PageViewModel: docs

This should advance on #4.

app/build.gradle

@@ -56,7 +56,7 @@ dependencies {
     implementation "androidx.navigation:navigation-fragment-ktx:$nav_version"
     implementation "androidx.navigation:navigation-ui-ktx:$nav_version"
     implementation 'androidx.preference:preference-ktx:1.1.1'
-    implementation 'androidx.recyclerview:recyclerview:1.2.0'
+    implementation 'androidx.recyclerview:recyclerview:1.2.1'
     implementation "androidx.room:room-runtime:$room_version"
     implementation "androidx.room:room-ktx:$room_version"
     implementation "androidx.cardview:cardview:1.0.0"

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

@@ -47,7 +47,7 @@ class HistoryFragment : Fragment(), HistoryItemAdapterListener {
 
     override fun onItemClick(url: String) {
         val bundle = bundleOf("url" to url)
-        findNavController().navigate(R.id.action_global_pageViewFragment, bundle)
+        findNavController().navigate(R.id.action_global_pageFragment, bundle)
     }
 
     @ExperimentalCoroutinesApi

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

@@ -6,7 +6,6 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.core.os.bundleOf
 import androidx.navigation.fragment.NavHostFragment
 import androidx.navigation.ui.setupWithNavController
-import androidx.preference.PreferenceManager
 import dev.lowrespalmtree.comet.databinding.ActivityMainBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 
@@ -27,10 +26,10 @@ class MainActivity : AppCompatActivity() {
     }
 
     /** Navigate to the PageViewFragment; this will automatically use the home URL if any. */
-    fun goHome(item: MenuItem) {
+    fun goHome(@Suppress("unused_parameter") item: MenuItem) {
         val bundle = bundleOf()
         Preferences.getHomeUrl(this)?.let { bundle.putString("url", it) }
-        nhf?.navController?.navigate(R.id.action_global_pageViewFragment, bundle)
+        nhf?.navController?.navigate(R.id.action_global_pageFragment, bundle)
         binding.drawerLayout.closeDrawers()
     }
 }

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

@@ -19,8 +19,8 @@ import dev.lowrespalmtree.comet.databinding.*
  * it could be a n-to-1 relation: many lines belong to the same block. This of course changes a bit
  * the way we have to render things.
  */
-class ContentAdapter(private val listener: ContentAdapterListener) :
-    RecyclerView.Adapter<ContentAdapter.ContentViewHolder>() {
+class PageAdapter(private val listener: ContentAdapterListener) :
+    RecyclerView.Adapter<PageAdapter.ContentViewHolder>() {
 
     private var lines = listOf<Line>()
     private var currentLine = 0
@@ -161,7 +161,7 @@ class ContentAdapter(private val listener: ContentAdapterListener) :
     override fun getItemCount(): Int = blocks.size
 
     companion object {
-        private const val TAG = "ContentRecycler"
+        private const val TAG = "PageAdapter"
         private const val TYPE_EMPTY = 0
         private const val TYPE_TITLE_1 = 1
         private const val TYPE_TITLE_2 = 2

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

@@ -19,39 +19,40 @@ import androidx.activity.addCallback
 import androidx.appcompat.app.AlertDialog
 import androidx.core.view.setMargins
 import androidx.fragment.app.Fragment
-import androidx.lifecycle.ViewModelProvider
+import androidx.fragment.app.viewModels
 import androidx.preference.PreferenceManager
 import androidx.recyclerview.widget.LinearLayoutManager
-import dev.lowrespalmtree.comet.ContentAdapter.ContentAdapterListener
+import dev.lowrespalmtree.comet.PageAdapter.ContentAdapterListener
 import dev.lowrespalmtree.comet.databinding.FragmentPageViewBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 
 @ExperimentalCoroutinesApi
-class PageViewFragment : Fragment(), ContentAdapterListener {
+class PageFragment : Fragment(), ContentAdapterListener {
+    private val vm: PageViewModel by viewModels()
     private lateinit var binding: FragmentPageViewBinding
-    private lateinit var pageViewModel: PageViewModel
-    private lateinit var adapter: ContentAdapter
+    private lateinit var adapter: PageAdapter
 
     /** Property to access and set the current address bar URL value. */
-    private var currentUrl
-        get() = binding.addressBar.text.toString()
-        set(value) = binding.addressBar.setText(value)
-
-    /** A non-saved list of visited URLs. Not an history, just used for going back. */
-    private val visitedUrls = mutableListOf<String>()
+    private var currentUrl: String
+        get() = vm.currentUrl
+        set(value) {
+            vm.currentUrl = value
+            binding.addressBar.setText(value)
+        }
 
