Java tutorial
/* * Copyright (C) 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 ch.hearc.drunksum; import android.Manifest; import android.annotation.SuppressLint; import android.app.Activity; import android.app.AlertDialog; import android.app.Dialog; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.content.IntentFilter; import android.content.pm.PackageManager; import android.hardware.Camera; import android.os.Bundle; import android.support.annotation.NonNull; import android.support.design.widget.Snackbar; import android.support.v4.app.ActivityCompat; import android.support.v7.app.AppCompatActivity; import android.text.InputType; import android.util.Log; import android.view.GestureDetector; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.View; import android.widget.EditText; import android.widget.SeekBar; import android.widget.Toast; import com.google.android.gms.common.ConnectionResult; import com.google.android.gms.common.GoogleApiAvailability; import com.google.android.gms.samples.vision.drunksum.R; import ch.hearc.drunksum.camera.CameraSource; import ch.hearc.drunksum.camera.CameraSourcePreview; import ch.hearc.drunksum.camera.GraphicOverlay; import com.google.android.gms.vision.text.Text; import com.google.android.gms.vision.text.TextRecognizer; import java.io.IOException; import java.text.DecimalFormat; import java.text.NumberFormat; /** * Activity for the Ocr Detecting app. This app detects text and displays the value with the * rear facing camera. During detection overlay graphics are drawn to indicate the position, * size, and contents of each TextBlock. */ public final class DrunkSumActivity extends AppCompatActivity { private static final String TAG = "DrunkSumActivity"; // 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 TextBlockObject = "String"; private CameraSource mCameraSource; private CameraSourcePreview mPreview; private GraphicOverlay<OcrGraphic> mGraphicOverlay; // Helper objects for detecting taps and pinches. private ScaleGestureDetector scaleGestureDetector; private GestureDetector gestureDetector; private double mSum; private static final NumberFormat formatter = new DecimalFormat("#0.00"); /** * Initializes the UI and creates the detector pipeline. */ @Override public void onCreate(Bundle bundle) { super.onCreate(bundle); setContentView(R.layout.ocr_capture); mPreview = (CameraSourcePreview) findViewById(R.id.preview); mGraphicOverlay = (GraphicOverlay<OcrGraphic>) 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, "Touch numbers to make the sum", Snackbar.LENGTH_LONG).show(); } @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.menu, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { /* Gre le clic sur un lment du menu */ if (item.getItemId() == R.id.reinit) { // remet la somme 0 Toast.makeText(this, "Sum reinitialized", Toast.LENGTH_SHORT).show(); mSum = 0; setTitle("Sum: " + formatter.format(mSum)); } else if (item.getItemId() == R.id.divide) { // propose de divisier la somme AlertDialog.Builder alert = new AlertDialog.Builder(this); alert.setTitle("Divide sum by:"); final EditText input = new EditText(this); // n'afficher que les chiffres input.setInputType(InputType.TYPE_CLASS_NUMBER); alert.setView(input); alert.setPositiveButton("Divide", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { double div = 0; try { // une exception survient si le texte est vide // si c'est 0, div vaut infinity div = mSum / Double.parseDouble(input.getText().toString()); } catch (Exception e) { } final Snackbar snackBar = Snackbar.make(mGraphicOverlay, "Divided sum: " + formatter.format(div), Snackbar.LENGTH_INDEFINITE); snackBar.setAction("OK", new View.OnClickListener() { @Override public void onClick(View v) { snackBar.dismiss(); } }); snackBar.show(); } }); alert.show(); } return true; } /** * 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(); // Create the TextRecognizer TextRecognizer textRecognizer = new TextRecognizer.Builder(context).build(); // Set the TextRecognizer's Processor. textRecognizer.setProcessor(new OcrDetectorProcessor(mGraphicOverlay)); // Check if the TextRecognizer is operational. if (!textRecognizer.isOperational()) { 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)); } } // Create the mCameraSource using the TextRecognizer. mCameraSource = new CameraSource.Builder(getApplicationContext(), textRecognizer) .setFacing(CameraSource.CAMERA_FACING_BACK).setRequestedPreviewSize(1280, 1024) .setRequestedFps(30.0f).setFlashMode(useFlash ? Camera.Parameters.FLASH_MODE_TORCH : null) .setFocusMode(autoFocus ? Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE : 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(); } } /** * Callback for the result from requesting permissions. This method * is invoked for every call on {@link #requestPermissions(String[], int)}. * <p> * <strong>Note:</strong> 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. * </p> * * @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) { OcrGraphic graphic = mGraphicOverlay.getGraphicAtLocation(rawX, rawY); Text text = null; if (graphic != null) { text = graphic.getText(); Log.d("onTap", "text tapped : " + text.getValue()); final double value = graphic.getValue(); if (value > 0) { Snackbar.make(mGraphicOverlay, "Add " + formatter.format(value) + " ?", Snackbar.LENGTH_LONG) .setAction("add", new View.OnClickListener() { @Override public void onClick(View v) { DrunkSumActivity.this.add(value); } }).show(); } } else { Log.d("onTap", "no text detected"); } return text != null; } private void add(double value) { mSum += value; Toast.makeText(this, "Sum: " + formatter.format(mSum), Toast.LENGTH_SHORT).show(); setTitle("Sum: " + formatter.format(mSum)); } 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) { if (mCameraSource != null) { mCameraSource.doZoom(detector.getScaleFactor()); } } } }