4. Now from inside your Android application, you can launch the ZBarScanner from any activity using this intent:
```java
Intent intent = new Intent(this, ZBarScannerActivity.class);
startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
```
To receive the results of the SCAN, add this method to your activity:
```java
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
if (resultCode == RESULT_OK)
{
// Scan result is available by making a call to data.getStringExtra(ZBarConstants.SCAN_RESULT)
// Type of the scan result is available by making a call to data.getStringExtra(ZBarConstants.SCAN_RESULT_TYPE)
Toast.makeText(this, "Scan Result = " + data.getStringExtra(ZBarConstants.SCAN_RESULT), Toast.LENGTH_SHORT).show();
Toast.makeText(this, "Scan Result Type = " + data.getIntExtra(ZBarConstants.SCAN_RESULT_TYPE, 0), Toast.LENGTH_SHORT).show();
// The value of type indicates one of the symbols listed in Advanced Options below.
} else if(resultCode == RESULT_CANCELED) {
Toast.makeText(this, "Camera unavailable", Toast.LENGTH_SHORT).show();
}
}
```
### Advanced Options
If you are interested in scanning only QR codes, you can specify the SCAN mode in the intent as shown below:
```java
Intent intent = new Intent(this, ZBarScannerActivity.class);
intent.putExtra(ZBarConstants.SCAN_MODES, new int[]{Symbol.QRCODE});
startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
```
You can pass an array or integers for SCAN_MODES. The exact values are specified in net.sourceforge.zbar.Symbol class:
```java
public static final int NONE = 0;
public static final int PARTIAL = 1;
public static final int EAN8 = 8;
public static final int UPCE = 9;
public static final int ISBN10 = 10;
public static final int UPCA = 12;
public static final int EAN13 = 13;
public static final int ISBN13 = 14;
public static final int I25 = 25;
public static final int DATABAR = 34;
public static final int DATABAR_EXP = 35;
public static final int CODABAR = 38;
public static final int CODE39 = 39;
public static final int PDF417 = 57;
public static final int QRCODE = 64;
public static final int CODE93 = 93;
public static final int CODE128 = 128;
```
If you do not specify scan_modes, the scanner processes all the above listed types.
But if you are interested in QRCodes and ISBN, you would setup the intent as follows:
```java
Intent intent = new Intent(this, ZBarScannerActivity.class);
intent.putExtra(ZBarConstants.SCAN_MODES, new int[]{Symbol.QRCODE, Symbol.ISBN10, Symbol.ISBN13});
startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
```
### Example app
There is a ZBarScannerDemo app in the examples folder which demonstrates the use of this library.
### Tests
I have tested the scanner functionality on these devices without any issues so far:
* Motorola Droid running Android 2.2.3
* HTC Thunderbolt running Android 2.3.4
* Samsung Galaxy Nexus running Android 4.0.4
###Credits
Almost all of the code for this library project has been taken from these two places:
1. CameraPreview app from Android SDK APIDemos
2. The ZBar Android SDK: http://sourceforge.net/projects/zbar/files/AndroidSDK/
###License
MIT
--------------------------------------------------------------------------------------
ATTENTION!
==========
This project will no longer be maintained. Moving forward, I am going to spend my time on development of this project here: https://github.com/dm77/barcodescanner
