私はバーコード デコード アプリケーションを持っています: https://play.google.com/store/apps/details?id=com.barcodereader
スキャンにZbarライブラリとGoogle Vision APIを使用しました
今私が欲しいのは、ユーザーがトーチ（フラッシュ）をオンにするためにアプリバーのボタンをタップした場合にバーコードをスキャンしているときに、オンとオフを逆にする必要があることです。
しかし、問題は、カメラがすべてのパラメーターで既にオンになっているため、ユーザーがボタンをタップしてトーチをオンにすると、進行中のカメラパラメーターを中断する必要があり、私はそれをしたくありません。
既存のカメラパラメータを変更せずにトーチをオンにする別の方法を探しています..
以下は ZBar と Google Vision のカメラ アクティビティです。どちらもカメラ プレビュー用に他のカメラ クラスを使用しています。
@SuppressWarnings("deprecation")
public class ZBarFirstScannerActivity extends AppCompatActivity{
//TextView tv;
ImageView iv;
LinearLayout ll;
private Camera mCamera;
private CameraPreview mPreview;
private Handler autoFocusHandler;
private ImageScanner scanner;
private boolean barcodeScanned = false;
private boolean previewing = true;
TextView tv;
static {
System.loadLibrary("iconv");
}
static {
System.loadLibrary("zbarjni");
}
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.barcode_capture1d);
tv = (TextView) findViewById(R.id.textVertical);
tv.setRotation(90);
initToolbar();
autoFocusHandler = new Handler();
mCamera = getCameraInstance();
// Instance barcode scanner
scanner = new ImageScanner();
scanner.setConfig(0, Config.X_DENSITY, 1);
scanner.setConfig(0, Config.Y_DENSITY, 1);
scanner.setConfig(Symbol.CODE128, Config.ENABLE,1);
scanner.setConfig(Symbol.EAN13, Config.ENABLE,1);
mPreview = new CameraPreview(this, mCamera, previewCb, autoFocusCB);
FrameLayout preview = (FrameLayout)findViewById(R.id.cameraPreview);
preview.addView(mPreview);
}
private void initToolbar() {
final Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
final ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.setHomeButtonEnabled(true);
actionBar.setHomeAsUpIndicator(ContextCompat.getDrawable(this, R.drawable.abc_ic_ab_back_mtrl_am_alpha));
actionBar.setDisplayHomeAsUpEnabled(true);
}
}
/** A safe way to get an instance of the Camera object. */
public static Camera getCameraInstance()
{
Camera c = null;
try
{
c = Camera.open();
} catch (Exception e)
{
//nada
}
return c;
}
private void releaseCamera()
{
if (mCamera != null)
{
previewing = false;
mCamera.setPreviewCallback(null);
mCamera.release();
mCamera = null;
}
}
PreviewCallback previewCb = new PreviewCallback()
{
public void onPreviewFrame(byte[] data, Camera camera)
{
Camera.Parameters parameters = camera.getParameters();
Size size = parameters.getPreviewSize();
Image barcode = new Image(size.width, size.height, "Y800");
barcode.setData(data);
int result = scanner.scanImage(barcode);
if (result != 0)
{
previewing = false;
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
SymbolSet syms = scanner.getResults();
for (Symbol sym : syms)
{
barcodeScanned = true;
Intent returnIntent = new Intent();
returnIntent.putExtra("BARCODE", sym.getData());
setResult(MainActivity.BAR_CODE_TYPE_128,returnIntent);
releaseCamera();
finish();
break;
}
}
}
};
// Mimic continuous auto-focusing
AutoFocusCallback autoFocusCB = new AutoFocusCallback()
{
public void onAutoFocus(boolean success, Camera camera)
{
autoFocusHandler.postDelayed(doAutoFocus, 3000);
}
};
private Runnable doAutoFocus = new Runnable()
{
public void run()
{
if (previewing)
mCamera.autoFocus(autoFocusCB);
}
};
public void onPause() {
super.onPause();
releaseCamera();
}
public void onResume(){
super.onResume();
new ZBarFirstScannerActivity();
}
@Override
public void onBackPressed() {
releaseCamera();
finish();
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
}
そしてGoogleScanner
public final class GoogleScannerActivity extends AppCompatActivity {
private static final String TAG = "Barcode-reader";
// intent request code to handle updating play services if needed.
private static final int RC_HANDLE_GMS = 9001;
// permission request codes need to be < 256
private static final int RC_HANDLE_CAMERA_PERM = 2;
// constants used to pass extra data in the intent
public static final String AutoFocus = "AutoFocus";
public static final String UseFlash = "UseFlash";
public static final String BarcodeObject = "Barcode";
Bitmap bmp;
FileOutputStream fos = null;
private Camera c;
Switch aSwitch;
private CameraSource mCameraSource;
private CameraSourcePreview mPreview;
private GraphicOverlay<BarcodeGraphic> mGraphicOverlay;
// helper objects for detecting taps and pinches.
private ScaleGestureDetector scaleGestureDetector;
private GestureDetector gestureDetector;
/**
* Initializes the UI and creates the detector pipeline.
