B4A Library Barcode Scanner - 100% embedded within B4A (15 Feb 2016 : New library files in Post #105)

Johan Schoeman · Nov 8, 2015

The attached project wraps this Github project. It is a barcode scanner based on the ZXING project. I have successfully scanned the following 1D and 2D barcodes:
1. Code 39
2. Code 93
3. Code 128
4. Two-of-Five Interleaved (TFI)
5. EAN13
6. EAN8
7. PDF417
8. QR Code
9. Aztec Code
10. Codabar

It is 100% embedded within the B4A project via a CustomView. Thus, you can add buttons, background images, background colors, labels, textviews, or whatever you like to the activity via the designer or via code. It does not have all the bells and whistles that the ZXING project offers (i.e ability to set the laser color etc) but it works 100% within B4A. It does not take over control of the B4A activity - set the size (width / height / left / top) of the CustomView in the B4A code and that will be the size of your barcode View Finder. Add buttons to start and stop the scanner. It is as simple as that.

For as long as what the scanner is active it will scan 1D/2D barcodes i.e no need to stop and start the scanner to start scanning a new barcode. Just point the scanner at the next barcode to scan.

I have added the following events to the B4A project:
1. scanresult - here you can get the decoded string/text result when a successful scan occurred
2. scanner_started - this event is raised when the scanner is activated via B4A code
3. scan_error - sorry, but have not seen this event in action yet as I have had no miss scans thus far
4. scanner_stopped - this event is raised when the scanner is stopped.

There are a number of files in the B4A project's Object/res/..... folders that are set to read only. Keep them like that.

There are permissions added to the B4A manifest - make sure you take note of it should you start a new B4A project.

You will need core-3.1.0.jar and android-support-v4.jar to be in your additional library folder. I have zipped them together - you can download them from HERE. Extract them from the zipped file and copy them to your additional library folder.

Some sample code:

B4X:

#Region  Project Attributes
    #ApplicationLabel: zxScannerLiveView
    #VersionCode: 1
    #VersionName:
    'SupportedOrientations possible values: unspecified, landscape or portrait.
    #SupportedOrientations: landscape
    #CanInstallToExternalStorage: False
#End Region

#Region  Activity Attributes
    #FullScreen: False
    #IncludeTitle: True
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

    Private zxslv As zxScannerLiveView
    Private b1 As Button
    Private b2 As Button
    Private l1 As Label

End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    Activity.LoadLayout("main")

    zxslv.Initialize("zxslv")

    Activity.AddView(zxslv, 50%x - 45%y, 5%y, 90%y, 90%y)

    zxslv.HudVisible = True
    zxslv.PlaySound = True
    zxslv.Visible = False

End Sub

Sub Activity_Resume


End Sub

Sub Activity_Pause (UserClosed As Boolean)

    zxslv.Visible = False
    zxslv.stopScanner

End Sub

Sub b1_Click

    zxslv.Visible = True
    zxslv.startScanner

End Sub
Sub b2_Click

    zxslv.Visible = False
    zxslv.stopScanner
    l1.Text = ""

End Sub

Sub zxslv_scanresult

    Log(zxslv.ScanResult)
    l1.Text = zxslv.ScanResult

End Sub

Sub zxslv_scanner_started

    Log("Scanner Started")

End Sub

Sub zxslv_scan_error

    Log("Scan Error")

End Sub

Sub zxslv_scanner_stopped

    Log("Scanner stopped")

End Sub

And this will add a coloured frame around the view finder - making use of panels via B4A code:

B4X:

#Region  Project Attributes
    #ApplicationLabel: zxScannerLiveView
    #VersionCode: 1
    #VersionName:
    'SupportedOrientations possible values: unspecified, landscape or portrait.
    #SupportedOrientations: landscape
    #CanInstallToExternalStorage: False
#End Region

#Region  Activity Attributes
    #FullScreen: False
    #IncludeTitle: True
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

    Private zxslv As zxScannerLiveView
    Private b1 As Button
    Private b2 As Button
    Private l1 As Label
    Private l2, l3, l4, l5 As Label

End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    Activity.LoadLayout("main")

    zxslv.Initialize("zxslv")
    Dim framecolor As Int = Colors.Red

    l2.Initialize("")
    l3.Initialize("")
    l4.Initialize("")
    l5.Initialize("")

