android/camera/Camera.java

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.camera;

import com.android.camera.ui.CameraPicker;
import com.android.camera.ui.FaceView;
import com.android.camera.ui.IndicatorControlContainer;
import com.android.camera.ui.RotateImageView;
import com.android.camera.ui.RotateLayout;
import com.android.camera.ui.SharePopup;
import com.android.camera.ui.ZoomControl;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.ContentProviderClient;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences.Editor;
import android.graphics.Bitmap;
import android.hardware.Camera.CameraInfo;
import android.hardware.Camera.Face;
import android.hardware.Camera.FaceDetectionListener;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.Size;
import android.location.Location;
import android.media.CameraProfile;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.os.MessageQueue;
import android.os.SystemClock;
import android.provider.MediaStore;
import android.util.Log;
import android.view.GestureDetector;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MenuItem.OnMenuItemClickListener;
import android.view.MotionEvent;
import android.view.OrientationEventListener;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.WindowManager;
import android.view.animation.AnimationUtils;
import android.widget.TextView;
import android.widget.Toast;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Formatter;
import java.util.List;

/** The Camera activity which can preview and take pictures. */
public class Camera extends ActivityBase implements FocusManager.Listener,
        View.OnTouchListener, ShutterButton.OnShutterButtonListener,
        SurfaceHolder.Callback, ModePicker.OnModeChangeListener,
        FaceDetectionListener, CameraPreference.OnPreferenceChangedListener,
        LocationManager.Listener {

    private static final String TAG = "camera";

    private static final int CROP_MSG = 1;
    private static final int FIRST_TIME_INIT = 2;
    private static final int CLEAR_SCREEN_DELAY = 3;
    private static final int SET_CAMERA_PARAMETERS_WHEN_IDLE = 4;
    private static final int CHECK_DISPLAY_ROTATION = 5;
    private static final int SHOW_TAP_TO_FOCUS_TOAST = 6;
    private static final int DISMISS_TAP_TO_FOCUS_TOAST = 7;

    // The subset of parameters we need to update in setCameraParameters().
    private static final int UPDATE_PARAM_INITIALIZE = 1;
    private static final int UPDATE_PARAM_ZOOM = 2;
    private static final int UPDATE_PARAM_PREFERENCE = 4;
    private static final int UPDATE_PARAM_ALL = -1;

    // When setCameraParametersWhenIdle() is called, we accumulate the subsets
    // needed to be updated in mUpdateSet.
    private int mUpdateSet;

    private static final int SCREEN_DELAY = 2 * 60 * 1000;

    private static final int ZOOM_STOPPED = 0;
    private static final int ZOOM_START = 1;
    private static final int ZOOM_STOPPING = 2;

    private int mZoomState = ZOOM_STOPPED;
    private boolean mSmoothZoomSupported = false;
    private int mZoomValue;  // The current zoom value.
    private int mZoomMax;
    private int mTargetZoomValue;
    private ZoomControl mZoomControl;

    private Parameters mParameters;
    private Parameters mInitialParams;
    private boolean mFocusAreaSupported;
    private boolean mMeteringAreaSupported;

    private MyOrientationEventListener mOrientationListener;
    // The degrees of the device rotated clockwise from its natural orientation.
    private int mOrientation = OrientationEventListener.ORIENTATION_UNKNOWN;
    // The orientation compensation for icons and thumbnails. Ex: if the value
    // is 90, the UI components should be rotated 90 degrees counter-clockwise.
    private int mOrientationCompensation = 0;
    private ComboPreferences mPreferences;

    private static final String sTempCropFilename = "crop-temp";

    private android.hardware.Camera mCameraDevice;
    private ContentProviderClient mMediaProviderClient;
    private SurfaceHolder mSurfaceHolder = null;
    private ShutterButton mShutterButton;
    private GestureDetector mPopupGestureDetector;
    private boolean mOpenCameraFail = false;
    private boolean mCameraDisabled = false;

    private View mPreviewPanel;  // The container of PreviewFrameLayout.
    private PreviewFrameLayout mPreviewFrameLayout;
    private View mPreviewFrame;  // Preview frame area.

    // A popup window that contains a bigger thumbnail and a list of apps to share.
    private SharePopup mSharePopup;
    // The bitmap of the last captured picture thumbnail and the URI of the
    // original picture.
    private Thumbnail mThumbnail;
    // An imageview showing showing the last captured picture thumbnail.
    private RotateImageView mThumbnailView;
    private ModePicker mModePicker;
    private FaceView mFaceView;
    private RotateLayout mFocusIndicator;

    // mCropValue and mSaveUri are used only if isImageCaptureIntent() is true.
    private String mCropValue;
    private Uri mSaveUri;

    // On-screen indicator
    private View mGpsNoSignalIndicator;
    private View mGpsHasSignalIndicator;
    private TextView mExposureIndicator;

    private final StringBuilder mBuilder = new StringBuilder();
    private final Formatter mFormatter = new Formatter(mBuilder);
    private final Object[] mFormatterArgs = new Object[1];

    /**
     * An unpublished intent flag requesting to return as soon as capturing
     * is completed.
     *
     * TODO: consider publishing by moving into MediaStore.
     */
    private final static String EXTRA_QUICK_CAPTURE =
            "android.intent.extra.quickCapture";

    // The display rotation in degrees. This is only valid when mCameraState is
    // not PREVIEW_STOPPED.
    private int mDisplayRotation;
    // The value for android.hardware.Camera.setDisplayOrientation.
    private int mDisplayOrientation;
    private boolean mPausing;
    private boolean mFirstTimeInitialized;
    private boolean mIsImageCaptureIntent;

    private static final int PREVIEW_STOPPED = 0;
    private static final int IDLE = 1;  // preview is active
    // Focus is in progress. The exact focus state is in Focus.java.
    private static final int FOCUSING = 2;
    private static final int SNAPSHOT_IN_PROGRESS = 3;
    private int mCameraState = PREVIEW_STOPPED;

    private ContentResolver mContentResolver;
    private boolean mDidRegister = false;

    private final ArrayList<MenuItem> mGalleryItems = new ArrayList<MenuItem>();

    private LocationManager mLocationManager;

    private final ShutterCallback mShutterCallback = new ShutterCallback();
    private final PostViewPictureCallback mPostViewPictureCallback =
            new PostViewPictureCallback();
    private final RawPictureCallback mRawPictureCallback =
            new RawPictureCallback();
    private final AutoFocusCallback mAutoFocusCallback =
            new AutoFocusCallback();
    private final ZoomListener mZoomListener = new ZoomListener();
    private final CameraErrorCallback mErrorCallback = new CameraErrorCallback();

    private long mFocusStartTime;
    private long mCaptureStartTime;
    private long mShutterCallbackTime;
    private long mPostViewPictureCallbackTime;
    private long mRawPictureCallbackTime;
    private long mJpegPictureCallbackTime;
    private long mOnResumeTime;
    private long mPicturesRemaining;
    private byte[] mJpegImageData;

    // These latency time are for the CameraLatency test.
    public long mAutoFocusTime;
    public long mShutterLag;
    public long mShutterToPictureDisplayedTime;
    public long mPictureDisplayedToJpegCallbackTime;
    public long mJpegCallbackFinishTime;

    // This handles everything about focus.
    private FocusManager mFocusManager;
    private String mSceneMode;
    private Toast mNotSelectableToast;
    private Toast mNoShareToast;

    private final Handler mHandler = new MainHandler();
    private IndicatorControlContainer mIndicatorControlContainer;
    private PreferenceGroup mPreferenceGroup;

    // multiple cameras support
    private int mNumberOfCameras;
    private int mCameraId;
    private int mFrontCameraId;
    private int mBackCameraId;

    private boolean mQuickCapture;