*/
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.barcode_capture2d);
initToolbar();
ActivitySource.caller = this;
mPreview = (CameraSourcePreview) findViewById(R.id.preview);
mGraphicOverlay = (GraphicOverlay<BarcodeGraphic>)findViewById(R.id.graphicOverlay);
boolean autoFocus = true;
boolean useFlash = false;
// Check for the camera permission before accessing the camera. If the
// permission is not granted yet, request permission.
int rc = ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
if (rc == PackageManager.PERMISSION_GRANTED) {
createCameraSource(autoFocus, useFlash);
} else {
requestCameraPermission();
}
gestureDetector = new GestureDetector(this, new CaptureGestureListener());
scaleGestureDetector = new ScaleGestureDetector(this, new ScaleListener());
/*Snackbar.make(mGraphicOverlay, "Tap to capture. Pinch/Stretch to zoom",
Snackbar.LENGTH_LONG)
.show();*/
}
private void initToolbar() {
final Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
final ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.setHomeButtonEnabled(true);
actionBar.setHomeAsUpIndicator(ContextCompat.getDrawable(this, R.drawable.abc_ic_ab_back_mtrl_am_alpha));
actionBar.setDisplayHomeAsUpEnabled(true);
}
}
private Camera.Size getBestPreviewSize(int width, int height, Camera.Parameters parameters){
Camera.Size bestSize = null;
List<Camera.Size> sizeList = parameters.getSupportedPreviewSizes();
bestSize = sizeList.get(0);
for(int i = 1; i < sizeList.size(); i++){
if((sizeList.get(i).width * sizeList.get(i).height) >
(bestSize.width * bestSize.height)){
bestSize = sizeList.get(i);
}
}
return bestSize;
}
/**
* Handles the requesting of the camera permission. This includes
* showing a "Snackbar" message of why the permission is needed then
* sending the request.
*/
private void requestCameraPermission() {
Log.w(TAG, "Camera permission is not granted. Requesting permission");
final String[] permissions = new String[]{Manifest.permission.CAMERA};
if (!ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.CAMERA)) {
ActivityCompat.requestPermissions(this, permissions, RC_HANDLE_CAMERA_PERM);
return;
}
final Activity thisActivity = this;
View.OnClickListener listener = new View.OnClickListener() {
@Override
public void onClick(View view) {
ActivityCompat.requestPermissions(thisActivity, permissions,
RC_HANDLE_CAMERA_PERM);
}
};
Snackbar.make(mGraphicOverlay, R.string.permission_camera_rationale,
Snackbar.LENGTH_INDEFINITE)
.setAction(R.string.ok, listener)
.show();
}
@Override
public boolean onTouchEvent(MotionEvent e) {
boolean b = scaleGestureDetector.onTouchEvent(e);
boolean c = gestureDetector.onTouchEvent(e);
return b || c || super.onTouchEvent(e);
}
/**
* Creates and starts the camera. Note that this uses a higher resolution in comparison
* to other detection examples to enable the barcode detector to detect small barcodes
* at long distances.
*
* Suppressing InlinedApi since there is a check that the minimum version is met before using
* the constant.
*/
@SuppressLint("InlinedApi")
private void createCameraSource(boolean autoFocus, boolean useFlash) {
Context context = getApplicationContext();
// A barcode detector is created to track barcodes. An associated multi-processor instance
// is set to receive the barcode detection results, track the barcodes, and maintain
// graphics for each barcode on screen. The factory is used by the multi-processor to
// create a separate tracker instance for each barcode.
BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(context).setBarcodeFormats(Barcode.CODE_128 | Barcode.DATA_MATRIX | Barcode.QR_CODE).build();
BarcodeTrackerFactory barcodeFactory = new BarcodeTrackerFactory(mGraphicOverlay);
barcodeDetector.setProcessor(
new MultiProcessor.Builder<>(barcodeFactory).build());
if (!barcodeDetector.isOperational()) {
// Note: The first time that an app using the barcode or face API is installed on a
// device, GMS will download a native libraries to the device in order to do detection.
// Usually this completes before the app is run for the first time. But if that
// download has not yet completed, then the above call will not detect any barcodes
// and/or faces.
//
// isOperational() can be used to check if the required native libraries are currently
// available. The detectors will automatically become operational once the library
// downloads complete on device.
Log.w(TAG, "Detector dependencies are not yet available.");
// Check for low storage. If there is low storage, the native library will not be
// downloaded, so detection will not become operational.
IntentFilter lowstorageFilter = new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW);
boolean hasLowStorage = registerReceiver(null, lowstorageFilter) != null;
if (hasLowStorage) {
Toast.makeText(this, R.string.low_storage_error, Toast.LENGTH_LONG).show();
Log.w(TAG, getString(R.string.low_storage_error));
}
}
// Creates and starts the camera. Note that this uses a higher resolution in comparison
// to other detection examples to enable the barcode detector to detect small barcodes
// at long distances.
