UriUtils: add a bunch of URI utilities

So we can now click on relative links, wow! Fast progress!

app/build.gradle

@@ -18,6 +18,9 @@ android {
     buildFeatures {
         viewBinding true
     }
+    testOptions {
+        unitTests.returnDefaultValues = true
+    }
     buildTypes {
         release {
             minifyEnabled false

app/src/androidTest/java/dev/lowrespalmtree/comet/ExampleInstrumentedTest.kt

@@ -1,24 +0,0 @@
-package dev.lowrespalmtree.comet
-
-import androidx.test.platform.app.InstrumentationRegistry
-import androidx.test.ext.junit.runners.AndroidJUnit4
-
-import org.junit.Test
-import org.junit.runner.RunWith
-
-import org.junit.Assert.*
-
-/**
- * Instrumented test, which will execute on an Android device.
- *
- * See [testing documentation](http://d.android.com/tools/testing).
- */
-@RunWith(AndroidJUnit4::class)
-class ExampleInstrumentedTest {
-    @Test
-    fun useAppContext() {
-        // Context of the app under test.
-        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
-        assertEquals("dev.lowrespalmtree.comet", appContext.packageName)
-    }
-}

app/src/androidTest/java/dev/lowrespalmtree/comet/UriUtilsTest.kt

@@ -0,0 +1,76 @@
+package dev.lowrespalmtree.comet
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class UriUtilsTest {
+    @Test
+    fun joinUrls() {
+        assertEquals(
+            "gemini://dece.space/some-file.gmi",
+            joinUrls("gemini://dece.space/", "some-file.gmi").toString()
+        )
+        assertEquals(
+            "gemini://dece.space/some-file.gmi",
+            joinUrls("gemini://dece.space/", "./some-file.gmi").toString()
+        )
+        assertEquals(
+            "gemini://dece.space/some-file.gmi",
+            joinUrls("gemini://dece.space/dir1", "/some-file.gmi").toString()
+        )
+        assertEquals(
+            "gemini://dece.space/dir1/other-file.gmi",
+            joinUrls("gemini://dece.space/dir1/file.gmi", "other-file.gmi").toString()
+        )
+        assertEquals(
+            "gemini://dece.space/top-level.gmi",
+            joinUrls("gemini://dece.space/dir1/file.gmi", "../top-level.gmi").toString()
+        )
+        assertEquals(
+            "s://hard/test/b/d/a.gmi",
+            joinUrls("s://hard/dir/a", "./../test/b/c/../d/e/f/../.././a.gmi").toString()
+        )
+    }
+
+    @Test
+    fun removeDotSegments() {
+        arrayOf(
+            Pair("index.gmi", "index.gmi"),
+            Pair("/index.gmi", "/index.gmi"),
+            Pair("./index.gmi", "index.gmi"),
+            Pair("/./index.gmi", "/index.gmi"),
+            Pair("/../index.gmi", "/index.gmi"),
+            Pair("/a/b/c/./../../g", "/a/g"),
+            Pair("mid/content=5/../6", "mid/6"),
+            Pair("../../../../g", "g")
+        ).forEach { (path, expected) ->
+            assertEquals(expected, removeDotSegments(path))
+        }
+    }
+
+    @Test
+    fun removeLastSegment() {
+        assertEquals("", removeLastSegment(""))
+        assertEquals("", removeLastSegment("/"))
+        assertEquals("", removeLastSegment("/a"))
+        assertEquals("/a", removeLastSegment("/a/"))
+        assertEquals("/a", removeLastSegment("/a/b"))
+        assertEquals("/a/b/c", removeLastSegment("/a/b/c/d"))
+        assertEquals("//", removeLastSegment("///"))
+    }
+
+    @Test
+    fun popFirstSegment() {
+        assertEquals(Pair("", ""), popFirstSegment(""))
+        assertEquals(Pair("a", ""), popFirstSegment("a"))
+        assertEquals(Pair("/a", ""), popFirstSegment("/a"))
+        assertEquals(Pair("/a", "/"), popFirstSegment("/a/"))
+        assertEquals(Pair("/a", "/b"), popFirstSegment("/a/b"))
+        assertEquals(Pair("a", "/b"), popFirstSegment("a/b"))
+    }
+}

