From 27d3c774b6f9892342ca44f0c94634d6fe1866be Mon Sep 17 00:00:00 2001
From: Sasikanth Miriyampalli <hello@sasikanth.dev>
Date: Thu, 21 Sep 2023 19:41:20 +0530
Subject: [PATCH] Add QR code image bitmap generator

---
 .../component/internal/qr/QrCodeGenerator.kt  | 43 ++++++++++++++++++
 .../component/internal/qr/QrCodeGenerator.kt  | 29 ++++++++++++
 .../component/internal/qr/QrCodeGenerator.kt  | 45 +++++++++++++++++++
 3 files changed, 117 insertions(+)
 create mode 100644 designsystem/src/androidMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt
 create mode 100644 designsystem/src/commonMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt
 create mode 100644 designsystem/src/desktopMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt

diff --git a/designsystem/src/androidMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt b/designsystem/src/androidMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt
new file mode 100644
index 000000000..0d7add078
--- /dev/null
+++ b/designsystem/src/androidMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt
@@ -0,0 +1,43 @@
+package org.hisp.dhis.mobile.ui.designsystem.component.internal.qr
+
+import android.graphics.Bitmap
+import android.graphics.Color
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.asImageBitmap
+import com.google.zxing.BarcodeFormat
+import com.google.zxing.EncodeHintType
+import com.google.zxing.common.BitMatrix
+import com.google.zxing.qrcode.QRCodeWriter
+
+internal actual class QrCodeGenerator {
+
+    actual fun generate(data: String): ImageBitmap {
+        val writer = QRCodeWriter()
+        val bitMatrix = writer.encode(
+            data,
+            BarcodeFormat.QR_CODE,
+            QR_CODE_SIZE,
+            QR_CODE_SIZE,
+            mapOf(Pair(EncodeHintType.MARGIN, 1)),
+        )
+        val bitmap = createAndroidBitmap(bitMatrix)
+
+        return bitmap.asImageBitmap()
+    }
+
+    private fun createAndroidBitmap(bitMatrix: BitMatrix): Bitmap {
+        val width = bitMatrix.width
+        val height = bitMatrix.height
+        val pixels = IntArray(width * height)
+
+        for (y in 0 until height) {
+            for (x in 0 until width) {
+                pixels[y * width + x] = if (bitMatrix[x, y]) Color.BLACK else Color.WHITE
+            }
+        }
+
+        return Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888).apply {
+            setPixels(pixels, 0, width, 0, 0, width, height)
+        }
+    }
+}
diff --git a/designsystem/src/commonMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt b/designsystem/src/commonMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt
new file mode 100644
index 000000000..902e0c6d0
--- /dev/null
+++ b/designsystem/src/commonMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt
@@ -0,0 +1,29 @@
+package org.hisp.dhis.mobile.ui.designsystem.component.internal.qr
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.State
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.graphics.ImageBitmap
+
+@Composable
+internal fun rememberQrCodeGenerator(value: String): State<ImageBitmap?> {
+    val qrCodeGenerator = LocalQrCodeGenerator.current
+    val result = remember(value) { mutableStateOf<ImageBitmap?>(null) }
+
+    LaunchedEffect(value) {
+        result.value = qrCodeGenerator.generate(value)
+    }
+
+    return result
+}
+
+internal expect class QrCodeGenerator() {
+    fun generate(data: String): ImageBitmap
+}
+
+internal const val QR_CODE_SIZE = 512 // px
+
+internal val LocalQrCodeGenerator = staticCompositionLocalOf { QrCodeGenerator() }
diff --git a/designsystem/src/desktopMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt b/designsystem/src/desktopMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt
new file mode 100644
index 000000000..0eb1797ba
--- /dev/null
+++ b/designsystem/src/desktopMain/kotlin/org/hisp/dhis/mobile/ui/designsystem/component/internal/qr/QrCodeGenerator.kt
@@ -0,0 +1,45 @@
+package org.hisp.dhis.mobile.ui.designsystem.component.internal.qr
+
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.toComposeImageBitmap
+import com.google.zxing.BarcodeFormat
+import com.google.zxing.EncodeHintType
+import com.google.zxing.common.BitMatrix
+import com.google.zxing.qrcode.QRCodeWriter
+import java.awt.image.BufferedImage
+
+internal actual class QrCodeGenerator {
+
+    private val colorBlack = 0xFF000000.toInt()
+    private val colorWhite = 0xFFFFFFFF.toInt()
+
+    actual fun generate(data: String): ImageBitmap {
+        val writer = QRCodeWriter()
+        val bitMatrix = writer.encode(
+            data,
+            BarcodeFormat.QR_CODE,
+            QR_CODE_SIZE,
+            QR_CODE_SIZE,
+            mapOf(Pair(EncodeHintType.MARGIN, 1)),
+        )
+        val image = createBufferedImage(bitMatrix)
+
+        return image.toComposeImageBitmap()
+    }
+
+    private fun createBufferedImage(bitMatrix: BitMatrix): BufferedImage {
+        val width = bitMatrix.width
+        val height = bitMatrix.height
+        val pixels = IntArray(width * height)
+
+        for (y in 0 until height) {
+            for (x in 0 until width) {
+                pixels[y * width + x] = if (bitMatrix[x, y]) colorBlack else colorWhite
+            }
+        }
+
+        return BufferedImage(width, height, BufferedImage.TYPE_INT_RGB).apply {
+            setRGB(0, 0, width, height, pixels, 0, width)
+        }
+    }
+}