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
     ): View {
+        Log.d(TAG, "onCreateView")
         binding = FragmentPageViewBinding.inflate(layoutInflater)
         return binding.root
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        pageViewModel = ViewModelProvider(this)[PageViewModel::class.java]
-        adapter = ContentAdapter(this)
+        Log.d(TAG, "onViewCreated")
+        adapter = PageAdapter(this)
         binding.contentRecycler.layoutManager = LinearLayoutManager(requireContext())
         binding.contentRecycler.adapter = adapter
 
@@ -59,16 +60,20 @@ class PageViewFragment : Fragment(), ContentAdapterListener {
 
         binding.contentSwipeLayout.setOnRefreshListener { openUrl(currentUrl) }
 
-        pageViewModel.state.observe(viewLifecycleOwner, { updateState(it) })
-        pageViewModel.lines.observe(viewLifecycleOwner, { updateLines(it) })
-        pageViewModel.event.observe(viewLifecycleOwner, { handleEvent(it) })
+        vm.state.observe(viewLifecycleOwner, { updateState(it) })
+        vm.lines.observe(viewLifecycleOwner, { updateLines(it) })
+        vm.event.observe(viewLifecycleOwner, { handleEvent(it) })
 
         activity?.onBackPressedDispatcher?.addCallback(viewLifecycleOwner) { onBackPressed() }
 
         val url = arguments?.getString("url")
         if (!url.isNullOrEmpty()) {
+            Log.d(TAG, "onViewCreated: open \"$url\"")
             openUrl(url)
-        } else if (visitedUrls.isEmpty()) {
+        } 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 { openUrl(it) }
         }
     }
@@ -78,9 +83,9 @@ class PageViewFragment : Fragment(), ContentAdapterListener {
     }
 
     private fun onBackPressed() {
-        if (visitedUrls.size >= 2) {
-            visitedUrls.removeLastOrNull()  // Always remove current page first.
-            visitedUrls.removeLastOrNull()?.also { openUrl(it) }
+        if (vm.visitedUrls.size >= 2) {
+            vm.visitedUrls.removeLastOrNull()  // Always remove current page first.
+            vm.visitedUrls.removeLastOrNull()?.also { openUrl(it) }
         }
     }
 
@@ -127,7 +132,7 @@ class PageViewFragment : Fragment(), ContentAdapterListener {
                     prefs.getInt("connection_timeout", Request.DEFAULT_CONNECTION_TIMEOUT_SEC)
                 val readTimeout =
                     prefs.getInt("read_timeout", Request.DEFAULT_READ_TIMEOUT_SEC)
-                pageViewModel.sendGeminiRequest(uri, connectionTimeout, readTimeout)
+                vm.sendGeminiRequest(uri, connectionTimeout, readTimeout)
             }
             else -> openUnknownScheme(uri)
         }
@@ -157,37 +162,15 @@ class PageViewFragment : Fragment(), ContentAdapterListener {
 
     private fun handleEvent(event: PageViewModel.Event) {
         Log.d(TAG, "handleEvent: $event")
-        if (!event.handled) {
+        if (event.handled)
+            return
         when (event) {
             is PageViewModel.InputEvent -> {
-                    val editText = EditText(requireContext())
-                    editText.inputType = InputType.TYPE_CLASS_TEXT
-                    val inputView = FrameLayout(requireContext()).apply {
-                        addView(FrameLayout(requireContext()).apply {
-                            addView(editText)
-                            val params = FrameLayout.LayoutParams(
-                                FrameLayout.LayoutParams.MATCH_PARENT,
-                                FrameLayout.LayoutParams.WRAP_CONTENT
-                            )
-                            params.setMargins(resources.getDimensionPixelSize(R.dimen.text_margin))
-                            layoutParams = params
-                        })
-                    }
-                    AlertDialog.Builder(requireContext())
-                        .setMessage(if (event.prompt.isNotEmpty()) event.prompt else "Input required")
-                        .setView(inputView)
-                        .setPositiveButton(android.R.string.ok) { _, _ ->
-                            val newUri =
-                                event.uri.buildUpon().query(editText.text.toString()).build()
-                            openUrl(newUri.toString(), base = currentUrl)
-                        }
-                        .setOnDismissListener { updateState(PageViewModel.State.IDLE) }
-                        .create()
-                        .show()
+                askForInput(event.prompt, event.uri)
             }
             is PageViewModel.SuccessEvent -> {
                 currentUrl = event.uri
-                    visitedUrls.add(event.uri)
+                vm.visitedUrls.add(event.uri)
             }
             is PageViewModel.RedirectEvent -> {
                 openUrl(event.uri, base = currentUrl, redirections = event.redirects)
@@ -204,7 +187,6 @@ class PageViewFragment : Fragment(), ContentAdapterListener {
         }
         event.handled = true
     }
-    }
 
