@Override    public void autoFocus() {        //记录当前聚焦开始时间        mFocusStartTime = System.currentTimeMillis();        //设置Camera的回调聚焦        mCameraDevice.autoFocus(mAutoFocusCallback);        //设置Camera的状态为Focusing        setCameraState(FOCUSING);    }

private void setCameraState(int state) {        mCameraState = state;        switch (state) {            case SNAPSHOT_IN_PROGRESS:            case FOCUSING:                enableCameraControls(false);                break;            case IDLE:            case PREVIEW_STOPPED:                enableCameraControls(true);                break;        }    }

/**     * 设置几个button或者view不可点击     * @param enable     */    private void enableCameraControls(boolean enable) {        if (mIndicatorControlContainer != null) {            mIndicatorControlContainer.setEnabled(enable);        }        if (mModePicker != null) mModePicker.setEnabled(enable);        if (mZoomControl != null) mZoomControl.setEnabled(enable);        if (mThumbnailView != null) mThumbnailView.setEnabled(enable);    }

Override    public void setEnabled(boolean enabled) {        super.setEnabled(enabled);        final int count = getChildCount();        for (int i = 0; i < count; i++) {            View v = getChildAt(i);            // Zoom buttons and shutter button are controlled by the activity.            if (v instanceof AbstractIndicatorButton) {                v.setEnabled(enabled);                // Show or hide the indicator buttons during recording.                if (mCurrentMode == MODE_VIDEO) {                    v.setVisibility(enabled ? View.VISIBLE : View.INVISIBLE);                }            }        }        if (mCameraPicker != null) {            mCameraPicker.setEnabled(enabled);            if (mCurrentMode == MODE_VIDEO) {                mCameraPicker.setVisibility(enabled ? View.VISIBLE : View.INVISIBLE);            }        }    }

private final class AutoFocusCallback            implements android.hardware.Camera.AutoFocusCallback {        public void onAutoFocus(                boolean focused, android.hardware.Camera camera) {            //如果是暂停状态，不聚焦            if (mPausing) return;            //算出当前到聚焦开始的时间差            mAutoFocusTime = System.currentTimeMillis() - mFocusStartTime;            Log.v(TAG, "mAutoFocusTime = " + mAutoFocusTime + "ms");            //设置Camera状态为            setCameraState(IDLE);            //调用FocusManager中的AutoFocus            mFocusManager.onAutoFocus(focused);        }    }

/**     * 聚焦     * @param focused     */    public void onAutoFocus(boolean focused) {        Log.i(TAG, "focus used : " + (System.currentTimeMillis() - focusStart));        //正在进行聚焦，拍照动作必须再聚焦完之后        if (mState == STATE_FOCUSING_SNAP_ON_FINISH) {            // 无论聚焦成功还是失败，都会拍照。如果要进行拍照发声，就无需AF发声了            if (focused) {                //聚焦成功                mState = STATE_SUCCESS;            } else {                //聚焦失败                mState = STATE_FAIL;            }            //更新聚焦框UI&&设置人脸识别UI已经各种状态的设置            updateFocusUI();            //拍照，mState的状态变为STATE_IDLE            capture();        } else if (mState == STATE_FOCUSING) {//如果是聚焦中的状态            //此状态的发生分为两种，half-pressing按压聚焦或者触摸聚焦被触发，这个时候不要发生拍照动作            if (focused) {                //聚焦成功                mState = STATE_SUCCESS;                //在连续聚焦状态不要发声，聚焦回调会在拍照前完成，所有状态一直为STATE_FOCUSING                if (!Parameters.FOCUS_MODE_CONTINUOUS_PICTURE.                        equals(mFocusMode)) {                    mListener.playSound(CameraSound.FOCUS_COMPLETE);                }            } else {                //聚焦失败                mState = STATE_FAIL;            }            //更新聚焦&&人脸UI            updateFocusUI();            // If this is triggered by touch focus, cancel focus after a            // while.            //如果是触摸聚焦，需要延迟一下取消掉聚焦            if (mFocusArea != null) {                mHandler.sendEmptyMessageDelayed(RESET_TOUCH_FOCUS, RESET_TOUCH_FOCUS_DELAY);            }        } else if (mState == STATE_IDLE) {//空闲            // User has released the focus key before focus completes.            // Do nothing.        }    }

private class MainHandler extends Handler {        @Override        public void handleMessage(Message msg) {            switch (msg.what) {                case RESET_TOUCH_FOCUS: {                    //取消掉聚焦                    cancelAutoFocus();                    //开始人脸识别                    mListener.startFaceDetection();                    break;                }            }        }    }

/**     * 再重置tap area之前调用mListener.cancelAutofocus，否则，聚焦模式将一直是自动&tap聚焦，并且驱动也不会重置     */    private void cancelAutoFocus() {        //放置聚焦框到屏幕中间        resetTouchFocus();        mListener.cancelAutoFocus();        if (mFaceView != null) mFaceView.resume();        mState = STATE_IDLE;        updateFocusUI();        mHandler.removeMessages(RESET_TOUCH_FOCUS);    }

