Android，androidadt

Android，androidadt

com.android.camera.Camera.java，主要的實現Activity，繼承於ActivityBase。

ActivityBase                                                                          

在ActivityBase中執行流程：

Camera.java                                                                          

接下來分析Camera.java，執行流程：

1、onCreate

// 獲得網路攝影機的數量，前置和後置getPreferredCameraId();// 獲得對焦設定eg：連續對焦或者其它String[] defaultFocusModes = getResources().getStringArray(R.array.pref_camera_focusmode_default_array);//執行個體化Focus管理對象mFocusManager = new FocusManager(mPreferences, defaultFocusModes);// 開啟線程來啟動網路攝影機mCameraOpenThread.start();// 是否是第三方應用啟動拍照功能mIsImageCaptureIntent = isImageCaptureIntent();// 設定UI布局檔案setContentView(R.layout.camera);if (mIsImageCaptureIntent) {       // 當第三方其送拍照，需要顯示不同的UI，比如取消鍵盤       mReviewDoneButton = (Rotatable) findViewById(R.id.btn_done);       mReviewCancelButton = (Rotatable) findViewById(R.id.btn_cancel);       findViewById(R.id.btn_cancel).setVisibility(View.VISIBLE);} else {       // 反之顯示縮圖       mThumbnailView = (RotateImageView) findViewById(R.id.thumbnail);       mThumbnailView.enableFilter(false);       mThumbnailView.setVisibility(View.VISIBLE);}// 一個能旋轉的dialog.比如相機設定的dialog,這個類實現了旋轉的父類mRotateDialog = new RotateDialogController(this, R.layout.rotate_dialog);// 設定camera的ID，寫道SharedPreference中mPreferences.setLocalId(this, mCameraId);// 更新preferenceCameraSettings.upgradeLocalPreferences(mPreferences.getLocal());// 獲得相機數mNumberOfCameras = CameraHolder.instance().getNumberOfCameras();//  貌似是獲得是否是快速拍照mQuickCapture = getIntent().getBooleanExtra(EXTRA_QUICK_CAPTURE, false);// 為當前的preview重設曝光值resetExposureCompensation();// 隱藏系統導覽列等Util.enterLightsOutMode(getWindow());//SurfaceView SurfaceView preview = (SurfaceView) findViewById(R.id.camera_preview);SurfaceHolder holder = preview.getHolder();holder.addCallback(this);holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);try {       // 這個join語句就是為了保證openCamera的線程執行完後，當前的線程才開始運行。主要是為了確保camera裝置被開啟了        mCameraOpenThread.join();        // 線程執行完後置為空白來讓系統回收資源        mCameraOpenThread = null;        if (mOpenCameraFail) {            // 開啟camera失敗，顯示“無法串連到相機”            Util.showErrorAndFinish(this, R.string.cannot_connect_camera);            return;        } else if (mCameraDisabled) {            // 由於安全政策限制，相機已被停用            Util.showErrorAndFinish(this, R.string.camera_disabled);            return;        }} catch (InterruptedException ex) {           // ignore}//開啟顯示的子線程mCameraPreviewThread.start();if (mIsImageCaptureIntent) {    //如果是第三方開啟的 ，setupCaptureParams 設定拍照的參數       setupCaptureParams();} else {      //設定ModePicker        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);mOnScreenIndicators = (Rotatable) findViewById(R.id.on_screen_indicators);mLocationManager = new LocationManager(this, this);//網路攝影機IDmBackCameraId = CameraHolder.instance().getBackCameraId();mFrontCameraId = CameraHolder.instance().getFrontCameraId();// 在startPreview裡面有notify方法synchronized (mCameraPreviewThread) {      try {          mCameraPreviewThread.wait();       } catch (InterruptedException ex) {            // ignore       }}// 初始化各種控制按鈕initializeIndicatorControl();//初始化拍照聲音mCameraSound = new CameraSound();try {       //確保顯示       mCameraPreviewThread.join();} catch (InterruptedException ex) {        // ignore}mCameraPreviewThread = null;

2、surfaceCreated

啥都沒做

3、surfaceChanged

// 確保在holder中有surface if (holder.getSurface() == null) {       Log.d(TAG, "holder.getSurface() == null");        return;}// 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;if (mCameraDevice == null) return;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) {        startPreview();        startFaceDetection();} else {        if (Util.getDisplayRotation(this) != mDisplayRotation) {            setDisplayOrientation();}        if (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);        }}// 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(); }

如果是第一次載入，則執行mHandler.sendEmptyMessage(FIRST_TIME_INIT); 對應處理的是initializeFirstTime();

/**     * 初始化，第一次初始化     *  // 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());        // 初始化螢幕最上方的標誌，比如開啟了曝光值啊，什麼的        initOnScreenIndicator();        // 位置服務        mLocationManager.recordLocation(recordLocation);        keepMediaProviderInstance();        // 檢查儲存空間和初始化儲存目錄        checkStorage();        // Initialize last picture button.        mContentResolver = getContentResolver();        if (!mIsImageCaptureIntent) {  // no thumbnail in image capture intent            // 初始化縮圖            initThumbnailButton();        }        // Initialize shutter button.        // 初始化拍照按鈕並設定監聽事件        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);        // 聚焦框        mFocusAreaIndicator = (RotateLayout) findViewById(R.id.focus_indicator_rotate_layout);        CameraInfo info = CameraHolder.instance().getCameraInfo()[mCameraId];        boolean mirror = (info.facing == CameraInfo.CAMERA_FACING_FRONT);        mFocusManager.initialize(mFocusAreaIndicator, mPreviewFrame, mFaceView, this,                mirror, mDisplayOrientation);        // 初始化一個圖片的儲存線程        mImageSaver = new ImageSaver();        // 設定螢幕亮度        Util.initializeScreenBrightness(getWindow(), getContentResolver());        // 註冊SD卡相關的廣播，比如拔出儲存卡什麼的        installIntentFilter();        // 初始化縮放UI        initializeZoom();        // 更新螢幕上的閃光燈什麼的標記        updateOnScreenIndicators();        // 開始面部檢測        startFaceDetection();        // Show the tap to focus toast if this is the first start.        // 假如是第一次啟動，提示使用者“觸摸對焦”        if (mFocusAreaSupported &&                mPreferences.getBoolean(CameraSettings.KEY_CAMERA_FIRST_USE_HINT_SHOWN, true)) {            // Delay the toast for one second to wait for orientation.            mHandler.sendEmptyMessageDelayed(SHOW_TAP_TO_FOCUS_TOAST, 1000);        }        mFirstTimeInitialized = true;        addIdleHandler();    }

如果不是，則執行initializeSecondTime();

/**     *  // 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.        //方向翻轉設定enable，其中包括翻轉的時候的動畫        mOrientationListener.enable();        // Start location update if needed.        boolean recordLocation = RecordLocationPreference.get(                mPreferences, getContentResolver());        mLocationManager.recordLocation(recordLocation);        //設定SD卡廣播        installIntentFilter();        mImageSaver = new ImageSaver();        //初始化Zoom        initializeZoom();        //mMediaProviderClient=媒體Provider對象        keepMediaProviderInstance();        //檢查硬碟        checkStorage();        //淡出retake和done的Button        hidePostCaptureAlert();        if (!mIsImageCaptureIntent) {            //如果不是第三方開啟，則更新縮圖            updateThumbnailButton();            mModePicker.setCurrentMode(ModePicker.MODE_CAMERA);        }    }

4、surfaceDestroyed

stopPreview();mSurfaceHolder = null;

我是天王蓋地虎的分割線