prebuilts/gradle/WatchFace/Wearable/src/main/java/com/example/android/wearable/watchface/provider/RandomNumberProviderService.java

package com.example.android.wearable.watchface.provider;

import android.support.wearable.complications.ComplicationData;
import android.support.wearable.complications.ComplicationManager;
import android.support.wearable.complications.ComplicationProviderService;
import android.support.wearable.complications.ComplicationText;
import android.util.Log;

import java.util.Locale;

/**
 * Example Watch Face Complication data provider provides a random number on every update.
 */
public class RandomNumberProviderService extends ComplicationProviderService {

    private static final String TAG = "RandomNumberProvider";

    /*
     * Called when a complication has been activated. The method is for any one-time
     * (per complication) set-up.
     *
     * You can continue sending data for the active complicationId until onComplicationDeactivated()
     * is called.
     */
    @Override
    public void onComplicationActivated(
            int complicationId, int dataType, ComplicationManager complicationManager) {
        Log.d(TAG, "onComplicationActivated(): " + complicationId);
        super.onComplicationActivated(complicationId, dataType, complicationManager);
    }

    /*
     * Called when the complication needs updated data from your provider. There are four scenarios
     * when this will happen:
     *
     *   1. An active watch face complication is changed to use this provider
     *   2. A complication using this provider becomes active
     *   3. The period of time you specified in the manifest has elapsed (UPDATE_PERIOD_SECONDS)
     *   4. You triggered an update from your own class via the
     *       ProviderUpdateRequester.requestUpdate() method.
     */
    @Override
    public void onComplicationUpdate(
            int complicationId, int dataType, ComplicationManager complicationManager) {
        Log.d(TAG, "onComplicationUpdate()");


        // Retrieve your data, in this case, we simply create a random number to display.
        int randomNumber = (int) Math.floor(Math.random() * 10);

        String randomNumberText =
                String.format(Locale.getDefault(), "%d!", randomNumber);

        ComplicationData complicationData = null;

        switch (dataType) {
            case ComplicationData.TYPE_RANGED_VALUE:
                complicationData = new ComplicationData.Builder(ComplicationData.TYPE_RANGED_VALUE)
                        .setValue(randomNumber)
                        .setMinValue(0)
                        .setMaxValue(10)
                        .setShortText(ComplicationText.plainText(randomNumberText))
                        .build();
                break;
            case ComplicationData.TYPE_SHORT_TEXT:
                complicationData = new ComplicationData.Builder(ComplicationData.TYPE_SHORT_TEXT)
                        .setShortText(ComplicationText.plainText(randomNumberText))
                        .build();
                break;
            case ComplicationData.TYPE_LONG_TEXT:
                complicationData = new ComplicationData.Builder(ComplicationData.TYPE_LONG_TEXT)
                        .setLongText(
                                ComplicationText.plainText("Random Number: " + randomNumberText))
                        .build();
                break;
            default:
                if (Log.isLoggable(TAG, Log.WARN)) {
                    Log.w(TAG, "Unexpected complication type " + dataType);
                }
        }

        if (complicationData != null) {
            complicationManager.updateComplicationData(complicationId, complicationData);
        }
    }

    /*
     * Called when the complication has been deactivated. If you are updating the complication
     * manager outside of this class with updates, you will want to update your class to stop.
     */
    @Override
    public void onComplicationDeactivated(int complicationId) {
        Log.d(TAG, "onComplicationDeactivated(): " + complicationId);
        super.onComplicationDeactivated(complicationId);
    }
}