Java tutorial
/* * Copyright (C) 2008 ZXing authors * * 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.chiemy.zxing.activity; import android.Manifest; import android.app.Activity; import android.app.AlertDialog; import android.content.DialogInterface; import android.content.pm.PackageManager; import android.graphics.Rect; import android.os.Bundle; import android.os.Handler; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.util.Log; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.Window; import android.view.WindowManager; import android.view.animation.Animation; import android.view.animation.TranslateAnimation; import android.widget.ImageView; import android.widget.RelativeLayout; import com.chiemy.zxing.R; import com.chiemy.zxing.camera.CameraManager; import com.chiemy.zxing.decode.DecodeThread; import com.chiemy.zxing.utils.BeepManager; import com.chiemy.zxing.utils.CaptureActivityHandler; import com.google.zxing.Result; import java.io.IOException; import java.lang.ref.WeakReference; import java.lang.reflect.Field; /** * This activity opens the camera and does the actual scanning on a background * thread. It draws a viewfinder to help the user place the barcode correctly, * shows feedback as the image processing is happening, and then overlays the * results when a scan is successful. * * @author dswitkin@google.com (Daniel Switkin) * @author Sean Owen */ public class CaptureActivity extends Activity implements SurfaceHolder.Callback { private static final String CAMERA_PERMISSION = Manifest.permission.CAMERA; private static final String TAG = CaptureActivity.class.getSimpleName(); private CameraManager cameraManager; private CaptureActivityHandler handler; //private InactivityTimer inactivityTimer; private BeepManager beepManager; private SurfaceView scanPreview = null; private RelativeLayout scanContainer; private RelativeLayout scanCropView; private ImageView scanLine; private Rect mCropRect = null; private boolean isHasSurface = false; private Handler redecodeHandler; private RedecodeRunnable redecodeRunnable; public Handler getHandler() { return handler; } public CameraManager getCameraManager() { return cameraManager; } @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); Window window = getWindow(); window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); setContentView(getLayoutId()); scanPreview = (SurfaceView) findViewById(R.id.capture_preview); scanContainer = (RelativeLayout) findViewById(R.id.capture_container); scanCropView = (RelativeLayout) findViewById(R.id.capture_crop_view); scanLine = (ImageView) findViewById(R.id.capture_scan_line); //inactivityTimer = new InactivityTimer(this); beepManager = new BeepManager(this); getWindow().getDecorView().post(new Runnable() { @Override public void run() { TranslateAnimation animation = new TranslateAnimation(Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.0f, Animation.RELATIVE_TO_PARENT, 0.9f); animation.setDuration(4500); animation.setRepeatCount(-1); animation.setRepeatMode(Animation.RESTART); scanLine.startAnimation(animation); } }); redecodeHandler = new Handler(); redecodeRunnable = new RedecodeRunnable(this); } protected int getLayoutId() { return R.layout.activity_capture; } private void resume() { // CameraManager must be initialized here, not in onCreate(). This is // necessary because we don't // want to open the camera driver and measure the screen size if we're // going to show the help on // first launch. That led to bugs where the scanning rectangle was the // wrong size and partially // off screen. if (cameraManager == null) { cameraManager = new CameraManager(getApplication()); } handler = null; if (isHasSurface) { // The activity was paused but not stopped, so the surface still // exists. Therefore // surfaceCreated() won't be called, so init the camera here. onInitCamera(scanPreview.getHolder()); } else { // Install the callback and wait for surfaceCreated() to init the // camera. scanPreview.getHolder().addCallback(this); } //inactivityTimer.onResume(); } @Override protected void onResume() { super.onResume(); resume(); } @Override protected void onPause() { if (handler != null) { handler.quitSynchronously(); handler = null; } //inactivityTimer.onPause(); if (cameraManager != null) { cameraManager.closeDriver(); } beepManager.close(); if (!isHasSurface) { scanPreview.getHolder().removeCallback(this); } super.onPause(); } @Override protected void onDestroy() { //inactivityTimer.shutdown(); super.onDestroy(); } @Override public void surfaceCreated(SurfaceHolder holder) { if (holder == null) { Log.e(TAG, "*** WARNING *** surfaceCreated() gave us a null surface!"); } if (!isHasSurface) { isHasSurface = true; onInitCamera(holder); } } @Override public void surfaceDestroyed(SurfaceHolder holder) { isHasSurface = false; } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } /** * A valid barcode has been found, so give an indication of success and show * the results. * * @param rawResult The contents of