Replaced xml navigation with self-handled

app/src/main/java/com/topjohnwu/magisk/ui/base/MagiskActivity.kt

@@ -1,13 +1,126 @@
 package com.topjohnwu.magisk.ui.base
 
+import android.content.Intent
+import android.os.Bundle
+import androidx.annotation.CallSuper
 import androidx.core.net.toUri
 import androidx.databinding.ViewDataBinding
+import androidx.fragment.app.Fragment
+import com.ncapdevi.fragnav.FragNavController
+import com.ncapdevi.fragnav.FragNavTransactionOptions
+import com.skoumal.teanity.viewevents.ViewEvent
+import com.topjohnwu.magisk.model.navigation.MagiskAnimBuilder
+import com.topjohnwu.magisk.model.navigation.MagiskNavigationEvent
+import com.topjohnwu.magisk.model.navigation.Navigator
 import com.topjohnwu.magisk.utils.Utils
+import timber.log.Timber
+import kotlin.reflect.KClass
 
 
 abstract class MagiskActivity<ViewModel : MagiskViewModel, Binding : ViewDataBinding> :
-    MagiskLeanbackActivity<ViewModel, Binding>() {
+    MagiskLeanbackActivity<ViewModel, Binding>(), FragNavController.RootFragmentListener,
+    Navigator {
+
+    override val numberOfRootFragments: Int get() = baseFragments.size
+    override val baseFragments: List<KClass<out Fragment>> = listOf()
+
+    protected open val defaultPosition: Int = 0
+
+    protected val navigationController by lazy {
+        if (navHostId == 0) throw IllegalStateException("Did you forget to override \"navHostId\"?")
+        FragNavController(supportFragmentManager, navHostId)
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        navigationController.apply {
+            rootFragmentListener = this@MagiskActivity
+            initialize(defaultPosition, savedInstanceState)
+        }
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        navigationController.onSaveInstanceState(outState)
+    }
+
+    @CallSuper
+    override fun onEventDispatched(event: ViewEvent) {
+        super.onEventDispatched(event)
+        when (event) {
+            is MagiskNavigationEvent -> navigateTo(event)
+        }
+    }
+
+    override fun getRootFragment(index: Int) = baseFragments[index].java.newInstance()
+
+    override fun navigateTo(event: MagiskNavigationEvent) {
+        val directions = event.navDirections
+
+        navigationController.defaultTransactionOptions = FragNavTransactionOptions.newBuilder()
+            .customAnimations(event.animOptions)
+            .build()
+
+        navigationController.currentStack
+            ?.indexOfFirst { it.javaClass == event.navOptions.popUpTo }
+            ?.let { if (it == -1) null else it } // invalidate if class is not found
+            ?.let { if (event.navOptions.inclusive) it + 1 else it }
+            ?.let { navigationController.popFragments(it) }
+
+        when (directions.isActivity) {
+            true -> navigateToActivity(event)
+            else -> navigateToFragment(event)
+        }
+    }
+
+    private fun navigateToActivity(event: MagiskNavigationEvent) {
+        val destination = event.navDirections.destination?.java ?: let {
+            Timber.e("Cannot navigate to null destination")
+            return
+        }
+        val options = event.navOptions
+
+        Intent(this, destination)
+            .putExtras(event.navDirections.args)
+            .apply {
+                if (options.singleTop) addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)
+                if (options.clearTask) addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK)
+            }
+            .let { startActivity(it) }
+    }
+
+    private fun navigateToFragment(event: MagiskNavigationEvent) {
+        val destination = event.navDirections.destination?.java ?: let {
+            Timber.e("Cannot navigate to null destination")
+            return
+        }
+
+        when (val index = baseFragments.indexOfFirst { it.java.name == destination.name }) {
+            -1 -> destination.newInstance()
+                .apply { arguments = event.navDirections.args }
+                .let { navigationController.pushFragment(it) }
+            // When it's desired that fragments of same class are put on top of one another edit this
+            else -> navigationController.switchTab(index)
+        }
+    }
+
+    override fun onBackPressed() {
+        val fragment = navigationController.currentFrag as? MagiskFragment<*, *>
+
+        if (fragment?.onBackPressed() == true) {
+            return
+        }
+
+        try {
+            navigationController.popFragment()
+        } catch (e: UnsupportedOperationException) {
+            super.onBackPressed()
+        }
+    }
 
     fun openUrl(url: String) = Utils.openLink(this, url.toUri())
 
+    private fun FragNavTransactionOptions.Builder.customAnimations(options: MagiskAnimBuilder) =
+        customAnimations(options.enter, options.exit, options.popEnter, options.popExit)
+
 }

app/src/main/java/com/topjohnwu/magisk/ui/base/MagiskFragment.kt

@@ -1,16 +1,35 @@
 package com.topjohnwu.magisk.ui.base
 
+import androidx.annotation.CallSuper
 import androidx.databinding.ViewDataBinding
+import androidx.fragment.app.Fragment
 import com.skoumal.teanity.view.TeanityFragment
+import com.skoumal.teanity.viewevents.ViewEvent
+import com.topjohnwu.magisk.model.navigation.MagiskNavigationEvent
+import com.topjohnwu.magisk.model.navigation.Navigator
+import kotlin.reflect.KClass
 
 
 abstract class MagiskFragment<ViewModel : MagiskViewModel, Binding : ViewDataBinding> :
-    TeanityFragment<ViewModel, Binding>() {
+    TeanityFragment<ViewModel, Binding>(), Navigator {
 
     protected val magiskActivity get() = activity as MagiskActivity<*, *>
 
-    fun openLink(url: String) {
-        magiskActivity.openUrl(url)
+    // We don't need nested fragments
+    override val baseFragments: List<KClass<Fragment>> = listOf()
+
+    override fun navigateTo(event: MagiskNavigationEvent) = magiskActivity.navigateTo(event)
+
+    @CallSuper
+    override fun onEventDispatched(event: ViewEvent) {
+        super.onEventDispatched(event)
+        when (event) {
+            is MagiskNavigationEvent -> navigateTo(event)
+        }
     }
 
+    fun openLink(url: String) = magiskActivity.openUrl(url)
+
+    open fun onBackPressed(): Boolean = false
+
 }