move page viewer logic into a fragment

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

@@ -19,7 +19,7 @@ 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: ContentAdapterListen) :
+class ContentAdapter(private val listener: ContentAdapterListener) :
     RecyclerView.Adapter<ContentAdapter.ContentViewHolder>() {
 
     private var lines = listOf<Line>()
@@ -27,7 +27,7 @@ class ContentAdapter(private val listener: ContentAdapterListen) :
     private var blocks = mutableListOf<ContentBlock>()
     private var lastBlockCount = 0
 
-    interface ContentAdapterListen {
+    interface ContentAdapterListener {
         fun onLinkClick(url: String)
     }
 

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

@@ -1,200 +1,31 @@
 package dev.lowrespalmtree.comet
 
-import android.app.Activity
-import android.content.ActivityNotFoundException
-import android.content.Intent
-import android.content.Intent.ACTION_VIEW
-import android.net.Uri
 import android.os.Bundle
-import android.text.InputType
-import android.util.Log
-import android.view.inputmethod.EditorInfo
-import android.view.inputmethod.InputMethodManager
-import android.widget.EditText
-import android.widget.FrameLayout
-import android.widget.FrameLayout.LayoutParams.MATCH_PARENT
-import android.widget.FrameLayout.LayoutParams.WRAP_CONTENT
-import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
-import androidx.core.view.setMargins
-import androidx.lifecycle.ViewModelProvider
-import androidx.recyclerview.widget.LinearLayoutManager
-import dev.lowrespalmtree.comet.databinding.ActivityMainBinding
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 
 
 @ExperimentalCoroutinesApi
-class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
+class MainActivity : AppCompatActivity() {
-    private lateinit var binding: ActivityMainBinding
-    private lateinit var pageViewModel: PageViewModel
-    private lateinit var adapter: ContentAdapter
-
-    /** 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>()
-
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_main)
 
-        Database.init(applicationContext)
+        Database.init(applicationContext)  // TODO move to App Startup?
 
-        binding = ActivityMainBinding.inflate(layoutInflater)
+        if (savedInstanceState == null) {
-        setContentView(binding.root)
+            supportFragmentManager
-
+                .beginTransaction()
-        pageViewModel = ViewModelProvider(this)[PageViewModel::class.java]
+                .add(R.id.main_content, PageViewFragment().apply { arguments = intent.extras })
-        adapter = ContentAdapter(this)
+                .commit()
-        binding.contentRecycler.layoutManager = LinearLayoutManager(this)
-        binding.contentRecycler.adapter = adapter
-
-        binding.addressBar.setOnEditorActionListener { view, actionId, _ ->
-            if (actionId == EditorInfo.IME_ACTION_DONE) {
-                openUrl(view.text.toString())
-                val imm = getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
-                imm.hideSoftInputFromWindow(view.windowToken, 0)
-                view.clearFocus()
-                true
-            } else {
-                false
         }
     }
 
-        binding.contentSwipeLayout.setOnRefreshListener { openUrl(currentUrl) }
-
-        pageViewModel.state.observe(this, { updateState(it) })
-        pageViewModel.lines.observe(this, { updateLines(it) })
-        pageViewModel.event.observe(this, { handleEvent(it) })
-    }
-
     override fun onBackPressed() {
-        visitedUrls.removeLastOrNull()  // Always remove current page first.
+        // TODO pass to PageViewFragment
-        val previousUrl = visitedUrls.removeLastOrNull()
-        if (previousUrl != null)
-            openUrl(previousUrl)
-        else
         super.onBackPressed()
     }
 
