ClockActivity.java

package ganachoco.customclockface;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.SystemClock;
import android.support.wearable.view.WatchViewStub;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.widget.TextView;

public class MyActivity extends Activity {

    private SurfaceView mSurfaceView;
    private Bitmap mHourHand;
    private Bitmap mMinHand;
    private Bitmap mSecHand;

    private android.text.format.Time mTimeFormat = new android.text.format.Time();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);
        final WatchViewStub stub = (WatchViewStub) findViewById(R.id.watch_view_stub);
        stub.setOnLayoutInflatedListener(new WatchViewStub.OnLayoutInflatedListener() {
            @Override
            public void onLayoutInflated(WatchViewStub stub) {
                mSurfaceView = (SurfaceView) stub.findViewById(R.id.canvas);
                updateTime();
            }
        });

        mHourHand = BitmapFactory.decodeResource(getResources(), R.drawable.clock_hour_hand);
        mMinHand = BitmapFactory.decodeResource(getResources(), R.drawable.clock_minute_hand);
        mSecHand = BitmapFactory.decodeResource(getResources(), R.drawable.clock_second_hand);
    }

    private void updateTime() {
        long time = SystemClock.currentThreadTimeMillis();
        float secAngle = (((time / 1000.0f) % 60) * (float)Math.PI * 2 / 60);
        float minAngle = (((time / 1000) % 3600) * (float)Math.PI * 2 / 3600);
        float hourAngle = (((time / 1000) % 43200) * (float)Math.PI * 2 / 43200);

        SurfaceHolder holder = mSurfaceView.getHolder();
        Canvas canvas = holder.lockCanvas();

        Matrix mat = new Matrix();
        Paint paint = new Paint();
        canvas.drawBitmap(mHourHand, mat, paint);

        canvas.drawBitmap(mMinHand, mat, paint);
        canvas.drawBitmap(mSecHand, mat, paint);
        holder.unlockCanvasAndPost(canvas);
    }

    private BroadcastReceiver mTickReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            updateTime();
        }
    };

    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(mTickReceiver, new IntentFilter(Intent.ACTION_TIME_TICK));
    }
    @Override
    protected void onPause()
    {
        unregisterReceiver(mTickReceiver);
        super.onPause();
    }
}