Add line chart to Flow Use Case 1

LukasLechnerDev · LukasLechnerDev · commit 94a663bade34 · 2022-06-27T11:28:34.000+02:00
diff --git a/.idea/jarRepositories.xml b/.idea/jarRepositories.xml
diff --git a/.idea/misc.xml b/.idea/misc.xml
diff --git a/app/build.gradle b/app/build.gradle
@@ -93,6 +93,8 @@ dependencies {
     implementation "androidx.room:room-ktx:$room_version"
     kapt "androidx.room:room-compiler:$room_version"
 
+    implementation 'com.github.PhilJay:MPAndroidChart:v3.1.0'
+
     testImplementation project(path: ':app')
 
     testImplementation 'junit:junit:4.12'
diff --git a/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/base/UseCase.kt b/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/base/UseCase.kt
@@ -60,6 +60,8 @@ const val useCase16Description =
 const val useCase17Description =
     "#17 Perform heavy calculation on Main Thread without freezing the UI"
 
+const val flowUseCase1Description = "#1 Read from database that exposes Flow, ViewModel exposes LiveData"
+
 private val coroutinesUseCases =
     UseCaseCategory(
         "Coroutine Use Cases", listOf(
@@ -164,7 +166,7 @@ private val flowUseCases =
         "Flow Use Cases",
         listOf(
             UseCase(
-                "Flow Use Case 1",
+                flowUseCase1Description,
                 FlowUseCase1Activity::class.java
             )
         )
diff --git a/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/mock/FlowMockApi.kt b/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/mock/FlowMockApi.kt
@@ -8,11 +8,8 @@ import retrofit2.http.GET
 
 interface FlowMockApi {
 
-    @GET("current-bitcoin-price")
-    suspend fun getCurrentBitcoinPrice(): BitcoinPrice
-
-    @GET("current-etherium-price")
-    suspend fun getCurrentEtheriumPrice(): EtheriumPrice
+    @GET("current-google-stock-price")
+    suspend fun getCurrentGoogleStockPrice(): GoogleStock
 }
 
 fun createFlowMockApi(interceptor: MockNetworkInterceptor): FlowMockApi {
diff --git a/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/mock/FlowMockData.kt b/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/mock/FlowMockData.kt
@@ -2,13 +2,11 @@ package com.lukaslechner.coroutineusecasesonandroid.usecases.flow.mock
 
 import kotlin.random.Random
 
-data class BitcoinPrice(val usd: Float)
+data class GoogleStock(val currentPriceUsd: Float)
 
-data class EtheriumPrice(val usd: Float)
-
-fun fakeCurrentBitcoinPrice(): BitcoinPrice {
-    val initialPrice = 50_000f
-    val increase = Random.nextInt(1000)
+fun fakeCurrentGoogleStockPrice(): GoogleStock {
+    val initialPrice = 2_000f
+    val increase = Random.nextInt(100)
     val currentPrice = initialPrice + increase
-    return BitcoinPrice(currentPrice)
+    return GoogleStock(currentPrice)
 }
diff --git a/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase1/FlowUseCase1Activity.kt b/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase1/FlowUseCase1Activity.kt
@@ -1,11 +1,15 @@
 package com.lukaslechner.coroutineusecasesonandroid.usecases.flow.usecase1
 
 import android.os.Bundle
-import android.view.View
 import androidx.activity.viewModels
+import androidx.core.content.ContextCompat
+import com.github.mikephil.charting.data.Entry
+import com.github.mikephil.charting.data.LineData
+import com.github.mikephil.charting.data.LineDataSet
+import com.lukaslechner.coroutineusecasesonandroid.R
 import com.lukaslechner.coroutineusecasesonandroid.base.BaseActivity
+import com.lukaslechner.coroutineusecasesonandroid.base.flowUseCase1Description
 import com.lukaslechner.coroutineusecasesonandroid.databinding.ActivityFlowUsecase1Binding
-import java.time.Instant
 
 class FlowUseCase1Activity : BaseActivity() {
 
@@ -17,23 +21,60 @@ class FlowUseCase1Activity : BaseActivity() {
         super.onCreate(savedInstanceState)
         setContentView(binding.root)
 
+        initChart()
+
         viewModel.whileTrueInCoroutine()
-        viewModel.bitcoinPrice.observe(this) { uiState ->
+        viewModel.currentGoogleStockPrice.observe(this) { uiState ->
             if (uiState != null) {
                 render(uiState)
             }
         }
     }
 
+    private fun initChart() {
+        val entries: ArrayList<Entry> = ArrayList()
+        entries.add(Entry(0f, 2000f))
+
+        val data = LineDataSet(entries, "Google Stock Price")
+
+        val colorPrimary = ContextCompat.getColor(this, R.color.colorPrimary)
+        data.color = colorPrimary
+        data.setCircleColor(colorPrimary)
+
+        val lineData = LineData(data)
+
+        with(binding.googleStockChart) {
+            this.data = lineData
+            setDrawGridBackground(false)
+            axisRight.isEnabled = false
+            xAxis.isEnabled = false
+        }
+
+        binding.googleStockChart.axisLeft.apply {
+            axisMinimum = 1990f
+            axisMaximum = 2100f
+        }
+    }
+
     private fun render(uiState: UiState) {
         when (uiState) {
             is UiState.Success -> {
-                binding.progressBar.visibility = View.GONE
-                binding.lastFetch.text = Instant.now().epochSecond.toString()
-                binding.bitcoinPrice.text = uiState.bitcoinPrice.usd.toString()
+                addNewChartEntry(uiState)
             }
         }
     }
 
