HMS core unified scanning service

Unified code scanning service （Scan Kit） Provide convenient barcode and QR code scanning 、 analysis 、 Generative power , Help you quickly build the scanning function in the application . Thanks to Huawei's ability to accumulate in the field of computer vision ,Scan Kit It can realize the detection and automatic amplification of long distance code or small code , At the same time, aiming at common complex code scanning scenarios （ Like reflection 、 Dark light 、 Stain 、 Fuzzy 、 cylinder ） It has done targeted identification optimization , Improve code scanning success rate and user experience .
Scan Kit Support Android and iOS System integration . among ,Android System integration Scan Kit Rear support horizontal screen code scanning capability .

guide ：
https://developer.huawei.com/consumer/cn/doc/development/HMSCore-Guides/service-introduction-0000001050041994

codelab：
https://developer.huawei.com/consumer/cn/codelabsPortal/carddetails/ScanKit

Build code scanning function
https://developer.huawei.com/consumer/cn/doc/development/HMSCore-Guides/android-overview-0000001050282308

gradle Add compilation dependency

implementation 'com.huawei.hms:scan:2.6.0.300'

Custom code scanning

Customized View Support developers to customize the code scanning interface , The scanning process and camera control will be controlled by Scan Kit complete .

// Set the code type that supports identification and initialize RemoteView, Set the operation of page elements 
// take RemoteView Load into Activity
@Override 
protected void onCreate(Bundle savedInstanceState) {
     
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_defined);
    //  Bind camera preview layout .
    frameLayout = findViewById(R.id.rim);
    //  Set the scanning identification area , You can adjust the parameters according to your needs .
    DisplayMetrics dm = getResources().getDisplayMetrics();
    float density = dm.density;
    mScreenWidth = getResources().getDisplayMetrics().widthPixels;
    mScreenHeight = getResources().getDisplayMetrics().heightPixels;
    //  At present Demo The width and height of the scanning frame is 300dp.
    final int SCAN_FRAME_SIZE = 300;
    int scanFrameSize = (int) (SCAN_FRAME_SIZE * density);
    Rect rect = new Rect();
    rect.left = mScreenWidth / 2 - scanFrameSize / 2;
    rect.right = mScreenWidth / 2 + scanFrameSize / 2;
    rect.top = mScreenHeight / 2 - scanFrameSize / 2;
    rect.bottom = mScreenHeight / 2 + scanFrameSize / 2;
    //  initialization RemoteView, And set parameters through the following methods :setContext()（ Mandatory ） Pass in context、setBoundingBox() Set the scanning area 、setFormat() Set the identification code system , After setting, call build() Method to complete the creation . adopt setContinuouslyScan（ Optional ） Method to set discontinuous scanning mode .
    remoteView = new RemoteView.Builder().setContext(this).setBoundingBox(rect).setContinuouslyScan(false).setFormat(HmsScan.QRCODE_SCAN_TYPE, HmsScan.DATAMATRIX_SCAN_TYPE).build();
    //  Will customize view Load into activity Of frameLayout in .
    remoteView.onCreate(savedInstanceState);
    FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);
    frameLayout.addView(remoteView, params);
}

// Yes RemoteView Set result callback listening , Get the scanning result object HmsScan, See code value analysis for the information contained therein 
@Override
protected void onCreate(Bundle savedInstanceState) {
    
    …
    //  Identify the result callback event subscription  
    remoteView.setOnResultCallback(new OnResultCallback() {
     
        @Override 
        public void onResult(HmsScan[] result) {
     
            //  Get the code scanning result HmsScan
            showResult(result);
        } 
    });
}

// Developers scan the code successfully , If you don't want to end the current “Activity” And continue with other operations , You can call the pause scanning interface . 
remoteView.pauseContinuouslyScan();

// You need to resume scanning from the suspended scanning state , You can call the recovery scanning interface , Restore the current “Activity” Receive code scanning results . 
remoteView.resumeContinuouslyScan();

// Set discontinuous scanning mode .
// adopt setContinuouslyScan Method setting , The default is true, Continuous scanning mode , At this time, the scanning result will return continuously ; Set to false, Discontinuous scanning mode , At this time, the same code value will only be returned once . 
// setContinuouslyScan Set to false, Discontinuous scanning mode .
remoteView = new RemoteView.Builder().setContext(this).setContinuouslyScan(false).build();

// Set whether to return to the original image after successful scanning .
// adopt enableReturnBitmap Method returns to the original image after successfully scanning the code , Do not return by default . Can pass HmsScan Object's getOriginalBitmap To get the results . 
remoteView = new RemoteView.Builder().setContext(this).enableReturnBitmap().build();

Picture scanning

//1. Get photo , Convert picture to Bitmap.
// data yes Intent type ,data.getData Is the barcode image to be scanned Uri.
Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), data.getData());

//2. initialization HmsScanAnalyzerOptions, Set the code system and settings that support identification Bitmap The mode is picture scanning mode .
// Developers can set optional parameters in the following ways .
//setHmsScanTypes()： Set the code system , Default recognition Scan Kit Supported coding system , Specify a specific code system for scanning , It can improve the scanning speed .
//setPhotoMode(true)： Set up Bitmap Pattern , The default is camera scan mode , Set here as picture scanning mode , The value is true.

// “QRCODE_SCAN_TYPE” and “DATAMATRIX_SCAN_TYPE” It means scan only QR and Data Matrix Code of 
HmsScanAnalyzerOptions options = new HmsScanAnalyzerOptions.Creator().setHmsScanTypes(HmsScan.QRCODE_SCAN_TYPE, HmsScan.DATAMATRIX_SCAN_TYPE).setPhotoMode(true).create();

//3. call ScanUtil Static method of decodeWithBitmap Send a code scanning request and obtain the code scanning result object HmsScan, Please refer to code value analysis for the information contained therein .
// If the developer does not need to specify to detect only a specific code system , Here “options” It can be set to “null”.
HmsScan[] hmsScans = ScanUtil.decodeWithBitmap(BitmapActivity.this, bitmap, options); 
//  Process scan results  
if (hmsScans != null && hmsScans.length > 0) {
     
    //  Show scan results 
    showResult(hmsScans);
}