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The scan service, allows an Android device with imaging hardware (camera) to scan barcodes or 2-D "graphical barcodes" and retrieve the data encoded. Information encoded often includes web addresses, geographical coordinates, and small pieces of text, in addition to commercial product codes. The Android-based system is given similar functionality to a hardware barcode reader.

This application supports many different types of barcode, including those used to identify products in commerce. The Barcode Scanner can automatically search the Web to identify a product with a barcode and use, for example, price-comparison information.

The application can decode several 2-D codes including the widely-used QR and Data Matrix codes. QR codes are often embedded in websites; Barcode Scanner can open a browser at the encoded site, for example, facilitating the download of an application.

== API Overview ==
 
There are many applications are developed based on smart POS. In one thing, many of the Smart POS developers also have POS industry background,but not professional Android developers. So when they start developing applications, they want to be provided with a convenient scan API by WizarPOS, instead of learning Zxing/Zbar themselves.In other thing,from the hardware point of view, the scan parts used on smart POS, are not necessarily the standard camera, there will be some transformation. In some cases, the scan part will be required to be a specialized hardware. Therefore, the direct use of Zxing/Zbar is not really applicable for WizarPOS smart POS, but need some modification and customization.
For the reasons above, we consider to develop WizarPOS Scan Services to facilitate the third party developers in developing applications with scan function.

=== IScanService ===
==== ScanBarcode  ====
  <syntaxhighlight lang="java">ScanResult scanBarcode(ScanParameter parameter);</syntaxhighlight >
scanBarcode is a synchronous calling interface. 

After the application calls the interface, the scan service opens the camera defined by the scan parameter and then starts the scan. Once getting the result of scanning, the camera is closes and the results are returned immediately.

{|class="wizarpostable"
|-
! scope="row" colspan="2" | Parameters
|-
| ''parameter'' || '''ScanParameter:''' [[#Scan Parameter|Scan Parameter]]
|}
{|
|-
| 
|}
{|class="wizarpostable"
|-
!  scope="row" colspan="2"| Returns
|-
| ScanResult || Scan result.
|}

==== StartScan ====
  <syntaxhighlight lang="java">void startScan(ScanParameter parameter, IScanCallBack callBack);</syntaxhighlight >
startScan is an asynchronous call interface and indicating the continuous scanning is started.

After the application calls this interface, the scan service opens the camera defined by the scan parameter and starts the scan. After every single scanning, the results will be returned during the callback. After each callback is done, the next scanning continue to run starts.

{|class="wizarpostable"
|-
! scope="row" colspan="2" | Parameters
|-
| ''parameter'' || '''ScanParameter:''' [[#Scan Parameter|Scan Parameter]]
|-
| ''callBack'' || '''IScanCallBack:''' callback
|}

==== StopScan ====
  <syntaxhighlight lang="java">boolean stopScan();</syntaxhighlight >
This interface Stops the continuous scan, and closes  the scan service's UI.

After stop, other callers can call startScan, or scanBarcode interface.

{|class="wizarpostable"
|-
!  scope="row" colspan="2"| Returns
|-
| boolean || true / false.
|}

=== IScanCallBack ===
==== FoundBarcode ====
  <syntaxhighlight lang="java">void foundBarcode(ScanResult result);</syntaxhighlight >
foundBarcode is a function of IScanCallBack that is a parameter of previous interface. 

The caller can get the Scan Result through this interface. When this interface is called, the scan service is in the pause state, and when the call in returned, then the next scanning  will be continued.
You can turn off the scan service that is in pause with “stopScan”  that is another interface . 

{|class="wizarpostable"
|-
! scope="row" colspan="2" | Parameters
|-
| ScanResult || '''ScanResult:'''  [[#Scan Result|Scan Result]]
|}

=== Scan Parameter ===
Scan Parameter is a parameter object, it defines the parameters that need by the scan service.
method: set(String key, String value)  (Value Not case sensitive)

{| class="wikitable"
|-
| Key 
| Value Type
| Value
| Description

|-
| window_top || int || Default: 0,Range: >0 || The distance to the screen top. Effect in overlaymode.(dp)

|-
| window_left || int || Default: 0,Range: >0 || The distance to the screen left. Effect in overlaymode.(dp)

|-
| window_width || int || Default: screen width,Range: >0 || Screen width. Effect in overlaymode.(dp)

|-
| window_height || int || Default: screen ,Range: >0 || Screen hight. Effect in overlaymode.(dp)

|-
| enable_scan_section || boolean || Default: true|| False: all the display window is the area for scanner, remove the scanner frame. 
True: customize the area of the scanner, has a scanner frame, the other part is semitransparent, the scanner frame is in center, can adjust the width or the height of the scanner frame.

|-
| scan_section_width || int || Default: 300dip,Range: >0 || The width of the scanner frame.

|-
| scan_section_height || int || Default: 300dip,Range: >0 || The height of the scanner frame.

|-
| display_scan_line || String || Default: moving,Range: No/fixed/moving || Display the red line in scanner area.
NO: Not display
Fixed: In center
Moving: Move up and down.(dp)

|-
| enable_flash_icon || boolean || Default(W1|Q1): (T|F) || Whether to display the hover button of controlling the flash.

|-
| enable_switch_icon || boolean || Default: T || Whether to display the hover button of switching camera.

|-
| enable_indicator_light || boolean || Default: F || Whether to display the indicator light button, only supported in Q1.

|-
| decodeformat || String || Default: BARCODE_ALL|| Decode format range.Default is BARCODE_ALL,the formats are separated by “,”.

|-
| decoder_mode || int || Default: 2,Range:0-2 || Decode mode:
0: mode1
1: mode2
2: mode3

|-
| enable_return_image || boolean || Default: F || Whether to return the scanned image.

