add viewmodel and flow example [FoKE-Developers#22]

- HomeViewModel 추가 및 예제 작성
- HomeScreen과 HomeViewModel 연결

Author: DokySp

presenter/src/main/java/com/foke/together/presenter/screen/HomeScreen.kt

@@ -8,18 +8,24 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.sp
+import androidx.hilt.navigation.compose.hiltViewModel
 import com.foke.together.presenter.ui.theme.FourCutTogetherTheme
+import com.foke.together.presenter.viewmodel.HomeViewModel
 
 @Composable
 fun HomeScreen(
     navigateToCamera: (String) -> Unit,
     navigateToSetting: (String) -> Unit,
-    popBackStack: () -> Unit
+    popBackStack: () -> Unit,
+    viewModel: HomeViewModel = hiltViewModel()
 ) {
+    val sampleData by viewModel.getSampleText().collectAsState()
 
     Column (
         modifier = Modifier.fillMaxWidth(),
@@ -33,6 +39,7 @@ fun HomeScreen(
         Button(onClick = { navigateToSetting("Setting") }){
             Text("Setting")
         }
+        Text(text = sampleData.sampleText)
     }
 }
 

presenter/src/main/java/com/foke/together/presenter/viewmodel/HomeViewModel.kt

@@ -0,0 +1,22 @@
+package com.foke.together.presenter.viewmodel
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.foke.together.domain.input.GetSampleDataInterface
+import com.foke.together.domain.input.SampleUiData
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.stateIn
+import javax.inject.Inject
+
+@HiltViewModel
+class HomeViewModel @Inject constructor(
+    private val getSampleData: GetSampleDataInterface
+): ViewModel() {
+    fun getSampleText() =
+        getSampleData().stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5000),
+            initialValue = SampleUiData("")
+        )
+}