    /**
     * This Handler is used to post message back onto the main thread of the
     * application
     */
    private class MainHandler extends Handler {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case CLEAR_SCREEN_DELAY: {
                    getWindow().clearFlags(
                            WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
                    break;
                }

                case FIRST_TIME_INIT: {
                    initializeFirstTime();
                    break;
                }

                case SET_CAMERA_PARAMETERS_WHEN_IDLE: {
                    setCameraParametersWhenIdle(0);
                    break;
                }

                case CHECK_DISPLAY_ROTATION: {
                    // Restart the preview if display rotation has changed.
                    // Sometimes this happens when the device is held upside
                    // down and camera app is opened. Rotation animation will
                    // take some time and the rotation value we have got may be
                    // wrong. Framework does not have a callback for this now.
                    if (Util.getDisplayRotation(Camera.this) != mDisplayRotation
                            && isCameraIdle()) {
                        startPreview();
                    }
                    if (SystemClock.uptimeMillis() - mOnResumeTime < 5000) {
                        mHandler.sendEmptyMessageDelayed(CHECK_DISPLAY_ROTATION, 100);
                    }
                    break;
                }

                case SHOW_TAP_TO_FOCUS_TOAST: {
                    showTapToFocusToast();
                    break;
                }

                case DISMISS_TAP_TO_FOCUS_TOAST: {
                    View v = findViewById(R.id.tap_to_focus_prompt);
                    v.setVisibility(View.GONE);
                    v.setAnimation(AnimationUtils.loadAnimation(Camera.this,
                            R.anim.on_screen_hint_exit));
                    break;
                }
            }
        }
    }

    private void resetExposureCompensation() {
        String value = mPreferences.getString(CameraSettings.KEY_EXPOSURE,
                CameraSettings.EXPOSURE_DEFAULT_VALUE);
        if (!CameraSettings.EXPOSURE_DEFAULT_VALUE.equals(value)) {
            Editor editor = mPreferences.edit();
            editor.putString(CameraSettings.KEY_EXPOSURE, "0");
            editor.apply();
            if (mIndicatorControlContainer != null) {
                mIndicatorControlContainer.reloadPreferences();
            }
        }
    }

    private void keepMediaProviderInstance() {
        // We want to keep a reference to MediaProvider in camera's lifecycle.
        // TODO: Utilize mMediaProviderClient instance to replace
        // ContentResolver calls.
        if (mMediaProviderClient == null) {
            mMediaProviderClient = getContentResolver()
                    .acquireContentProviderClient(MediaStore.AUTHORITY);
        }
    }

    // Snapshots can only be taken after this is called. It should be called
    // once only. We could have done these things in onCreate() but we want to
    // make preview screen appear as soon as possible.
    private void initializeFirstTime() {
        if (mFirstTimeInitialized) return;

        // Create orientation listenter. This should be done first because it
        // takes some time to get first orientation.
        mOrientationListener = new MyOrientationEventListener(Camera.this);
        mOrientationListener.enable();

        // Initialize location sevice.
        boolean recordLocation = RecordLocationPreference.get(
                mPreferences, getContentResolver());
        initOnScreenIndicator();
        mLocationManager.recordLocation(recordLocation);

        keepMediaProviderInstance();
        checkStorage();

        // Initialize last picture button.
        mContentResolver = getContentResolver();
        if (!mIsImageCaptureIntent) {  // no thumbnail in image capture intent
            initThumbnailButton();
        }

        // Initialize shutter button.
        mShutterButton = (ShutterButton) findViewById(R.id.shutter_button);
        mShutterButton.setOnShutterButtonListener(this);
        mShutterButton.setVisibility(View.VISIBLE);

        // Initialize focus UI.
        mPreviewFrame = findViewById(R.id.camera_preview);
        mPreviewFrame.setOnTouchListener(this);
        mFocusIndicator = (RotateLayout) findViewById(R.id.focus_indicator_rotate_layout);
        mFocusManager.initialize(mFocusIndicator, mPreviewFrame, mFaceView, this);
        mFocusManager.initializeToneGenerator();
        Util.initializeScreenBrightness(getWindow(), getContentResolver());
        installIntentFilter();
        initializeZoom();
        // Show the tap to focus toast if this is the first start.
        if (mFocusAreaSupported &&
                mPreferences.getBoolean(CameraSettings.KEY_TAP_TO_FOCUS_PROMPT_SHOWN, true)) {
            // Delay the toast for one second to wait for orientation.
            mHandler.sendEmptyMessageDelayed(SHOW_TAP_TO_FOCUS_TOAST, 1000);
        }

        mFirstTimeInitialized = true;
        addIdleHandler();
    }

    private void addIdleHandler() {
        MessageQueue queue = Looper.myQueue();
        queue.addIdleHandler(new MessageQueue.IdleHandler() {
            public boolean queueIdle() {
                Storage.ensureOSXCompatible();
                return false;
            }
        });
    }

    private void initThumbnailButton() {
        // Load the thumbnail from the disk.
        mThumbnail = Thumbnail.loadFrom(new File(getFilesDir(), Thumbnail.LAST_THUMB_FILENAME));
        updateThumbnailButton();
    }

    private void updateThumbnailButton() {
        // Update last image if URI is invalid and the storage is ready.
        if ((mThumbnail == null || !Util.isUriValid(mThumbnail.getUri(), mContentResolver))
                && mPicturesRemaining >= 0) {
            mThumbnail = Thumbnail.getLastThumbnail(mContentResolver);
        }
        if (mThumbnail != null) {
            mThumbnailView.setBitmap(mThumbnail.getBitmap());
        } else {
            mThumbnailView.setBitmap(null);
        }
    }

    // If the activity is paused and resumed, this method will be called in
    // onResume.
    private void initializeSecondTime() {
        // Start orientation listener as soon as possible because it takes
        // some time to get first orientation.
        mOrientationListener.enable();

        // Start location update if needed.
        boolean recordLocation = RecordLocationPreference.get(
                mPreferences, getContentResolver());
        mLocationManager.recordLocation(recordLocation);

        installIntentFilter();
        mFocusManager.initializeToneGenerator();
        initializeZoom();
        keepMediaProviderInstance();
        checkStorage();
        hidePostCaptureAlert();

        if (!mIsImageCaptureIntent) {
            updateThumbnailButton();
            mModePicker.setCurrentMode(ModePicker.MODE_CAMERA);
        }
    }

    private class ZoomChangeListener implements ZoomControl.OnZoomChangedListener {
        // only for immediate zoom
        @Override
        public void onZoomValueChanged(int index) {
            Camera.this.onZoomValueChanged(index);
        }

        // only for smooth zoom
        @Override
        public void onZoomStateChanged(int state) {
            if (mPausing) return;

            Log.v(TAG, "zoom picker state=" + state);
            if (state == ZoomControl.ZOOM_IN) {
                Camera.this.onZoomValueChanged(mZoomMax);
            } else if (state == ZoomControl.ZOOM_OUT) {
                Camera.this.onZoomValueChanged(0);
            } else {
                mTargetZoomValue = -1;
                if (mZoomState == ZOOM_START) {
                    mZoomState = ZOOM_STOPPING;
                    mCameraDevice.stopSmoothZoom();
                }
            }
        }
    }

    private void initializeZoom() {
        if (!mParameters.isZoomSupported()) return;
        mZoomMax = mParameters.getMaxZoom();
        // Currently we use immediate zoom for fast zooming to get better UX and
        // there is no plan to take advantage of the smooth zoom.
        mZoomControl.setZoomMax(mZoomMax);
        mZoomControl.setZoomIndex(mParameters.getZoom());
        mZoomControl.setSmoothZoomSupported(mSmoothZoomSupported);
        mZoomControl.setOnZoomChangeListener(new ZoomChangeListener());
        mCameraDevice.setZoomChangeListener(mZoomListener);
    }

    private void onZoomValueChanged(int index) {
        // Not useful to change zoom value when the activity is paused.
        if (mPausing) return;

        if (mSmoothZoomSupported) {
            if (mTargetZoomValue != index && mZoomState != ZOOM_STOPPED) {
                mTargetZoomValue = index;
                if (mZoomState == ZOOM_START) {
                    mZoomState = ZOOM_STOPPING;
                    mCameraDevice.stopSmoothZoom();
                }
            } else if (mZoomState == ZOOM_STOPPED && mZoomValue != index) {
                mTargetZoomValue = index;
                mCameraDevice.startSmoothZoom(index);
                mZoomState = ZOOM_START;
            }
        } else {
            mZoomValue = index;
            setCameraParametersWhenIdle(UPDATE_PARAM_ZOOM);
        }
    }

