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 com.sparshik.monalisa; import android.Manifest; import android.app.Activity; import android.app.AlertDialog; import android.app.Dialog; import android.app.DialogFragment; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.content.SharedPreferences; import android.content.pm.PackageManager; import android.graphics.Bitmap; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.os.Bundle; import android.preference.PreferenceManager; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v4.app.ActivityCompat; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.Menu; import android.view.MenuItem; import android.view.View; import com.google.android.gms.common.ConnectionResult; import com.google.android.gms.common.GoogleApiAvailability; import com.google.android.gms.vision.CameraSource; import com.google.android.gms.vision.MultiProcessor; import com.google.android.gms.vision.Tracker; import com.google.android.gms.vision.face.Face; import com.google.android.gms.vision.face.FaceDetector; import com.google.firebase.crash.FirebaseCrash; import com.sparshik.monalisa.base.BaseActivity; import com.sparshik.monalisa.emojis.EmojiDialogFragment; import com.sparshik.monalisa.ui.camera.CameraSourcePreview; import com.sparshik.monalisa.ui.camera.GraphicOverlay; import com.sparshik.monalisa.utils.Constants; import java.io.IOException; /** * Activity for the face tracker app. This app detects faces with the rear facing camera, and draws * overlay graphics to indicate the position, size, and ID of each face. */ public final class FaceTrackerActivity extends BaseActivity implements EmojiDialogFragment.Callback { private static final String TAG = "FaceTracker"; private static final int RC_HANDLE_GMS = 9001; // permission request codes need to be < 256 private static final int RC_HANDLE_CAMERA_PERM = 2; private CameraSource mCameraSource = null; private CameraSourcePreview mPreview; private GraphicOverlay mGraphicOverlay; private SharedPreferences preferences; //============================================================================================== // Activity Methods //============================================================================================== /** * Initializes the UI and initiates the creation of a face detector. */ @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.main); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); mPreview = (CameraSourcePreview) findViewById(R.id.preview); mGraphicOverlay = (GraphicOverlay) findViewById(R.id.faceOverlay); preferences = PreferenceManager.getDefaultSharedPreferences(this); // 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(); } else { requestCameraPermission(); } FloatingActionButton fab_emoji = (FloatingActionButton) findViewById(R.id.fab_emoji); fab_emoji.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { showEmojiDialog(view); } }); } /** * 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 onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_live, menu); return super.onCreateOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_photo) { startActivity(new Intent(this, PhotoActivity.class)); return true; } return super.onOptionsItemSelected(item); } /** * 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. */ private void createCameraSource() { Context context = getApplicationContext(); FaceDetector detector = new FaceDetector.Builder(context) .setClassificationType(FaceDetector.ALL_CLASSIFICATIONS).build(); detector.setProcessor(new MultiProcessor.Builder<>(new GraphicFaceTrackerFactory()).build()); if (!detector.isOperational()) { // Note: The first time that an app using face API is installed on a device, GMS will // download a native library 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 faces. // // isOperational() can be used to check if the required native library is currently // available. The detector will automatically become operational once the library // download completes on device. Log.w(TAG, "Face detector dependencies are not yet available."); } mCameraSource = new CameraSource.Builder(context, detector).setRequestedPreviewSize(640, 480) .setFacing(CameraSource.CAMERA_FACING_FRONT).setRequestedFps(30.0f).build(); } /** * Restarts the camera. */ @Override protected void onResume() { super.onResume(); startCameraSource(); } /** * Stops the camera. */ @Override protected void onPause() { super.onPause(); mPreview.stop(); } /** * Releases the resources associated with the camera source, the associated detector, and the * rest of the processing pipeline. */ @Override protected void onDestroy() { super.onDestroy(); if (mCameraSource != null) { mCameraSource.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, String[] permissions, 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 createCameraSource(); return; } FirebaseCrash.log(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("Face Tracker sample").setMessage(R.string.no_camera_permission) .setPositiveButton(R.string.ok, listener).show(); } //============================================================================================== // Camera Source Preview //============================================================================================== /** * 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() { // 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); FirebaseCrash.report(e); mCameraSource.release(); mCameraSource = null; } } } //============================================================================================== // Graphic Face Tracker //============================================================================================== public void showEmojiDialog(View view) { DialogFragment dialogFragment = new EmojiDialogFragment(); dialogFragment.show(FaceTrackerActivity.this.getFragmentManager(), "EmojiDialogFragment"); } @Override public void onClose() { } /** * Factory for creating a face tracker to be associated with a new face. The multiprocessor * uses this factory to create face trackers as needed -- one for each individual. */ private class GraphicFaceTrackerFactory implements MultiProcessor.Factory<Face> { @Override public Tracker<Face> create(Face face) { return new GraphicFaceTracker(mGraphicOverlay); } } /** * Face tracker for each detected individual. This maintains a face graphic within the app's * associated face overlay. */ private class GraphicFaceTracker extends Tracker<Face> { private GraphicOverlay mOverlay; private FaceGraphic mFaceGraphic; GraphicFaceTracker(GraphicOverlay overlay) { mOverlay = overlay; mFaceGraphic = new FaceGraphic(overlay); } /** * Start tracking the detected face instance within the face overlay. */ @Override public void onNewItem(int faceId, Face item) { mFaceGraphic.setId(faceId); } /** * Update the position/characteristics of the face within the overlay. */ @Override public void onUpdate(FaceDetector.Detections<Face> detectionResults, Face face) { mOverlay.add(mFaceGraphic); int current_emoji = preferences.getInt(Constants.KEY_CURRENT_EMOJI, Constants.DEFAULT_EMOJI); Drawable d = getResources().getDrawable(current_emoji); Bitmap secondBitmap = ((BitmapDrawable) (d)).getBitmap(); mFaceGraphic.updateFace(face, secondBitmap); } /** * Hide the graphic when the corresponding face was not detected. This can happen for * intermediate frames temporarily (e.g., if the face was momentarily blocked from * view). */ @Override public void onMissing(FaceDetector.Detections<Face> detectionResults) { mOverlay.remove(mFaceGraphic); } /** * Called when the face is assumed to be gone for good. Remove the graphic annotation from * the overlay. */ @Override public void onDone() { mOverlay.remove(mFaceGraphic); } } }