|-
| camera_index || int || Default: 0,Range:0-2 || 0: fixed camera.
1:zomm camera.
2:customer display camera

|-
| scan_time_out || long (ms) || Default: -1,Range: >0 || <=0:scan forever
>0:scan with timeout,when timeout, return timeout error, only effected in synchronized interface.

|-
| scan_section_border_color || int || Default: Color.WHITE || The color of scan border, use Color.argb

|-
| scan_section_corner_color || int || Default: Color.argb(0xFF,0x21, 0xDB, 0xD5) || The color of the scan corner

|-
| scan_section_line_color || int || Default: Color.RED || The color of the scan line

|-
| scan_tip_textSize || int || Default: 15 || The size of the tip text Unit: sp

|-
| scan_tip_textColor || int || Default: Color.WHITE || The distance between the tip text and the bottom of the screen Unit: dp

|-
| scan_tip_textMargin || int || Default: 30|| The distance between thetip text and the bottom of the screen Unit: dp

|-
| flash_light_state || boolean || Default: F || Initial state of indicator light
true: opened
false: closed

|-
| indicator_light_state || iboolean || Default: F || Initial state of indicator light
true: opened
false: closed

|-
| scan_mode || String || Default: dialog || Scanner window mode dialog: activity with specified UI 
overlay:only has scanner window, without UItitles, UI buttons, the scanner window on top of other UI activities

|-
| scan_camera_exposure || int || Default: 0 || Camera exposure compensation for zoom camera

|-
| scan_time_limit || int || Default: 50 || The max decode time

|-
| enable_mirror_scan || boolean || Default: T || Enable mirror scan Default is true, opened

|}

=== Scan Result ===

{| class="wikitable"
|-
| Field 
| Type
| Description

|-
| resultCode || int || >=0: Success
<0: Failure
(See also [[#Error Code|Error Code]])

|-
| text || String || The text result, return null when error occurred, the format of the text is UTF-8, if need the other format, please get the raw buffer and change by yourself.

|-
| rawBuffer || Byte[] || The raw buffer

|-
| bitmap || Bitmap || The scanned image, it will return when set the parameter enable_return_image is true.

|-
| barcodeFormat || String || barcodeFormat, see Appendix
|}

== Error Code ==

{| class="wikitable"
|-
| Value
| Description


|-
| 1 || Success

|-
| 0 || Cancel

|-
| 2 || The scan UI fully display

|-
| -1 || The service has been occupied

|-
| -2 || Can not open the camera

|-
| -3 || Scan timeout

|-
| -3 || Illegal parameter

|}
== Scan Mode ==
In dialog mode, the scanner UI has drawed by the camera scanner service, the third app don’t need to consider about the UI.

In overlay mode, the camera scanner service only provide the scanner window, the window will display on top of the third app UI. So the third app can draw the UI by itself, such as the title, the buttons. In this mode, if the app need to switch the camera, the flash light, the indicator light, it must use the broadcast like belows:
* <big>Camera</big>:

Broadcast Action : com.wizarpos.scanner.setcamera

Broadcast Key: overlay_config

Value: 0 Fixed camera;1 zoom camera; 2 customer display* camera

* <big>Flash light</big>:
Broadcast Action : com.wizarpos.scanner.setflashlight

Broadcast Key: overlay_config

Value: true opened; false closed

* <big>Indicator light</big>:
Broadcast Action : com.wizarpos.scanner.setindicator

Broadcast Key : overlay_config

Value: true opened; false closed

Sample Code:
<syntaxhighlight lang="java" >
// open the flash light
Intent intent = new Intent();
intent.setAction(ScanParameter.BROADCAST_SET_FLASHLIGHT);
intent.putExtra(ScanParameter.BROADCAST_VALUE, true);
sendBroadcast(intent);
</syntaxhighlight>
== Getting Started ==
The scan service use AIDL, so the third app must include the AIDL files which provided by WizarPOS.
== Bind service ==
Sample code:
<syntaxhighlight lang="java">
AidlController.getInstance().startScanService(this, this);
.
.
private IScannService scanService; //Scanner service
private ServiceConnection scanConn;
@Override
public void serviceConnected(Object objService, ServiceConnection connection) {
if(objService instanceof IScannService){
scanService = (IScannService) objService;
scanConn = connection;
}
}
.
.
if(scanService != null){
this.unbindService(scanConn);
scanService = null;
scanConn = null;
}
</syntaxhighlight>
== Appendix ==
=== Barcode Format ===
Example:
<syntaxhighlight lang="java" >
ScanParameter parameter = new ScanParameter();
parameter.set(ScanParameter.KEY_DECODEFORMAT, " SymbologyType_Aztec, ITF ");
</syntaxhighlight>
compound barcode format
{| class="wikitable"
|-
| BARCODE_ALL
| Includes all the barcodes in the table

|-
| BARCODE_1D || Includes all the 1D barcodes in the table

|-
| BARCODE_2D || Includes all the 2D barcodes in the table

|}

Barcode format
{| class="wikitable"
|-
| AZTEC || 2D barcode

|-
| DATAMATRIX || 2D barcode

|-
| QR || 2D barcode

|-
| MAXICODE || 2D barcode

|-
| PDF417 || 2D barcode

|-
| CODABAR || 1D barcode

|-
| CODE39 || 1D barcode

|-
| CODE93 || 1D barcode

|-
| CODE128 || 1D barcode

|-
| EAN8 || 1D barcode

|-
| EAN13 || 1D barcode

|-
| ITF || 1D barcode(Interleaved Two of Five)

|-
| RSS_14 || 1D barcode

|-
| RSS_EXPANDED || 1D barcode

|-
| UPCA || 1D barcode

|-
| UPCE || 1D barcode

|-
| CODE11 || 1D barcode

|}