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

@@ -0,0 +1,109 @@
+package dev.lowrespalmtree.comet
+
+import android.text.SpannableString
+import android.text.style.UnderlineSpan
+import android.util.Log
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView
+import dev.lowrespalmtree.comet.databinding.*
+
+class ContentAdapter(private var content: List<Line>, private val listener: ContentAdapterListen) :
+    RecyclerView.Adapter<ContentAdapter.ContentViewHolder>() {
+
+    interface ContentAdapterListen {
+        fun onLinkClick(url: String)
+    }
+
+    override fun getItemViewType(position: Int): Int =
+        when (content[position]) {
+            is EmptyLine -> TYPE_EMPTY
+            is ParagraphLine -> TYPE_PARAGRAPH
+            is LinkLine -> TYPE_LINK
+            is PreFenceLine -> TYPE_PRE_FENCE
+            is PreTextLine -> TYPE_PRE_TEXT
+            is BlockquoteLine -> TYPE_BLOCKQUOTE
+            is ListItemLine -> TYPE_LIST_ITEM
+            is TitleLine -> when ((content[position] as TitleLine).level) {
+                1 -> TYPE_TITLE_1
+                2 -> TYPE_TITLE_2
+                3 -> TYPE_TITLE_3
+                else -> error("invalid title level")
+            }
+            else -> error("unknown line type")
+        }
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ContentViewHolder {
+        Log.d(TAG, "onCreateViewHolder: type $viewType")
+        return LayoutInflater.from(parent.context).let {
+            when (viewType) {
+                TYPE_EMPTY -> ContentViewHolder.Empty(GemtextEmptyBinding.inflate(it))
+                TYPE_PARAGRAPH -> ContentViewHolder.Paragraph(GemtextParagraphBinding.inflate(it))
+                TYPE_TITLE_1 -> ContentViewHolder.Title1(GemtextTitle1Binding.inflate(it))
+                TYPE_TITLE_2 -> ContentViewHolder.Title2(GemtextTitle2Binding.inflate(it))
+                TYPE_TITLE_3 -> ContentViewHolder.Title3(GemtextTitle3Binding.inflate(it))
+                TYPE_LINK -> ContentViewHolder.Link(GemtextLinkBinding.inflate(it))
+                TYPE_PRE_FENCE -> ContentViewHolder.PreFence(GemtextEmptyBinding.inflate(it))
+                TYPE_PRE_TEXT -> ContentViewHolder.PreText(GemtextPreformattedBinding.inflate(it))
+                TYPE_BLOCKQUOTE -> ContentViewHolder.Blockquote(GemtextBlockquoteBinding.inflate(it))
+                TYPE_LIST_ITEM -> ContentViewHolder.ListItem(GemtextListItemBinding.inflate(it))
+                else -> error("invalid view type")
+            }
+        }
+    }
+
+    override fun onBindViewHolder(holder: ContentViewHolder, position: Int) {
+        Log.d(TAG, "onBindViewHolder: position $position")
+        val line = content[position]
+        when (holder) {
+            is ContentViewHolder.Paragraph -> holder.binding.textView.text =
+                (line as ParagraphLine).text
+            is ContentViewHolder.Title1 -> holder.binding.textView.text = (line as TitleLine).text
+            is ContentViewHolder.Title2 -> holder.binding.textView.text = (line as TitleLine).text
+            is ContentViewHolder.Title3 -> holder.binding.textView.text = (line as TitleLine).text
+            is ContentViewHolder.Link -> {
+                val text = if ((line as LinkLine).label.isNotEmpty()) line.label else line.url
+                val underlined = SpannableString(text)
+                underlined.setSpan(UnderlineSpan(), 0, underlined.length, 0)
+                holder.binding.textView.text = underlined
+                holder.binding.root.setOnClickListener { listener.onLinkClick(line.url) }
+            }
+            else -> {}
+        }
+    }
+
+    override fun getItemCount(): Int = content.size
+
+    fun setContent(content: List<Line>) {
+        this.content = content
+        notifyDataSetChanged()
+    }
+
+    sealed class ContentViewHolder(view: View) : RecyclerView.ViewHolder(view) {
+        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)
+        class Title3(val binding: GemtextTitle3Binding) : ContentViewHolder(binding.root)
+        class Link(val binding: GemtextLinkBinding) : ContentViewHolder(binding.root)
+        class PreFence(val binding: GemtextEmptyBinding) : ContentViewHolder(binding.root)
+        class PreText(val binding: GemtextPreformattedBinding) : ContentViewHolder(binding.root)
+        class Blockquote(val binding: GemtextBlockquoteBinding) : ContentViewHolder(binding.root)
+        class ListItem(val binding: GemtextListItemBinding) : ContentViewHolder(binding.root)
+    }
+
+    companion object {
+        const val TAG = "ContentRecycler"
+        const val TYPE_EMPTY = 0
+        const val TYPE_PARAGRAPH = 1
+        const val TYPE_TITLE_1 = 2
+        const val TYPE_TITLE_2 = 3
+        const val TYPE_TITLE_3 = 4
+        const val TYPE_LINK = 5
+        const val TYPE_PRE_FENCE = 6
+        const val TYPE_PRE_TEXT = 7
+        const val TYPE_BLOCKQUOTE = 8
+        const val TYPE_LIST_ITEM = 9
+    }
+}