    Activity.AddView(zxslv, 50%x - 45%y, 5%y, 90%y, 90%y)
    Activity.AddView(l2, 50%x - 45%y - 1%y, 4%y, 1%y, 92%y)
    Activity.AddView(l3, 50%x + 45%y, 4%y, 1%y, 92%y)
    Activity.AddView(l4, 50%x - 45%y - 1%y, 4%y, 91%y, 1%y)
    Activity.AddView(l5, 50%x - 45%y - 1%y, 5%y + 90%y, 91%y, 1%y)


    l2.Color = framecolor
    l2.Visible = False

    l3.Color = framecolor
    l3.Visible = False

    l4.Color = framecolor
    l4.Visible = False

    l5.Color = framecolor
    l5.Visible = False

    zxslv.HudVisible = True
    zxslv.PlaySound = True
    zxslv.Visible = False


End Sub

Sub Activity_Resume


End Sub

Sub Activity_Pause (UserClosed As Boolean)

    zxslv.Visible = False
    zxslv.stopScanner

    l2.Visible = False
    l3.Visible = False
    l4.Visible = False
    l5.Visible = False

End Sub

Sub b1_Click

    zxslv.Visible = True
    zxslv.startScanner

    l2.Visible = True
    l3.Visible = True
    l4.Visible = True
    l5.Visible = True

End Sub
Sub b2_Click

    zxslv.Visible = False
    zxslv.stopScanner
    l1.Text = ""

    l2.Visible = False
    l3.Visible = False
    l4.Visible = False
    l5.Visible = False



End Sub

Sub zxslv_scanresult

    Log(zxslv.ScanResult)
    l1.Text = zxslv.ScanResult

End Sub

Sub zxslv_scanner_started

    Log("Scanner Started")

End Sub

Sub zxslv_scan_error

    Log("Scan Error")

End Sub

Sub zxslv_scanner_stopped

    Log("Scanner stopped")

End Sub

It will look like this:

zxScannerLiveView
Author: Github: Dmitri Livotov, Wrapper: Johan Schoeman
Version: 1

zxScannerLiveView
Events:

scan_error ( )

scanner_started ( )

scanner_stopped ( )

scanresult ( )

Fields:

BACK As String

FRONT As String

ba As BA

mfrontOrBack As String

Methods:

BringToFront

DesignerCreateView (base As PanelWrapper, lw As LabelWrapper, props As Map)

Initialize (EventName As String)

Invalidate

Invalidate2 (arg0 As Rect)

Invalidate3 (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int)

IsInitialized As Boolean

RemoveView

RequestFocus As Boolean

SendToBack

SetBackgroundImage (arg0 As Bitmap)

SetColorAnimated (arg0 As Int, arg1 As Int, arg2 As Int)

SetLayout (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int)

SetLayoutAnimated (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int, arg4 As Int)

SetVisibleAnimated (arg0 As Int, arg1 As Boolean)

startScanner
Starts scanner, using device default camera

stopScanner
Stops currently running scanner

toggleFlash

Properties:

BackgroudImage As String [write only]

Background As Drawable

CameraToUse As String [write only]

Color As Int [write only]

Enabled As Boolean

Height As Int

HudVisible As Boolean [write only]

Left As Int

PlaySound As Boolean [write only]

SameCodeRescanProtectionTime As Long [write only]

ScanResult As String [read only]

Tag As Object

Top As Int

Visible As Boolean

Width As Int

You can download and test any posting of mine in this thread but if you want to use it then you need to

romario87027 · Mar 26, 2021

Johan Schoeman said:
Ok. So you have target SDK set to 30. Then you need to add RuntimePermissions to the B4A project code for permission to access the camera. A simple test would be to set the TargetSDK to 22 and see if the camera fires up. You might have to delete the installation of the app on your device before compiling with the SDK in the manifest set to 22.

I followed your instructions and now the camera is open.
But it has to work on Sdk Version 22 ?

Johan Schoeman · Mar 26, 2021

romario87027 said:
I followed your instructions and now the camera is open.
But it has to work on Sdk Version 22 ?

Now you need to browse the forum to see how you need to add RuntimePermissions to you B4A code when using SDK 26+. Change the targetSDK in the manifest back to 30 (or 29) and then add the required RTP code to the B4A project.

romario87027 · Mar 26, 2021

Johan Schoeman said:
Now you need to browse the forum to see how you need to add RuntimePermissions to you B4A code when using SDK 26+. Change the targetSDK in the manifest back to 30 (or 29) and then add the required RTP code to the B4A project.

thank you so much

Mwinsor · May 12, 2021

I am having the same problem with the camera. It does not turn on. Does this not run in B4XPages? The sample program works fine but when I move it to my project (even with the same manifest), the camera does not turn on

B4A Library Barcode Scanner - 100% embedded within B4A (15 Feb 2016 : New library files in Post #105)

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