================================================
FILE: ZBarScannerLibrary/AndroidManifest.xml
================================================
================================================
FILE: ZBarScannerLibrary/ant.properties
================================================
# This file is used to override default values used by the Ant build system.
#
# This file must be checked into Version Control Systems, as it is
# integral to the build system of your project.
# This file is only used by the Ant script.
# You can use this to override default values such as
# 'source.dir' for the location of your java source folder and
# 'out.dir' for the location of your output folder.
# You can also use it define how the release builds are signed by declaring
# the following properties:
# 'key.store' for the location of your keystore and
# 'key.alias' for the name of the key to use.
# The password will be asked during the build when you use the 'release' target.
================================================
FILE: ZBarScannerLibrary/build.properties
================================================
================================================
FILE: ZBarScannerLibrary/build.xml
================================================
================================================
FILE: ZBarScannerLibrary/default.properties
================================================
================================================
FILE: ZBarScannerLibrary/proguard-project.txt
================================================
# To enable ProGuard in your project, edit project.properties
# to define the proguard.config property as described in that file.
#
# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in ${sdk.dir}/tools/proguard/proguard-android.txt
# You can edit the include path and order by changing the ProGuard
# include property in project.properties.
#
# For more details, see
# http://developer.android.com/guide/developing/tools/proguard.html
# Add any project specific keep options here:
# If your project uses WebView with JS, uncomment the following
# and specify the fully qualified class name to the JavaScript interface
# class:
#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
# public *;
#}
================================================
FILE: ZBarScannerLibrary/project.properties
================================================
# This file is automatically generated by Android Tools.
# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
#
# This file must be checked in Version Control Systems.
#
# To customize properties used by the Ant build system edit
# "ant.properties", and override values to adapt the script to your
# project structure.
#
# To enable ProGuard to shrink and obfuscate your code, uncomment this (available properties: sdk.dir, user.home):
#proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
# Project target.
target=android-16
android.library=true
================================================
FILE: ZBarScannerLibrary/res/values/strings.xml
================================================
ZBar Scanner
================================================
FILE: ZBarScannerLibrary/src/com/dm/zbar/android/scanner/CameraPreview.java
================================================
package com.dm.zbar.android.scanner;
import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PreviewCallback;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
import java.io.IOException;
import java.util.List;
class CameraPreview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "CameraPreview";
SurfaceView mSurfaceView;
SurfaceHolder mHolder;
Size mPreviewSize;
List mSupportedPreviewSizes;
Camera mCamera;
PreviewCallback mPreviewCallback;
AutoFocusCallback mAutoFocusCallback;
CameraPreview(Context context, PreviewCallback previewCallback, AutoFocusCallback autoFocusCb) {
super(context);
mPreviewCallback = previewCallback;
mAutoFocusCallback = autoFocusCb;
mSurfaceView = new SurfaceView(context);
addView(mSurfaceView);
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void setCamera(Camera camera) {
mCamera = camera;
if (mCamera != null) {
mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
requestLayout();
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// We purposely disregard child measurements because act as a
// wrapper to a SurfaceView that centers the camera preview instead
// of stretching it.
final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
setMeasuredDimension(width, height);
if (mSupportedPreviewSizes != null) {
mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (changed && getChildCount() > 0) {
final View child = getChildAt(0);
final int width = r - l;
final int height = b - t;
int previewWidth = width;
int previewHeight = height;
if (mPreviewSize != null) {
previewWidth = mPreviewSize.width;
previewHeight = mPreviewSize.height;
}
// Center the child SurfaceView within the parent.
if (width * previewHeight > height * previewWidth) {
final int scaledChildWidth = previewWidth * height / previewHeight;
child.layout((width - scaledChildWidth) / 2, 0,
(width + scaledChildWidth) / 2, height);
} else {
final int scaledChildHeight = previewHeight * width / previewWidth;
child.layout(0, (height - scaledChildHeight) / 2,
width, (height + scaledChildHeight) / 2);
}
}
}
public void hideSurfaceView() {
mSurfaceView.setVisibility(View.INVISIBLE);
}
public void showSurfaceView() {
mSurfaceView.setVisibility(View.VISIBLE);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, acquire the camera and tell it where
// to draw.
try {
if (mCamera != null) {
mCamera.setPreviewDisplay(holder);
}
} catch (IOException exception) {
Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
if (mCamera != null) {
mCamera.cancelAutoFocus();
mCamera.stopPreview();
}
}
private Size getOptimalPreviewSize(List sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null) return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (Size size : sizes) {
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if (holder.getSurface() == null){
// preview surface does not exist
return;
}
if (mCamera != null) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
requestLayout();
mCamera.setParameters(parameters);
mCamera.setPreviewCallback(mPreviewCallback);
mCamera.startPreview();
mCamera.autoFocus(mAutoFocusCallback);
}
}
}
================================================
FILE: ZBarScannerLibrary/src/com/dm/zbar/android/scanner/ZBarConstants.java
================================================
package com.dm.zbar.android.scanner;
public interface ZBarConstants {
public static final String SCAN_MODES = "SCAN_MODES";
public static final String SCAN_RESULT = "SCAN_RESULT";
public static final String SCAN_RESULT_TYPE = "SCAN_RESULT_TYPE";
public static final String ERROR_INFO = "ERROR_INFO";
}
================================================
FILE: ZBarScannerLibrary/src/com/dm/zbar/android/scanner/ZBarScannerActivity.java
================================================
package com.dm.zbar.android.scanner;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.os.Bundle;
import android.os.Handler;
import android.text.TextUtils;
import android.view.Window;
import android.view.WindowManager;
import net.sourceforge.zbar.Config;
import net.sourceforge.zbar.Image;
import net.sourceforge.zbar.ImageScanner;
import net.sourceforge.zbar.Symbol;
import net.sourceforge.zbar.SymbolSet;
public class ZBarScannerActivity extends Activity implements Camera.PreviewCallback, ZBarConstants {
private static final String TAG = "ZBarScannerActivity";
private CameraPreview mPreview;
private Camera mCamera;
private ImageScanner mScanner;
private Handler mAutoFocusHandler;
private boolean mPreviewing = true;
static {
System.loadLibrary("iconv");
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(!isCameraAvailable()) {
// Cancel request if there is no rear-facing camera.