    @Override
    public void startFaceDetection() {
        if (mParameters.getMaxNumDetectedFaces() > 0) {
            mFaceView = (FaceView) findViewById(R.id.face_view);
            mFaceView.clear();
            mFaceView.setVisibility(View.VISIBLE);
            mFaceView.setDisplayOrientation(mDisplayOrientation);
            CameraInfo info = CameraHolder.instance().getCameraInfo()[mCameraId];
            mFaceView.setMirror(info.facing == CameraInfo.CAMERA_FACING_FRONT);
            mFaceView.resume();
            mCameraDevice.setFaceDetectionListener(this);
            mCameraDevice.startFaceDetection();
        }
    }

    @Override
    public void stopFaceDetection() {
        if (mParameters.getMaxNumDetectedFaces() > 0) {
            mCameraDevice.setFaceDetectionListener(null);
            mCameraDevice.stopFaceDetection();
            if (mFaceView != null) mFaceView.clear();
        }
    }

    private class PopupGestureListener
            extends GestureDetector.SimpleOnGestureListener {
        @Override
        public boolean onDown(MotionEvent e) {
            // Check if the popup window is visible.
            View popup = mIndicatorControlContainer.getActiveSettingPopup();
            if (popup == null) return false;


            // Let popup window, indicator control or preview frame handle the
            // event by themselves. Dismiss the popup window if users touch on
            // other areas.
            if (!Util.pointInView(e.getX(), e.getY(), popup)
                    && !Util.pointInView(e.getX(), e.getY(), mIndicatorControlContainer)
                    && !Util.pointInView(e.getX(), e.getY(), mPreviewFrame)) {
                mIndicatorControlContainer.dismissSettingPopup();
                // Let event fall through.
            }
            return false;
        }
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent m) {
        // Check if the popup window should be dismissed first.
        if (mPopupGestureDetector != null && mPopupGestureDetector.onTouchEvent(m)) {
            return true;
        }

        return super.dispatchTouchEvent(m);
    }

    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Log.d(TAG, "Received intent action=" + action);
            if (action.equals(Intent.ACTION_MEDIA_MOUNTED)
                    || action.equals(Intent.ACTION_MEDIA_UNMOUNTED)
                    || action.equals(Intent.ACTION_MEDIA_CHECKING)) {
                checkStorage();
            } else if (action.equals(Intent.ACTION_MEDIA_SCANNER_FINISHED)) {
                checkStorage();
                if (!mIsImageCaptureIntent) {
                    updateThumbnailButton();
                }
            }
        }
    };

    private void initOnScreenIndicator() {
        mGpsNoSignalIndicator = findViewById(R.id.onscreen_gps_indicator_no_signal);
        mGpsHasSignalIndicator = findViewById(R.id.onscreen_gps_indicator_on);
        mExposureIndicator = (TextView) findViewById(R.id.onscreen_exposure_indicator);
    }

    @Override
    public void showGpsOnScreenIndicator(boolean hasSignal) {
        if (hasSignal) {
            if (mGpsNoSignalIndicator != null) {
                mGpsNoSignalIndicator.setVisibility(View.GONE);
            }
            if (mGpsHasSignalIndicator != null) {
                mGpsHasSignalIndicator.setVisibility(View.VISIBLE);
            }
        } else {
            if (mGpsNoSignalIndicator != null) {
                mGpsNoSignalIndicator.setVisibility(View.VISIBLE);
            }
            if (mGpsHasSignalIndicator != null) {
                mGpsHasSignalIndicator.setVisibility(View.GONE);
            }
        }
    }

    @Override
    public void hideGpsOnScreenIndicator() {
        if (mGpsNoSignalIndicator != null) mGpsNoSignalIndicator.setVisibility(View.GONE);
        if (mGpsHasSignalIndicator != null) mGpsHasSignalIndicator.setVisibility(View.GONE);
    }

    private void updateExposureOnScreenIndicator(int value) {
        if (mExposureIndicator == null) return;

        if (value == 0) {
            mExposureIndicator.setText("");
            mExposureIndicator.setVisibility(View.GONE);
        } else {
            float step = mParameters.getExposureCompensationStep();
            mFormatterArgs[0] = value * step;
            mBuilder.delete(0, mBuilder.length());
            mFormatter.format("%+1.1f", mFormatterArgs);
            String exposure = mFormatter.toString();
            mExposureIndicator.setText(exposure);
            mExposureIndicator.setVisibility(View.VISIBLE);
        }
    }

    private final class ShutterCallback
            implements android.hardware.Camera.ShutterCallback {
        public void onShutter() {
            mShutterCallbackTime = System.currentTimeMillis();
            mShutterLag = mShutterCallbackTime - mCaptureStartTime;
            Log.v(TAG, "mShutterLag = " + mShutterLag + "ms");
            mFocusManager.onShutter();
        }
    }

    private final class PostViewPictureCallback implements PictureCallback {
        public void onPictureTaken(
                byte [] data, android.hardware.Camera camera) {
            mPostViewPictureCallbackTime = System.currentTimeMillis();
            Log.v(TAG, "mShutterToPostViewCallbackTime = "
                    + (mPostViewPictureCallbackTime - mShutterCallbackTime)
                    + "ms");
        }
    }

    private final class RawPictureCallback implements PictureCallback {
        public void onPictureTaken(
                byte [] rawData, android.hardware.Camera camera) {
            mRawPictureCallbackTime = System.currentTimeMillis();
            Log.v(TAG, "mShutterToRawCallbackTime = "
                    + (mRawPictureCallbackTime - mShutterCallbackTime) + "ms");
        }
    }

    private final class JpegPictureCallback implements PictureCallback {
        Location mLocation;

        public JpegPictureCallback(Location loc) {
            mLocation = loc;
        }

        public void onPictureTaken(
                final byte [] jpegData, final android.hardware.Camera camera) {
            if (mPausing) {
                return;
            }

            mJpegPictureCallbackTime = System.currentTimeMillis();
            // If postview callback has arrived, the captured image is displayed
            // in postview callback. If not, the captured image is displayed in
            // raw picture callback.
            if (mPostViewPictureCallbackTime != 0) {
                mShutterToPictureDisplayedTime =
                        mPostViewPictureCallbackTime - mShutterCallbackTime;
                mPictureDisplayedToJpegCallbackTime =
                        mJpegPictureCallbackTime - mPostViewPictureCallbackTime;
            } else {
                mShutterToPictureDisplayedTime =
                        mRawPictureCallbackTime - mShutterCallbackTime;
                mPictureDisplayedToJpegCallbackTime =
                        mJpegPictureCallbackTime - mRawPictureCallbackTime;
            }
            Log.v(TAG, "mPictureDisplayedToJpegCallbackTime = "
                    + mPictureDisplayedToJpegCallbackTime + "ms");

            if (!mIsImageCaptureIntent) {
                enableCameraControls(true);

                startPreview();
            }

            if (!mIsImageCaptureIntent) {
                storeImage(jpegData, mLocation);
            } else {
                mJpegImageData = jpegData;
                if (!mQuickCapture) {
                    showPostCaptureAlert();
                } else {
                    doAttach();
                }
            }

            // Check this in advance of each shot so we don't add to shutter
            // latency. It's true that someone else could write to the SD card in
            // the mean time and fill it, but that could have happened between the
            // shutter press and saving the JPEG too.
            checkStorage();

            long now = System.currentTimeMillis();
            mJpegCallbackFinishTime = now - mJpegPictureCallbackTime;
            Log.v(TAG, "mJpegCallbackFinishTime = "
                    + mJpegCallbackFinishTime + "ms");
            mJpegPictureCallbackTime = 0;
        }
    }

    private final class AutoFocusCallback
            implements android.hardware.Camera.AutoFocusCallback {
        public void onAutoFocus(
                boolean focused, android.hardware.Camera camera) {
            if (mPausing) return;

            mAutoFocusTime = System.currentTimeMillis() - mFocusStartTime;
            Log.v(TAG, "mAutoFocusTime = " + mAutoFocusTime + "ms");
            mFocusManager.onAutoFocus(focused);
            // If focus completes and the snapshot is not started, enable the
            // controls.
            if (mFocusManager.isFocusCompleted()) {
                enableCameraControls(true);
            }
        }
    }

    private final class ZoomListener
            implements android.hardware.Camera.OnZoomChangeListener {
        @Override
        public void onZoomChange(
                int value, boolean stopped, android.hardware.Camera camera) {
            Log.v(TAG, "Zoom changed: value=" + value + ". stopped="+ stopped);
            mZoomValue = value;