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

@@ -7,16 +7,16 @@ import java.nio.ByteBuffer
 import java.nio.CharBuffer
 import java.nio.charset.Charset
 
-open class Line
+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 PreFenceLine(val caption: String) : Line()
-class PreTextLine(val text: String) : Line()
-class BlockquoteLine(val text: String) : Line()
-class ListItemLine(val text: String) : 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 PreFenceLine(val caption: String) : Line
+class PreTextLine(val text: String) : Line
+class BlockquoteLine(val text: String) : Line
+class ListItemLine(val text: String) : Line
 
 fun parseData(
     inChannel: Channel<ByteArray>,
@@ -60,5 +60,3 @@ private fun parseLine(line: CharBuffer, isPreformatted: Boolean): Line =
     }
 
 private fun getCharsFrom(line: CharBuffer, index: Int) = line.substring(index).removePrefix(" ")
-
-private const val TAG = "Gemtext"

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

@@ -2,6 +2,8 @@ package dev.lowrespalmtree.comet
 
 import android.annotation.SuppressLint
 import android.app.Activity
+import android.content.Intent
+import android.content.Intent.ACTION_VIEW
 import android.net.Uri
 import android.os.Bundle
 import android.util.Log
@@ -13,15 +15,17 @@ import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
+import androidx.recyclerview.widget.LinearLayoutManager
 import dev.lowrespalmtree.comet.databinding.ActivityMainBinding
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
-import java.nio.ByteBuffer
+import java.net.UnknownHostException
 import java.nio.charset.Charset
 
-class MainActivity : AppCompatActivity() {
+class MainActivity : AppCompatActivity(), ContentAdapter.ContentAdapterListen {
     private lateinit var binding: ActivityMainBinding
     private lateinit var pageViewModel: PageViewModel
+    private lateinit var adapter: ContentAdapter
 
     @SuppressLint("SetTextI18n")
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -30,10 +34,13 @@ class MainActivity : AppCompatActivity() {
         setContentView(binding.root)
 
         pageViewModel = ViewModelProvider(this)[PageViewModel::class.java]
+        adapter = ContentAdapter(listOf(), this)
+        binding.contentRecycler.layoutManager = LinearLayoutManager(this)
+        binding.contentRecycler.adapter = adapter
 
         binding.addressBar.setOnEditorActionListener { view, actionId, _ ->
             if (actionId == EditorInfo.IME_ACTION_DONE) {
-                pageViewModel.sendRequest(view.text.toString())
+                openUrl(view.text.toString())
                 val imm = getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
                 imm.hideSoftInputFromWindow(view.windowToken, 0)
                 view.clearFocus()
@@ -43,37 +50,64 @@ class MainActivity : AppCompatActivity() {
             }
         }
 