-    override fun onLinkClick(url: String) {
-        openUrl(url, base = if (currentUrl.isNotEmpty()) currentUrl else null)
-    }
-
-    /**
-     * Open an URL.
-     *
-     * This function can be called after the user entered an URL in the app bar, clicked on a link,
-     * whatever. To make the user's life a bit easier, this function also makes a few guesses:
-     * - If the URL is not absolute, make it so from a base URL (e.g. the current URL) or assume
-     *   the user only typed a hostname without scheme and use a utility function to make it
-     *   absolute.
-     * - If it's an absolute Gemini URL with an empty path, use "/" instead as per the spec.
-     */
-    private fun openUrl(url: String, base: String? = null, redirections: Int = 0) {
-        if (redirections >= 5) {
-            alert("Too many redirections.")
-            return
-        }
-
-        var uri = Uri.parse(url)
-        if (!uri.isAbsolute) {
-            uri = if (!base.isNullOrEmpty()) joinUrls(base, url) else toGeminiUri(uri)
-        } else if (uri.scheme == "gemini" && uri.path.isNullOrEmpty()) {
-            uri = uri.buildUpon().path("/").build()
-        }
-
-        when (uri.scheme) {
-            "gemini" -> pageViewModel.sendGeminiRequest(uri)
-            else -> openUnknownScheme(uri)
-        }
-    }
-
-    private fun updateState(state: PageViewModel.State) {
-        Log.d(TAG, "updateState: $state")
-        when (state) {
-            PageViewModel.State.IDLE -> {
-                binding.contentProgressBar.hide()
-                binding.contentSwipeLayout.isRefreshing = false
-            }
-            PageViewModel.State.CONNECTING -> {
-                binding.contentProgressBar.show()
-            }
-            PageViewModel.State.RECEIVING -> {
-                binding.appBar.setExpanded(true, true)
-                binding.contentSwipeLayout.isRefreshing = false
-            }
-        }
-    }
-
-    private fun updateLines(lines: List<Line>) {
-        Log.d(TAG, "updateLines: ${lines.size} lines")
-        adapter.setLines(lines)
-    }
-
-    private fun handleEvent(event: PageViewModel.Event) {
-        Log.d(TAG, "handleEvent: $event")
-        if (!event.handled) {
-            when (event) {
-                is PageViewModel.InputEvent -> {
-                    val editText = EditText(this).apply { inputType = InputType.TYPE_CLASS_TEXT }
-                    val inputView = FrameLayout(this).apply {
-                        addView(FrameLayout(this@MainActivity).apply {
-                            addView(editText)
-                            val params = FrameLayout.LayoutParams(MATCH_PARENT, WRAP_CONTENT)
-                            params.setMargins(resources.getDimensionPixelSize(R.dimen.text_margin))
-                            layoutParams = params
-                        })
-                    }
-                    AlertDialog.Builder(this)
-                        .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()
-                }
-                is PageViewModel.SuccessEvent -> {
-                    currentUrl = event.uri
-                    visitedUrls.add(event.uri)
-                }
-                is PageViewModel.RedirectEvent -> {
-                    openUrl(event.uri, base = currentUrl, redirections = event.redirects)
-                }
-                is PageViewModel.FailureEvent -> {
-                    var message = event.details
-                    if (!event.serverDetails.isNullOrEmpty())
-                        message += "\n\nServer details: ${event.serverDetails}"
-                    if (!isConnectedToNetwork(this))
-                        message += "\n\nInternet may be inaccessible…"
-                    alert(message, title = event.short)
-                    updateState(PageViewModel.State.IDLE)
-                }
-            }
-            event.handled = true
-        }
-    }
-
-    private fun alert(message: String, title: String? = null) {
-        AlertDialog.Builder(this)
-            .setTitle(title ?: getString(R.string.error_alert_title))
-            .setMessage(message)
-            .create()
-            .show()
-    }
-
-    private fun openUnknownScheme(uri: Uri) {
-        try {
-            startActivity(Intent(ACTION_VIEW, uri))
-        } catch (e: ActivityNotFoundException) {
-            alert("Can't find an app to open \"${uri.scheme}\" URLs.")
-        }
-    }
-
     companion object {
         const val TAG = "MainActivity"
     }

