app: use real Navigation component flow

This fixes a lot of oddities in navigation, but also introduces UI
changes, like moving the address bar to a specific sub-toolbar in the
PageFragment. Unsure if this is the classiest choice but will do for
now. Probably introduces more issues.

app/build.gradle

@@ -2,6 +2,7 @@ plugins {
     id 'com.android.application'
     id 'kotlin-android'
     id 'kotlin-kapt'
+    id 'androidx.navigation.safeargs.kotlin'
 }
 
 android {

app/src/main/java/dev/lowrespalmtree/comet/HistoryFragment.kt

@@ -4,7 +4,6 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.core.os.bundleOf
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
 import androidx.lifecycle.MutableLiveData
@@ -46,8 +45,7 @@ class HistoryFragment : Fragment(), HistoryAdapter.Listener {
     }
 
     override fun onItemClick(url: String) {
-        val bundle = bundleOf("url" to url)
+        findNavController().navigate(PageFragmentDirections.actionGlobalPageFragment(url))
-        findNavController().navigate(R.id.action_global_pageFragment, bundle)
     }
 
     class HistoryViewModel(

app/src/main/java/dev/lowrespalmtree/comet/MainActivity.kt

@@ -3,39 +3,51 @@ package dev.lowrespalmtree.comet
 import android.os.Bundle
 import android.util.Log
 import android.view.MenuItem
+import androidx.appcompat.app.ActionBarDrawerToggle
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.os.bundleOf
 import androidx.navigation.fragment.NavHostFragment
+import androidx.navigation.ui.setupActionBarWithNavController
 import androidx.navigation.ui.setupWithNavController
 import dev.lowrespalmtree.comet.databinding.ActivityMainBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 
+
 @ExperimentalCoroutinesApi
 class MainActivity : AppCompatActivity() {
-    private lateinit var binding: ActivityMainBinding
+    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }
-    private var nhf: NavHostFragment? = null
+    private val nhf by lazy { supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment }
+    private val navController by lazy { nhf.navController }
 
     override fun onCreate(savedInstanceState: Bundle?) {
-        Log.i(TAG, "onCreate")
+        Log.d(TAG, "onCreate")
         super.onCreate(savedInstanceState)
-        binding = ActivityMainBinding.inflate(layoutInflater)
         setContentView(binding.root)
+        setSupportActionBar(binding.toolbar)
 
         Database.init(applicationContext)  // TODO move to App Startup?
 
-        nhf = supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment?
+        val toggle = ActionBarDrawerToggle(
-        nhf?.also { binding.drawerNavigation.setupWithNavController(it.navController) }
+            this,
+            binding.drawerLayout,
+            binding.toolbar,
+            R.string.navigation_drawer_open,
+            R.string.navigation_drawer_close
+        )
+        binding.drawerLayout.addDrawerListener(toggle)
+        toggle.syncState()
+        setupActionBarWithNavController(navController, binding.drawerLayout)
+        binding.drawerNavigation.setupWithNavController(nhf.navController)
     }
 
-    /** Navigate to the PageViewFragment; this will automatically use the home URL if any. */
+//    /** Navigate to the PageViewFragment; this will automatically use the home URL if any. */
-    fun goHome(@Suppress("unused_parameter") item: MenuItem) {
+//    fun goHome(@Suppress("unused_parameter") item: MenuItem) {
-        val bundle = bundleOf()
+//        val bundle = bundleOf()
-        Preferences.getHomeUrl(this)?.let { bundle.putString("url", it) }
+//        Preferences.getHomeUrl(this)?.let { bundle.putString("url", it) }
-        nhf?.navController?.navigate(R.id.action_global_pageFragment, bundle)
+//    }
-        binding.drawerLayout.closeDrawers()
-    }
 
     companion object {
         private const val TAG = "MainActivity"
     }
+
 }

app/src/main/java/dev/lowrespalmtree/comet/PageFragment.kt

@@ -16,6 +16,7 @@ import androidx.activity.addCallback
 import androidx.appcompat.app.AlertDialog
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
+import androidx.navigation.fragment.navArgs
 import androidx.recyclerview.widget.LinearLayoutManager
 import com.google.android.material.snackbar.Snackbar
 import dev.lowrespalmtree.comet.databinding.FragmentPageViewBinding
@@ -26,6 +27,7 @@ import kotlinx.coroutines.ExperimentalCoroutinesApi
 @ExperimentalCoroutinesApi
 class PageFragment : Fragment(), PageAdapter.Listener {
     private val vm: PageViewModel by viewModels()
+    private val args: PageFragmentArgs by navArgs()
     private lateinit var binding: FragmentPageViewBinding
     private lateinit var adapter: PageAdapter
 