the barcode. * @param bundle The extras */ public void handleDecode(Result rawResult, Bundle bundle) { beepManager.playBeepSoundAndVibrate(); onDecode(rawResult, bundle); } protected void onDecode(Result rawResult, Bundle bundle) { } protected void restartPreviewAndDecode(long delay) { redecodeHandler.postDelayed(redecodeRunnable, delay); } protected void onInitCamera(SurfaceHolder surfaceHolder) { // ????? int hasCameraPermission = ContextCompat.checkSelfPermission(this, CAMERA_PERMISSION); // ??? if (hasCameraPermission != PackageManager.PERMISSION_GRANTED) { // ????????true if (ActivityCompat.shouldShowRequestPermissionRationale(this, CAMERA_PERMISSION)) { showMessageOKCancel("???", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { requestCameraPermission(); } }); } else { if (!permissionDeny) { requestCameraPermission(); } } } else { initCamera(surfaceHolder); } } private void requestCameraPermission() { ActivityCompat.requestPermissions(this, new String[] { CAMERA_PERMISSION }, REQUEST_CODE_ASK_PERMISSIONS); } private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) { new android.support.v7.app.AlertDialog.Builder(this).setMessage(message) .setPositiveButton("", okListener).setNegativeButton("?", null).create().show(); } protected void initCamera(final SurfaceHolder surfaceHolder) { if (surfaceHolder == null) { throw new IllegalStateException("No SurfaceHolder provided"); } if (cameraManager.isOpen()) { Log.w(TAG, "initCamera() while already open -- late SurfaceView callback?"); return; } new Thread(new Runnable() { @Override public void run() { try { cameraManager.openDriver(surfaceHolder); // Creating the handler starts the preview, which can also throw a // RuntimeException. if (handler == null) { handler = new CaptureActivityHandler(CaptureActivity.this, cameraManager, DecodeThread.BARCODE_MODE); } initCrop(); } catch (IOException ioe) { Log.w(TAG, ioe); displayFrameworkBugMessageAndExit(); } catch (RuntimeException e) { // Barcode Scanner has seen crashes in the wild of this variety: // java.?lang.?RuntimeException: Fail to connect to camera service Log.w(TAG, "Unexpected error initializing camera", e); displayFrameworkBugMessageAndExit(); } } }).start(); } private void displayFrameworkBugMessageAndExit() { // camera error AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setTitle(getString(R.string.app_name)); builder.setMessage("Camera error"); builder.setPositiveButton("OK", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { finish(); } }); builder.setOnCancelListener(new DialogInterface.OnCancelListener() { @Override public void onCancel(DialogInterface dialog) { finish(); } }); builder.show(); } public void restartPreviewAfterDelay(long delayMS) { if (handler != null) { handler.sendEmptyMessageDelayed(R.id.restart_preview, delayMS); } } public Rect getCropRect() { return mCropRect; } /** * ?? */ private void initCrop() { int cameraWidth = cameraManager.getCameraResolution().y; int cameraHeight = cameraManager.getCameraResolution().x; /** ????? */ int[] location = new int[2]; scanCropView.getLocationInWindow(location); int cropLeft = location[0]; int cropTop = location[1] - getStatusBarHeight(); int cropWidth = scanCropView.getWidth(); int cropHeight = scanCropView.getHeight(); /** ? */ int containerWidth = scanContainer.getWidth(); int containerHeight = scanContainer.getHeight(); /** ?x?? */ int x = cropLeft * cameraWidth / containerWidth; /** ?y?? */ int y = cropTop * cameraHeight / containerHeight; /** ? */ int width = cropWidth * cameraWidth / containerWidth; /** ? */ int height = cropHeight * cameraHeight / containerHeight; /** ?? */ mCropRect = new Rect(x, y, width + x, height + y); } private int getStatusBarHeight() { try { Class<?> c = Class.forName("com.android.internal.R$dimen"); Object obj = c.newInstance(); Field field = c.getField("status_bar_height"); int x = Integer.parseInt(field.get(obj).toString()); return getResources().getDimensionPixelSize(x); } catch (Exception e) { e.printStackTrace(); } return 0; } private static class RedecodeRunnable implements Runnable { private WeakReference<CaptureActivity> weakReference; public RedecodeRunnable(CaptureActivity activity) { weakReference = new WeakReference<CaptureActivity>(activity); } @Override public void run() { CaptureActivity activity = weakReference.get(); if (activity != null && activity.handler != null) { activity.handler.restartPreviewAndDecode(); } } } private boolean permissionDeny = false; private static final int REQUEST_CODE_ASK_PERMISSIONS = 1; @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { switch (requestCode) { case REQUEST_CODE_ASK_PERMISSIONS: if (grantResults[0] == PackageManager.PERMISSION_GRANTED) { // Permission Granted initCamera(scanPreview.getHolder()); } else { // Permission Denied //Toast.makeText(this, "", Toast.LENGTH_SHORT).show(); permissionDeny = true; // ?onResumeonResume??? } break; default: super.onRequestPermissionsResult(requestCode, permissions, grantResults); } } }