Merge pull request #5 from Velord/feature/BackHandling

Feature/back handling

app/build.gradle.kts

@@ -2,12 +2,13 @@ plugins {
     id(libs.plugins.android.application.get().pluginId)
     id(libs.plugins.kotlin.android.get().pluginId)
     id(libs.plugins.kotlin.kapt.get().pluginId)
+    id(libs.plugins.dagger.hilt.get().pluginId)
 }
 
 // When app incompatible with previous version change this value
 val globalVersion = 0
 // When you create huge feature(or many) release change this value
-val majorVersion = 3
+val majorVersion = 5
 // When you create feature release change this value
 val minorVersion = 0
 // When you create fix change this value
@@ -104,10 +105,15 @@ dependencies {
     // Templates
     implementation(libs.bundles.kotlin.module)
     implementation(libs.bundles.androidx.module)
+    implementation(libs.bundles.androidx.activity)
     // Compose
     implementation(libs.bundles.compose.material.third)
     implementation(libs.bundles.compose.ui)
     implementation(libs.bundles.compose.accompanist.core)
+    // DI
+    implementation(libs.bundles.dagger.all)
+    kapt(libs.bundles.dagger.kapt)
+    kapt(libs.hilt.compiler)
 }
 
 tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile::class).all {

app/src/main/AndroidManifest.xml

@@ -3,16 +3,15 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <application
+        android:name=".ui.App"
         android:allowBackup="true"
-        android:dataExtractionRules="@xml/data_extraction_rules"
-        android:fullBackupContent="@xml/backup_rules"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:supportsRtl="true"
         android:theme="@style/Theme.ComposeMultipleBackstackDemo"
         android:enableOnBackInvokedCallback="true"
-        tools:targetApi="31"
-        >
+        tools:targetApi="33">
+
         <activity
             android:name=".ui.main.MainActivity"
             android:exported="true"
@@ -23,6 +22,7 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
     </application>
 
 </manifest>

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/App.kt

@@ -0,0 +1,7 @@
+package com.velord.composemultiplebackstackdemo.ui
+
+import android.app.Application
+import dagger.hilt.android.HiltAndroidApp
+
+@HiltAndroidApp
+class App : Application()

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/di/AppModule.kt

@@ -0,0 +1,17 @@
+package com.velord.composemultiplebackstackdemo.ui.di
+
+import com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation.BottomNavEventService
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object AppModule {
+
+    @Singleton
+    @Provides
+    fun provideBottomNavEventService(): BottomNavEventService = BottomNavEventService
+}

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/main/MainActivity.kt

@@ -8,7 +8,9 @@ import androidx.core.view.WindowCompat
 import androidx.navigation.fragment.NavHostFragment
 import com.velord.composemultiplebackstackdemo.R
 import com.velord.composemultiplebackstackdemo.databinding.ActivityMainBinding
+import dagger.hilt.android.AndroidEntryPoint
 
+@AndroidEntryPoint
 class MainActivity : AppCompatActivity() {
 
     companion object {

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/main/bottomNavigation/BottomNavEventService.kt

@@ -0,0 +1,18 @@
+package com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation
+
+import kotlinx.coroutines.flow.MutableStateFlow
+
+data class BottomNavBackHandlingState(
+    val isAtStartGraphDestination: Boolean = true,
+    val isGrantedToProceed: Boolean = false
+) {
+    val isEnabled: Boolean get() = isAtStartGraphDestination && isGrantedToProceed
+}
+
+object BottomNavEventService {
+    val backHandlingStateFlow = MutableStateFlow(BottomNavBackHandlingState())
+
+    fun updateBackHandlingState(newState: BottomNavBackHandlingState) {
+        backHandlingStateFlow.value =  newState
+    }
+}

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/main/bottomNavigation/BottomNavFragment.kt

@@ -1,8 +1,12 @@
 package com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation
 
+import android.content.Context
 import android.os.Bundle
 import android.util.Log
+import android.view.Gravity
 import android.view.View
+import android.widget.Toast
+import androidx.activity.addCallback
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.navigationBarsPadding
@@ -38,10 +42,35 @@ import com.velord.composemultiplebackstackdemo.ui.navigation.BottomNavigationIte
 import com.velord.composemultiplebackstackdemo.ui.utils.viewLifecycleScope
 import com.velord.multiplebackstackapplier.MultipleBackstack
 import com.velord.multiplebackstackapplier.utils.compose.SnackBarOnBackPressHandler
+import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.launch
 
