PageAdapter: show visited links with another color

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

@@ -13,7 +13,7 @@ interface Line
 class EmptyLine : Line
 class ParagraphLine(val text: String) : Line
 class TitleLine(val level: Int, val text: String) : Line
-class LinkLine(val url: String, val label: String) : Line
+class LinkLine(val url: String, val label: String, var visited: Boolean = false) : Line
 class PreFenceLine(val caption: String) : Line
 class PreTextLine(val text: String) : Line
 class BlockquoteLine(val text: String) : Line
@@ -21,7 +21,7 @@ class ListItemLine(val text: String) : Line
 
 private const val TAG = "Gemtext"
 
-/** Pipe incoming gemtext data into parsed Lines. */
+/** Pipe incoming Gemtext data into parsed Lines. */
 fun parseData(
     inChannel: Channel<ByteArray>,
     charset: Charset,

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

@@ -38,6 +38,10 @@ object History {
             dao.update(entry.also { it.title = title; it.lastVisit = now })
     }
 
+    suspend fun contains(uri: String): Boolean = get(uri) != null
+
+    suspend fun get(uri: String): HistoryEntry? = Database.INSTANCE.historyEntryDao().get(uri)
+
     suspend fun getAll(): List<HistoryEntry> = Database.INSTANCE.historyEntryDao().getAll()
 
     suspend fun getLast(): HistoryEntry? = Database.INSTANCE.historyEntryDao().getLast()

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

@@ -1,6 +1,7 @@
 package dev.lowrespalmtree.comet
 
 import android.os.Bundle
+import android.util.Log
 import android.view.MenuItem
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.os.bundleOf
@@ -15,6 +16,7 @@ class MainActivity : AppCompatActivity() {
     private var nhf: NavHostFragment? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
+        Log.i(TAG, "onCreate")
         super.onCreate(savedInstanceState)
         binding = ActivityMainBinding.inflate(layoutInflater)
         setContentView(binding.root)
@@ -32,4 +34,8 @@ class MainActivity : AppCompatActivity() {
         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/PageAdapter.kt

@@ -1,6 +1,7 @@
 package dev.lowrespalmtree.comet
 
 import android.annotation.SuppressLint
+import android.net.Uri
 import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
@@ -33,7 +34,7 @@ class PageAdapter(private val listener: Listener) :
         object Empty : ContentBlock()
         class Paragraph(val text: String) : ContentBlock()
         class Title(val text: String, val level: Int) : ContentBlock()
-        class Link(val url: String, val label: String) : ContentBlock()
+        class Link(val url: String, val label: String, val visited: Boolean) : ContentBlock()
         class Pre(val caption: String, var content: String, var closed: Boolean) : ContentBlock()
         class Blockquote(var text: String) : ContentBlock()
         class ListItem(val text: String) : ContentBlock()
@@ -54,7 +55,7 @@ class PageAdapter(private val listener: Listener) :
                 when (val line = lines[currentLine]) {
                     is EmptyLine -> blocks.add(ContentBlock.Empty)
                     is ParagraphLine -> blocks.add(ContentBlock.Paragraph(line.text))
-                    is LinkLine -> blocks.add(ContentBlock.Link(line.url, line.label))
+                    is LinkLine -> blocks.add(ContentBlock.Link(line.url, line.label, line.visited))
                     is ListItemLine -> blocks.add(ContentBlock.ListItem(line.text))
                     is TitleLine -> blocks.add(ContentBlock.Title(line.text, line.level))
                     is PreFenceLine -> {
@@ -95,8 +96,8 @@ class PageAdapter(private val listener: Listener) :
         lastBlockCount = blocks.size
     }
 
-    sealed class ContentViewHolder(view: View) : RecyclerView.ViewHolder(view) {
+    sealed class ContentViewHolder(val view: View) : RecyclerView.ViewHolder(view) {
-        class Empty(binding: GemtextEmptyBinding) : ContentViewHolder(binding.root)
+        class Empty(val binding: GemtextEmptyBinding) : ContentViewHolder(binding.root)
         class Paragraph(val binding: GemtextParagraphBinding) : ContentViewHolder(binding.root)
         class Title1(val binding: GemtextTitle1Binding) : ContentViewHolder(binding.root)
         class Title2(val binding: GemtextTitle2Binding) : ContentViewHolder(binding.root)
@@ -156,6 +157,15 @@ class PageAdapter(private val listener: Listener) :
                 val label = block.label.ifBlank { block.url }
                 (holder as ContentViewHolder.Link).binding.textView.text = label
                 holder.binding.root.setOnClickListener { listener.onLinkClick(block.url) }
+
+                // Color links differently if it has been already visited or not.
+                val resources = holder.binding.root.context.resources
+                holder.binding.textView.setTextColor(
+                    if (block.visited)
+                        resources.getColor(R.color.link_visited, null)
+                    else
+                        resources.getColor(R.color.link, null)
+                )
             }
             is ContentBlock.Pre ->
                 (holder as ContentViewHolder.Pre).binding.textView.text = block.content

