Barcode blog MainActivity.kt

barcode-MainActivity.kt

package uk.co.brightec.barcodeblogpost

import android.graphics.Bitmap
import android.os.Bundle
import androidx.annotation.ColorInt
import androidx.appcompat.app.AppCompatActivity
import com.google.zxing.BarcodeFormat
import com.google.zxing.oned.Code128Writer
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        displayBitmap("9781407189178")
    }

    private fun displayBitmap(value: String) {
        val widthPixels = resources.getDimensionPixelSize(R.dimen.width_barcode)
        val heightPixels = resources.getDimensionPixelSize(R.dimen.height_barcode)

        image_barcode.setImageBitmap(
            createBarcodeBitmap(
                barcodeValue = value,
                barcodeColor = getColor(R.color.colorPrimary),
                backgroundColor = getColor(android.R.color.white),
                widthPixels = widthPixels,
                heightPixels = heightPixels
            )
        )
        text_barcode_number.text = value
    }

    private fun createBarcodeBitmap(
        barcodeValue: String,
        @ColorInt barcodeColor: Int,
        @ColorInt backgroundColor: Int,
        widthPixels: Int,
        heightPixels: Int
    ): Bitmap {
        val bitMatrix = Code128Writer().encode(
            barcodeValue,
            BarcodeFormat.CODE_128,
            widthPixels,
            heightPixels
        )

        val pixels = IntArray(bitMatrix.width * bitMatrix.height)
        for (y in 0 until bitMatrix.height) {
            val offset = y * bitMatrix.width
            for (x in 0 until bitMatrix.width) {
                pixels[offset + x] =
                    if (bitMatrix.get(x, y)) barcodeColor else backgroundColor
            }
        }

        val bitmap = Bitmap.createBitmap(
            bitMatrix.width,
            bitMatrix.height,
            Bitmap.Config.ARGB_8888
        )
        bitmap.setPixels(
            pixels,
            0,
            bitMatrix.width,
            0,
            0,
            bitMatrix.width,
            bitMatrix.height
        )
        return bitmap
    }
}