MobileVisionBarcodeScanner

Barcode Scanner supported by Mobile Vision Api

Update 2.0.0

• Bug fixes and Better Performance
• Capturing scanned screen
• support two or more barcode format
• release a barcode detector
• use the front camera for scanning
• immediate refresh functionality
• update to 11.0.4 mobile vision sdk

adding as a dependency

on JCenter

dependencies {
	        implementation ''xyz.belvi.mobilevision:barcodescanner:2.0.3''

	}

on JitPack

Step 1.

Add the JitPack repository to your build file in your root build.gradle at the end of repositories:

allprojects {
	repositories {
		...
		maven { url "https://jitpack.io" }
	}
}

Step 2.

Add the dependency

dependencies {
        compile 'com.github.KingsMentor:MobileVisionBarcodeScanner:2.0.0'
}

Supported Attributes

        <attr name="gvb_show_text" format="boolean" />
        <attr name="gvb_draw" format="boolean" />
        <attr name="gvb_multiple" format="boolean" />
        <attr name="gvb_touch" format="boolean" />
        <attr name="gvb_auto_focus" format="boolean" />
        <attr name="gvb_flash" format="boolean" />
        <attr name="gvb_rect_colors" format="reference" />
        <attr name="gvb_camera_facing" format="enum">
            <enum name="back" value="0"></enum>
            <enum name="front" value="0"></enum>
        </attr>
        <attr name="gvb_code_format">
            <flag name="all_format" value="0"></flag>
            <flag name="code_128" value="1"></flag>
            <flag name="code_39" value="2"></flag>
            <flag name="code_93" value="4"></flag>
            <flag name="code_bar" value="8"></flag>
            <flag name="data_matrix" value="16"></flag>
            <flag name="ean_13" value="32"></flag>
            <flag name="ean_8" value="64"></flag>
            <flag name="itf" value="128"></flag>
            <flag name="qr_code" value="256"></flag>
            <flag name="upc_a" value="512"></flag>
            <flag name="upc_e" value="1024"></flag>
            <flag name="pdf417" value="2028"></flag>
            <flag name="aztec" value="4029"></flag>
        </attr>

What are the attibutes for :

• gvb_draw - enable rect drawn around codes when scanning
• gvb_multiple - want the camera to return as many qr codes that was scanned. This works with gvb_touch attribute. it only returns result when the screen is clicked or touch
• gvb_touch - turn on touch listener for screen
• gvb_auto_focus - support auto focus
• gvb_flash - turn on flash
• gvb_rect_colors - arrays of colors to draw rect
• gvb_code_format - barcode format that should be support . Default is all_format

Note these attributes can also be initialised from java code . We would look into that later

Using the Mobile Vision Powered Camera.

Step 1 - Add layout in xml:

<fragment
            android:id="@+id/barcode"
            android:name="com.google.android.gms.samples.vision.barcodereader.BarcodeCapture"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            app:gvb_auto_focus="true"
            app:gvb_code_format="all_format"
            app:gvb_flash="false"
            app:gvb_rect_colors="@array/rect_color" />

and this is rect_color in colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <color name="color_green">#14808d</color>
    <color name="color_brown">#343838</color>
    <color name="color_orange">#f38a32</color>
    <color name="color_blue">#1479b7</color>
    <color name="divider_grey">#e4e4e5</color>

    <array name="rect_color">
        <item>@color/color_blue</item>
        <item>@color/color_brown</item>
        <item>@color/color_green</item>
        <item>@color/divider_grey</item>
        <item>@color/color_orange</item>
    </array>
</resources>

Step 2 - Initialise in java

BarcodeCapture barcodeCapture = (BarcodeCapture) getSupportFragmentManager().findFragmentById(R.id.barcode);
barcodeCapture.setRetrieval(this);

also make sure your java class implements BarcodeRetriever

public class MainActivity extends AppCompatActivity implements BarcodeRetriever {

...


    // for one time scan
  @Override
    public void onRetrieved(final Barcode barcode) {
        Log.d(TAG, "Barcode read: " + barcode.displayValue);
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this)
                        .setTitle("code retrieved")
                        .setMessage(barcode.displayValue);
                builder.show();
            }
        });


    }

    // for multiple callback
    @Override
    public void onRetrievedMultiple(final Barcode closetToClick, final List<BarcodeGraphic> barcodeGraphics) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                String message = "Code selected : " + closetToClick.displayValue + "\n\nother " +
                        "codes in frame include : \n";
                for (int index = 0; index < barcodeGraphics.size(); index++) {
                    Barcode barcode = barcodeGraphics.get(index).getBarcode();
                    message += (index + 1) + ". " + barcode.displayValue + "\n";
                }
                AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this)
                        .setTitle("code retrieved")
                        .setMessage(message);
                builder.show();
            }
        });

    }

    @Override
    public void onBitmapScanned(SparseArray<Barcode> sparseArray) {
        // when image is scanned and processed
    }

    @Override
    public void onRetrievedFailed(String reason) {
        // in case of failure
    }
}

as you can see, BarcodeRetriever interface handles the callback when a code is scanned successfully based on specified attributes.

Extras

• To scan a bitmap,

BarcodeBitmapScanner.scanBitmap(this, bitmap, Barcode.ALL_FORMATS, this);

• Set attributes from java - Use the BarcodeCapture instance to reference setter methods

barcodeCapture.setShowDrawRect(true);

• Stop barcode detection

barcodeCapture.stopScanning();

• Retrieve Image of Scanned Screen. This will return a Camera object that you can use to retrieve other neccessary information:

barcodeCapture.retrieveCamera();

• Refresh - make update to barcodeCapture and use refresh for immediate screen update.

                    barcodeCapture.setShowDrawRect(drawRect.isChecked())
                            .setSupportMultipleScan(supportMultiple.isChecked())
                            .setTouchAsCallback(touchBack.isChecked())
                            .shouldAutoFocus(autoFocus.isChecked())
                            .setShowFlash(flash.isChecked())
                            .setBarcodeFormat(Barcode.ALL_FORMATS)
                            .setCameraFacing(frontCam.isChecked() ? CameraSource.CAMERA_FACING_FRONT : CameraSource.CAMERA_FACING_BACK)
                            .setShouldShowText(drawText.isChecked());
                    barcodeCapture.refresh();

Resources and Credits

• <a href="https://codelabs.developers.google.com/codelabs/bar-codes" target="_blank">Barcode codelab</a>
• <a href="https://github.com/googlesamples/android-vision/tree/master/visionSamples/barcode-reader" target="_blank"> google mobile vision barcode sample</a>

Contributions

Contributions are welcome. Generally, contributions are managed by issues and pull requests.

1. Submit an issue describing your proposed fix or feature.
2. If your proposed fix or feature is accepted then, fork, implement your code change.
3. Ensure your code change follows the <a href="https://source.android.com/source/code-style.html" target="_blank">accepted code style and structure.<a>
4. Ensure your code is properly tested.
5. Ensure your commits follow the <a href="https://udacity.github.io/git-styleguide/" target="_blank">accepted commit message style</a>
6. Submit a pull request.

#License The MIT License (MIT). Please see the License File for more information.