cancelRequest();
return;
}
// Hide the window title.
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
mAutoFocusHandler = new Handler();
// Create and configure the ImageScanner;
setupScanner();
// Create a RelativeLayout container that will hold a SurfaceView,
// and set it as the content of our activity.
mPreview = new CameraPreview(this, this, autoFocusCB);
setContentView(mPreview);
}
public void setupScanner() {
mScanner = new ImageScanner();
mScanner.setConfig(0, Config.X_DENSITY, 3);
mScanner.setConfig(0, Config.Y_DENSITY, 3);
int[] symbols = getIntent().getIntArrayExtra(SCAN_MODES);
if (symbols != null) {
mScanner.setConfig(Symbol.NONE, Config.ENABLE, 0);
for (int symbol : symbols) {
mScanner.setConfig(symbol, Config.ENABLE, 1);
}
}
}
@Override
protected void onResume() {
super.onResume();
// Open the default i.e. the first rear facing camera.
mCamera = Camera.open();
if(mCamera == null) {
// Cancel request if mCamera is null.
cancelRequest();
return;
}
mPreview.setCamera(mCamera);
mPreview.showSurfaceView();
mPreviewing = true;
}
@Override
protected void onPause() {
super.onPause();
// Because the Camera object is a shared resource, it's very
// important to release it when the activity is paused.
if (mCamera != null) {
mPreview.setCamera(null);
mCamera.cancelAutoFocus();
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mCamera.release();
// According to Jason Kuang on http://stackoverflow.com/questions/6519120/how-to-recover-camera-preview-from-sleep,
// there might be surface recreation problems when the device goes to sleep. So lets just hide it and
// recreate on resume
mPreview.hideSurfaceView();
mPreviewing = false;
mCamera = null;
}
}
public boolean isCameraAvailable() {
PackageManager pm = getPackageManager();
return pm.hasSystemFeature(PackageManager.FEATURE_CAMERA);
}
public void cancelRequest() {
Intent dataIntent = new Intent();
dataIntent.putExtra(ERROR_INFO, "Camera unavailable");
setResult(Activity.RESULT_CANCELED, dataIntent);
finish();
}
public void onPreviewFrame(byte[] data, Camera camera) {
Camera.Parameters parameters = camera.getParameters();
Camera.Size size = parameters.getPreviewSize();
Image barcode = new Image(size.width, size.height, "Y800");
barcode.setData(data);
int result = mScanner.scanImage(barcode);
if (result != 0) {
mCamera.cancelAutoFocus();
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mPreviewing = false;
SymbolSet syms = mScanner.getResults();
for (Symbol sym : syms) {
String symData = sym.getData();
if (!TextUtils.isEmpty(symData)) {
Intent dataIntent = new Intent();
dataIntent.putExtra(SCAN_RESULT, symData);
dataIntent.putExtra(SCAN_RESULT_TYPE, sym.getType());
setResult(Activity.RESULT_OK, dataIntent);
finish();
break;
}
}
}
}
private Runnable doAutoFocus = new Runnable() {
public void run() {
if(mCamera != null && mPreviewing) {
mCamera.autoFocus(autoFocusCB);
}
}
};
// Mimic continuous auto-focusing
Camera.AutoFocusCallback autoFocusCB = new Camera.AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
mAutoFocusHandler.postDelayed(doAutoFocus, 1000);
}
};
