ZCycleWatchFaceService.java

 @Override
        public void onDraw(Canvas canvas, Rect bounds) {
            /* draw your watch face */
            // Update the time
            mTime.setToNow();

            int width = bounds.width();
            int height = bounds.height();

            // Find the center. Ignore the window insets so that, on round watches
            // with a "chin", the watch face is centered on the entire screen, not
            // just the usable portion.
            float centerX = width / 2f;
            float centerY = height / 2f;
            float circleCenter = centerY + FLAT_TIRE_OFFSET;

            float minsPassed = mTime.minute;
            float hoursPassed = mTime.hour;
            float secsPassed = mTime.second;

            float timePassedForCircle = minsPassed + hoursPassed * 60;
            double rads = 0.87222222292 * timePassedForCircle;

            canvas.drawArc();

            // Compute rotations and lengths for the clock hands.
            float secRot = mTime.second / 30f * (float) Math.PI;
            int minutes = mTime.minute;
            float minRot = minutes / 30f * (float) Math.PI;
            float hrRot = ((mTime.hour + (minutes / 60f)) / 6f ) * (float) Math.PI;

            float secLength = centerX - 20;
            float minLength = centerX - 40;
            float hrLength = centerX - 80;

            // Only draw the second hand in interactive mode.
            /*if (!mAmbient) {
                float secX = (float) Math.sin(secRot) * secLength;
                float secY = (float) -Math.cos(secRot) * secLength;
                canvas.drawLine(centerX, centerY, centerX + secX, centerY +
                        secY, mSecondPaint);
            }*/

            // Draw the minute and hour hands.
            float minX = (float) Math.sin(minRot) * minLength;
            float minY = (float) -Math.cos(minRot) * minLength;
            canvas.drawLine(centerX, centerY, centerX + minX, centerY + minY,
                    mMinutePaint);
            float hrX = (float) Math.sin(hrRot) * hrLength;
            float hrY = (float) -Math.cos(hrRot) * hrLength;
            canvas.drawLine(centerX, centerY, centerX + hrX, centerY + hrY,
                    mHourPaint);
        }