Add QR code generation from text input

app/build.gradle.kts

@@ -96,6 +96,8 @@ dependencies {
 
     implementation(libs.android.billing.client)
 
+    implementation(libs.zxing.core)
+
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)

app/src/main/java/com/creative/qrcodescanner/ui/QRApp.kt

@@ -17,6 +17,7 @@ import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
 import com.creative.qrcodescanner.R
+import com.creative.qrcodescanner.ui.generate.GenerateQRScreenLayout
 import com.creative.qrcodescanner.ui.history.HistoryScreenLayout
 import com.creative.qrcodescanner.ui.main.MainScreenLayout
 import com.creative.qrcodescanner.ui.main.MainViewModel
@@ -167,6 +168,9 @@ fun QRApp(vm: MainViewModel = hiltViewModel(),
         composable(route = AppScreen.PREMIUM.value) {
             PremiumScreenLayout(appNav = appNavHost)
         }
+        composable(route = AppScreen.GENERATE.value) {
+            GenerateQRScreenLayout(appNav = appNavHost)
+        }
     }
 }
 
@@ -175,5 +179,6 @@ enum class AppScreen(val value: String) {
     SETTING("setting"),
     PREMIUM("premium"),
     HISTORY("history"),
-    RESULT("result/{id}")
+    RESULT("result/{id}"),
+    GENERATE("generate")
 }

app/src/main/java/com/creative/qrcodescanner/ui/generate/GenerateQRScreenLayout.kt

@@ -0,0 +1,142 @@
+package com.creative.qrcodescanner.ui.generate
+
+import androidx.activity.compose.BackHandler
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.navigationBars
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.windowInsetsBottomHeight
+import androidx.compose.foundation.layout.wrapContentHeight
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.compose.ui.platform.LocalSoftwareKeyboardController
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.navigation.NavHostController
+import com.creative.qrcodescanner.R
+import com.creative.qrcodescanner.ui.nav.TopNavBar
+import com.creative.qrcodescanner.ui.shadow
+
+@Composable
+fun GenerateQRScreenLayout(
+    appNav: NavHostController,
+    viewModel: GenerateQRViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    var inputText by rememberSaveable { mutableStateOf("") }
+    val keyboardController = LocalSoftwareKeyboardController.current
+
+    BackHandler {
+        appNav.popBackStack()
+    }
+
+    Scaffold(
+        topBar = {
+            TopNavBar(titleResId = R.string.generate_qr_code) {
+                appNav.popBackStack()
+            }
+        },
+        bottomBar = {
+            Spacer(modifier = Modifier.windowInsetsBottomHeight(WindowInsets.navigationBars))
+        }
+    ) { paddingValues ->
+        Column(
+            modifier = Modifier
+                .padding(paddingValues)
+                .fillMaxSize()
+                .padding(16.dp),
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(16.dp)
+        ) {
+            OutlinedTextField(
+                value = inputText,
+                onValueChange = { inputText = it },
+                label = { Text(text = stringResource(R.string.enter_text_to_generate_qr)) },
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .wrapContentHeight(),
+                maxLines = 5,
+                keyboardOptions = KeyboardOptions(imeAction = ImeAction.Done),
+                keyboardActions = KeyboardActions(onDone = {
+                    keyboardController?.hide()
+                    viewModel.generateQRCode(inputText)
+                })
+            )
+
+            TextButton(
+                onClick = {
+                    keyboardController?.hide()
+                    viewModel.generateQRCode(inputText)
+                },
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .shadow(
+                        MaterialTheme.colorScheme.primary.copy(alpha = 0.3f),
+                        blurRadius = 8.dp, borderRadius = 8.dp, spread = 0.dp, offsetY = 0.dp, offsetX = 0.dp
+                    )
+                    .background(MaterialTheme.colorScheme.primary, shape = RoundedCornerShape(8.dp))
+                    .clip(RoundedCornerShape(8.dp))
+            ) {
+                Text(
+                    text = stringResource(R.string.generate).uppercase(),
+                    color = MaterialTheme.colorScheme.onPrimary
+                )
+            }
+
+            when (val state = uiState) {
+                is GenerateQRUIState.Success -> {
+                    Image(
+                        bitmap = state.bitmap.asImageBitmap(),
+                        contentDescription = stringResource(R.string.qr_code_generated),
+                        modifier = Modifier
+                            .size(256.dp)
+                            .shadow(
+                                MaterialTheme.colorScheme.onBackground.copy(alpha = 0.1f),
+                                blurRadius = 8.dp, borderRadius = 8.dp, spread = 0.dp, offsetY = 0.dp, offsetX = 0.dp
+                            )
+                            .background(Color.White, shape = RoundedCornerShape(8.dp))
+                            .padding(8.dp)
+                    )
+                }
+
+                is GenerateQRUIState.Error -> {
+                    Text(
+                        text = state.message,
+                        color = MaterialTheme.colorScheme.error,
+                        style = MaterialTheme.typography.bodyMedium
+                    )
+                }
+
+                is GenerateQRUIState.Idle -> {
+                    // No content to show yet
+                }
+            }
+        }
+    }
+}

