feat: Enhance QuizScreen UI and introduce core design system module

This commit significantly revamps the `QuizScreen` UI to display question details including image and text, and introduces a new `core:designsystem` module to centralize theme, colors, typography, and drawable resources.

Key changes:

- **UI Layer (`ui:quiz` module):**
    - Updated `QuizScreen.kt`:
        - Implemented a background image for the screen.
        - Added a `Toolbar` composable to display question progress and type.
        - Created `QuestionContent` composable to show the question image (using Coil for image loading) and text.
        - Added a placeholder `Choices` composable (currently an empty `LazyVerticalGrid`).
        - Applied `fillMaxSize()` to the main `QuizScreen` modifier.
        - Included a `@Preview` for `QuizScreen` with sample data.
    - Modified `QuizScreenViewModel.kt` to update `QuizUiState` with the first `Question` from the fetched quiz.
    - Added a `quiz` string resource in `strings.xml`.
    - Added dependencies for Coil (compose and okhttp) in `ui/quiz/build.gradle.kts`.
- **Core Design System (`core:designsystem` module):**
    - Created a new Android library module `core:designsystem`.
    - Moved `Color.kt`, `Theme.kt`, and `Type.kt` from `app/src/main/java/dev/adriankuta/kahootquiz/ui/theme` to this new module.
    - Added a new `Grey` color to `Color.kt`.
    - Added `bg_image.webp` and `ic_type.xml` drawable resources.
    - Configured the module with `kahootquiz.android.library.compose` plugin.
- **App Module (`app` module):**
    - Updated `MainActivity.kt` to import `KahootQuizTheme` from the new `core.designsystem` package.
    - Added `implementation(projects.core.designsystem)` dependency in `app/build.gradle.kts`.
- **Domain Layer (`domain` module):**
    - Made several fields in `Question.kt` and `Choice.kt` nullable and provided default null values to accommodate potential missing data from the API.
    - Specifically, `Question.image` is now non-nullable (`String`).
- **Build System:**
    - Added `coilCompose` and `coilNetworkOkhttp` versions to `gradle/libs.versions.toml`.
    - Included `:core:designsystem` in `settings.gradle.kts`.

.idea/gradle.xml

@@ -26,6 +26,7 @@
             <option value="$PROJECT_DIR$/build-logic" />
             <option value="$PROJECT_DIR$/build-logic/convention" />
             <option value="$PROJECT_DIR$/core" />
+            <option value="$PROJECT_DIR$/core/designsystem" />
             <option value="$PROJECT_DIR$/core/network" />
             <option value="$PROJECT_DIR$/domain" />
             <option value="$PROJECT_DIR$/model" />

app/build.gradle.kts

@@ -27,10 +27,10 @@ android {
 }
 
 dependencies {
-    implementation(projects.ui.quiz)
+    implementation(projects.core.designsystem)
     implementation(projects.domain)
-
     implementation(projects.model.data)
+    implementation(projects.ui.quiz)
 
     implementation(libs.androidx.activity.compose)
     implementation(libs.androidx.hilt.navigation.compose)

app/src/main/java/dev/adriankuta/kahootquiz/MainActivity.kt

@@ -5,7 +5,7 @@ import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import dagger.hilt.android.AndroidEntryPoint
-import dev.adriankuta.kahootquiz.ui.theme.KahootQuizTheme
+import dev.adriankuta.kahootquiz.core.designsystem.KahootQuizTheme
 
 @AndroidEntryPoint
 class MainActivity : ComponentActivity() {

core/designsystem/build.gradle.kts

@@ -0,0 +1,7 @@
+plugins {
+    alias(libs.plugins.kahootquiz.android.library.compose)
+}
+
+android {
+    namespace = "dev.adriankuta.kahootquiz.core.designsystem"
+}

core/designsystem/src/main/kotlin/dev/adriankuta/kahootquiz/core/designsystem/Color.kt

@@ -1,4 +1,4 @@
-package dev.adriankuta.kahootquiz.ui.theme
+package dev.adriankuta.kahootquiz.core.designsystem
 
 import androidx.compose.ui.graphics.Color
 
@@ -8,4 +8,6 @@ val Pink80 = Color(0xFFEFB8C8)
 
 val Purple40 = Color(0xFF6650a4)
 val PurpleGrey40 = Color(0xFF625b71)
-val Pink40 = Color(0xFF7D5260)
+val Pink40 = Color(0xFF7D5260)
+
+val Grey = Color(0xFFFAFAFA)

core/designsystem/src/main/kotlin/dev/adriankuta/kahootquiz/core/designsystem/Theme.kt

