android7.1的SnapdragonCamera之CameraActivity逻辑流程分析整体

不积跬步无以至千里
“一花一世界，一树一乾坤，一草一天堂，一木一浮生”,这句话告诉我们通过一小部分可以知道整个整体，同样的Camera也一样，本文主要分析这个CameraActivity。
其实我发现AndroidMainfest.xml中，启动Activity就是CameraActivity的别名的CameraLauncher，如下图：

下面看一下这个CameraActivity的整个生命周期（代码的逻辑，我通过加注释给大家解释一下）。

onCreate方法

    public void onCreate(Bundle state) {        super.onCreate(state);        //检查权限,如果权限没检查过，或者没有批准的权限直接关闭。另说一嘴，大家都知道吗？android7.1又对权限做了新的处理。        if (checkPermissions() || !mHasCriticalPermissions) {            Log.v(TAG, "onCreate: Missing critical permissions.");            //关闭本Activity，即跳出整个程序            finish();            return;        }         // Check if this is in the secure camera mode.检查是否为安全相机模式        Intent intent = getIntent();        String action = intent.getAction();        if (INTENT_ACTION_STILL_IMAGE_CAMERA_SECURE.equals(action)                || ACTION_IMAGE_CAPTURE_SECURE.equals(action)                || intent.getComponent().getClassName().equals(GESTURE_CAMERA_NAME)) {            mSecureCamera = true;        } else {            mSecureCamera = intent.getBooleanExtra(SECURE_CAMERA_EXTRA, false);        }        //根据相机是不是安全相机模式做处理        if (mSecureCamera) {            // Change the window flags so that secure camera can show when locked 当被锁住时，为安全模式时，改变窗口。            Window win = getWindow();            WindowManager.LayoutParams params = win.getAttributes();            params.flags |= WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED;            if (intent.getComponent().getClassName().equals(GESTURE_CAMERA_NAME)) {                params.flags |= WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON;                //获取唤醒锁                PowerManager pm = ((PowerManager) getSystemService(POWER_SERVICE));                mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);                mWakeLock.acquire();                Log.d(TAG, "acquire wake lock");            }            win.setAttributes(params);        }        GcamHelper.init(getContentResolver());        //设置actionBar        getWindow().requestFeature(Window.FEATURE_ACTION_BAR);        setContentView(R.layout.camera_filmstrip);        //为ActionBa设置菜单可见监听        mActionBar = getActionBar();        mActionBar.addOnMenuVisibilityListener(this);        //当大于4.3版本，设置窗口的旋转动画        if (ApiHelper.HAS_ROTATION_ANIMATION) {            setRotationAnimation();        }        //声明一个主线程的Handler,主要用于ActionBar的隐藏和显示        mMainHandler = new MainHandler(getMainLooper());        //关联控件 mAboveFilmstripControlLayout =                (FrameLayout) findViewById(R.id.camera_above_filmstrip_layout);        mAboveFilmstripControlLayout。setFitsSystemWindows(true);mAboveFilmstripControlLayout。setFitsSystemWindows(true);this.setSystemBarsVisibility(false);        mPanoramaManager = AppManagerFactory.getInstance(this)                。getPanoramaStitchingManager();        mPlaceholderManager = AppManagerFactory.getInstance(this)                。getGcamProcessingManager();                //添加图片加载监听        mPanoramaManager。addTaskListener(mStitchingListener);        mPlaceholderManager。addTaskListener(mPlaceholderListener);         LayoutInflater inflater = getLayoutInflater();        View rootLayout = inflater。inflate(R。layout。camera, null, false);        mCameraRootFrame = (FrameLayout)rootLayout。findViewById(R。id。camera_root_frame);        mCameraPhotoModuleRootView = rootLayout。findViewById(R。id。camera_photo_root);        mCameraVideoModuleRootView = rootLayout。findViewById(R。id。camera_video_root);        mCameraPanoModuleRootView = rootLayout。findViewById(R。id。camera_pano_root);        mPanoStitchingPanel = findViewById(R。id。pano_stitching_progress_panel);        mBottomProgress = (ProgressBar) findViewById(R。id。pano_stitching_progress_bar);        mCameraPreviewData = new CameraPreviewData(rootLayout,                FilmStripView。ImageData。SIZE_FULL,                FilmStripView。ImageData。SIZE_FULL);        // Put a CameraPreviewData at the first position        mWrappedDataAdapter = new FixedFirstDataAdapter(                new CameraDataAdapter(new ColorDrawable(                        getResources()。getColor(R。color.photo_placeholder))),                mCameraPreviewData);        mFilmStripView = (FilmStripView) findViewById(R。id.filmstrip_view);        mFilmStripView。setViewGap(                getResources()。getDimensionPixelSize(R。dimen.camera_film_strip_gap));        mPanoramaViewHelper = new PanoramaViewHelper(this);        mPanoramaViewHelper。onCreate();        mFilmStripView。setPanoramaViewHelper(mPanoramaViewHelper);        // Set up the camera preview first so the preview shows up ASAP        mFilmStripView。