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 tw.jwzhuang.ipcamviewer.devices; import java.io.IOException; import java.util.Collection; import org.json.JSONException; import org.json.JSONObject; import tw.jwzhuang.ipcamviewer.R; import tw.jwzhuang.ipcamviewer.preview.MyApplication; import android.app.Activity; import android.app.AlertDialog; import android.content.Intent; import android.content.SharedPreferences; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Rect; import android.net.Uri; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.preference.PreferenceManager; import android.util.Log; import android.view.KeyEvent; import android.view.Menu; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.View; import android.view.Window; import android.view.WindowManager; import com.google.zxing.BarcodeFormat; import com.google.zxing.Result; import com.google.zxing.ResultPoint; import com.laomo.zxing.camera.CameraManager; import com.laomo.zxing.decode.CaptureActivityHandler; import com.laomo.zxing.decode.DecodeFormatManager; import com.laomo.zxing.decode.FinishListener; import com.laomo.zxing.decode.InactivityTimer; import com.laomo.zxing.decode.IntentSource; import com.laomo.zxing.decode.Intents; import com.laomo.zxing.result.ResultHandler; import com.laomo.zxing.result.ResultHandlerFactory; import com.laomo.zxing.util.Contant; import com.laomo.zxing.view.ViewfinderView; /** * 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 Activity implements SurfaceHolder.Callback { private static final String TAG = CaptureActivity.class.getSimpleName(); private static final int SHARE_ID = Menu.FIRST; private static final String PRODUCT_SEARCH_URL_PREFIX = "http://www.google"; private static final String PRODUCT_SEARCH_URL_SUFFIX = "/m/products/scan"; private static final String[] ZXING_URLS = { "http://zxing.appspot.com/scan", "zxing://scan/" }; private static final String RETURN_URL_PARAM = "ret"; public static final int HISTORY_REQUEST_CODE = 0x0000bacc; private CameraManager cameraManager; private CaptureActivityHandler handler; private Result savedResultToShow; private ViewfinderView viewfinderView; private Result lastResult; private boolean hasSurface; private boolean copyToClipboard; private IntentSource source; private String sourceUrl; private Collection<BarcodeFormat> decodeFormats; private String characterSet; private InactivityTimer inactivityTimer; // private ImageView barcodeImageView = null; public ViewfinderView getViewfinderView() { return viewfinderView; } public Handler getHandler() { return handler; } public CameraManager getCameraManager() { return cameraManager; } @Override public void onCreate(Bundle icicle) { MyApplication.getInstance().addActivity(CaptureActivity.this); super.onCreate(icicle); setContentView(R.layout.scan); Window window = getWindow(); window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); hasSurface = false; inactivityTimer = new InactivityTimer(this); } @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()); viewfinderView = (ViewfinderView) findViewById(R.id.viewfinder_view); viewfinderView.setCameraManager(cameraManager); handler = null; lastResult = null; resetStatusView(); SurfaceView surfaceView = (SurfaceView) findViewById(R.id.preview_view); SurfaceHolder surfaceHolder = surfaceView.getHolder(); if (hasSurface) { // The activity was paused but not stopped, so the surface still // exists. Therefore // surfaceCreated() won't be called, so init the camera here. initCamera(surfaceHolder); } else { // Install the callback and wait for surfaceCreated() to init the // camera. surfaceHolder.addCallback(this); surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } inactivityTimer.onResume(); Intent intent = getIntent(); SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this); copyToClipboard = prefs.getBoolean(Contant.KEY_COPY_TO_CLIPBOARD, true) && (intent == null || intent.getBooleanExtra(Intents.Scan.SAVE_HISTORY, true)); source = IntentSource.NONE; decodeFormats = null; characterSet = null; if (intent != null) { String action = intent.getAction(); String dataString = intent.getDataString(); if (Intents.Scan.ACTION.equals(action)) { // Scan the formats the intent requested, and return the result // to the calling activity. source = IntentSource.NATIVE_APP_INTENT; decodeFormats = DecodeFormatManager.parseDecodeFormats(intent); if (intent.hasExtra(Intents.Scan.WIDTH) && intent.hasExtra(Intents.Scan.HEIGHT)) { int width = intent.getIntExtra(Intents.Scan.WIDTH, 0); int height = intent.getIntExtra(Intents.Scan.HEIGHT, 0); if (width > 0 && height > 0) { cameraManager.setManualFramingRect(width, height); } } } else if (dataString != null && dataString.contains(PRODUCT_SEARCH_URL_PREFIX) && dataString.contains(PRODUCT_SEARCH_URL_SUFFIX)) { // Scan only products and send the result to mobile Product // Search. source = IntentSource.PRODUCT_SEARCH_LINK; sourceUrl = dataString; decodeFormats = DecodeFormatManager.PRODUCT_FORMATS; } else if (isZXingURL(dataString)) { // Scan formats requested in query string (all formats if none // specified). // If a return URL is specified, send the results there. // Otherwise, handle it ourselves. source = IntentSource.ZXING_LINK; sourceUrl = dataString; Uri inputUri = Uri.parse(sourceUrl); inputUri.getQueryParameter(RETURN_URL_PARAM); decodeFormats = DecodeFormatManager.parseDecodeFormats(inputUri); } characterSet = intent.getStringExtra(Intents.Scan.CHARACTER_SET); } } private static boolean isZXingURL(String dataString) { if (dataString == null) { return false; } for (String url : ZXING_URLS) { if (dataString.startsWith(url)) { return true; } } return