     private fun alert(message: String, title: String? = null) {
         AlertDialog.Builder(requireContext())
@@ -214,6 +196,32 @@ class PageViewFragment : Fragment(), ContentAdapterListener {
             .show()
     }
 
+    private fun askForInput(prompt: String, uri: Uri) {
+        val editText = EditText(requireContext())
+        editText.inputType = InputType.TYPE_CLASS_TEXT
+        val inputView = FrameLayout(requireContext()).apply {
+            addView(FrameLayout(requireContext()).apply {
+                addView(editText)
+                val params = FrameLayout.LayoutParams(
+                    FrameLayout.LayoutParams.MATCH_PARENT,
+                    FrameLayout.LayoutParams.WRAP_CONTENT
+                )
+                params.setMargins(resources.getDimensionPixelSize(R.dimen.text_margin))
+                layoutParams = params
+            })
+        }
+        AlertDialog.Builder(requireContext())
+            .setMessage(if (prompt.isNotEmpty()) prompt else "Input required")
+            .setView(inputView)
+            .setPositiveButton(android.R.string.ok) { _, _ ->
+                val newUri = uri.buildUpon().query(editText.text.toString()).build()
+                openUrl(newUri.toString(), base = currentUrl)
+            }
+            .setOnDismissListener { updateState(PageViewModel.State.IDLE) }
+            .create()
+            .show()
+    }
+
     private fun openUnknownScheme(uri: Uri) {
         try {
             startActivity(Intent(Intent.ACTION_VIEW, uri))
@@ -223,6 +231,6 @@ class PageViewFragment : Fragment(), ContentAdapterListener {
     }
 
     companion object {
-        private const val TAG = "PageViewFragment"
+        private const val TAG = "PageFragment"
     }
 }

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

@@ -3,6 +3,7 @@ package dev.lowrespalmtree.comet
 import android.net.Uri
 import android.util.Log
 import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.*
@@ -13,12 +14,22 @@ import java.net.UnknownHostException
 import java.nio.charset.Charset
 
 @ExperimentalCoroutinesApi
-class PageViewModel : ViewModel() {
-    private var requestJob: Job? = null
+class PageViewModel(@Suppress("unused") private val savedStateHandle: SavedStateHandle) :
+    ViewModel() {
+    /** Currently viewed page URL. */
+    var currentUrl: String = ""
+    /** Observable page viewer state. */
     val state: MutableLiveData<State> by lazy { MutableLiveData<State>(State.IDLE) }
-    private var linesList = ArrayList<Line>()
+    /** Observable page viewer lines (backed up by `linesList` but updated less often). */
     val lines: MutableLiveData<List<Line>> by lazy { MutableLiveData<List<Line>>() }
+    /** Observable page viewer latest event. */
     val event: MutableLiveData<Event> by lazy { MutableLiveData<Event>() }
+    /** A non-saved list of visited URLs. Not an history, just used for going back. */
+    val visitedUrls = mutableListOf<String>()
+    /** Latest request job created, stored to cancel it if needed. */
+    private var requestJob: Job? = null
+    /** Lines for the current page. */
+    private var linesList = ArrayList<Line>()
 
     enum class State {
         IDLE, CONNECTING, RECEIVING

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

@@ -2,15 +2,15 @@
 <navigation xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/main"
-    app:startDestination="@id/pageViewFragment">
+    app:startDestination="@id/pageFragment">
 
     <fragment
-        android:id="@+id/pageViewFragment"
-        android:name="dev.lowrespalmtree.comet.PageViewFragment"
+        android:id="@+id/pageFragment"
+        android:name="dev.lowrespalmtree.comet.PageFragment"
         android:label="PageViewFragment" />
     <action
-        android:id="@+id/action_global_pageViewFragment"
-        app:destination="@id/pageViewFragment"
+        android:id="@+id/action_global_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"