-private const val TAG = "multiplebackstackapplierDEMO"
+private const val TAG = "BottomNav"
 
+private fun Context.fireToast(text: String) {
+    val description = "I am at the first at $text"
+    Toast.makeText(this, description, Toast.LENGTH_SHORT).apply {
+        setGravity(Gravity.CENTER_VERTICAL, 0, 0)
+        show()
+    }
+}
+
+internal fun Fragment.addTestCallback(
+    tag: String,
+    viewModel: BottomNavViewModel
+) {
+    requireActivity().onBackPressedDispatcher.addCallback(
+        this,
+        true
+    ) {
+        requireContext().fireToast(tag)
+        isEnabled = false
+        viewModel.graphCompletedHandling()
+        Log.d(TAG, "onBackPressedDispatcher")
+    }
+}
+
+@AndroidEntryPoint
 class BottomNavFragment : Fragment(R.layout.fragment_bottom_nav) {
 
     private val navController by lazy {
@@ -105,24 +134,25 @@ class BottomNavFragment : Fragment(R.layout.fragment_bottom_nav) {
 @Composable
 private fun BottomNavScreen(viewModel: BottomNavViewModel) {
     val tabFlow = viewModel.currentTabFlow.collectAsStateWithLifecycle()
-    val isBackHandlingEnabledState =
-        viewModel.isBackHandlingEnabledFlow.collectAsStateWithLifecycle()
-    Log.d(TAG, "isBackHandlingEnabledState: ${isBackHandlingEnabledState.value}")
+    val backHandlingState = viewModel.backHandlingStateFlow.collectAsStateWithLifecycle()
+    Log.d(TAG, "isBackHandlingEnabledState: ${backHandlingState.value}")
 
     Content(
         selectedItem = tabFlow.value,
         onClick = viewModel::onTabClick,
     )
 
-    val str = stringResource(id = R.string.press_again_to_exit)
-    SnackBarOnBackPressHandler(
-        message = str,
-        modifier = Modifier.padding(horizontal = 8.dp),
-        enabled = isBackHandlingEnabledState.value,
-        onBackClickLessThanDuration = viewModel::onBackDoubleClick,
-    ) {
-        Snackbar {
-            Text(text = it.visuals.message)
+    if (backHandlingState.value.isEnabled) {
+        val str = stringResource(id = R.string.press_again_to_exit)
+        SnackBarOnBackPressHandler(
+            message = str,
+            modifier = Modifier.padding(horizontal = 8.dp),
+            enabled = backHandlingState.value.isEnabled,
+            onBackClickLessThanDuration = viewModel::onBackDoubleClick,
+        ) {
+            Snackbar {
+                Text(text = it.visuals.message)
+            }
         }
     }
 }

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/main/bottomNavigation/BottomNavViewModel.kt

@@ -5,17 +5,22 @@ import androidx.lifecycle.viewModelScope
 import androidx.navigation.NavDestination
 import com.velord.composemultiplebackstackdemo.ui.navigation.BottomNavigationItem
 import com.velord.multiplebackstackapplier.utils.isCurrentStartDestination
+import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.launch
+import javax.inject.Inject
 
-class BottomNavViewModel : ViewModel() {
+@HiltViewModel
+class BottomNavViewModel @Inject constructor(
+    private val bottomNavEventService: BottomNavEventService
+): ViewModel() {
 
     val currentTabFlow = MutableStateFlow(BottomNavigationItem.Left)
-    val isBackHandlingEnabledFlow = MutableStateFlow(false)
+    val backHandlingStateFlow = bottomNavEventService.backHandlingStateFlow
     val finishAppEvent: MutableSharedFlow<Unit> = MutableSharedFlow()
 