app/src/main/java/com/creative/qrcodescanner/ui/generate/GenerateQRViewModel.kt

@@ -0,0 +1,51 @@
+package com.creative.qrcodescanner.ui.generate
+
+import android.graphics.Bitmap
+import android.graphics.Color
+import androidx.lifecycle.ViewModel
+import com.google.zxing.BarcodeFormat
+import com.google.zxing.EncodeHintType
+import com.google.zxing.qrcode.QRCodeWriter
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import javax.inject.Inject
+
+sealed class GenerateQRUIState {
+    data object Idle : GenerateQRUIState()
+    data class Success(val bitmap: Bitmap) : GenerateQRUIState()
+    data class Error(val message: String) : GenerateQRUIState()
+}
+
+@HiltViewModel
+class GenerateQRViewModel @Inject constructor() : ViewModel() {
+
+    private val _uiState: MutableStateFlow<GenerateQRUIState> = MutableStateFlow(GenerateQRUIState.Idle)
+    val uiState: StateFlow<GenerateQRUIState> = _uiState.asStateFlow()
+
+    fun generateQRCode(text: String, size: Int = 512) {
+        if (text.isBlank()) {
+            _uiState.value = GenerateQRUIState.Error("Please enter text")
+            return
+        }
+        try {
+            val hints = mapOf(
+                EncodeHintType.MARGIN to 1,
+                EncodeHintType.CHARACTER_SET to "UTF-8"
+            )
+            val bitMatrix = QRCodeWriter().encode(text, BarcodeFormat.QR_CODE, size, size, hints)
+            val pixels = IntArray(size * size)
+            for (y in 0 until size) {
+                for (x in 0 until size) {
+                    pixels[y * size + x] = if (bitMatrix[x, y]) Color.BLACK else Color.WHITE
+                }
+            }
+            val bitmap = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888)
+            bitmap.setPixels(pixels, 0, size, 0, 0, size, size)
+            _uiState.value = GenerateQRUIState.Success(bitmap)
+        } catch (e: Exception) {
+            _uiState.value = GenerateQRUIState.Error(e.message ?: "Failed to generate QR code")
+        }
+    }
+}

app/src/main/java/com/creative/qrcodescanner/ui/main/FooterTools.kt

@@ -26,7 +26,7 @@ import com.creative.qrcodescanner.ui.theme.QRCodeScannerTheme
 
 @Composable
 @Stable
-fun BoxScope.FooterTools(navToHistory: () -> Unit, pickGallery: () -> Unit) {
+fun BoxScope.FooterTools(navToHistory: () -> Unit, pickGallery: () -> Unit, navToGenerate: () -> Unit) {
     Image(
         painter = painterResource(id = R.drawable.add_photo_alternate),
         contentDescription = stringResource(R.string.gallery_picker),
@@ -42,6 +42,21 @@ fun BoxScope.FooterTools(navToHistory: () -> Unit, pickGallery: () -> Unit) {
             .padding(18.dp)
     )
 