@@ -1,6 +1,5 @@
-package dev.adriankuta.kahootquiz.ui.theme
+package dev.adriankuta.kahootquiz.core.designsystem
 
-import android.app.Activity
 import android.os.Build
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.material3.MaterialTheme

core/designsystem/src/main/kotlin/dev/adriankuta/kahootquiz/core/designsystem/Type.kt

@@ -1,4 +1,4 @@
-package dev.adriankuta.kahootquiz.ui.theme
+package dev.adriankuta.kahootquiz.core.designsystem
 
 import androidx.compose.material3.Typography
 import androidx.compose.ui.text.TextStyle

core/designsystem/src/main/res/drawable/ic_type.xml

@@ -0,0 +1,50 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:pathData="M12,22C6.477,22 2,17.523 2,12C2,6.477 6.477,2 12,2C17.523,2 22,6.477 22,12C22,17.523 17.523,22 12,22Z"
+      android:fillColor="#F2F2F2"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M19.802,21.989L7.899,23.992C7.584,24.045 7.285,23.833 7.232,23.517L3.724,2.678C3.671,2.363 3.883,2.064 4.198,2.011L16.101,0.008C16.416,-0.045 16.715,0.168 16.768,0.483L20.276,21.322C20.33,21.637 20.117,21.936 19.802,21.989Z"
+      android:fillColor="#333333"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M19.083,20.611L8.127,22.455C7.951,22.485 7.784,22.366 7.754,22.189L4.538,3.09C4.509,2.913 4.627,2.746 4.804,2.716L15.759,0.872C15.936,0.843 16.103,0.962 16.133,1.139L19.349,20.238C19.378,20.414 19.259,20.582 19.083,20.611Z"
+      android:fillColor="#FAFAFA"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M18.499,20.05L13.849,20.833C13.79,20.843 13.733,20.803 13.724,20.744L12.306,12.325C12.296,12.266 12.336,12.209 12.395,12.199L17.045,11.417C17.104,11.407 17.16,11.447 17.17,11.506L18.587,19.925C18.597,19.984 18.558,20.04 18.499,20.05Z"
+      android:fillColor="#26890C"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M12.967,20.981L8.317,21.764C8.258,21.774 8.202,21.733 8.192,21.674L6.775,13.255C6.765,13.196 6.805,13.14 6.864,13.13L11.514,12.347C11.573,12.337 11.629,12.377 11.639,12.437L13.057,20.856C13.066,20.915 13.026,20.971 12.967,20.981Z"
+      android:fillColor="#FFA602"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M16.947,10.835L12.297,11.618C12.238,11.628 12.182,11.588 12.172,11.529L10.64,2.434C10.631,2.374 10.67,2.318 10.73,2.308L15.379,1.526C15.439,1.516 15.495,1.556 15.505,1.615L17.036,10.71C17.046,10.769 17.006,10.825 16.947,10.835Z"
+      android:fillColor="#1368CE"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M11.416,11.766L6.766,12.548C6.707,12.558 6.651,12.518 6.641,12.459L5.109,3.364C5.099,3.305 5.139,3.249 5.199,3.239L9.848,2.456C9.907,2.446 9.964,2.486 9.974,2.546L11.505,11.641C11.515,11.7 11.475,11.756 11.416,11.766Z"
+      android:fillColor="#E11C3C"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M7.317,8.677L8.107,6.504L9.544,8.316L7.317,8.677Z"
+      android:fillColor="#FAFAFA"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M13.596,5.437L15.014,6.416L14.017,7.822L12.598,6.842L13.596,5.437Z"
+      android:fillColor="#FAFAFA"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M10.79,16.727C10.704,16.175 10.188,15.796 9.637,15.881C9.086,15.967 8.709,16.484 8.795,17.037C8.881,17.59 9.397,17.968 9.948,17.883C10.498,17.798 10.875,17.28 10.79,16.727Z"
+      android:fillColor="#FAFAFA"
+      android:fillType="evenOdd"/>
+  <path
+      android:pathData="M16.618,16.843L14.628,17.181L14.288,15.184L16.278,14.846L16.618,16.843Z"
+      android:fillColor="#FAFAFA"
+      android:fillType="evenOdd"/>
+</vector>