-        pageViewModel.sourceLiveData.observe(this, {
-            binding.sourceBlock.text = it
-        })
-        pageViewModel.alertLiveData.observe(this, {
+        pageViewModel.linesLiveData.observe(this, { adapter.setContent(it) })
+        pageViewModel.alertLiveData.observe(this, { alert(it) })
+    }
+
+    override fun onLinkClick(url: String) {
+        val base = binding.addressBar.text.toString()
+        openUrl(url, base = if (base.isNotEmpty()) base else null)
+    }
+
+    private fun openUrl(url: String, base: String? = null) {
+        var uri = Uri.parse(url)
+        if (!uri.isAbsolute) {
+            uri = if (!base.isNullOrEmpty()) joinUrls(base, url) else toGeminiUri(uri)
+            Log.d(TAG, "openUrl: '$url' - '$base' - '$uri'")
+            Log.d(TAG, "openUrl: ${uri.authority} - ${uri.path} - ${uri.query}")
+            binding.addressBar.setText(uri.toString())
+        }
+
+        when (uri.scheme) {
+            "gemini" -> pageViewModel.sendGeminiRequest(uri)
+            else -> startActivity(Intent(ACTION_VIEW, uri))
+        }
+    }
+
+    private fun alert(message: String) {
         AlertDialog.Builder(this)
             .setTitle(R.string.alert_title)
-                .setMessage(it)
+            .setMessage(message)
             .create()
             .show()
-        })
     }
 
     class PageViewModel : ViewModel() {
-        var source = ""
-        val sourceLiveData: MutableLiveData<String> by lazy { MutableLiveData<String>() }
+        private var lines = ArrayList<Line>()
+        val linesLiveData: MutableLiveData<List<Line>> by lazy { MutableLiveData<List<Line>>() }
         val alertLiveData: MutableLiveData<String> by lazy { MutableLiveData<String>() }
 
-        fun sendRequest(url: String) {
-            Log.d(TAG, "sendRequest: $url")
-            source = ""
+        /**
+         * Perform a request against this URI.
+         *
+         * The URI must be valid, absolute and with a gemini scheme.
+         */
+        fun sendGeminiRequest(uri: Uri) {
+            Log.d(TAG, "sendRequest: $uri")
             viewModelScope.launch(Dispatchers.IO) {
-                val uri = Uri.parse(url)
-                if (uri.scheme != "gemini") {
-                    alertLiveData.postValue("Can't process scheme \"${uri.scheme}\".")
-                    return@launch
-                }
-
+                val response = try {
                     val request = Request(uri)
                     val socket = request.connect()
                     val channel = request.proceed(socket, this)
-                val response = Response.from(channel, viewModelScope)
+                    Response.from(channel, viewModelScope)
+                } catch (e: UnknownHostException) {
+                    alertLiveData.postValue("Unknown host \"${uri.authority}\".")
+                    return@launch
+                } catch (e: Exception) {
+                    Log.e(TAG, "sendGeminiRequest coroutine: ${e.stackTraceToString()}")
+                    alertLiveData.postValue("Oops! Whatever we tried to do failed!")
+                    return@launch
+                }
                 if (response == null) {
                     alertLiveData.postValue("Can't parse server response.")
                     return@launch
@@ -85,22 +119,15 @@ class MainActivity : AppCompatActivity() {
                     else -> alertLiveData.postValue("Can't handle code ${response.code}.")
                 }
             }
+
         }
 
         private suspend fun handleRequestSuccess(response: Response) {
+            lines.clear()
             val charset = Charset.defaultCharset()
             for (line in parseData(response.data, charset, viewModelScope)) {
-                when (line) {
-                    is EmptyLine -> { source += "\n" }
-                    is ParagraphLine -> { source += line.text + "\n" }
-                    is TitleLine -> { source += "TTL-${line.level} ${line.text}\n" }
-                    is LinkLine -> { source += "LNK ${line.url} + ${line.label}\n" }
-                    is PreFenceLine -> { source += "PRE ${line.caption}\n" }
-                    is PreTextLine -> { source += line.text + "\n" }
-                    is BlockquoteLine -> { source += "QUO ${line.text}\n" }
-                    is ListItemLine -> { source += "LST ${line.text}\n" }
-                }
-                sourceLiveData.postValue(source)
+                lines.add(line)
+                linesLiveData.postValue(lines)
             }
         }
     }