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

@@ -0,0 +1,210 @@
+package dev.lowrespalmtree.comet
+
+import android.app.Activity
+import android.content.ActivityNotFoundException
+import android.content.Intent
+import android.net.Uri
+import android.os.Bundle
+import android.text.InputType
+import android.util.Log
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.view.inputmethod.EditorInfo
+import android.view.inputmethod.InputMethodManager
+import android.widget.EditText
+import android.widget.FrameLayout
+import androidx.appcompat.app.AlertDialog
+import androidx.core.view.setMargins
+import androidx.fragment.app.Fragment
+import androidx.lifecycle.ViewModelProvider
+import androidx.recyclerview.widget.LinearLayoutManager
+import dev.lowrespalmtree.comet.databinding.FragmentPageViewBinding
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+
+@ExperimentalCoroutinesApi
+class PageViewFragment : Fragment(), ContentAdapter.ContentAdapterListener {
+    private lateinit var binding: FragmentPageViewBinding
+    private lateinit var pageViewModel: PageViewModel
+    private lateinit var adapter: ContentAdapter
+
+    /** 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>()
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View {
+        binding = FragmentPageViewBinding.inflate(layoutInflater)
+        return binding.root
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        pageViewModel = ViewModelProvider(this)[PageViewModel::class.java]
+        adapter = ContentAdapter(this)
+        binding.contentRecycler.layoutManager = LinearLayoutManager(requireContext())
+        binding.contentRecycler.adapter = adapter
+
+        binding.addressBar.setOnEditorActionListener { editText, actionId, _ ->
+            if (actionId == EditorInfo.IME_ACTION_DONE) {
+                openUrl(editText.text.toString())
+                activity?.run {
+                    val imm = getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
+                    imm.hideSoftInputFromWindow(editText.windowToken, 0)
+                }
+                editText.clearFocus()
+                true
+            } else {
+                false
+            }
+        }
+
+        binding.contentSwipeLayout.setOnRefreshListener { openUrl(currentUrl) }
+
+        pageViewModel.state.observe(viewLifecycleOwner, { updateState(it) })
+        pageViewModel.lines.observe(viewLifecycleOwner, { updateLines(it) })
+        pageViewModel.event.observe(viewLifecycleOwner, { handleEvent(it) })
+    }
+
+    override fun onLinkClick(url: String) {
+        openUrl(url, base = if (currentUrl.isNotEmpty()) currentUrl else null)
+    }
+
+    fun onBackPressed(): Boolean {
+        visitedUrls.removeLastOrNull()  // Always remove current page first.
+        val previousUrl = visitedUrls.removeLastOrNull()
+        if (previousUrl != null) {
+            openUrl(previousUrl)
+            return true
+        }
+        return false
+    }
+
+    /**
+     * Open an URL.
+     *
+     * This function can be called after the user entered an URL in the app bar, clicked on a link,
+     * whatever. To make the user's life a bit easier, this function also makes a few guesses:
+     * - If the URL is not absolute, make it so from a base URL (e.g. the current URL) or assume
+     *   the user only typed a hostname without scheme and use a utility function to make it
+     *   absolute.
+     * - If it's an absolute Gemini URL with an empty path, use "/" instead as per the spec.
+     */
+    private fun openUrl(url: String, base: String? = null, redirections: Int = 0) {
+        if (redirections >= 5) {
+            alert("Too many redirections.")
+            return
+        }
+
+        var uri = Uri.parse(url)
+        if (!uri.isAbsolute) {
+            uri = if (!base.isNullOrEmpty()) joinUrls(base, url) else toGeminiUri(uri)
+        } else if (uri.scheme == "gemini" && uri.path.isNullOrEmpty()) {
+            uri = uri.buildUpon().path("/").build()
+        }
+
+        when (uri.scheme) {
+            "gemini" -> pageViewModel.sendGeminiRequest(uri)
+            else -> openUnknownScheme(uri)
+        }
+    }
+
+    private fun updateState(state: PageViewModel.State) {
+        Log.d(TAG, "updateState: $state")
+        when (state) {
+            PageViewModel.State.IDLE -> {
+                binding.contentProgressBar.hide()
+                binding.contentSwipeLayout.isRefreshing = false
+            }
+            PageViewModel.State.CONNECTING -> {
+                binding.contentProgressBar.show()
+            }
+            PageViewModel.State.RECEIVING -> {
+                binding.appBar.setExpanded(true, true)
+                binding.contentSwipeLayout.isRefreshing = false
+            }
+        }
+    }
+
+    private fun updateLines(lines: List<Line>) {
+        Log.d(TAG, "updateLines: ${lines.size} lines")
+        adapter.setLines(lines)
+    }
+
+    private fun handleEvent(event: PageViewModel.Event) {
+        Log.d(TAG, "handleEvent: $event")
+        if (!event.handled) {
+            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()
+                }
+                is PageViewModel.SuccessEvent -> {
+                    currentUrl = event.uri
+                    visitedUrls.add(event.uri)
+                }
+                is PageViewModel.RedirectEvent -> {
+                    openUrl(event.uri, base = currentUrl, redirections = event.redirects)
+                }
+                is PageViewModel.FailureEvent -> {
+                    var message = event.details
+                    if (!event.serverDetails.isNullOrEmpty())
+                        message += "\n\nServer details: ${event.serverDetails}"
+                    if (!isConnectedToNetwork(requireContext()))
+                        message += "\n\nInternet may be inaccessible…"
+                    alert(message, title = event.short)
+                    updateState(PageViewModel.State.IDLE)
+                }
+            }
+            event.handled = true
+        }
+    }
+
+    private fun alert(message: String, title: String? = null) {
+        AlertDialog.Builder(requireContext())
+            .setTitle(title ?: getString(R.string.error_alert_title))
+            .setMessage(message)
+            .create()
+            .show()
+    }
+
+    private fun openUnknownScheme(uri: Uri) {
+        try {
+            startActivity(Intent(Intent.ACTION_VIEW, uri))
+        } catch (e: ActivityNotFoundException) {
+            alert("Can't find an app to open \"${uri.scheme}\" URLs.")
+        }
+    }
+
+    companion object {
+        private const val TAG = "PageViewFragment"
+    }
+}