domain/src/main/kotlin/dev/adriankuta/kahootquiz/domain/models/Choice.kt

@@ -3,5 +3,5 @@ package dev.adriankuta.kahootquiz.domain.models
 data class Choice(
     val answer: String?,
     val correct: Boolean?,
-    val languageInfo: LanguageInfo?
+    val languageInfo: LanguageInfo? = null
 )

domain/src/main/kotlin/dev/adriankuta/kahootquiz/domain/models/Question.kt

@@ -8,16 +8,16 @@ data class Question(
     val type: String?,
     val question: String?,
     val time: Duration?,
-    val points: Boolean?,
+    val points: Boolean? = null,
     val pointsMultiplier: Int?,
     val choices: List<Choice>?,
-    val layout: String?,
+    val layout: String? = null,
-    val image: String?,
+    val image: String,
     val imageMetadata: ImageMetadata?,
-    val resources: String?,
+    val resources: String? = null,
-    val video: Video?,
+    val video: Video? = null,
-    val questionFormat: Int?,
+    val questionFormat: Int? = null,
-    val languageInfo: LanguageInfo?,
+    val languageInfo: LanguageInfo? = null,
-    val media: List<MediaItem>?,
+    val media: List<MediaItem>? = null,
-    val choiceRange: ChoiceRange?
+    val choiceRange: ChoiceRange? = null
 )

gradle/libs.versions.toml

@@ -1,4 +1,6 @@
 [versions]
+coilCompose = "3.3.0"
+coilNetworkOkhttp = "3.3.0"
 retrofit = "3.0.0"
 targetSdk = "36"
 compileSdk = "36"
@@ -94,6 +96,8 @@ androidx-work-testing = { group = "androidx.work", name = "work-testing", versio
 app-update-ktx = { module = "com.google.android.play:app-update-ktx", version.ref = "appUpdateKtx" }
 appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "appcompat" }
 billing-ktx = { group = "com.android.billingclient", name = "billing-ktx", version.ref = "billing" }
+coil-compose = { module = "io.coil-kt.coil3:coil-compose", version.ref = "coilCompose" }
+coil-network-okhttp = { module = "io.coil-kt.coil3:coil-network-okhttp", version.ref = "coilNetworkOkhttp" }
 detekt-compose = { module = "io.nlopez.compose.rules:detekt", version.ref = "detektCompose" }
 detekt-ktlint = { module = "io.gitlab.arturbosch.detekt:detekt-formatting", version.ref = "detekt" }
 dotlottie-android = { module = "com.github.LottieFiles:dotlottie-android", version.ref = "dotlottieAndroid" }

settings.gradle.kts

@@ -25,6 +25,7 @@ rootProject.name = "KahootQuiz"
 
 enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS")
 include(":app")
+include(":core:designsystem")
 include(":core:network")
 include(":domain")
 include(":model:data")

ui/quiz/build.gradle.kts

@@ -9,7 +9,11 @@ android {
 }
 
 dependencies {
+    implementation(projects.core.designsystem)
     implementation(projects.domain)
+
     implementation(libs.androidx.hilt.navigation.compose)
     implementation(libs.timber)
+    implementation(libs.coil.compose)
+    implementation(libs.coil.network.okhttp)
 }

ui/quiz/src/main/kotlin/dev/adriankuta/kahootquiz/ui/quiz/QuizScreen.kt

@@ -1,12 +1,40 @@
 package dev.adriankuta.kahootquiz.ui.quiz
 
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import coil3.compose.AsyncImage
+import dev.adriankuta.kahootquiz.core.designsystem.Grey
+import dev.adriankuta.kahootquiz.core.designsystem.KahootQuizTheme
+import dev.adriankuta.kahootquiz.domain.models.Choice
+import dev.adriankuta.kahootquiz.domain.models.Question
+import kotlin.time.Duration.Companion.seconds
+import dev.adriankuta.kahootquiz.core.designsystem.R as DesignR
 
 @Composable
 fun QuizScreen(
@@ -18,7 +46,7 @@ fun QuizScreen(
 
     QuizScreen(
         uiState = uiState,
-        modifier = modifier
+        modifier = modifier.fillMaxSize()
     )
 }
 
