Java tutorial
/* * Copyright (C) 2016 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 cn.yibulz.caviewtest; import com.google.android.cameraview.CameraView; import android.Manifest; import android.app.Dialog; import android.content.DialogInterface; import android.content.pm.PackageManager; import android.os.Build; import android.os.Bundle; import android.os.Environment; import android.os.Handler; import android.os.HandlerThread; import android.support.annotation.NonNull; import android.support.annotation.StringRes; import android.support.design.widget.FloatingActionButton; import android.support.v4.app.ActivityCompat; import android.support.v4.app.DialogFragment; import android.support.v4.content.ContextCompat; import android.support.v7.app.ActionBar; import android.support.v7.app.AlertDialog; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Toast; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; public class MainActivity extends AppCompatActivity implements ActivityCompat.OnRequestPermissionsResultCallback { private static final String TAG = "MainActivity"; private static final int REQUEST_CAMERA_PERMISSION = 1; private static final String FRAGMENT_DIALOG = "dialog"; private static final int[] FLASH_OPTIONS = { CameraView.FLASH_AUTO, CameraView.FLASH_OFF, CameraView.FLASH_ON, }; private static final int[] FLASH_ICONS = { R.drawable.ic_flash_auto, R.drawable.ic_flash_off, R.drawable.ic_flash_on, }; private static final int[] FLASH_TITLES = { R.string.flash_auto, R.string.flash_off, R.string.flash_on, }; private int mCurrentFlash; private CameraView mCameraView; private Handler mBackgroundHandler; private View.OnClickListener mOnClickListener = new View.OnClickListener() { @Override public void onClick(View v) { switch (v.getId()) { case R.id.take_picture: if (mCameraView != null) { mCameraView.takePicture(); } break; } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mCameraView = (CameraView) findViewById(R.id.camera); if (mCameraView != null) { mCameraView.addCallback(mCallback); } FloatingActionButton takePicture = (FloatingActionButton) findViewById(R.id.take_picture); if (takePicture != null) { takePicture.setOnClickListener(mOnClickListener); } Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); ActionBar actionBar = getSupportActionBar(); if (actionBar != null) { actionBar.setDisplayShowTitleEnabled(false); } } @Override protected void onResume() { super.onResume(); if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) { mCameraView.start(); } else if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA)) { ConfirmationDialogFragment .newInstance(R.string.camera_permission_confirmation, new String[] { Manifest.permission.CAMERA }, REQUEST_CAMERA_PERMISSION, R.string.camera_permission_not_granted) .show(getSupportFragmentManager(), FRAGMENT_DIALOG); } else { ActivityCompat.requestPermissions(this, new String[] { Manifest.permission.CAMERA }, REQUEST_CAMERA_PERMISSION); } } @Override protected void onPause() { mCameraView.stop(); super.onPause(); } @Override protected void onDestroy() { super.onDestroy(); if (mBackgroundHandler != null) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) { mBackgroundHandler.getLooper().quitSafely(); } else { mBackgroundHandler.getLooper().quit(); } mBackgroundHandler = null; } } @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { switch (requestCode) { case REQUEST_CAMERA_PERMISSION: if (permissions.length != 1 || grantResults.length != 1) { throw new RuntimeException("Error on requesting camera permission."); } if (grantResults[0] != PackageManager.PERMISSION_GRANTED) { Toast.makeText(this, R.string.camera_permission_not_granted, Toast.LENGTH_SHORT).show(); } // No need to start camera here; it is handled by onResume break; } } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.switch_flash: if (mCameraView != null) { mCurrentFlash = (mCurrentFlash + 1) % FLASH_OPTIONS.length; item.setTitle(FLASH_TITLES[mCurrentFlash]); item.setIcon(FLASH_ICONS[mCurrentFlash]); mCameraView.setFlash(FLASH_OPTIONS[mCurrentFlash]); } break; case R.id.switch_camera: if (mCameraView != null) { int facing = mCameraView.getFacing(); mCameraView.setFacing( facing == CameraView.FACING_FRONT ? CameraView.FACING_BACK : CameraView.FACING_FRONT); } break; } return false; } private Handler getBackgroundHandler() { if (mBackgroundHandler == null) { HandlerThread thread = new HandlerThread("background"); thread.start(); mBackgroundHandler = new Handler(thread.getLooper()); } return mBackgroundHandler; } private CameraView.Callback mCallback = new CameraView.Callback() { @Override public void onCameraOpened(CameraView cameraView) { Log.d(TAG, "onCameraOpened"); } @Override public void onCameraClosed(CameraView cameraView) { Log.d(TAG, "onCameraClosed"); } @Override public void onPictureTaken(CameraView cameraView, final byte[] data) { Log.d(TAG, "onPictureTaken " + data.length); Toast.makeText(cameraView.getContext(), R.string.picture_taken, Toast.LENGTH_SHORT).show(); getBackgroundHandler().post(new Runnable() { @Override public void run() { // This demo app saves the taken picture to a constant file. // $ adb pull /sdcard/Android/data/com.google.android.cameraview.demo/files/Pictures/picture.jpg File file = new File(getExternalFilesDir(Environment.DIRECTORY_PICTURES), "picture.jpg"); OutputStream os = null; try { os = new FileOutputStream(file); os.write(data); os.close(); } catch (IOException e) { Log.w(TAG, "Cannot write to " + file, e); } finally { if (os != null) { try { os.close(); } catch (IOException e) { // Ignore } } } } }); } }; public static class ConfirmationDialogFragment extends DialogFragment { private static final String ARG_MESSAGE = "message"; private static final String ARG_PERMISSIONS = "permissions"; private static final String ARG_REQUEST_CODE = "request_code"; private static final String ARG_NOT_GRANTED_MESSAGE = "not_granted_message"; public static ConfirmationDialogFragment newInstance(@StringRes int message, String[] permissions, int requestCode, @StringRes int notGrantedMessage) { ConfirmationDialogFragment fragment = new ConfirmationDialogFragment(); Bundle args = new Bundle(); args.putInt(ARG_MESSAGE, message); args.putStringArray(ARG_PERMISSIONS, permissions); args.putInt(ARG_REQUEST_CODE, requestCode); args.putInt(ARG_NOT_GRANTED_MESSAGE, notGrantedMessage); fragment.setArguments(args); return fragment; } @NonNull @Override public Dialog onCreateDialog(Bundle savedInstanceState) { final Bundle args = getArguments(); return new AlertDialog.Builder(getActivity()).setMessage(args.getInt(ARG_MESSAGE)) .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { String[] permissions = args.getStringArray(ARG_PERMISSIONS); if (permissions == null) { throw new IllegalArgumentException(); } ActivityCompat.requestPermissions(getActivity(), permissions, args.getInt(ARG_REQUEST_CODE)); } }).setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { Toast.makeText(getActivity(), args.getInt(ARG_NOT_GRANTED_MESSAGE), Toast.LENGTH_SHORT) .show(); } }).create(); } } }