@@ -35,12 +37,12 @@ class PageFragment : Fragment(), PageAdapter.Listener {
         savedInstanceState: Bundle?
     ): View {
         Log.d(TAG, "onCreateView")
-        binding = FragmentPageViewBinding.inflate(layoutInflater)
+        binding = FragmentPageViewBinding.inflate(layoutInflater, container, false)
         return binding.root
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        Log.d(TAG, "onViewCreated")
+        Log.d(TAG, "onViewCreated (args: ${args})")
         binding.contentRecycler.layoutManager = LinearLayoutManager(requireContext())
         adapter = PageAdapter(this)
         binding.contentRecycler.adapter = adapter
@@ -53,14 +55,15 @@ class PageFragment : Fragment(), PageAdapter.Listener {
         vm.lines.observe(viewLifecycleOwner) { updateLines(it.second, it.first) }
         vm.event.observe(viewLifecycleOwner) { handleEvent(it) }
 
-        activity?.onBackPressedDispatcher?.addCallback(viewLifecycleOwner) { onBackPressed() }
+        (activity as MainActivity?)?.let {
+            it.onBackPressedDispatcher.addCallback(viewLifecycleOwner) { onBackPressed() }
+            it.supportActionBar?.title = vm.currentTitle
+        }
 
-        val url = arguments?.getString("url")
+        val url = args.url
-        if (!url.isNullOrEmpty()) {
+        if (vm.currentUrl.isEmpty() && url.isNotEmpty()) {
             Log.d(TAG, "onViewCreated: open \"$url\"")
             openUrl(url)
-        } else if (vm.currentUrl.isNotEmpty()) {
-            Log.d(TAG, "onViewCreated: reuse current URL, probably fragment recreation")
         } else if (vm.visitedUrls.isEmpty()) {
             Log.d(TAG, "onViewCreated: no current URL, open home if configured")
             Preferences.getHomeUrl(requireContext())?.let { if (it.isNotBlank()) openUrl(it) }
@@ -72,6 +75,7 @@ class PageFragment : Fragment(), PageAdapter.Listener {
     }
 
     private fun onBackPressed() {
+        Log.d(TAG, "onBackPressed")
         if (vm.visitedUrls.size >= 2) {
             vm.visitedUrls.removeLastOrNull()  // Always remove current page first.
             vm.visitedUrls.removeLastOrNull()?.also { openUrl(it) }
@@ -157,9 +161,11 @@ class PageFragment : Fragment(), PageAdapter.Listener {
             }
             is PageViewModel.SuccessEvent -> {
                 vm.currentUrl = event.uri
+                vm.currentTitle = event.mainTitle ?: ""
                 if (vm.visitedUrls.isEmpty() || vm.visitedUrls.last() != event.uri)
                     vm.visitedUrls.add(event.uri)
                 binding.addressBar.setText(event.uri)
+                (activity as MainActivity?)?.supportActionBar?.title = vm.currentTitle
             }
             is PageViewModel.BinaryEvent -> {
                 // TODO this should present the user with options on what to do according to the

app/src/main/java/dev/lowrespalmtree/comet/PageViewModel.kt

@@ -25,6 +25,9 @@ class PageViewModel(
     /** Currently viewed page URL. */
     var currentUrl: String = ""
 
+    /** The first level 1 header of the current page (default is an empty string). */
+    var currentTitle: String = ""
+
     /** Latest Uri requested using `sendGeminiRequest`. */
     var loadingUrl: Uri? = null
 
@@ -58,7 +61,7 @@ class PageViewModel(
     data class InputEvent(val uri: Uri, val prompt: String) : Event()
 
     /** The server responded with a success code and *has finished* its response. */
-    data class SuccessEvent(val uri: String) : Event()
+    data class SuccessEvent(val uri: String, val mainTitle: String?) : Event()
 
     /** The server responded with a success code and a binary MIME type (not delivered yet). */
     data class BinaryEvent(
@@ -243,7 +246,7 @@ class PageViewModel(
         // We record the history entry here: it's nice because we have the main title available
         // and we're already in a coroutine for database access.
         History.record(uriString, mainTitle)
-        event.postValue(SuccessEvent(uriString))
+        event.postValue(SuccessEvent(uriString, mainTitle))
         state.postValue(State.IDLE)
     }
 

app/src/main/res/layout/activity_main.xml

@@ -1,19 +1,33 @@
 <?xml version="1.0" encoding="utf-8"?>
 <androidx.drawerlayout.widget.DrawerLayout
-    android:id="@+id/drawer_layout"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/drawer_layout"
     android:layout_height="match_parent"
     android:layout_width="match_parent"
-    android:fitsSystemWindows="true">
+    android:fitsSystemWindows="true"
+    tools:openDrawer="start"
+    tools:context="dev.lowrespalmtree.comet.MainActivity">
 
