) findViewById(R.id.graphicOverlay);
// Set good defaults for capturing text.
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 Speak. Pinch/Stretch to zoom",
Snackbar.LENGTH_LONG)
.show();
// TODO: Set up the Text To Speech engine.
}
/**
* 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 ocr detector to detect small text samples
* 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();
// TODO: Create the TextRecognizer
// TODO: Set the TextRecognizer's Processor.
// TODO: Check if the TextRecognizer is operational.
// TODO: Create the mCameraSource using the TextRecognizer.
}
/**
* 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();
}
}
/**
* Callback for the result from requesting permissions. This method
* is invoked for every call on {@link #requestPermissions(String[], int)}.
*
* Note: It is possible that the permissions request interaction
* with the user is interrupted. In this case you will receive empty permissions
* and results arrays which should be treated as a cancellation.
*
*
* @param requestCode The request code passed in {@link #requestPermissions(String[], int)}.
* @param permissions The requested permissions. Never null.
* @param grantResults The grant results for the corresponding permissions
* which is either {@link PackageManager#PERMISSION_GRANTED}
* or {@link PackageManager#PERMISSION_DENIED}. Never null.
* @see #requestPermissions(String[], int)
*/
@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 speak the tapped TextBlock, if any, out loud.
*
* @param rawX - the raw position of the tap
* @param rawY - the raw position of the tap.
* @return true if the tap was on a TextBlock
*/
private boolean onTap(float rawX, float rawY) {
// TODO: Speak the text when the user taps on screen.
return false;
}
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.
*
* 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) {
if (mCameraSource != null) {
mCameraSource.doZoom(detector.getScaleFactor());
}
}
}
}