BluetoothEnabler.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.bluetooth;

import com.android.settings.R;
import com.android.settings.WirelessSettings;

import android.bluetooth.BluetoothAdapter;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.preference.Preference;
import android.preference.CheckBoxPreference;
import android.provider.Settings;
import android.text.TextUtils;
import android.widget.Toast;

/**
 * BluetoothEnabler is a helper to manage the Bluetooth on/off checkbox
 * preference. It is turns on/off Bluetooth and ensures the summary of the
 * preference reflects the current state.
 */
public class BluetoothEnabler implements Preference.OnPreferenceChangeListener {
    private final Context mContext;
    private final CheckBoxPreference mCheckBox;
    private final CharSequence mOriginalSummary;

    private final LocalBluetoothManager mLocalManager;
    private final IntentFilter mIntentFilter;
    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BluetoothAdapter.ERROR);
            handleStateChanged(state);
        }
    };

    public BluetoothEnabler(Context context, CheckBoxPreference checkBox) {
        mContext = context;
        mCheckBox = checkBox;
        mOriginalSummary = checkBox.getSummary();
        checkBox.setPersistent(false);

        mLocalManager = LocalBluetoothManager.getInstance(context);
        if (mLocalManager == null) {
            // Bluetooth is not supported
            checkBox.setEnabled(false);
        }
        mIntentFilter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
    }

    public void resume() {
        if (mLocalManager == null) {
            return;
        }

        // Bluetooth state is not sticky, so set it manually
        handleStateChanged(mLocalManager.getBluetoothState());

        mContext.registerReceiver(mReceiver, mIntentFilter);
        mCheckBox.setOnPreferenceChangeListener(this);
    }

    public void pause() {
        if (mLocalManager == null) {
            return;
        }

        mContext.unregisterReceiver(mReceiver);
        mCheckBox.setOnPreferenceChangeListener(null);
    }

    public boolean onPreferenceChange(Preference preference, Object value) {
        boolean enable = (Boolean) value;

        // Show toast message if Bluetooth is not allowed in airplane mode
        if (enable && !WirelessSettings
                .isRadioAllowed(mContext, Settings.System.RADIO_BLUETOOTH)) {
            Toast.makeText(mContext, R.string.wifi_in_airplane_mode,
                    Toast.LENGTH_SHORT).show();
            return false;
        }

        mLocalManager.setBluetoothEnabled(enable);
        mCheckBox.setEnabled(false);

        // Don't update UI to opposite state until we're sure
        return false;
    }

    private void handleStateChanged(int state) {
        switch (state) {
            case BluetoothAdapter.STATE_TURNING_ON:
                mCheckBox.setSummary(R.string.wifi_starting);
                mCheckBox.setEnabled(false);
                break;
            case BluetoothAdapter.STATE_ON:
                mCheckBox.setChecked(true);
                mCheckBox.setSummary(null);
                mCheckBox.setEnabled(true);
                break;
            case BluetoothAdapter.STATE_TURNING_OFF:
                mCheckBox.setSummary(R.string.wifi_stopping);
                mCheckBox.setEnabled(false);
                break;
            case BluetoothAdapter.STATE_OFF:
                mCheckBox.setChecked(false);
                mCheckBox.setSummary(mOriginalSummary);
                mCheckBox.setEnabled(true);
                break;
            default:
                mCheckBox.setChecked(false);
                mCheckBox.setSummary(R.string.wifi_error);
                mCheckBox.setEnabled(true);
        }
    }
}