Override
    public boolean onPreferenceChange(Preference preference, Object objValue) {
        final String key = preference.getKey();
        if (KEY_SCREEN_TIMEOUT.equals(key)) {
            try {
                int value = Integer.parseInt((String) objValue);
                Settings.System.putInt(getContentResolver(), SCREEN_OFF_TIMEOUT, value);
                updateTimeoutPreferenceDescription(value);
            } catch (NumberFormatException e) {
                Log.e(TAG, "could not persist screen timeout setting", e);
            }
        }
        if (KEY_FONT_SIZE.equals(key)) {
            writeFontSizePreference(objValue);
        }
        if (preference == mAutoBrightnessPreference) {
            boolean auto = (Boolean) objValue;
            Settings.System.putInt(getContentResolver(), SCREEN_BRIGHTNESS_MODE,
                    auto ? SCREEN_BRIGHTNESS_MODE_AUTOMATIC : SCREEN_BRIGHTNESS_MODE_MANUAL);
        }
        return true;
    }

    @Override
    public boolean onPreferenceClick(Preference preference) {
        if (preference == mFontSizePref) {
            if (Utils.hasMultipleUsers(getActivity())) {
                showDialog(DLG_GLOBAL_CHANGE_WARNING);
                return true;
            } else {
                mFontSizePref.click();
            }
        }
        return false;
    }

    public static final Indexable.SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
            new BaseSearchIndexProvider() {
                @Override
                public List<SearchIndexableResource> getXmlResourcesToIndex(Context context,
                        boolean enabled) {
                    ArrayList<SearchIndexableResource> result = new ArrayList<>(1);

                    SearchIndexableResource sir = new SearchIndexableResource(context);
                    sir.xmlResId = R.xml.display_settings;
                    result.add(sir);

                    return result;
                }

                @Override
                public List<String> getNonIndexableKeys(Context context) {
                    ArrayList<String> nonIndexableKeys = new ArrayList<>(1);
                    if (!isAutomaticBrightnessAvailable(context.getResources())) {
                        nonIndexableKeys.add(KEY_AUTO_BRIGHTNESS);
                    }
                    return nonIndexableKeys;
                }
            };
}