+    Image(
+        painter = painterResource(id = R.drawable.icon_qr_generate),
+        contentDescription = stringResource(R.string.generate_qr_button),
+        contentScale = ContentScale.Inside,
+        modifier = Modifier
+            .align(Alignment.BottomCenter)
+            .padding(16.dp)
+            .shadow(Color(0x901c1c1c).copy(alpha = 0.5f), blurRadius = 12.dp, borderRadius = 32.dp, spread = 0.dp, offsetY = 1.dp, offsetX = 1.dp)
+            .size(64.dp)
+            .background(color = Color(0x901c1c1c), shape = CircleShape)
+            .clip(CircleShape)
+            .clickable(onClick = navToGenerate)
+            .padding(18.dp)
+    )
+
     Image(
         painter = painterResource(id = R.drawable.history),
         contentDescription = stringResource(R.string.history_picker),
@@ -63,7 +78,7 @@ fun BoxScope.FooterTools(navToHistory: () -> Unit, pickGallery: () -> Unit) {
 fun FooterToolsPreview() {
     QRCodeScannerTheme {
         Box(modifier = Modifier.fillMaxWidth()) {
-            FooterTools(navToHistory = {}, pickGallery = {})
+            FooterTools(navToHistory = {}, pickGallery = {}, navToGenerate = {})
         }
     }
 }

app/src/main/java/com/creative/qrcodescanner/ui/main/MainScreenLayout.kt

@@ -210,6 +210,11 @@ fun MainScreenLayout(vm: MainViewModel, appNavHost: NavHostController) {
                             PickVisualMediaRequest(ActivityResultContracts.PickVisualMedia.ImageOnly)
                         )
                     }
+                },
+                navToGenerate = remember {
+                    {
+                        appNavHost.navigate(AppScreen.GENERATE.value)
+                    }
                 })
         }
 

app/src/main/res/drawable/icon_qr_generate.xml

@@ -0,0 +1,30 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="M3,11V3H11V11H3ZM5,5V9H9V5H5Z"/>
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="M3,21V13H11V21H3ZM5,15V19H9V15H5Z"/>
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="M13,3V11H21V3H13ZM19,9H15V5H19V9Z"/>
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="M18,13H21V16H18V13Z"/>
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="M13,13H16V16H13V13Z"/>
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="M16,16H18V18H16V16Z"/>
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="M18,18H21V21H18V18Z"/>
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="M13,18H16V21H13V18Z"/>
+</vector>

app/src/main/res/values/strings.xml

@@ -73,4 +73,10 @@
     <string name="only_2_99_first_3_months">2.99$ First 3 Months</string>
     <string name="processing_purchase">Processing purchase...</string>
     <string name="billing_service_is_not_available_please_check_your_network_connection_and_try_again">Billing Service is not available, please check your network connection and try again.</string>
+    <string name="generate_qr_code">Generate QR Code</string>
+    <string name="generate_qr_button">Generate QR</string>
+    <string name="enter_text_to_generate_qr">Enter text to generate QR code</string>
+    <string name="generate">Generate</string>
+    <string name="qr_code_generated">QR Code Generated</string>
+    <string name="please_enter_text">Please enter text</string>
 </resources>

gradle/libs.versions.toml

@@ -20,6 +20,7 @@ datastore_version = "1.0.0"
 billing_version = "6.1.0"
 firebaseCrashlyticsBuildtools = "2.9.9"
 ksp_version = "1.9.0-1.0.13"
+zxing_version = "3.5.3"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -71,6 +72,7 @@ androidx-datastore-preferences = { group = "androidx.datastore", name = "datasto
 
 android-billing-client = { group = "com.android.billingclient", name = "billing", version.ref = "billing_version" }
 firebase-crashlytics-buildtools = { group = "com.google.firebase", name = "firebase-crashlytics-buildtools", version.ref = "firebaseCrashlyticsBuildtools" }
+zxing-core = { group = "com.google.zxing", name = "core", version.ref = "zxing_version" }
 
 [plugins]
 androidApplication = { id = "com.android.application", version.ref = "agp" }