setListener(mFilmStripListener);        //获取当前的拍照模式：视频、照相        int moduleIndex = -1;        if (MediaStore。INTENT_ACTION_VIDEO_CAMERA。equals(getIntent()。getAction())                || MediaStore。ACTION_VIDEO_CAPTURE。equals(getIntent()。getAction())) {            moduleIndex = ModuleSwitcher。VIDEO_MODULE_INDEX;        } else if (MediaStore。INTENT_ACTION_STILL_IMAGE_CAMERA.equals(getIntent()。getAction())                || MediaStore.INTENT_ACTION_STILL_IMAGE_CAMERA_SECURE。equals(getIntent()                        。getAction())) {            moduleIndex = ModuleSwitcher。PHOTO_MODULE_INDEX;            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);            if (prefs.getInt(CameraSettings.KEY_STARTUP_MODULE_INDEX, -1)                        == ModuleSwitcher.GCAM_MODULE_INDEX && GcamHelper.hasGcamCapture()) {                moduleIndex = ModuleSwitcher.GCAM_MODULE_INDEX;            }        } else if (MediaStore.ACTION_IMAGE_CAPTURE.equals(getIntent().getAction())                || MediaStore.ACTION_IMAGE_CAPTURE_SECURE.equals(getIntent().getAction())) {            moduleIndex = ModuleSwitcher.PHOTO_MODULE_INDEX;        } else {            // If the activity has not been started using an explicit intent,            // read the module index from the last time the user changed modes            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);            moduleIndex = prefs.getInt(CameraSettings.KEY_STARTUP_MODULE_INDEX, -1);            if ((moduleIndex == ModuleSwitcher.GCAM_MODULE_INDEX &&                    !GcamHelper.hasGcamCapture()) || moduleIndex < 0) {                moduleIndex = ModuleSwitcher.PHOTO_MODULE_INDEX;            }        }        //设置重力感应监听        mOrientationListener = new MyOrientationEventListener(this);        //根据上面获取、判断的模式，去设置界面的显示等等。        setModuleFromIndex(moduleIndex);        //根据是不是安全相机来处理if (!mSecureCamera) {            mDataAdapter = mWrappedDataAdapter;            mFilmStripView。setDataAdapter(mDataAdapter);            if (!isCaptureIntent()) {                mDataAdapter。requestLoad(getContentResolver());                mDataRequested = true;            }        } else {            // Put a lock placeholder as the last image by setting its date to            // 0.            //点击照片跳转意图            ImageView v = (ImageView) getLayoutInflater().inflate(                    R.layout.secure_album_placeholder, null);            v.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View view) {                    try {                        UsageStatistics.onEvent(UsageStatistics.COMPONENT_CAMERA,                                UsageStatistics.ACTION_GALLERY, null);                //跳转到相册        startActivity(IntentHelper.getGalleryIntent(CameraActivity.this));                    } catch (ActivityNotFoundException e) {                        Log.w(TAG, "Failed to launch gallery activity, closing");                    }                    finish();                }            });            mDataAdapter = new FixedLastDataAdapter(                    mWrappedDataAdapter,                    new SimpleViewData(                            v,                            v.getDrawable().getIntrinsicWidth(),                            v.getDrawable().getIntrinsicHeight(),                            0, 0));            // Flush out all the original data.            mDataAdapter.flush();            mFilmStripView.setDataAdapter(mDataAdapter);        }        //设置nfc        setupNfcBeamPush();        //设置观察者，来分别观察图片的变化和视频资源的变化        mLocalImagesObserver = new LocalMediaObserver();        mLocalVideosObserver = new LocalMediaObserver();        getContentResolver().registerContentObserver(                MediaStore.Images.Media.EXTERNAL_CONTENT_URI, true,                mLocalImagesObserver);        getContentResolver().registerContentObserver(                MediaStore.Video.Media.EXTERNAL_CONTENT_URI, true,                mLocalVideosObserver);        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);        mDeveloperMenuEnabled = prefs.getBoolean(CameraSettings.KEY_DEVELOPER_MENU, false);        //设置窗口大小        Display display = getWindowManager().getDefaultDisplay();        Point size = new Point();        display.getSize(size);        int width = size.x;        int height = size.y;        int lower = Math.min(width, height);        int offset = lower * 10 / 100;        SETTING_LIST_WIDTH_1 = lower / 2 + offset;        SETTING_LIST_WIDTH_2 = lower / 2 - offset;        //注册关于sd的挂载的广播        registerSDcardMountedReceiver();    }