}
================================================
FILE: examples/ZBarScannerDemo/AndroidManifest.xml
================================================
================================================
FILE: examples/ZBarScannerDemo/ant.properties
================================================
# This file is used to override default values used by the Ant build system.
#
# This file must be checked into Version Control Systems, as it is
# integral to the build system of your project.
# This file is only used by the Ant script.
# You can use this to override default values such as
# 'source.dir' for the location of your java source folder and
# 'out.dir' for the location of your output folder.
# You can also use it define how the release builds are signed by declaring
# the following properties:
# 'key.store' for the location of your keystore and
# 'key.alias' for the name of the key to use.
# The password will be asked during the build when you use the 'release' target.
================================================
FILE: examples/ZBarScannerDemo/build.properties
================================================
================================================
FILE: examples/ZBarScannerDemo/build.xml
================================================
================================================
FILE: examples/ZBarScannerDemo/default.properties
================================================
================================================
FILE: examples/ZBarScannerDemo/proguard-project.txt
================================================
# To enable ProGuard in your project, edit project.properties
# to define the proguard.config property as described in that file.
#
# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in ${sdk.dir}/tools/proguard/proguard-android.txt
# You can edit the include path and order by changing the ProGuard
# include property in project.properties.
#
# For more details, see
# http://developer.android.com/guide/developing/tools/proguard.html
# Add any project specific keep options here:
# If your project uses WebView with JS, uncomment the following
# and specify the fully qualified class name to the JavaScript interface
# class:
#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
# public *;
#}
================================================
FILE: examples/ZBarScannerDemo/project.properties
================================================
# This file is automatically generated by Android Tools.
# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
#
# This file must be checked in Version Control Systems.
#
# To customize properties used by the Ant build system edit
# "ant.properties", and override values to adapt the script to your
# project structure.
#
# To enable ProGuard to shrink and obfuscate your code, uncomment this (available properties: sdk.dir, user.home):
#proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
# Project target.
target=android-16
android.library.reference.1=../../ZBarScannerLibrary
================================================
FILE: examples/ZBarScannerDemo/res/layout/main.xml
================================================
================================================
FILE: examples/ZBarScannerDemo/res/values/strings.xml
================================================
ZBar Scanner DemoScanScan only QR Codes
================================================
FILE: examples/ZBarScannerDemo/src/com/dm/zbar/android/examples/MainActivity.java
================================================
package com.dm.zbar.android.examples;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Toast;
import com.dm.zbar.android.scanner.ZBarConstants;
import com.dm.zbar.android.scanner.ZBarScannerActivity;
import net.sourceforge.zbar.Symbol;
public class MainActivity extends Activity {
private static final int ZBAR_SCANNER_REQUEST = 0;
private static final int ZBAR_QR_SCANNER_REQUEST = 1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void launchScanner(View v) {
if (isCameraAvailable()) {
Intent intent = new Intent(this, ZBarScannerActivity.class);
startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
} else {
Toast.makeText(this, "Rear Facing Camera Unavailable", Toast.LENGTH_SHORT).show();
}
}
public void launchQRScanner(View v) {
if (isCameraAvailable()) {
Intent intent = new Intent(this, ZBarScannerActivity.class);
intent.putExtra(ZBarConstants.SCAN_MODES, new int[]{Symbol.QRCODE});
startActivityForResult(intent, ZBAR_SCANNER_REQUEST);
} else {
Toast.makeText(this, "Rear Facing Camera Unavailable", Toast.LENGTH_SHORT).show();
}
}
public boolean isCameraAvailable() {
PackageManager pm = getPackageManager();
return pm.hasSystemFeature(PackageManager.FEATURE_CAMERA);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case ZBAR_SCANNER_REQUEST:
case ZBAR_QR_SCANNER_REQUEST:
if (resultCode == RESULT_OK) {
Toast.makeText(this, "Scan Result = " + data.getStringExtra(ZBarConstants.SCAN_RESULT), Toast.LENGTH_SHORT).show();
} else if(resultCode == RESULT_CANCELED && data != null) {
String error = data.getStringExtra(ZBarConstants.ERROR_INFO);
if(!TextUtils.isEmpty(error)) {
Toast.makeText(this, error, Toast.LENGTH_SHORT).show();
}
}
break;
}
}
}