-    <androidx.fragment.app.FragmentContainerView
+    <androidx.appcompat.widget.LinearLayoutCompat
-        android:id="@+id/nav_host_fragment"
-        android:name="androidx.navigation.fragment.NavHostFragment"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        app:navGraph="@navigation/main"
+        android:orientation="vertical">
-        app:defaultNavHost="true" />
+        <androidx.appcompat.widget.Toolbar
+            android:id="@+id/toolbar"
+            android:minHeight="?attr/actionBarSize"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:background="@color/background_emph" />
+        <androidx.fragment.app.FragmentContainerView
+            android:id="@+id/nav_host_fragment"
+            android:name="androidx.navigation.fragment.NavHostFragment"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            app:navGraph="@navigation/main"
+            app:defaultNavHost="true" />
+    </androidx.appcompat.widget.LinearLayoutCompat>
 
     <com.google.android.material.navigation.NavigationView
         android:id="@+id/drawer_navigation"
@@ -21,6 +35,7 @@
         android:layout_height="match_parent"
         android:layout_gravity="start"
         android:fitsSystemWindows="true"
+        app:headerLayout="@layout/activity_main_nav_header"
         app:menu="@menu/drawer" />
 
 </androidx.drawerlayout.widget.DrawerLayout>

app/src/main/res/layout/activity_main_nav_header.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="176dp">
+
+    <ImageView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:contentDescription="@string/logo"
+        android:src="@mipmap/ic_logo"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.5"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_bias="0.5" />
+</androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/layout/fragment_page_view.xml

@@ -4,13 +4,12 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/root"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
+    android:layout_height="match_parent">
-    >
 
     <com.google.android.material.appbar.AppBarLayout
         android:id="@+id/app_bar_layout"
         android:layout_width="match_parent"
-        android:layout_height="56dp">
+        android:layout_height="48dp">
 
         <Toolbar
             android:id="@+id/toolbar"

app/src/main/res/menu/drawer.xml

@@ -1,10 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
-    <item
-        android:id="@+id/homeItem"
-        android:icon="@android:drawable/ic_menu_myplaces"
-        android:onClick="goHome"
-        android:title="@string/home" />
     <item
         android:id="@+id/historyFragment"
         android:icon="@android:drawable/ic_menu_recent_history"

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

@@ -7,7 +7,12 @@
     <fragment
         android:id="@+id/pageFragment"
         android:name="dev.lowrespalmtree.comet.PageFragment"
-        android:label="PageViewFragment" />
+        android:label="">
+        <argument
+            android:name="url"
+            app:argType="string"
+            android:defaultValue="" />
+    </fragment>
     <action
         android:id="@+id/action_global_pageFragment"
         app:destination="@id/pageFragment"
@@ -19,7 +24,15 @@
     <fragment
         android:id="@+id/historyFragment"
         android:name="dev.lowrespalmtree.comet.HistoryFragment"
-        android:label="HistoryFragment" />
+        android:label="@string/history" >
+        <action
+            android:id="@+id/action_historyFragment_to_pageFragment"
+            app:destination="@id/pageFragment"
+            app:enterAnim="@anim/nav_default_enter_anim"
+            app:exitAnim="@anim/nav_default_exit_anim"
+            app:popEnterAnim="@anim/nav_default_pop_enter_anim"
+            app:popExitAnim="@anim/nav_default_pop_exit_anim" />
+    </fragment>
     <action
         android:id="@+id/action_global_historyFragment"
         app:destination="@id/historyFragment"
@@ -31,12 +44,19 @@
     <fragment
         android:id="@+id/identitiesFragment"
         android:name="dev.lowrespalmtree.comet.IdentitiesFragment"
-        android:label="IdentitiesFragment" />
+        android:label="@string/identities" />
+    <action
+        android:id="@+id/action_global_identitiesFragment"
+        app:destination="@id/identitiesFragment"
+        app:enterAnim="@anim/nav_default_enter_anim"
+        app:exitAnim="@anim/nav_default_exit_anim"
+        app:popEnterAnim="@anim/nav_default_pop_enter_anim"
+        app:popExitAnim="@anim/nav_default_pop_exit_anim" />
 
     <fragment
         android:id="@+id/settingsFragment"
         android:name="dev.lowrespalmtree.comet.SettingsFragment"
-        android:label="SettingsFragment" />
+        android:label="@string/settings" />
     <action
         android:id="@+id/action_global_settingsFragment"
         app:destination="@id/settingsFragment"

app/src/main/res/values/strings.xml

@@ -50,5 +50,8 @@
     <string name="open">Open</string>
     <string name="download_completed">File downloaded.</string>
     <string name="image_download_completed">Image downloaded.</string>
+    <string name="navigation_drawer_open">Open navigation drawer</string>
+    <string name="navigation_drawer_close">Close navigation drawer</string>
+    <string name="logo">Logo</string>
 
 </resources>