onStart方法：

@Override    public void onStart() {        super.onStart();        //开启添加图片、视频的service        bindMediaSaveService();        mPanoramaViewHelper.onStart();    }

onResume方法：

@Override    public void onResume() {        //权限检测        if (checkPermissions() || !mHasCriticalPermissions) {            super。onResume();            Log.v(TAG, "onResume: Missing critical permissions.");            finish();            return;        }        UsageStatistics.onEvent(UsageStatistics.COMPONENT_CAMERA,                UsageStatistics.ACTION_FOREGROUNDED, this.getClass().getSimpleName());        mOrientationListener.enable();        mCurrentModule.onResumeBeforeSuper();        super.onResume();        mCurrentModule.onResumeAfterSuper();        //设置预览画面能否滑动        setSwipingEnabled(true);        if (mResetToPreviewOnResume) {            // Go to the preview on resume.            mFilmStripView.getController().goToFirstItem();        }        // Default is showing the preview, unless disabled by explicitly        // starting an activity we want to return from to the filmstrip rather        // than the preview.        mResetToPreviewOnResume = true;        //查看图片和视频资源有无变化，有则重新加载        if (mLocalVideosObserver.isMediaDataChangedDuringPause()                || mLocalImagesObserver.isMediaDataChangedDuringPause()) {            if (!mSecureCamera) {                // If it's secure camera, requestLoad() should not be called                // as it will load all the data.                mDataAdapter.requestLoad(getContentResolver());                mThumbnailDrawable = null;            }        }        //重置观察者标志位        mLocalImagesObserver.setActivityPaused(false);        mLocalVideosObserver.setActivityPaused(false);        //This is a temporal solution to share LED resource        //as Android doesn’t have any default intent to share the state.        // if the led flash light is open, turn it off        Log.d(TAG, "send the turn off Flashlight broadcast");        //关闭闪光灯        Intent intent = new Intent("org.codeaurora.snapcam.action.CLOSE_FLASHLIGHT");        intent.putExtra("camera_led", true);        sendBroadcast(intent);    }

onPause方法：

    @Override    public void onPause() {        // Delete photos that are pending deletion        //删除照片时正好界面pause了的处理        performDeletion();        //关闭重力传感器监听        mOrientationListener.disable();        mCurrentModule.onPauseBeforeSuper();        super.onPause();        mCurrentModule.onPauseAfterSuper();        //设置观察者的标志位        mLocalImagesObserver.setActivityPaused(true);        mLocalVideosObserver.setActivityPaused(true);    }

onStop方法：

    @Override    protected void onStop() {        super.onStop();        mPanoramaViewHelper.onStop();        //断开存储视频、图片的service        unbindMediaSaveService();    }

onDestory方法：

@Override    public void onDestroy() {        //释放唤醒锁        if (mWakeLock != null && mWakeLock.isHeld()) {            mWakeLock.release();            Log.d(TAG, "wake lock release");        }        //注销观察者和sd卡的挂载广播        if (mLocalImagesObserver != null) {            getContentResolver().unregisterContentObserver(mLocalImagesObserver);            getContentResolver().unregisterContentObserver(mLocalVideosObserver);            unregisterReceiver(mSDcardMountedReceiver);        }        super.onDestroy();    }

先分析到这，接下在再补充。。。