            // Update the UI when we get zoom value.
            mZoomControl.setZoomIndex(value);

            // Keep mParameters up to date. We do not getParameter again in
            // takePicture. If we do not do this, wrong zoom value will be set.
            mParameters.setZoom(value);

            if (stopped && mZoomState != ZOOM_STOPPED) {
                if (mTargetZoomValue != -1 && value != mTargetZoomValue) {
                    mCameraDevice.startSmoothZoom(mTargetZoomValue);
                    mZoomState = ZOOM_START;
                } else {
                    mZoomState = ZOOM_STOPPED;
                }
            }
        }
    }

    private void storeImage(final byte[] data, Location loc) {
        long dateTaken = System.currentTimeMillis();
        String title = Util.createJpegName(dateTaken);
        int orientation = Exif.getOrientation(data);
        Uri uri = Storage.addImage(mContentResolver, title, dateTaken,
                loc, orientation, data);
        if (uri != null) {
            // Create a thumbnail whose width is equal or bigger than that of the preview.
            int ratio = (int) Math.ceil((double) mParameters.getPictureSize().width
                    / mPreviewFrameLayout.getWidth());
            int inSampleSize = Integer.highestOneBit(ratio);
            mThumbnail = Thumbnail.createThumbnail(data, orientation, inSampleSize, uri);
            if (mThumbnail != null) {
                mThumbnailView.setBitmap(mThumbnail.getBitmap());
            }
            Util.broadcastNewPicture(this, uri);
        }
    }

    @Override
    public boolean capture() {
        // If we are already in the middle of taking a snapshot then ignore.
        if (mCameraState == SNAPSHOT_IN_PROGRESS || mCameraDevice == null) {
            return false;
        }
        mCaptureStartTime = System.currentTimeMillis();
        mPostViewPictureCallbackTime = 0;
        enableCameraControls(false);
        mJpegImageData = null;

        // Set rotation and gps data.
        Util.setRotationParameter(mParameters, mCameraId, mOrientation);
        Location loc = mLocationManager.getCurrentLocation();
        Util.setGpsParameters(mParameters, loc);
        mCameraDevice.setParameters(mParameters);

        mCameraDevice.takePicture(mShutterCallback, mRawPictureCallback,
                mPostViewPictureCallback, new JpegPictureCallback(loc));
        mCameraState = SNAPSHOT_IN_PROGRESS;
        return true;
    }

    @Override
    public void setFocusParameters() {
        setCameraParameters(UPDATE_PARAM_PREFERENCE);
    }

    private boolean saveDataToFile(String filePath, byte[] data) {
        FileOutputStream f = null;
        try {
            f = new FileOutputStream(filePath);
            f.write(data);
        } catch (IOException e) {
            return false;
        } finally {
            Util.closeSilently(f);
        }
        return true;
    }

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);

        mIsImageCaptureIntent = isImageCaptureIntent();
        setContentView(R.layout.camera);
        if (mIsImageCaptureIntent) {
            findViewById(R.id.btn_cancel).setVisibility(View.VISIBLE);
        } else {
            mThumbnailView = (RotateImageView) findViewById(R.id.thumbnail);
            mThumbnailView.setVisibility(View.VISIBLE);
        }

        mPreferences = new ComboPreferences(this);
        CameraSettings.upgradeGlobalPreferences(mPreferences.getGlobal());
        mFocusManager = new FocusManager(mPreferences,
                getString(R.string.pref_camera_focusmode_default));

        mCameraId = CameraSettings.readPreferredCameraId(mPreferences);

        // Testing purpose. Launch a specific camera through the intent extras.
        int intentCameraId = Util.getCameraFacingIntentExtras(this);
        if (intentCameraId != -1) {
            mCameraId = intentCameraId;
        }

        mPreferences.setLocalId(this, mCameraId);
        CameraSettings.upgradeLocalPreferences(mPreferences.getLocal());

        mNumberOfCameras = CameraHolder.instance().getNumberOfCameras();
        mQuickCapture = getIntent().getBooleanExtra(EXTRA_QUICK_CAPTURE, false);

        // we need to reset exposure for the preview
        resetExposureCompensation();

        /*
         * To reduce startup time, we start the preview in another thread.
         * We make sure the preview is started at the end of onCreate.
         */
        Thread startPreviewThread = new Thread(new Runnable() {
            public void run() {
                try {
                    mCameraDevice = Util.openCamera(Camera.this, mCameraId);
                    initializeCapabilities();
                    startPreview();
                } catch (CameraHardwareException e) {
                    mOpenCameraFail = true;
                } catch (CameraDisabledException e) {
                    mCameraDisabled = true;
                }
            }
        });
        startPreviewThread.start();

        Util.enterLightsOutMode(getWindow());

        // don't set mSurfaceHolder here. We have it set ONLY within
        // surfaceChanged / surfaceDestroyed, other parts of the code
        // assume that when it is set, the surface is also set.
        SurfaceView preview = (SurfaceView) findViewById(R.id.camera_preview);
        SurfaceHolder holder = preview.getHolder();
        holder.addCallback(this);
        holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        if (mIsImageCaptureIntent) {
            setupCaptureParams();
        } else {
            mModePicker = (ModePicker) findViewById(R.id.mode_picker);
            mModePicker.setVisibility(View.VISIBLE);
            mModePicker.setOnModeChangeListener(this);
            mModePicker.setCurrentMode(ModePicker.MODE_CAMERA);
        }

        mZoomControl = (ZoomControl) findViewById(R.id.zoom_control);
        mLocationManager = new LocationManager(this, this);

        // Make sure preview is started.
        try {
            startPreviewThread.join();
            if (mOpenCameraFail) {
                Util.showErrorAndFinish(this, R.string.cannot_connect_camera);
                return;
            } else if (mCameraDisabled) {
                Util.showErrorAndFinish(this, R.string.camera_disabled);
                return;
            }
        } catch (InterruptedException ex) {
            // ignore
        }

        mBackCameraId = CameraHolder.instance().getBackCameraId();
        mFrontCameraId = CameraHolder.instance().getFrontCameraId();

        // Do this after starting preview because it depends on camera
        // parameters.
        initializeIndicatorControl();
    }

    private void overrideCameraSettings(final String flashMode,
            final String whiteBalance, final String focusMode) {
        if (mIndicatorControlContainer != null) {
            mIndicatorControlContainer.overrideSettings(
                    CameraSettings.KEY_FLASH_MODE, flashMode,
                    CameraSettings.KEY_WHITE_BALANCE, whiteBalance,
                    CameraSettings.KEY_FOCUS_MODE, focusMode);
        }
    }

    private void updateSceneModeUI() {
        // If scene mode is set, we cannot set flash mode, white balance, and
        // focus mode, instead, we read it from driver
        if (!Parameters.SCENE_MODE_AUTO.equals(mSceneMode)) {
            overrideCameraSettings(mParameters.getFlashMode(),
                    mParameters.getWhiteBalance(), mParameters.getFocusMode());
        } else {
            overrideCameraSettings(null, null, null);
        }
    }

    private void loadCameraPreferences() {
        CameraSettings settings = new CameraSettings(this, mInitialParams,
                mCameraId, CameraHolder.instance().getCameraInfo());
        mPreferenceGroup = settings.getPreferenceGroup(R.xml.camera_preferences);
    }

    private void initializeIndicatorControl() {
        // setting the indicator buttons.
        mIndicatorControlContainer =
                (IndicatorControlContainer) findViewById(R.id.indicator_control);
        if (mIndicatorControlContainer == null) return;
        loadCameraPreferences();
        final String[] SETTING_KEYS = {
                CameraSettings.KEY_FLASH_MODE,
                CameraSettings.KEY_WHITE_BALANCE,
                CameraSettings.KEY_SCENE_MODE};
        final String[] OTHER_SETTING_KEYS = {
                CameraSettings.KEY_RECORD_LOCATION,
                CameraSettings.KEY_FOCUS_MODE,
                CameraSettings.KEY_EXPOSURE,
                CameraSettings.KEY_PICTURE_SIZE};