CameraSource.Builder builder = new CameraSource.Builder(getApplicationContext(), barcodeDetector)
.setFacing(CameraSource.CAMERA_FACING_BACK)
.setRequestedPreviewSize(1100, 844)
.setRequestedFps(15.0f);
// make sure that auto focus is an available option
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
builder = builder.setFocusMode(
autoFocus ? Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE : null);
}
mCameraSource = builder
.setFlashMode(useFlash ? Camera.Parameters.FLASH_MODE_TORCH : null)
.build();
}
/**
* Restarts the camera.
*/
@Override
protected void onResume() {
super.onResume();
startCameraSource();
}
/**
* Stops the camera.
*/
@Override
protected void onPause() {
super.onPause();
if (mPreview != null) {
mPreview.stop();
}
}
/**
* Releases the resources associated with the camera source, the associated detectors, and the
* rest of the processing pipeline.
*/
@Override
protected void onDestroy() {
super.onDestroy();
if (mPreview != null) {
mPreview.release();
}
}
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull String[] permissions,
@NonNull int[] grantResults) {
if (requestCode != RC_HANDLE_CAMERA_PERM) {
Log.d(TAG, "Got unexpected permission result: " + requestCode);
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
return;
}
if (grantResults.length != 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "Camera permission granted - initialize the camera source");
// we have permission, so create the camerasource
boolean autoFocus = getIntent().getBooleanExtra(AutoFocus,false);
boolean useFlash = getIntent().getBooleanExtra(UseFlash, false);
createCameraSource(autoFocus, useFlash);
return;
}
Log.e(TAG, "Permission not granted: results len = " + grantResults.length +
" Result code = " + (grantResults.length > 0 ? grantResults[0] : "(empty)"));
DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
finish();
}
};
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Multitracker sample")
.setMessage(R.string.no_camera_permission)
.setPositiveButton(R.string.ok, listener)
.show();
}
/**
* Starts or restarts the camera source, if it exists. If the camera source doesn't exist yet
* (e.g., because onResume was called before the camera source was created), this will be called
* again when the camera source is created.
*/
private void startCameraSource() throws SecurityException {
// check that the device has play services available.
int code = GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(
getApplicationContext());
if (code != ConnectionResult.SUCCESS) {
Dialog dlg =
GoogleApiAvailability.getInstance().getErrorDialog(this, code, RC_HANDLE_GMS);
dlg.show();
}
if (mCameraSource != null) {
try {
mPreview.start(mCameraSource, mGraphicOverlay);
} catch (IOException e) {
Log.e(TAG, "Unable to start camera source.", e);
mCameraSource.release();
mCameraSource = null;
}
}
}
/**
* onTap is called to capture the oldest barcode currently detected and
* return it to the caller.
*
* @param rawX - the raw position of the tap
* @param rawY - the raw position of the tap.
* @return true if the activity is ending.
*/
private boolean onTap(float rawX, float rawY) {
//TODO: use the tap position to select the barcode.
BarcodeGraphic graphic = mGraphicOverlay.getFirstGraphic();
Barcode barcode = null;
if (graphic != null) {
barcode = graphic.getBarcode();
if (barcode != null) {
Intent data = new Intent();
data.putExtra(BarcodeObject, barcode);
setResult(CommonStatusCodes.SUCCESS, data);
finish();
}
else {
Log.d(TAG, "barcode data is null");
}
}
else {
Log.d(TAG,"no barcode detected");
}
return barcode != null;
}
private class CaptureGestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
return onTap(e.getRawX(), e.getRawY()) || super.onSingleTapConfirmed(e);
}
}
private class ScaleListener implements ScaleGestureDetector.OnScaleGestureListener {
/**
* Responds to scaling events for a gesture in progress.
* Reported by pointer motion.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
* @return Whether or not the detector should consider this event
* as handled. If an event was not handled, the detector
* will continue to accumulate movement until an event is
* handled. This can be useful if an application, for example,
* only wants to update scaling factors if the change is
* greater than 0.01.
*/
@Override
public boolean onScale(ScaleGestureDetector detector) {
return false;
}
/**
* Responds to the beginning of a scaling gesture. Reported by
* new pointers going down.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
* @return Whether or not the detector should continue recognizing
* this gesture. For example, if a gesture is beginning
* with a focal point outside of a region where it makes
* sense, onScaleBegin() may return false to ignore the
* rest of the gesture.
*/
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
return true;
}
/**
* Responds to the end of a scale gesture. Reported by existing
* pointers going up.
* <p/>
* Once a scale has ended, {@link ScaleGestureDetector#getFocusX()}
* and {@link ScaleGestureDetector#getFocusY()} will return focal point
* of the pointers remaining on the screen.
*
* @param detector The detector reporting the event - use this to
* retrieve extended info about event state.
*/
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
mCameraSource.doZoom(detector.getScaleFactor());
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
}