false; } @Override protected void onPause() { if (handler != null) { handler.quitSynchronously(); handler = null; } inactivityTimer.onPause(); cameraManager.closeDriver(); if (!hasSurface) { SurfaceView surfaceView = (SurfaceView) findViewById(R.id.preview_view); SurfaceHolder surfaceHolder = surfaceView.getHolder(); surfaceHolder.removeCallback(this); } super.onPause(); } @Override protected void onDestroy() { inactivityTimer.shutdown(); super.onDestroy(); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_BACK) { if (source == IntentSource.NATIVE_APP_INTENT) { setResult(RESULT_CANCELED); finish(); return true; } else if ((source == IntentSource.NONE || source == IntentSource.ZXING_LINK) && lastResult != null) { restartPreviewAfterDelay(0L); return true; } } else if (keyCode == KeyEvent.KEYCODE_FOCUS || keyCode == KeyEvent.KEYCODE_CAMERA) { // Handle these events so they don't launch the Camera app return true; } return super.onKeyDown(keyCode, event); } private void decodeOrStoreSavedBitmap(Bitmap bitmap, Result result) { // Bitmap isn't used yet -- will be used soon if (handler == null) { savedResultToShow = result; } else { if (result != null) { savedResultToShow = result; } if (savedResultToShow != null) { Message message = Message.obtain(handler, R.id.decode_succeeded, savedResultToShow); handler.sendMessage(message); } savedResultToShow = null; } } @Override public void surfaceCreated(SurfaceHolder holder) { if (holder == null) { Log.e(TAG, "*** WARNING *** surfaceCreated() gave us a null surface!"); } if (!hasSurface) { hasSurface = true; initCamera(holder); } } @Override public void surfaceDestroyed(SurfaceHolder holder) { hasSurface = 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 barcode * A greyscale bitmap of the camera data which was decoded. */ public void handleDecode(Result rawResult, Bitmap barcode) { inactivityTimer.onActivity(); lastResult = rawResult; ResultHandler resultHandler = ResultHandlerFactory.makeResultHandler(this, rawResult); if (barcode == null) { // This is from history -- no saved barcode handleDecodeInternally(rawResult, resultHandler, null); } else { drawResultPoints(barcode, rawResult); switch (source) { case NONE: handleDecodeInternally(rawResult, resultHandler, barcode); break; } } } /** * Superimpose a line for 1D or dots for 2D to highlight the key features of * the barcode. * * @param barcode * A bitmap of the captured image. * @param rawResult * The decoded results which contains the points to draw. */ private void drawResultPoints(Bitmap barcode, Result rawResult) { ResultPoint[] points = rawResult.getResultPoints(); if (points != null && points.length > 0) { Canvas canvas = new Canvas(barcode); Paint paint = new Paint(); paint.setColor(getResources().getColor(R.color.result_image_border)); paint.setStrokeWidth(3.0f); paint.setStyle(Paint.Style.STROKE); Rect border = new Rect(2, 2, barcode.getWidth() - 2, barcode.getHeight() - 2); canvas.drawRect(border, paint); paint.setColor(getResources().getColor(R.color.result_points)); if (points.length == 2) { paint.setStrokeWidth(4.0f); drawLine(canvas, paint, points[0], points[1]); } else if (points.length == 4 && (rawResult.getBarcodeFormat() == BarcodeFormat.UPC_A || rawResult.getBarcodeFormat() == BarcodeFormat.EAN_13)) { // Hacky special case -- draw two lines, for the barcode and // metadata drawLine(canvas, paint, points[0], points[1]); drawLine(canvas, paint, points[2], points[3]); } else { paint.setStrokeWidth(10.0f); for (ResultPoint point : points) { canvas.drawPoint(point.getX(), point.getY(), paint); } } } } private static void drawLine(Canvas canvas, Paint paint, ResultPoint a, ResultPoint b) { canvas.drawLine(a.getX(), a.getY(), b.getX(), b.getY(), paint); } // Put up our own UI for how to handle the decoded contents. private void handleDecodeInternally(Result rawResult, ResultHandler resultHandler, Bitmap barcode) { viewfinderView.setVisibility(View.GONE); // barcodeImageView = (ImageView) findViewById(R.id.barcode_image_view); // if (barcode != null) { // barcodeImageView.setImageBitmap(barcode); // } CharSequence displayContents = resultHandler.getDisplayContents(); add(String.valueOf(displayContents)); } private void add(final String contents) { try { JSONObject jobj = new JSONObject(contents); Bundle data = new Bundle(); data.putString("pwd", jobj.getString("pwd")); data.putString("ip", jobj.getString("ip")); Message message = Message.obtain(); message.what = handler.ASKADD; message.setData(data); handler.sendMessage(message); } catch (JSONException e) { restartPreviewAfterDelay(0L); } } private void initCamera(SurfaceHolder surfaceHolder) { try { cameraManager.openDriver(surfaceHolder); // Creating the handler starts the preview, which can also throw a // RuntimeException. if (handler == null) { handler = new CaptureActivityHandler(this, decodeFormats, characterSet, cameraManager); } decodeOrStoreSavedBitmap(null, null); } 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() { AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setTitle(getString(R.string.app_name)); builder.setPositiveButton(R.string.yes, new FinishListener(this)); builder.setOnCancelListener(new FinishListener(this)); builder.show(); } public void restartPreviewAfterDelay(long delayMS) { // if (barcodeImageView != null) { // barcodeImageView.setImageBitmap(null); // } if (handler != null) { handler.sendEmptyMessageDelayed(R.id.restart_preview, delayMS); } resetStatusView(); } private void resetStatusView() { viewfinderView.setVisibility(View.VISIBLE); lastResult = null; } public void drawViewfinder() { viewfinderView.drawViewfinder(); } }