-    fun getNavigationItems() = BottomNavigationItem.values().toList()
+    fun getNavigationItems() = BottomNavigationItem.entries
 
     fun onTabClick(newTab: BottomNavigationItem) {
         if (newTab == currentTabFlow.value) return
@@ -28,6 +33,20 @@ class BottomNavViewModel : ViewModel() {
 
     fun updateBackHandling(currentNavigationDestination: NavDestination?) {
         val isStart = currentNavigationDestination.isCurrentStartDestination(getNavigationItems())
-        isBackHandlingEnabledFlow.value = isStart
+        val newState = backHandlingStateFlow.value.copy(isAtStartGraphDestination = isStart)
+        bottomNavEventService.updateBackHandlingState(newState)
+    }
+
+    private fun changeGrantedToProceed(isGranted: Boolean) {
+        val newState = backHandlingStateFlow.value.copy(isGrantedToProceed = isGranted)
+        bottomNavEventService.updateBackHandlingState(newState)
+    }
+
+    fun graphCompletedHandling() {
+        changeGrantedToProceed(true)
+    }
+
+    fun graphTakeResponsibility() {
+        changeGrantedToProceed(false)
     }
 }

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/main/bottomNavigation/center/CenterGraphFragment.kt

@@ -5,13 +5,22 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import androidx.fragment.app.viewModels
 import androidx.navigation.findNavController
 import com.velord.composemultiplebackstackdemo.R
 import com.velord.composemultiplebackstackdemo.ui.compose.screen.AddNewScreen
 import com.velord.composemultiplebackstackdemo.ui.compose.theme.setContentWithTheme
+import com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation.BottomNavViewModel
+import com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation.addTestCallback
+import dagger.hilt.android.AndroidEntryPoint
 
+private const val TAG = "center"
+
+@AndroidEntryPoint
 class CenterGraphFragment : Fragment() {
 
+    private val viewModel by viewModels<BottomNavViewModel>()
+
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
@@ -21,4 +30,9 @@ class CenterGraphFragment : Fragment() {
             findNavController().navigate(R.id.toInDevelopmentFragmentFromCenterGraphFragment)
         }
     }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        addTestCallback(TAG, viewModel)
+    }
 }

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/main/bottomNavigation/left/LeftGraphFragment.kt

@@ -5,13 +5,22 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import androidx.fragment.app.viewModels
 import androidx.navigation.findNavController
 import com.velord.composemultiplebackstackdemo.R
 import com.velord.composemultiplebackstackdemo.ui.compose.screen.AddNewScreen
 import com.velord.composemultiplebackstackdemo.ui.compose.theme.setContentWithTheme
+import com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation.BottomNavViewModel
+import com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation.addTestCallback
+import dagger.hilt.android.AndroidEntryPoint
 
+private const val TAG = "left"
+
+@AndroidEntryPoint
 class LeftGraphFragment : Fragment() {
 
+    private val viewModel by viewModels<BottomNavViewModel>()
+
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
@@ -21,4 +30,9 @@ class LeftGraphFragment : Fragment() {
             findNavController().navigate(R.id.toInDevelopmentFragmentFromLeftGraphFragment)
         }
     }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        addTestCallback(TAG, viewModel)
+    }
 }

app/src/main/java/com/velord/composemultiplebackstackdemo/ui/main/bottomNavigation/right/RightGraphFragment.kt

@@ -5,18 +5,30 @@ import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
+import androidx.fragment.app.viewModels
 import androidx.navigation.findNavController
 import com.velord.composemultiplebackstackdemo.R
 import com.velord.composemultiplebackstackdemo.ui.compose.screen.AddNewScreen
 import com.velord.composemultiplebackstackdemo.ui.compose.theme.setContentWithTheme
+import com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation.BottomNavViewModel
+import com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation.addTestCallback
+import dagger.hilt.android.AndroidEntryPoint
 
+private const val TAG = "right"
+
+@AndroidEntryPoint
 class RightGraphFragment : Fragment() {
 
+    private val viewModel by viewModels<BottomNavViewModel>()
+
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
     ): View = setContentWithTheme {
+        viewModel.graphTakeResponsibility()
+        addTestCallback(TAG, viewModel)
+
         AddNewScreen(R.string.add_new_screen_right) {
             findNavController().navigate(R.id.toInDevelopmentFragmentFromRightGraphFragment)
         }

app/src/main/res/navigation/main_nav_graph.xml

@@ -10,6 +10,7 @@
         android:name="com.velord.composemultiplebackstackdemo.ui.main.bottomNavigation.BottomNavFragment"
         android:label="BottomNavFragment"/>
 
+
     <fragment
         android:id="@+id/inDevelopmentFragment"
         android:name="com.velord.composemultiplebackstackdemo.ui.main.overlay.OverlayFragment"