        CameraPicker.setImageResourceId(R.drawable.ic_switch_photo_facing_holo_light);
        mIndicatorControlContainer.initialize(this, mPreferenceGroup,
                mParameters.isZoomSupported(),
                SETTING_KEYS, OTHER_SETTING_KEYS);
        updateSceneModeUI();
        mIndicatorControlContainer.setListener(this);
    }

    private boolean collapseCameraControls() {
        if ((mIndicatorControlContainer != null)
                && mIndicatorControlContainer.dismissSettingPopup()) {
            return true;
        }
        return false;
    }

    private void enableCameraControls(boolean enable) {
        if (mIndicatorControlContainer != null) {
            mIndicatorControlContainer.setEnabled(enable);
        }
        if (mModePicker != null) mModePicker.setEnabled(enable);
        if (mZoomControl != null) mZoomControl.setEnabled(enable);
    }

    public static int roundOrientation(int orientation) {
        return ((orientation + 45) / 90 * 90) % 360;
    }

    private class MyOrientationEventListener
            extends OrientationEventListener {
        public MyOrientationEventListener(Context context) {
            super(context);
        }

        @Override
        public void onOrientationChanged(int orientation) {
            // We keep the last known orientation. So if the user first orient
            // the camera then point the camera to floor or sky, we still have
            // the correct orientation.
            if (orientation == ORIENTATION_UNKNOWN) return;
            mOrientation = roundOrientation(orientation);
            // When the screen is unlocked, display rotation may change. Always
            // calculate the up-to-date orientationCompensation.
            int orientationCompensation = mOrientation
                    + Util.getDisplayRotation(Camera.this);
            if (mOrientationCompensation != orientationCompensation) {
                mOrientationCompensation = orientationCompensation;
                setOrientationIndicator(mOrientationCompensation);
            }

            // Show the toast after getting the first orientation changed.
            if (mHandler.hasMessages(SHOW_TAP_TO_FOCUS_TOAST)) {
                mHandler.removeMessages(SHOW_TAP_TO_FOCUS_TOAST);
                showTapToFocusToast();
            }
        }
    }

    private void setOrientationIndicator(int degree) {
        if (mThumbnailView != null) mThumbnailView.setDegree(degree);
        if (mModePicker != null) mModePicker.setDegree(degree);
        if (mSharePopup != null) mSharePopup.setOrientation(degree);
        if (mIndicatorControlContainer != null) mIndicatorControlContainer.setDegree(degree);
        if (mZoomControl != null) mZoomControl.setDegree(degree);
        if (mFocusIndicator != null) mFocusIndicator.setOrientation(degree);
        if (mFaceView != null) mFaceView.setOrientation(degree);
    }

    @Override
    public void onStop() {
        super.onStop();
        if (mMediaProviderClient != null) {
            mMediaProviderClient.release();
            mMediaProviderClient = null;
        }
    }

    private void checkStorage() {
        mPicturesRemaining = Storage.getAvailableSpace();
        if (mPicturesRemaining > 0) {
            mPicturesRemaining /= 1500000;
        }
        updateStorageHint();
    }

    @OnClickAttr
    public void onThumbnailClicked(View v) {
        if (isCameraIdle() && mThumbnail != null) {
            showSharePopup();
        }
    }

    @OnClickAttr
    public void onRetakeButtonClicked(View v) {
        hidePostCaptureAlert();
        startPreview();
    }

    @OnClickAttr
    public void onDoneButtonClicked(View v) {
        doAttach();
    }

    @OnClickAttr
    public void onCancelButtonClicked(View v) {
        doCancel();
    }

    private void doAttach() {
        if (mPausing) {
            return;
        }

        byte[] data = mJpegImageData;

        if (mCropValue == null) {
            // First handle the no crop case -- just return the value.  If the
            // caller specifies a "save uri" then write the data to it's
            // stream. Otherwise, pass back a scaled down version of the bitmap
            // directly in the extras.
            if (mSaveUri != null) {
                OutputStream outputStream = null;
                try {
                    outputStream = mContentResolver.openOutputStream(mSaveUri);
                    outputStream.write(data);
                    outputStream.close();

                    setResultEx(RESULT_OK);
                    finish();
                } catch (IOException ex) {
                    // ignore exception
                } finally {
                    Util.closeSilently(outputStream);
                }
            } else {
                int orientation = Exif.getOrientation(data);
                Bitmap bitmap = Util.makeBitmap(data, 50 * 1024);
                bitmap = Util.rotate(bitmap, orientation);
                setResultEx(RESULT_OK,
                        new Intent("inline-data").putExtra("data", bitmap));
                finish();
            }
        } else {
            // Save the image to a temp file and invoke the cropper
            Uri tempUri = null;
            FileOutputStream tempStream = null;
            try {
                File path = getFileStreamPath(sTempCropFilename);
                path.delete();
                tempStream = openFileOutput(sTempCropFilename, 0);
                tempStream.write(data);
                tempStream.close();
                tempUri = Uri.fromFile(path);
            } catch (FileNotFoundException ex) {
                setResultEx(Activity.RESULT_CANCELED);
                finish();
                return;
            } catch (IOException ex) {
                setResultEx(Activity.RESULT_CANCELED);
                finish();
                return;
            } finally {
                Util.closeSilently(tempStream);
            }

            Bundle newExtras = new Bundle();
            if (mCropValue.equals("circle")) {
                newExtras.putString("circleCrop", "true");
            }
            if (mSaveUri != null) {
                newExtras.putParcelable(MediaStore.EXTRA_OUTPUT, mSaveUri);
            } else {
                newExtras.putBoolean("return-data", true);
            }

            Intent cropIntent = new Intent("com.android.camera.action.CROP");

            cropIntent.setData(tempUri);
            cropIntent.putExtras(newExtras);

            startActivityForResult(cropIntent, CROP_MSG);
        }
    }

    private void doCancel() {
        setResultEx(RESULT_CANCELED, new Intent());
        finish();
    }

    public void onShutterButtonFocus(ShutterButton button, boolean pressed) {
        switch (button.getId()) {
            case R.id.shutter_button:
                doFocus(pressed);
                break;
        }
    }

    public void onShutterButtonClick(ShutterButton button) {
        switch (button.getId()) {
            case R.id.shutter_button:
                doSnap();
                break;
        }
    }

    private OnScreenHint mStorageHint;

    private void updateStorageHint() {
        String noStorageText = null;

        if (mPicturesRemaining == Storage.UNAVAILABLE) {
            noStorageText = getString(R.string.no_storage);
        } else if (mPicturesRemaining == Storage.PREPARING) {
            noStorageText = getString(R.string.preparing_sd);
        } else if (mPicturesRemaining == Storage.UNKNOWN_SIZE) {
            noStorageText = getString(R.string.access_sd_fail);
        } else if (mPicturesRemaining < 1L) {
            noStorageText = getString(R.string.not_enough_space);
        }

        if (noStorageText != null) {
            if (mStorageHint == null) {
                mStorageHint = OnScreenHint.makeText(this, noStorageText);
            } else {
                mStorageHint.setText(noStorageText);
            }
            mStorageHint.show();
        } else if (mStorageHint != null) {
            mStorageHint.cancel();
            mStorageHint = null;
        }
    }

    private void installIntentFilter() {
        // install an intent filter to receive SD card related events.
        IntentFilter intentFilter =
                new IntentFilter(Intent.ACTION_MEDIA_MOUNTED);
        intentFilter.addAction(Intent.ACTION_MEDIA_UNMOUNTED);
        intentFilter.addAction(Intent.ACTION_MEDIA_SCANNER_FINISHED);
        intentFilter.addAction(Intent.ACTION_MEDIA_CHECKING);
        intentFilter.addDataScheme("file");
        registerReceiver(mReceiver, intentFilter);
        mDidRegister = true;
    }

    @Override
    protected void onResume() {
        super.onResume();
        mPausing = false;
        if (mOpenCameraFail || mCameraDisabled) return;

        mJpegPictureCallbackTime = 0;
        mZoomValue = 0;