-    override fun getToolbarTitle() = "Flow Use Case 1 Activity"
+    private fun addNewChartEntry(uiState: UiState.Success) {
+        val currentLineData = binding.googleStockChart.data
+        currentLineData.addEntry(
+            Entry(
+                currentLineData.entryCount.toFloat(),
+                uiState.googleStock.currentPriceUsd
+            ), 0
+        )
+        binding.googleStockChart.data = currentLineData
+        binding.googleStockChart.invalidate()
+    }
+
+    override fun getToolbarTitle() = flowUseCase1Description
 }
diff --git a/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase1/FlowUseCase1ViewModel.kt b/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase1/FlowUseCase1ViewModel.kt
@@ -11,14 +11,14 @@ class FlowUseCase1ViewModel(
     private val mockApi: FlowMockApi = mockApi()
 ) : BaseViewModel<UiState>() {
 
-    val bitcoinPrice = MutableLiveData<UiState>(UiState.Loading)
+    val currentGoogleStockPrice = MutableLiveData<UiState>(UiState.Loading)
 
     fun whileTrueInCoroutine() {
         viewModelScope.launch {
             while (true) {
-                val currentBitcoinPrice = mockApi.getCurrentBitcoinPrice()
-                bitcoinPrice.value = UiState.Success(currentBitcoinPrice)
-                delay(5_000)
+                val currentGoogleStockPrice = mockApi.getCurrentGoogleStockPrice()
+                this@FlowUseCase1ViewModel.currentGoogleStockPrice.value = UiState.Success(currentGoogleStockPrice)
+                delay(2000)
             }
         }
     }
diff --git a/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase1/MockApi.kt b/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase1/MockApi.kt
@@ -2,16 +2,16 @@ package com.lukaslechner.coroutineusecasesonandroid.usecases.flow.usecase1
 
 import com.google.gson.Gson
 import com.lukaslechner.coroutineusecasesonandroid.usecases.flow.mock.createFlowMockApi
-import com.lukaslechner.coroutineusecasesonandroid.usecases.flow.mock.fakeCurrentBitcoinPrice
+import com.lukaslechner.coroutineusecasesonandroid.usecases.flow.mock.fakeCurrentGoogleStockPrice
 import com.lukaslechner.coroutineusecasesonandroid.utils.MockNetworkInterceptor
 
 fun mockApi() =
     createFlowMockApi(
         MockNetworkInterceptor()
             .mock(
-                path = "http://localhost/current-bitcoin-price",
-                body = { Gson().toJson(fakeCurrentBitcoinPrice()) },
+                path = "http://localhost/current-google-stock-price",
+                body = { Gson().toJson(fakeCurrentGoogleStockPrice()) },
                 status = 200,
-                delayInMs = 1500,
+                delayInMs = 100,
             )
     )
diff --git a/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase1/UiState.kt b/app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase1/UiState.kt
@@ -1,9 +1,9 @@
 package com.lukaslechner.coroutineusecasesonandroid.usecases.flow.usecase1
 
-import com.lukaslechner.coroutineusecasesonandroid.usecases.flow.mock.BitcoinPrice
+import com.lukaslechner.coroutineusecasesonandroid.usecases.flow.mock.GoogleStock
 
 sealed class UiState {
     object Loading : UiState()
-    data class Success(val bitcoinPrice: BitcoinPrice) : UiState()
+    data class Success(val googleStock: GoogleStock) : UiState()
     data class Error(val message: String) : UiState()
 }
diff --git a/app/src/main/res/layout/activity_flow_usecase1.xml b/app/src/main/res/layout/activity_flow_usecase1.xml
@@ -6,43 +6,9 @@
 
     <include layout="@layout/toolbar" />
 
-    <ProgressBar
-        android:id="@+id/progressBar"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_gravity="center"
-        android:layout_marginBottom="32dp" />
-
-    <LinearLayout
+    <com.github.mikephil.charting.charts.LineChart
+        android:id="@+id/googleStockChart"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content">
-
-        <TextView
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:text="Fetched at:" />
-
-        <TextView
-            android:id="@+id/lastFetch"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content" />
-
-    </LinearLayout>
-
-    <LinearLayout
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content">
-
-        <TextView
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:text="Bitcoin Price:" />
-
-        <TextView
-            android:id="@+id/bitcoinPrice"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content" />
-
-    </LinearLayout>
+        android:layout_height="match_parent"/>
 
 </LinearLayout>
diff --git a/build.gradle b/build.gradle
@@ -19,6 +19,7 @@ allprojects {
     repositories {
         google()
         mavenCentral()
+        maven { url 'https://jitpack.io' }
     }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -11,14 +11,14 @@ class FlowUseCase1ViewModel(`
`11`	`11`	`private val mockApi: FlowMockApi = mockApi()`
`12`	`12`	`) : BaseViewModel<UiState>() {`
`13`	`13`
`14`		`- val bitcoinPrice = MutableLiveData<UiState>(UiState.Loading)`
	`14`	`+ val currentGoogleStockPrice = MutableLiveData<UiState>(UiState.Loading)`
`15`	`15`
`16`	`16`	`fun whileTrueInCoroutine() {`
`17`	`17`	`viewModelScope.launch {`
`18`	`18`	`while (true) {`
`19`		`- val currentBitcoinPrice = mockApi.getCurrentBitcoinPrice()`
`20`		`- bitcoinPrice.value = UiState.Success(currentBitcoinPrice)`
`21`		`- delay(5_000)`
	`19`	`+ val currentGoogleStockPrice = mockApi.getCurrentGoogleStockPrice()`
	`20`	`+ this@FlowUseCase1ViewModel.currentGoogleStockPrice.value = UiState.Success(currentGoogleStockPrice)`
	`21`	`+ delay(2000)`
`22`	`22`	`}`
`23`	`23`	`}`
`24`	`24`	`}`