@@ -27,7 +55,132 @@ private fun QuizScreen(
     uiState: QuizUiState,
     modifier: Modifier = Modifier,
 ) {
-    Column(modifier) {
+    Box(modifier.fillMaxSize()) {
-        Text(uiState.quiz?.id?.value ?: "")
+        Image(
+            painter = painterResource(id = DesignR.drawable.bg_image),
+            contentDescription = null,
+            contentScale = ContentScale.Crop,
+            modifier = Modifier.fillMaxSize()
+        )
+        Column(
+            modifier = Modifier.fillMaxSize()
+        ) {
+            Toolbar(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .height(72.dp)
+                    .padding(8.dp)
+            )
+            QuestionContent(
+                question = uiState.currentQuestion ?: return,
+                modifier = Modifier.padding(horizontal = 8.dp)
+            )
+            Choices(
+                choices = uiState.currentQuestion.choices ?: emptyList() // TODO remove empty list
+            )
+        }
+    }
+}
+
+@Composable
+private fun Toolbar(
+    modifier: Modifier = Modifier
+) {
+    Box(
+        modifier = modifier
+    ) {
+        Text(
+            text = "2/24",
+            modifier = Modifier
+                .align(Alignment.CenterStart)
+                .background(
+                    color = Grey,
+                    shape = RoundedCornerShape(60.dp)
+                )
+                .padding(horizontal = 8.dp, vertical = 4.dp)
+        )
+
+        Row(
+            modifier = Modifier
+                .align(Alignment.Center)
+                .background(
+                    color = Grey,
+                    shape = RoundedCornerShape(60.dp)
+                )
+                .padding(horizontal = 8.dp, vertical = 4.dp)
+        ) {
+            Image(
+                painter = painterResource(id = DesignR.drawable.ic_type),
+                contentDescription = "",
+                modifier = Modifier.size(24.dp)
+            )
+            Spacer(Modifier.width(4.dp))
+            Text(
+                text = stringResource(R.string.quiz),
+            )
+        }
+    }
+}
+
+@Composable
+private fun QuestionContent(
+    question: Question,
+    modifier: Modifier = Modifier,
+) {
+    Column(
+        modifier = modifier
+    ) {
+        AsyncImage(
+            model = question.image,
+            contentDescription = question.imageMetadata?.altText,
+            contentScale = ContentScale.Crop,
+            modifier = Modifier
+                .fillMaxWidth()
+                .height(200.dp)
+        )
+        Spacer(Modifier.height(16.dp))
+        Text(
+            text = question.question ?: "",
+            textAlign = TextAlign.Center,
+            modifier = Modifier
+                .fillMaxWidth()
+                .background(
+                    color = Color.White,
+                    shape = RoundedCornerShape(4.dp)
+                )
+                .padding(horizontal = 8.dp, vertical = 16.dp)
+        )
+    }
+}
+
+@Composable
+private fun Choices(
+    choices: List<Choice>
+) {
+    LazyVerticalGrid() { }
+}
+
+@Preview
+@Composable
+private fun QuizScreenPreview() {
+    KahootQuizTheme {
+        val sampleQuestion = Question(
+            type = "quiz",
+            image = "", // Add a sample image URL or leave empty
+            question = "What is the capital of France?",
+            choices = listOf(
+                Choice(answer = "Berlin", correct = false),
+                Choice(answer = "Madrid", correct = false),
+                Choice(answer = "Paris", correct = true),
+                Choice(answer = "Rome", correct = false)
+            ),
+            pointsMultiplier = 1,
+            time = 30.seconds,
+            questionFormat = 0,
+            imageMetadata = null,
+        )
+        QuizScreen(
+            uiState = QuizUiState(currentQuestion = sampleQuestion)
+        )
     }
 }

ui/quiz/src/main/kotlin/dev/adriankuta/kahootquiz/ui/quiz/QuizScreenViewModel.kt

@@ -3,7 +3,7 @@ package dev.adriankuta.kahootquiz.ui.quiz
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
-import dev.adriankuta.kahootquiz.domain.models.Quiz
+import dev.adriankuta.kahootquiz.domain.models.Question
 import dev.adriankuta.kahootquiz.domain.usecases.GetQuizUseCase
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -20,12 +20,12 @@ class QuizScreenViewModel @Inject constructor(
 
     init {
         viewModelScope.launch {
-            _uiState.value = QuizUiState(getQuizUseCase())
+            _uiState.value = QuizUiState(getQuizUseCase().questions.first())
         }
     }
 
 }
 
 data class QuizUiState(
-    val quiz: Quiz? = null
+    val currentQuestion: Question? = null
 )

ui/quiz/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="quiz">Quiz</string>
+</resources>