        // Start the preview if it is not started.
        if (mCameraState == PREVIEW_STOPPED) {
            try {
                mCameraDevice = Util.openCamera(this, mCameraId);
                initializeCapabilities();
                resetExposureCompensation();
                startPreview();
            } catch(CameraHardwareException e) {
                Util.showErrorAndFinish(this, R.string.cannot_connect_camera);
                return;
            } catch(CameraDisabledException e) {
                Util.showErrorAndFinish(this, R.string.camera_disabled);
                return;
            }
        }

        if (mSurfaceHolder != null) {
            // If first time initialization is not finished, put it in the
            // message queue.
            if (!mFirstTimeInitialized) {
                mHandler.sendEmptyMessage(FIRST_TIME_INIT);
            } else {
                initializeSecondTime();
            }
        }
        keepScreenOnAwhile();

        if (mCameraState == IDLE) {
            mOnResumeTime = SystemClock.uptimeMillis();
            mHandler.sendEmptyMessageDelayed(CHECK_DISPLAY_ROTATION, 100);
        }
    }

    @Override
    protected void onPause() {
        mPausing = true;
        stopPreview();
        // Close the camera now because other activities may need to use it.
        closeCamera();
        resetScreenOn();

        // Clear UI.
        collapseCameraControls();
        if (mSharePopup != null) mSharePopup.dismiss();
        if (mFaceView != null) mFaceView.clear();

        if (mFirstTimeInitialized) {
            mOrientationListener.disable();
            if (!mIsImageCaptureIntent) {
                if (mThumbnail != null) {
                    mThumbnail.saveTo(new File(getFilesDir(), Thumbnail.LAST_THUMB_FILENAME));
                }
            }
        }

        if (mDidRegister) {
            unregisterReceiver(mReceiver);
            mDidRegister = false;
        }
        mLocationManager.recordLocation(false);
        updateExposureOnScreenIndicator(0);

        mFocusManager.releaseToneGenerator();

        if (mStorageHint != null) {
            mStorageHint.cancel();
            mStorageHint = null;
        }

        // If we are in an image capture intent and has taken
        // a picture, we just clear it in onPause.
        mJpegImageData = null;

        // Remove the messages in the event queue.
        mHandler.removeMessages(FIRST_TIME_INIT);
        mHandler.removeMessages(CHECK_DISPLAY_ROTATION);
        mFocusManager.removeMessages();

        super.onPause();
    }

    @Override
    protected void onActivityResult(
            int requestCode, int resultCode, Intent data) {
        switch (requestCode) {
            case CROP_MSG: {
                Intent intent = new Intent();
                if (data != null) {
                    Bundle extras = data.getExtras();
                    if (extras != null) {
                        intent.putExtras(extras);
                    }
                }
                setResultEx(resultCode, intent);
                finish();

                File path = getFileStreamPath(sTempCropFilename);
                path.delete();

                break;
            }
        }
    }

    private boolean canTakePicture() {
        return isCameraIdle() && (mPicturesRemaining > 0);
    }

    @Override
    public void autoFocus() {
        mFocusStartTime = System.currentTimeMillis();
        mCameraDevice.autoFocus(mAutoFocusCallback);
        mCameraState = FOCUSING;
        enableCameraControls(false);
    }

    @Override
    public void cancelAutoFocus() {
        mCameraDevice.cancelAutoFocus();
        mCameraState = IDLE;
        enableCameraControls(true);
        setCameraParameters(UPDATE_PARAM_PREFERENCE);
    }

    // Preview area is touched. Handle touch focus.
    @Override
    public boolean onTouch(View v, MotionEvent e) {
        if (mPausing || mCameraDevice == null || !mFirstTimeInitialized
                || mCameraState == SNAPSHOT_IN_PROGRESS) {
            return false;
        }

        // Do not trigger touch focus if popup window is opened.
        if (collapseCameraControls()) return false;

        // Check if metering area or focus area is supported.
        if (!mFocusAreaSupported && !mMeteringAreaSupported) return false;

        return mFocusManager.onTouch(e);
    }

    @Override
    public void onBackPressed() {
        if (!isCameraIdle()) {
            // ignore backs while we're taking a picture
            return;
        } else if (!collapseCameraControls()) {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        switch (keyCode) {
            case KeyEvent.KEYCODE_FOCUS:
                if (mFirstTimeInitialized && event.getRepeatCount() == 0) {
                    doFocus(true);
                }
                return true;
            case KeyEvent.KEYCODE_CAMERA:
                if (mFirstTimeInitialized && event.getRepeatCount() == 0) {
                    doSnap();
                }
                return true;
            case KeyEvent.KEYCODE_DPAD_CENTER:
                // If we get a dpad center event without any focused view, move
                // the focus to the shutter button and press it.
                if (mFirstTimeInitialized && event.getRepeatCount() == 0) {
                    // Start auto-focus immediately to reduce shutter lag. After
                    // the shutter button gets the focus, doFocus() will be
                    // called again but it is fine.
                    if (collapseCameraControls()) return true;
                    doFocus(true);
                    if (mShutterButton.isInTouchMode()) {
                        mShutterButton.requestFocusFromTouch();
                    } else {
                        mShutterButton.requestFocus();
                    }
                    mShutterButton.setPressed(true);
                }
                return true;
        }

        return super.onKeyDown(keyCode, event);
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        switch (keyCode) {
            case KeyEvent.KEYCODE_FOCUS:
                if (mFirstTimeInitialized) {
                    doFocus(false);
                }
                return true;
        }
        return super.onKeyUp(keyCode, event);
    }

    private void doSnap() {
        if (mPausing || collapseCameraControls()) return;

        // Do not take the picture if there is not enough storage.
        if (mPicturesRemaining <= 0) {
            Log.i(TAG, "Not enough space or storage not ready. remaining=" + mPicturesRemaining);
            return;
        }

        Log.v(TAG, "doSnap: mCameraState=" + mCameraState);
        mFocusManager.doSnap();
    }

    private void doFocus(boolean pressed) {
        if (mPausing || collapseCameraControls()) return;

        // Do not do focus if there is not enough storage.
        if (pressed && !canTakePicture()) return;

        mFocusManager.doFocus(pressed);
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // Make sure we have a surface in the holder before proceeding.
        if (holder.getSurface() == null) {
            Log.d(TAG, "holder.getSurface() == null");
            return;
        }

        Log.v(TAG, "surfaceChanged. w=" + w + ". h=" + h);

        // We need to save the holder for later use, even when the mCameraDevice
        // is null. This could happen if onResume() is invoked after this
        // function.
        mSurfaceHolder = holder;

        // The mCameraDevice will be null if it fails to connect to the camera
        // hardware. In this case we will show a dialog and then finish the
        // activity, so it's OK to ignore it.
        if (mCameraDevice == null) return;

        // Sometimes surfaceChanged is called after onPause or before onResume.
        // Ignore it.
        if (mPausing || isFinishing()) return;

        // Set preview display if the surface is being created. Preview was
        // already started. Also restart the preview if display rotation has
        // changed. Sometimes this happens when the device is held in portrait
        // and camera app is opened. Rotation animation takes some time and
        // display rotation in onCreate may not be what we want.
        if (mCameraState != PREVIEW_STOPPED
                && (Util.getDisplayRotation(this) == mDisplayRotation)
                && holder.isCreating()) {
            // Set preview display if the surface is being created and preview
            // was already started. That means preview display was set to null
            // and we need to set it now.
            setPreviewDisplay(holder);
        } else {
            // 1. Restart the preview if the size of surface was changed. The
            // framework may not support changing preview display on the fly.
            // 2. Start the preview now if surface was destroyed and preview
            // stopped.
            startPreview();
        }

        // If first time initialization is not finished, send a message to do
        // it later. We want to finish surfaceChanged as soon as possible to let
        // user see preview first.
        if (!mFirstTimeInitialized) {
            mHandler.sendEmptyMessage(FIRST_TIME_INIT);
        } else {
            initializeSecondTime();
        }
    }

    public void surfaceCreated(SurfaceHolder holder) {
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        stopPreview();
        mSurfaceHolder = null;
    }

    private void closeCamera() {
        if (mCameraDevice != null) {
            CameraHolder.instance().release();
            mCameraDevice.setZoomChangeListener(null);
            mCameraDevice.setFaceDetectionListener(null);
            mCameraDevice = null;
            mCameraState = PREVIEW_STOPPED;
            mFocusManager.onCameraReleased();
        }
    }

    private void setPreviewDisplay(SurfaceHolder holder) {
        try {
            mCameraDevice.setPreviewDisplay(holder);
        } catch (Throwable ex) {
            closeCamera();
            throw new RuntimeException("setPreviewDisplay failed", ex);
        }
    }

    private void startPreview() {
        if (mPausing || isFinishing()) return;

        mFocusManager.resetTouchFocus();

        mCameraDevice.setErrorCallback(mErrorCallback);