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

@@ -51,7 +51,7 @@ class PageFragment : Fragment(), PageAdapter.Listener {
         binding.contentSwipeLayout.setOnRefreshListener { openUrl(vm.currentUrl) }
 
         vm.state.observe(viewLifecycleOwner) { updateState(it) }
-        vm.lines.observe(viewLifecycleOwner) { updateLines(it) }
+        vm.lines.observe(viewLifecycleOwner) { updateLines(it.second, it.first) }
         vm.event.observe(viewLifecycleOwner) { handleEvent(it) }
 
         activity?.onBackPressedDispatcher?.addCallback(viewLifecycleOwner) { onBackPressed() }
@@ -151,8 +151,8 @@ class PageFragment : Fragment(), PageAdapter.Listener {
         }
     }
 
-    private fun updateLines(lines: List<Line>) {
+    private fun updateLines(lines: List<Line>, url: String) {
-        Log.d(TAG, "updateLines: ${lines.size} lines")
+        Log.d(TAG, "updateLines: ${lines.size} lines from $url")
         adapter.setLines(lines)
     }
 

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

@@ -6,6 +6,7 @@ import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import dev.lowrespalmtree.comet.utils.joinUrls
 import kotlinx.coroutines.*
 import kotlinx.coroutines.channels.onSuccess
 import java.net.ConnectException
@@ -21,8 +22,8 @@ class PageViewModel(@Suppress("unused") private val savedStateHandle: SavedState
     var loadingUrl: Uri? = null
     /** Observable page viewer state. */
     val state: MutableLiveData<State> by lazy { MutableLiveData<State>(State.IDLE) }
-    /** Observable page viewer lines (backed up by `linesList` but updated less often). */
+    /** Observable page viewer lines (backed up by `linesList` but updated less often). Left element is associated URL. */
-    val lines: MutableLiveData<List<Line>> by lazy { MutableLiveData<List<Line>>() }
+    val lines: MutableLiveData<Pair<String, List<Line>>> by lazy { MutableLiveData<Pair<String, 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. */
@@ -113,9 +114,10 @@ class PageViewModel(@Suppress("unused") private val savedStateHandle: SavedState
     @ExperimentalCoroutinesApi
     private suspend fun handleSuccessResponse(response: Response, uri: Uri) {
         state.postValue(State.RECEIVING)
+        val uriString = uri.toString()
 
         linesList.clear()
-        lines.postValue(linesList)
+        lines.postValue(Pair(uriString, linesList))
         val charset = Charset.defaultCharset()
         var mainTitle: String? = null
         var lastUpdate = System.currentTimeMillis()
@@ -126,7 +128,16 @@ class PageViewModel(@Suppress("unused") private val savedStateHandle: SavedState
             while (!lineChannel.isClosedForReceive) {
                 val lineChannelResult = withTimeout(100) { lineChannel.tryReceive() }
                 lineChannelResult.onSuccess { line ->
+                    if (line is LinkLine) {
+                        // Mark visited links here as we have a access to the history.
+                        val fullUrl =
+                            if (Uri.parse(line.url).isAbsolute) line.url
+                            else joinUrls(uriString, line.url).toString()
+                        if (History.contains(fullUrl))
+                            line.visited = true
+                    }
                     linesList.add(line)
+                    // Get the first level 1 header as the page main title.
                     if (mainTitle == null && line is TitleLine && line.level == 1)
                         mainTitle = line.text
                 }
@@ -135,7 +146,7 @@ class PageViewModel(@Suppress("unused") private val savedStateHandle: SavedState
                 if (linesList.size > lastNumLines) {
                     val time = System.currentTimeMillis()
                     if (time - lastUpdate >= 100) {
-                        lines.postValue(linesList)
+                        lines.postValue(Pair(uriString, linesList))
                         lastUpdate = time
                         lastNumLines = linesList.size
                     }
@@ -147,7 +158,7 @@ class PageViewModel(@Suppress("unused") private val savedStateHandle: SavedState
             return
         }
         Log.d(TAG, "handleSuccessResponse: done parsing line data")
-        lines.postValue(linesList)
+        lines.postValue(Pair(uriString, linesList))
 
         // 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.

app/src/main/res/values-night/colors.xml

@@ -8,7 +8,8 @@
     <color name="main_accent_dark">#073642</color>
     <color name="second_accent">#2aa198</color>
     <color name="second_accent_dark">#073642</color>
-    <color name="link">#2aa198</color>
+    <color name="link">#268bd2</color>
+    <color name="link_visited">#2aa198</color>
     <color name="url_bar">#fdf6e3</color>
     <color name="url_bar_loading">#586e75</color>
 </resources>

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

@@ -11,6 +11,7 @@
     <color name="second_accent">#6c71c4</color>
     <color name="second_accent_dark">#073642</color>
     <color name="link">#268bd2</color>
+    <color name="link_visited">#2aa198</color>
     <color name="url_bar">#002b36</color>
     <color name="url_bar_loading">#fdf6e3</color>
     <!--