/**     * 触摸，，这里会发生触摸聚焦     * @param e     * @return     */    public boolean onTouch(MotionEvent e) {        //没有初始化或者拍照前的聚焦的状态，直接返回        if (!mInitialized || mState == STATE_FOCUSING_SNAP_ON_FINISH) return false;        //让用户可以取消掉之前未消失的触摸聚焦        if ((mFocusArea != null) && (mState == STATE_FOCUSING ||                    mState == STATE_SUCCESS || mState == STATE_FAIL)) {            cancelAutoFocus();        }        // Initialize variables.        int x = Math.round(e.getX());        int y = Math.round(e.getY());        int focusWidth = mFocusIndicatorRotateLayout.getWidth();        int focusHeight = mFocusIndicatorRotateLayout.getHeight();        int previewWidth = mPreviewFrame.getWidth();        int previewHeight = mPreviewFrame.getHeight();        if (mFocusArea == null) {            mFocusArea = new ArrayList<Area>();            mFocusArea.add(new Area(new Rect(), 1));            mMeteringArea = new ArrayList<Area>();            mMeteringArea.add(new Area(new Rect(), 1));        }        //将坐标转换为驱动的格式。AE面积更大,因为曝光会敏感和容易，或者说曝光不足,如果面积太小了。        calculateTapArea(focusWidth, focusHeight, 1f, x, y, previewWidth, previewHeight,                mFocusArea.get(0).rect);        calculateTapArea(focusWidth, focusHeight, 1.5f, x, y, previewWidth, previewHeight,                mMeteringArea.get(0).rect);        // Use margin to set the focus indicator to the touched area.        RelativeLayout.LayoutParams p =                (RelativeLayout.LayoutParams) mFocusIndicatorRotateLayout.getLayoutParams();        int left = Util.clamp(x - focusWidth / 2, 0, previewWidth - focusWidth);        int top = Util.clamp(y - focusHeight / 2, 0, previewHeight - focusHeight);        p.setMargins(left, top, 0, 0);        // Disable "center" rule because we no longer want to put it in the center.        int[] rules = p.getRules();        rules[RelativeLayout.CENTER_IN_PARENT] = 0;        mFocusIndicatorRotateLayout.requestLayout();        //停止人脸识别，因为要进行识别聚焦和测量area        mListener.stopFaceDetection();        //设置聚焦区域&测量区域        mListener.setFocusParameters();        //如果支持触摸聚焦&&手指抬起        if (mFocusAreaSupported && (e.getAction() == MotionEvent.ACTION_UP)) {            autoFocus();        } else {  // Just show the indicator in all other cases.            updateFocusUI();            // Reset the metering area in 3 seconds.            mHandler.removeMessages(RESET_TOUCH_FOCUS);            mHandler.sendEmptyMessageDelayed(RESET_TOUCH_FOCUS, RESET_TOUCH_FOCUS_DELAY);        }        return true;    }

doSnap()：空闲状态可以执行拍照onAutoFocus(boolean focused)：用户再聚焦完成前放掉了聚焦按钮，所以不做任何事。onPreviewStarted()，onPreviewStopped()：状态都变为空闲cancelAutoFocus()：取消聚焦，状态变为空闲updateFocusUI()：如果空闲&有聚焦区域，显示聚焦框框

onShutterUp()：如果是focusmode为自动聚焦，状态为正在聚焦，则取消掉聚焦doSnap()：如果是正在聚焦状态，将状态改为聚焦完拍照状态onAutoFocus(boolean focused)：判断focused，为true变为聚焦成功状态，为false变为聚焦失败状态onTouch(MotionEvent e)：如果正在聚焦&之前有手动聚焦了，则取消掉之前的聚焦autoFocus()：状态变为聚焦状态updateFocusUI()：显示聚焦的框框

onShutterUp()：状态不是聚焦完拍照，可以设置FocusParametersonAutoFocus(boolean focused)：判断focused，为true变为聚焦成功状态，为false变为聚焦失败状态，更新聚焦框UIonTouch(MotionEvent e)：直接不继续操作下去updateFocusUI()：显示聚焦的框框

onShutterDown()：如果是自动聚焦mode，并且不为聚焦成功状态，执行聚焦onShutterUp()： 如果是自动聚焦mode，并且为聚焦成功状态，执行取消聚焦doSnap()：拍照onTouch(MotionEvent e)：让用户可以取消掉之前未消失的触摸聚焦updateFocusUI()：聚焦框框显示成功

onShutterDown()：如果是自动聚焦mode，并且不为聚焦失败状态，执行聚焦onShutterUp()： 如果是自动聚焦mode，并且为聚焦失败状态，执行取消聚焦doSnap()：拍照onTouch(MotionEvent e)：让用户可以取消掉之前未消失的触摸聚焦updateFocusUI()：聚焦框框显示失败