        // If we're previewing already, stop the preview first (this will blank
        // the screen).
        if (mCameraState != PREVIEW_STOPPED) stopPreview();

        setPreviewDisplay(mSurfaceHolder);
        mDisplayRotation = Util.getDisplayRotation(this);
        mDisplayOrientation = Util.getDisplayOrientation(mDisplayRotation, mCameraId);
        mCameraDevice.setDisplayOrientation(mDisplayOrientation);
        if (mFaceView != null) {
            mFaceView.setDisplayOrientation(mDisplayOrientation);
        }
        setCameraParameters(UPDATE_PARAM_ALL);

        try {
            Log.v(TAG, "startPreview");
            mCameraDevice.startPreview();
        } catch (Throwable ex) {
            closeCamera();
            throw new RuntimeException("startPreview failed", ex);
        }

        startFaceDetection();
        mZoomState = ZOOM_STOPPED;
        mCameraState = IDLE;
        mFocusManager.onPreviewStarted();
    }

    private void stopPreview() {
        if (mCameraDevice != null && mCameraState != PREVIEW_STOPPED) {
            Log.v(TAG, "stopPreview");
            mCameraDevice.stopPreview();
        }
        mCameraState = PREVIEW_STOPPED;
        mFocusManager.onPreviewStopped();
    }

    private static boolean isSupported(String value, List<String> supported) {
        return supported == null ? false : supported.indexOf(value) >= 0;
    }

    private void updateCameraParametersInitialize() {
        // Reset preview frame rate to the maximum because it may be lowered by
        // video camera application.
        List<Integer> frameRates = mParameters.getSupportedPreviewFrameRates();
        if (frameRates != null) {
            Integer max = Collections.max(frameRates);
            mParameters.setPreviewFrameRate(max);
        }

        mParameters.setRecordingHint(false);
    }

    private void updateCameraParametersZoom() {
        // Set zoom.
        if (mParameters.isZoomSupported()) {
            mParameters.setZoom(mZoomValue);
        }
    }

    private void updateCameraParametersPreference() {
        if (mFocusAreaSupported) {
            mParameters.setFocusAreas(mFocusManager.getTapArea());
        }

        if (mMeteringAreaSupported) {
            // Use the same area for focus and metering.
            mParameters.setMeteringAreas(mFocusManager.getTapArea());
        }

        // Set picture size.
        String pictureSize = mPreferences.getString(
                CameraSettings.KEY_PICTURE_SIZE, null);
        if (pictureSize == null) {
            CameraSettings.initialCameraPictureSize(this, mParameters);
        } else {
            List<Size> supported = mParameters.getSupportedPictureSizes();
            CameraSettings.setCameraPictureSize(
                    pictureSize, supported, mParameters);
        }

        // Set the preview frame aspect ratio according to the picture size.
        Size size = mParameters.getPictureSize();

        mPreviewPanel = findViewById(R.id.frame_layout);
        mPreviewFrameLayout = (PreviewFrameLayout) findViewById(R.id.frame);
        mPreviewFrameLayout.setAspectRatio((double) size.width / size.height);

        // Set a preview size that is closest to the viewfinder height and has
        // the right aspect ratio.
        List<Size> sizes = mParameters.getSupportedPreviewSizes();
        Size optimalSize = Util.getOptimalPreviewSize(this,
                sizes, (double) size.width / size.height);
        Size original = mParameters.getPreviewSize();
        if (!original.equals(optimalSize)) {
            mParameters.setPreviewSize(optimalSize.width, optimalSize.height);

            // Zoom related settings will be changed for different preview
            // sizes, so set and read the parameters to get lastest values
            mCameraDevice.setParameters(mParameters);
            mParameters = mCameraDevice.getParameters();
        }
        Log.v(TAG, "Preview size is " + optimalSize.width + "x" + optimalSize.height);

        // Since change scene mode may change supported values,
        // Set scene mode first,
        mSceneMode = mPreferences.getString(
                CameraSettings.KEY_SCENE_MODE,
                getString(R.string.pref_camera_scenemode_default));
        if (isSupported(mSceneMode, mParameters.getSupportedSceneModes())) {
            if (!mParameters.getSceneMode().equals(mSceneMode)) {
                mParameters.setSceneMode(mSceneMode);
                mCameraDevice.setParameters(mParameters);

                // Setting scene mode will change the settings of flash mode,
                // white balance, and focus mode. Here we read back the
                // parameters, so we can know those settings.
                mParameters = mCameraDevice.getParameters();
            }
        } else {
            mSceneMode = mParameters.getSceneMode();
            if (mSceneMode == null) {
                mSceneMode = Parameters.SCENE_MODE_AUTO;
            }
        }

        // Set JPEG quality.
        int jpegQuality = CameraProfile.getJpegEncodingQualityParameter(mCameraId,
                CameraProfile.QUALITY_HIGH);
        mParameters.setJpegQuality(jpegQuality);

        // For the following settings, we need to check if the settings are
        // still supported by latest driver, if not, ignore the settings.

        // Set exposure compensation
        int value = CameraSettings.readExposure(mPreferences);
        int max = mParameters.getMaxExposureCompensation();
        int min = mParameters.getMinExposureCompensation();
        if (value >= min && value <= max) {
            mParameters.setExposureCompensation(value);
        } else {
            Log.w(TAG, "invalid exposure range: " + value);
        }

        if (Parameters.SCENE_MODE_AUTO.equals(mSceneMode)) {
            // Set flash mode.
            String flashMode = mPreferences.getString(
                    CameraSettings.KEY_FLASH_MODE,
                    getString(R.string.pref_camera_flashmode_default));
            List<String> supportedFlash = mParameters.getSupportedFlashModes();
            if (isSupported(flashMode, supportedFlash)) {
                mParameters.setFlashMode(flashMode);
            } else {
                flashMode = mParameters.getFlashMode();
                if (flashMode == null) {
                    flashMode = getString(
                            R.string.pref_camera_flashmode_no_flash);
                }
            }

            // Set white balance parameter.
            String whiteBalance = mPreferences.getString(
                    CameraSettings.KEY_WHITE_BALANCE,
                    getString(R.string.pref_camera_whitebalance_default));
            if (isSupported(whiteBalance,
                    mParameters.getSupportedWhiteBalance())) {
                mParameters.setWhiteBalance(whiteBalance);
            } else {
                whiteBalance = mParameters.getWhiteBalance();
                if (whiteBalance == null) {
                    whiteBalance = Parameters.WHITE_BALANCE_AUTO;
                }
            }

            // Set focus mode.
            mFocusManager.overrideFocusMode(null);
            mParameters.setFocusMode(mFocusManager.getFocusMode());
        } else {
            mFocusManager.overrideFocusMode(mParameters.getFocusMode());
        }
    }

    // We separate the parameters into several subsets, so we can update only
    // the subsets actually need updating. The PREFERENCE set needs extra
    // locking because the preference can be changed from GLThread as well.
    private void setCameraParameters(int updateSet) {
        mParameters = mCameraDevice.getParameters();

        if ((updateSet & UPDATE_PARAM_INITIALIZE) != 0) {
            updateCameraParametersInitialize();
        }

        if ((updateSet & UPDATE_PARAM_ZOOM) != 0) {
            updateCameraParametersZoom();
        }

        if ((updateSet & UPDATE_PARAM_PREFERENCE) != 0) {
            updateCameraParametersPreference();
        }

        mCameraDevice.setParameters(mParameters);
    }

    // If the Camera is idle, update the parameters immediately, otherwise
    // accumulate them in mUpdateSet and update later.
    private void setCameraParametersWhenIdle(int additionalUpdateSet) {
        mUpdateSet |= additionalUpdateSet;
        if (mCameraDevice == null) {
            // We will update all the parameters when we open the device, so
            // we don't need to do anything now.
            mUpdateSet = 0;
            return;
        } else if (isCameraIdle()) {
            setCameraParameters(mUpdateSet);
            updateSceneModeUI();
            mUpdateSet = 0;
        } else {
            if (!mHandler.hasMessages(SET_CAMERA_PARAMETERS_WHEN_IDLE)) {
                mHandler.sendEmptyMessageDelayed(
                        SET_CAMERA_PARAMETERS_WHEN_IDLE, 1000);
            }
        }
    }

