SignalText.java

package com.android.systemui.statusbar.policy;

import java.lang.ref.WeakReference;

import com.android.internal.telephony.PhoneStateIntentReceiver;

import android.R.integer;
import android.content.ContentResolver;
import android.content.Context;
import android.content.res.Resources;
import android.database.ContentObserver;
import android.os.Handler;
import android.os.Message;
import android.provider.Settings;
import android.telephony.PhoneStateListener;
import android.telephony.ServiceState;
import android.telephony.SignalStrength;
import android.telephony.TelephonyManager;
import android.text.Spannable;
import android.text.SpannableStringBuilder;
import android.text.style.CharacterStyle;
import android.text.style.RelativeSizeSpan;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.widget.TextView;

public class SignalText extends TextView {

    private static final String TAG = "SignalText";
    int dBm = 0;
    int ASU = 0;
    private SignalStrength signal;
    private boolean mAttached;
    private boolean mInAirplaneMode;
    private static final int STYLE_HIDE = 0;
    private static final int STYLE_SHOW = 1;
    private static final int STYLE_SHOW_DBM = 2;
    private static final int EVENT_SIGNAL_STRENGTH_CHANGED = 200;
    private int style;
    private Handler mHandler;
    private Context mContext;
    protected int mSignalColor = com.android.internal.R.color.holo_blue_light;
    private PhoneStateIntentReceiver mPhoneStateReceiver;

    private SignalText mSignalText;

    private static class MyHandler extends Handler {
        private WeakReference<SignalText> mSignalText;

        public MyHandler(SignalText activity) {
            mSignalText = new WeakReference<SignalText>(activity);
        }

        @Override
        public void handleMessage(Message msg) {
            SignalText st = mSignalText.get();
            if (st == null) {
                return;
            }
            if (msg.what == EVENT_SIGNAL_STRENGTH_CHANGED) {
                st.updateSignalStrength();
            }
        }
    }

    public SignalText(Context context) {
        this(context, null);
    }

    public SignalText(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public SignalText(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        mContext = context;
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();

        if (!mAttached) {
            mAttached = true;
            mHandler = new MyHandler(this);
            SettingsObserver settingsObserver = new SettingsObserver(mHandler);
            settingsObserver.observe();
            mPhoneStateReceiver = new PhoneStateIntentReceiver(mContext, mHandler);
            mPhoneStateReceiver.notifySignalStrength(EVENT_SIGNAL_STRENGTH_CHANGED);
            mPhoneStateReceiver.registerIntent();
            updateSettings();
        }
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        if (mAttached) {
            mAttached = false;
            mPhoneStateReceiver.unregisterIntent();
        }
    }

    class SettingsObserver extends ContentObserver {
        SettingsObserver(Handler handler) {
            super(handler);
        }

        void observe() {
            ContentResolver resolver = mContext.getContentResolver();
            resolver.registerContentObserver(
                    Settings.System.getUriFor(Settings.System.STATUSBAR_SIGNAL_TEXT), false,
                    this);
            resolver.registerContentObserver(
                    Settings.System.getUriFor(Settings.System.STATUSBAR_SIGNAL_TEXT_COLOR), false,
                    this);
        }

        @Override
        public void onChange(boolean selfChange) {
            updateSettings();
        }
    }

    private void updateSettings() {
        ContentResolver resolver = getContext().getContentResolver();
        mSignalColor = Settings.System.getInt(resolver,
                Settings.System.STATUSBAR_SIGNAL_TEXT_COLOR,
                0xFF33B5E5);
        if (mSignalColor == Integer.MIN_VALUE) {
            // flag to reset the color
            mSignalColor = 0xFF33B5E5;
        }
        setTextColor(mSignalColor);
        updateSignalText();
    }

    public void updateSignalStrength() {
        dBm = mPhoneStateReceiver.getSignalStrengthDbm();

        if (-1 == dBm) dBm = 0;

        ASU = mPhoneStateReceiver.getSignalStrengthLevelAsu();

        if (-1 == ASU) ASU = 0;
        updateSignalText();
    }

    private void updateSignalText() {
        style = Settings.System.getInt(getContext().getContentResolver(),
                Settings.System.STATUSBAR_SIGNAL_TEXT, STYLE_HIDE);

        if (style == STYLE_SHOW) {
            String result = Integer.toString(dBm);

            setText(result + " ");
        } else if (style == STYLE_SHOW_DBM) {
            String result = Integer.toString(dBm) + " dBm ";

            SpannableStringBuilder formatted = new SpannableStringBuilder(result);
            int start = result.indexOf("d");

            CharacterStyle style = new RelativeSizeSpan(0.7f);
            formatted.setSpan(style, start, start + 3, Spannable.SPAN_EXCLUSIVE_INCLUSIVE);

            setText(formatted);
        }
    }
}