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

@@ -1,71 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
+    xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/root"
+    android:id="@+id/main_content"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent">
-
-    <com.google.android.material.appbar.AppBarLayout
-        android:id="@+id/app_bar"
-        android:layout_width="match_parent"
-        android:layout_height="56dp">
-
-        <Toolbar
-            android:id="@+id/toolbar"
-            android:layout_width="match_parent"
     android:layout_height="match_parent"
-            app:contentScrim="?attr/colorPrimary"
+    android:layout_width="match_parent" />
-            app:layout_scrollFlags="scroll|enterAlways"
-            app:toolbarId="@+id/toolbar">
-
-            <EditText
-                android:id="@+id/address_bar"
-                android:layout_width="match_parent"
-                android:layout_height="match_parent"
-                android:layout_margin="4dp"
-                android:hint="@string/url"
-                android:imeOptions="actionDone|actionGo"
-                android:importantForAutofill="no"
-                android:inputType="textUri"
-                android:text=""
-                tools:ignore="TextContrastCheck" />
-
-        </Toolbar>
-
-    </com.google.android.material.appbar.AppBarLayout>
-
-    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
-        android:id="@+id/content_swipe_layout"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        app:layout_behavior="@string/appbar_scrolling_view_behavior">
-
-        <RelativeLayout
-            android:id="@+id/content_inner_layout"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            app:layout_behavior="@string/appbar_scrolling_view_behavior">
-
-            <androidx.recyclerview.widget.RecyclerView
-                android:id="@+id/content_recycler"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                android:orientation="vertical"
-                app:layout_constraintTop_toTopOf="parent" />
-
-            <androidx.core.widget.ContentLoadingProgressBar
-                android:id="@+id/content_progress_bar"
-                style="?android:attr/progressBarStyleHorizontal"
-                android:layout_width="match_parent"
-                android:layout_height="16dp"
-                android:layout_alignParentTop="true"
-                android:layout_marginTop="-8dp"
-                android:indeterminate="true"
-                android:visibility="gone" />
-
-        </RelativeLayout>
-
-    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
-
-</androidx.coordinatorlayout.widget.CoordinatorLayout>

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

@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/root"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/app_bar"
+        android:layout_width="match_parent"
+        android:layout_height="56dp">
+
+        <Toolbar
+            android:id="@+id/toolbar"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            app:contentScrim="?attr/colorPrimary"
+            app:layout_scrollFlags="scroll|enterAlways"
+            app:toolbarId="@+id/toolbar">
+
+            <EditText
+                android:id="@+id/address_bar"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:layout_margin="4dp"
+                android:hint="@string/url"
+                android:imeOptions="actionDone|actionGo"
+                android:importantForAutofill="no"
+                android:inputType="textUri"
+                android:text=""
+                tools:ignore="TextContrastCheck" />
+
+        </Toolbar>
+
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+        android:id="@+id/content_swipe_layout"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior">
+
+        <RelativeLayout
+            android:id="@+id/content_inner_layout"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            app:layout_behavior="@string/appbar_scrolling_view_behavior">
+
+            <androidx.recyclerview.widget.RecyclerView
+                android:id="@+id/content_recycler"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:orientation="vertical"
+                app:layout_constraintTop_toTopOf="parent" />
+
+            <androidx.core.widget.ContentLoadingProgressBar
+                android:id="@+id/content_progress_bar"
+                style="?android:attr/progressBarStyleHorizontal"
+                android:layout_width="match_parent"
+                android:layout_height="16dp"
+                android:layout_alignParentTop="true"
+                android:layout_marginTop="-8dp"
+                android:indeterminate="true"
+                android:visibility="gone" />
+
+        </RelativeLayout>
+
+    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+
+</androidx.coordinatorlayout.widget.CoordinatorLayout>