    private void gotoGallery() {
        MenuHelper.gotoCameraImageGallery(this);
    }

    private boolean isCameraIdle() {
        return (mCameraState == IDLE) || (mFocusManager.isFocusCompleted());
    }

    private boolean isImageCaptureIntent() {
        String action = getIntent().getAction();
        return (MediaStore.ACTION_IMAGE_CAPTURE.equals(action));
    }

    private void setupCaptureParams() {
        Bundle myExtras = getIntent().getExtras();
        if (myExtras != null) {
            mSaveUri = (Uri) myExtras.getParcelable(MediaStore.EXTRA_OUTPUT);
            mCropValue = myExtras.getString("crop");
        }
    }

    private void showPostCaptureAlert() {
        if (mIsImageCaptureIntent) {
            Util.fadeOut(mIndicatorControlContainer);
            Util.fadeOut(mShutterButton);

            int[] pickIds = {R.id.btn_retake, R.id.btn_done};
            for (int id : pickIds) {
                Util.fadeIn(findViewById(id));
            }
        }
    }

    private void hidePostCaptureAlert() {
        if (mIsImageCaptureIntent) {
            enableCameraControls(true);

            int[] pickIds = {R.id.btn_retake, R.id.btn_done};
            for (int id : pickIds) {
                Util.fadeOut(findViewById(id));
            }

            Util.fadeIn(mShutterButton);
            Util.fadeIn(mIndicatorControlContainer);
        }
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        super.onPrepareOptionsMenu(menu);
        // Only show the menu when camera is idle.
        for (int i = 0; i < menu.size(); i++) {
            menu.getItem(i).setVisible(isCameraIdle());
        }

        return true;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);

        if (mIsImageCaptureIntent) {
            // No options menu for attach mode.
            return false;
        } else {
            addBaseMenuItems(menu);
        }
        return true;
    }

    private void addBaseMenuItems(Menu menu) {
        MenuHelper.addSwitchModeMenuItem(menu, ModePicker.MODE_VIDEO, new Runnable() {
            public void run() {
                switchToOtherMode(ModePicker.MODE_VIDEO);
            }
        });
        MenuHelper.addSwitchModeMenuItem(menu, ModePicker.MODE_PANORAMA, new Runnable() {
            public void run() {
                switchToOtherMode(ModePicker.MODE_PANORAMA);
            }
        });
        MenuItem gallery = menu.add(R.string.camera_gallery_photos_text)
                .setOnMenuItemClickListener(new OnMenuItemClickListener() {
            public boolean onMenuItemClick(MenuItem item) {
                gotoGallery();
                return true;
            }
        });
        gallery.setIcon(android.R.drawable.ic_menu_gallery);
        mGalleryItems.add(gallery);

        if (mNumberOfCameras > 1) {
            menu.add(R.string.switch_camera_id)
                    .setOnMenuItemClickListener(new OnMenuItemClickListener() {
                public boolean onMenuItemClick(MenuItem item) {
                    CameraSettings.writePreferredCameraId(mPreferences,
                            ((mCameraId == mFrontCameraId)
                            ? mBackCameraId : mFrontCameraId));
                    onSharedPreferenceChanged();
                    return true;
                }
            }).setIcon(android.R.drawable.ic_menu_camera);
        }
    }

    private boolean switchToOtherMode(int mode) {
        if (isFinishing() || !isCameraIdle()) return false;
        MenuHelper.gotoMode(mode, Camera.this);
        mHandler.removeMessages(FIRST_TIME_INIT);
        finish();
        return true;
    }

    public boolean onModeChanged(int mode) {
        if (mode != ModePicker.MODE_CAMERA) {
            return switchToOtherMode(mode);
        } else {
            return true;
        }
    }

    public void onSharedPreferenceChanged() {
        // ignore the events after "onPause()"
        if (mPausing) return;

        boolean recordLocation = RecordLocationPreference.get(
                mPreferences, getContentResolver());
        mLocationManager.recordLocation(recordLocation);

        int cameraId = CameraSettings.readPreferredCameraId(mPreferences);
        if (mCameraId != cameraId) {
            // Restart the activity to have a crossfade animation.
            // TODO: Use SurfaceTexture to implement a better and faster
            // animation.
            if (mIsImageCaptureIntent) {
                // If the intent is camera capture, stay in camera capture mode.
                MenuHelper.gotoCameraMode(this, getIntent());
            } else {
                MenuHelper.gotoCameraMode(this);
            }

            finish();
        } else {
            setCameraParametersWhenIdle(UPDATE_PARAM_PREFERENCE);
        }

        int exposureValue = CameraSettings.readExposure(mPreferences);
        updateExposureOnScreenIndicator(exposureValue);
    }

    @Override
    public void onUserInteraction() {
        super.onUserInteraction();
        keepScreenOnAwhile();
    }

    private void resetScreenOn() {
        mHandler.removeMessages(CLEAR_SCREEN_DELAY);
        getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
    }

    private void keepScreenOnAwhile() {
        mHandler.removeMessages(CLEAR_SCREEN_DELAY);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        mHandler.sendEmptyMessageDelayed(CLEAR_SCREEN_DELAY, SCREEN_DELAY);
    }

    public void onRestorePreferencesClicked() {
        if (mPausing) return;
        Runnable runnable = new Runnable() {
            public void run() {
                restorePreferences();
            }
        };
        MenuHelper.confirmAction(this,
                getString(R.string.confirm_restore_title),
                getString(R.string.confirm_restore_message),
                runnable);
    }

    private void restorePreferences() {
        // Reset the zoom. Zoom value is not stored in preference.
        if (mParameters.isZoomSupported()) {
            mZoomValue = 0;
            setCameraParametersWhenIdle(UPDATE_PARAM_ZOOM);
            mZoomControl.setZoomIndex(0);
        }
        if (mIndicatorControlContainer != null) {
            mIndicatorControlContainer.dismissSettingPopup();
            CameraSettings.restorePreferences(Camera.this, mPreferences,
                    mParameters);
            mIndicatorControlContainer.reloadPreferences();
            onSharedPreferenceChanged();
        }
    }

    public void onOverriddenPreferencesClicked() {
        if (mPausing) return;
        if (mNotSelectableToast == null) {
            String str = getResources().getString(R.string.not_selectable_in_scene_mode);
            mNotSelectableToast = Toast.makeText(Camera.this, str, Toast.LENGTH_SHORT);
        }
        mNotSelectableToast.show();
    }

    private void showSharePopup() {
        Uri uri = mThumbnail.getUri();
        if (mSharePopup == null || !uri.equals(mSharePopup.getUri())) {
            // SharePopup window takes the mPreviewPanel as its size reference.
            mSharePopup = new SharePopup(this, uri, mThumbnail.getBitmap(),
                    mOrientationCompensation, mPreviewPanel);
        }
        mSharePopup.showAtLocation(mThumbnailView, Gravity.NO_GRAVITY, 0, 0);
    }

    @Override
    public void onFaceDetection(Face[] faces, android.hardware.Camera camera) {
        mFaceView.setFaces(faces);
    }

    private void showTapToFocusToast() {
        // Show the toast.
        RotateLayout v = (RotateLayout) findViewById(R.id.tap_to_focus_prompt);
        v.setOrientation(mOrientationCompensation);
        v.startAnimation(AnimationUtils.loadAnimation(this, R.anim.on_screen_hint_enter));
        v.setVisibility(View.VISIBLE);
        mHandler.sendEmptyMessageDelayed(DISMISS_TAP_TO_FOCUS_TOAST, 5000);
        // Clear the preference.
        Editor editor = mPreferences.edit();
        editor.putBoolean(CameraSettings.KEY_TAP_TO_FOCUS_PROMPT_SHOWN, false);
        editor.apply();
    }

    private void initializeCapabilities() {
        mInitialParams = mCameraDevice.getParameters();
        mFocusManager.initializeParameters(mInitialParams);
        mFocusAreaSupported = (mInitialParams.getMaxNumFocusAreas() > 0
                && isSupported(Parameters.FOCUS_MODE_AUTO,
                        mInitialParams.getSupportedFocusModes()));
        mMeteringAreaSupported = (mInitialParams.getMaxNumMeteringAreas() > 0);
    }
}