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.melvin.share.zxing.activity; import android.app.Activity; import android.app.AlertDialog; import android.content.DialogInterface; import android.content.Intent; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Rect; import android.net.Uri; import android.os.Bundle; import android.os.Environment; import android.os.Handler; import android.provider.MediaStore; import android.support.v4.view.GravityCompat; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.Menu; import android.view.MenuItem; 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 android.widget.Toast; import com.melvin.share.R; import com.melvin.share.Utils.Utils; import com.melvin.share.ui.activity.common.BaseActivity; import com.melvin.share.zxing.camera.CameraManager; import com.melvin.share.zxing.decode.DecodeThread; import com.melvin.share.zxing.utils.BeepManager; import com.melvin.share.zxing.utils.CaptureActivityHandler; import com.melvin.share.zxing.utils.InactivityTimer; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; 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 final class CaptureActivity extends BaseActivity implements SurfaceHolder.Callback { 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 Toolbar toolbar; public Handler getHandler() { return handler; } public CameraManager getCameraManager() { return cameraManager; } private boolean isHasSurface = false; @Override protected void initView() { Window window = getWindow(); window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); setContentView(R.layout.activity_capture); initWindow(); toolbar = (Toolbar) findViewById(R.id.toolbar); initToolbar(toolbar); 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); 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); } @Override protected void onResume() { super.onResume(); // 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. 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. initCamera(scanPreview.getHolder()); } else { // Install the callback and wait for surfaceCreated() to init the // camera. scanPreview.getHolder().addCallback(this); } inactivityTimer.onResume(); } @Override protected void onPause() { if (handler != null) { handler.quitSynchronously(); handler = null; } inactivityTimer.onPause(); beepManager.close(); cameraManager.closeDriver(); 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; initCamera(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 resultString The contents of the barcode. * @param dle The extras */ public void handleDecode(String resultString, Bundle dle) { inactivityTimer.onActivity(); beepManager.playBeepSoundAndVibrate(); if (resultString.equals("")) { Toast.makeText(CaptureActivity.this, "??!", Toast.LENGTH_SHORT).show(); } else { Intent resultIntent = new Intent(); Bundle bundle = new Bundle(); bundle.putString("result", resultString); resultIntent.putExtras(bundle); this.setResult(RESULT_OK, resultIntent); } CaptureActivity.this.finish(); } private void initCamera(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; } try { cameraManager.openDriver(surfaceHolder); // Creating the handler starts the preview, which can also throw a // RuntimeException. if (handler == null) { handler = new CaptureActivityHandler(this, cameraManager, DecodeThread.ALL_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(); } } private void displayFrameworkBugMessageAndExit() { // camera error AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setTitle(getString(R.string.app_name)); builder.setMessage("???"); builder.setPositiveButton("", 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; } /** * toolbar?? */ @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_scan_code, menu); return super.onCreateOptionsMenu(menu); } /** * toolbar?? */ @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: finish(); return true; case R.id.camera: Intent pickIntent = new Intent(Intent.ACTION_PICK, null); // ??"image/jpeg ? image/png" pickIntent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*"); startActivityForResult(pickIntent, 10); return true; } return super.onOptionsItemSelected(item); } @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { if (resultCode != RESULT_CANCELED) { switch (requestCode) { case 10:// ? Utils.showToast(this, ""); break; } } super.onActivityResult(requestCode, resultCode, data); } }