feature: predictive back gesture

Author: Lennoard

app/build.gradle.kts

@@ -114,6 +114,7 @@ dependencies {
     implementation(project(Modules.utils))
     implementation(project(Modules.design))
 
+    implementation(AndroidX.activity)
     implementation(AndroidX.splashScreen)
     implementation(AndroidX.lifecycleLiveData)
     implementation(AndroidX.lifecycleRuntimeCompose)

app/src/main/AndroidManifest.xml

@@ -15,6 +15,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme"
+        android:enableOnBackInvokedCallback="true"
         tools:ignore="GoogleAppIndexingWarning">
 
         <activity

app/src/main/kotlin/com/androidvip/sysctlgui/ui/params/browse/KernelParamBrowseFragment.kt

@@ -26,6 +26,7 @@ import androidx.compose.material.pullrefresh.rememberPullRefreshState
 import androidx.compose.material3.Divider
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.SideEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -55,6 +56,16 @@ import org.koin.android.ext.android.inject
 class KernelParamBrowseFragment : BaseSearchFragment(), OnParamItemClickedListener {
     private var actionBarMenu: Menu? = null
     private val viewModel: BrowseParamsViewModel by inject()
+    private val currentPath: String get() = viewModel.currentState.currentPath
+    private val canGoBack: Boolean get() = currentPath != Consts.PROC_SYS
+
+    private val onBackPressedCallback = object : OnBackPressedCallback(true) {
+        override fun handleOnBackPressed() {
+            if (canGoBack) {
+                onDirectoryChanged(File(currentPath).parentFile ?: File(Consts.PROC_SYS))
+            }
+        }
+    }
 
     @OptIn(ExperimentalMaterialApi::class)
     override fun onCreateView(
@@ -91,6 +102,8 @@ class KernelParamBrowseFragment : BaseSearchFragment(), OnParamItemClickedListen
                             contentColor = MaterialTheme.colorScheme.onTertiaryContainer
                         )
                     }
+
+                    SideEffect { onBackPressedCallback.isEnabled = canGoBack }
                 }
             }
         }
@@ -104,24 +117,7 @@ class KernelParamBrowseFragment : BaseSearchFragment(), OnParamItemClickedListen
             viewModel.effect.collect(::handleViewEffect)
         }
 
-        requireActivity().onBackPressedDispatcher.addCallback(
-            viewLifecycleOwner,
-            object : OnBackPressedCallback(true) {
-                override fun handleOnBackPressed() {
-                    val currentPath = viewModel.currentState.currentPath
-                    if (currentPath == Consts.PROC_SYS) {
-                        if (isEnabled) {
-                            isEnabled = false
-                            requireActivity().onBackPressedDispatcher.onBackPressed()
-                        }
-                    } else {
-                        onDirectoryChanged(
-                            File(currentPath).parentFile ?: File(Consts.PROC_SYS)
-                        )
-                    }
-                }
-            }
-        )
+        requireActivity().onBackPressedDispatcher.addCallback(onBackPressedCallback)
     }
 
     override fun onStart() {

app/src/main/kotlin/com/androidvip/sysctlgui/ui/start/StartActivity.kt

@@ -27,7 +27,6 @@ import org.koin.android.ext.android.inject
 
 class StartActivity : BaseAppCompatActivity() {
     private lateinit var binding: ActivitySplashBinding
-    private val prefs: AppPrefs by inject()
     private val rootUtils: RootUtils by inject()
     private val performDatabaseMigrationUseCase: PerformDatabaseMigrationUseCase by inject()
     private val dispatcher: CoroutineDispatcher by lazy { Dispatchers.Default }

buildSrc/src/main/kotlin/AndroidX.kt

@@ -1,4 +1,5 @@
 object AndroidX {
+    const val activity = "androidx.activity:activity-ktx:1.7.2"
     const val appCompat = "androidx.appcompat:appcompat:1.6.1"
     const val constraintLayout = "androidx.constraintlayout:constraintlayout:2.1.4"
     const val core = "androidx.core:core-ktx:1.10.1"

common/design/build.gradle.kts

@@ -49,6 +49,7 @@ dependencies {
     api(composeBom)
     androidTestImplementation(composeBom)
 
+    api(AndroidX.activity)
     api(AndroidX.appCompat)
     api(AndroidX.constraintLayout)
     api(AndroidX.core)