add navigation framework and implement it

app/src/main/java/com/hako/friendlists/di/AppModules.kt

@@ -3,8 +3,11 @@ package com.hako.friendlists.di
 import androidx.room.Room
 import com.hako.base.domain.database.DatabaseClient
 import com.hako.base.domain.network.RemoteClient
+import com.hako.base.navigation.NavigationRouter
 import com.hako.friendlists.BuildConfig
+import com.hako.friendlists.viewmodel.NavigationViewmodel
 import com.squareup.picasso.Picasso
+import org.koin.androidx.viewmodel.dsl.viewModel
 import org.koin.dsl.module
 
 val appModules = module {
@@ -19,4 +22,8 @@ val appModules = module {
 
     // Picasso
     single { Picasso.get() }
+
+    // Navigation
+    single { NavigationRouter() }
+    viewModel { NavigationViewmodel() }
 }

app/src/main/java/com/hako/friendlists/view/MainActivity.kt

@@ -3,20 +3,43 @@ package com.hako.friendlists.view
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import androidx.navigation.findNavController
+import com.hako.base.extensions.observeNonNull
+import com.hako.base.navigation.NavigationRouter
+import com.hako.friendlists.BuildConfig
 import com.hako.friendlists.R
+import com.hako.friendlists.viewmodel.NavigationViewmodel
+import com.squareup.picasso.Picasso
+import org.koin.android.ext.android.inject
+import org.koin.androidx.viewmodel.ext.android.viewModel
 
 class MainActivity : AppCompatActivity() {
 
     private val navController by lazy { findNavController(R.id.main_fragment_container) }
+    private val navRouter: NavigationRouter by inject()
+    private val picasso: Picasso by inject()
+    private val viewModel: NavigationViewmodel by viewModel()
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
         setupNavigation()
+        setupPicasso()
     }
 
     private fun setupNavigation() {
         navController.setGraph(R.navigation.main_navigation)
+        navRouter.setOnNavigationEvent {
+            viewModel.onNavigationEvent(it)
+        }
+        viewModel.navigate.observeNonNull(this) { pair ->
+            // Pair.first is a Navigation Id
+            // Pair.second is a Bundle
+            navController.navigate(pair.first, pair.second)
+        }
     }
 
+    private fun setupPicasso() {
+        // Show cache indicator on images just for debug builds
+        picasso.setIndicatorsEnabled(BuildConfig.DEBUG)
+    }
 }

app/src/main/java/com/hako/friendlists/viewmodel/NavigationViewmodel.kt

@@ -0,0 +1,46 @@
+package com.hako.friendlists.viewmodel
+
+import android.os.Bundle
+import androidx.annotation.IdRes
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import com.hako.albumlist.feature.ALBUMLIST_FRAGMENT_BUNDLE_USER_ID
+import com.hako.albumlist.navigation.AlbumlistNavigation
+import com.hako.base.extensions.buildNavigation
+import com.hako.base.navigation.NavigationEvent
+import com.hako.friendlists.R
+import com.hako.photolist.feature.PHOTOLIST_FRAGMENT_BUNDLE_ALBUM_ID
+import com.hako.userlist.navigation.UserlistNavigation
+
+class NavigationViewmodel : ViewModel() {
+
+    val navigate = MutableLiveData<Pair<@IdRes Int, Bundle>>()
+
+    fun onNavigationEvent(event: NavigationEvent) {
+        when (event) {
+            is UserlistNavigation -> handleUserlistNavigation(event)
+            is AlbumlistNavigation -> handleAlbumlistNavigation(event)
+            else -> throw NoWhenBranchMatchedException("Undefined navigation event parent")
+        }
+    }
+
+    private fun handleUserlistNavigation(event: UserlistNavigation) {
+        when (event) {
+            is UserlistNavigation.ClickedOnUser -> navigate.postValue(
+                buildNavigation(R.id.action_userlistFragment_to_albumlistFragment, Bundle().apply {
+                    putInt(ALBUMLIST_FRAGMENT_BUNDLE_USER_ID, event.userId)
+                })
+            )
+        }
+    }
+
+    private fun handleAlbumlistNavigation(event: AlbumlistNavigation) {
+        when (event) {
+            is AlbumlistNavigation.ClickedOnAlbum -> navigate.postValue(
+                buildNavigation(R.id.action_albumlistFragment_to_photolistFragment, Bundle().apply {
+                    putInt(PHOTOLIST_FRAGMENT_BUNDLE_ALBUM_ID, event.albumId)
+                })
+            )
+        }
+    }
+}