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

@@ -0,0 +1,88 @@
+package dev.lowrespalmtree.comet
+
+import android.net.Uri
+import android.util.Log
+
+/**
+ * Transform a relative URI to an absolute Gemini URI
+ *
+ * This is mostly to translate user-friendly URLs such as "medusae.space" into
+ * "gemini://medusae.space". This assumes that the Uri parsing put what the user probably intended
+ * as the hostname into the path field instead of the authority. Thus, it will NOT merely translate
+ * any absolute URI into a gemini-scheme URI.
+ */
+fun toGeminiUri(uri: Uri): Uri =
+    Uri.Builder()
+        .scheme("gemini")
+        .authority(uri.path)
+        .query(uri.query)
+        .fragment(uri.fragment)
+        .build()
+
+/** Return the URI obtained from considering the relative part of an URI wrt/ a base URI. */
+fun joinUrls(base: String, relative: String): Uri {
+    val baseUri = Uri.parse(base)
+    val relUri = Uri.parse(relative)
+    val newPath = removeDotSegments(
+        if (relative.startsWith("/")) {
+            relUri.path ?: ""
+        } else {
+            removeLastSegment(
+                baseUri.path ?: ""
+            ) + "/" +
+                    (relUri.path ?: "")
+        }
+    )
+    return Uri.Builder()
+        .scheme(baseUri.scheme)
+        .authority(baseUri.authority)
+        .path(newPath)
+        .query(relUri.query)
+        .fragment(relUri.fragment)
+        .build()
+}
+
+/** Remove all the sneaky dot segments from the path. */
+internal fun removeDotSegments(path: String): String {
+    var output = ""
+    var slice = path
+    while (slice.isNotEmpty()) {
+        if (slice.startsWith("../")) {
+            slice = slice.substring(3)
+        } else if (slice.startsWith("./") || slice.startsWith("/./")) {
+            slice = slice.substring(2)
+        } else if (slice == "/.") {
+            slice = "/"
+        } else if (slice.startsWith("/../")) {
+            slice = "/" + slice.substring(4)
+            output = removeLastSegment(output)
+        } else if (slice == "/..") {
+            slice = "/"
+            output = removeLastSegment(output)
+        } else if (slice == "." || slice == "..") {
+            slice = ""
+        } else {
+            val (firstSegment, remaining) = popFirstSegment(slice)
+            output += firstSegment
+            slice = remaining
+        }
+    }
+    return output
+}
+
+/** Remove the last segment of that path, including preceding "/" if any. */
+internal fun removeLastSegment(path: String): String {
+    val lastSlashIndex = path.indexOfLast { it == '/' }
+    return if (lastSlashIndex > -1) path.slice(0 until lastSlashIndex) else path
+}
+
+/** Return first segment and the rest. */
+internal fun popFirstSegment(path: String): Pair<String, String> {
+    if (path.isEmpty())
+        return Pair(path, "")
+    var nextSlash = path.substring(1).indexOf("/")
+    if (nextSlash == -1)
+        return Pair(path, "")
+    nextSlash++
+    return Pair(path.substring(0, nextSlash), path.substring(nextSlash))
+}

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

@@ -38,26 +38,14 @@
     <androidx.core.widget.NestedScrollView
         android:id="@+id/scroll_view"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_height="wrap_content"
         app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior">
 
-        <LinearLayout
+        <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/content_recycler"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
-            android:orientation="vertical">
-
-            <TextView
-                android:id="@+id/source_block"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                android:layout_marginStart="16dp"
-                android:layout_marginEnd="16dp"
-                android:text=""
-                android:textAlignment="textStart"
-                app:layout_constraintEnd_toEndOf="parent"
-                app:layout_constraintStart_toStartOf="parent" />
-
-        </LinearLayout>
+            android:orientation="vertical" />
     </androidx.core.widget.NestedScrollView>
 
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

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

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/text_view"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="@color/teal_200" />

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

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Space xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="8dp"
+    android:background="@color/black">
+</Space>

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

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/text_view"
+    android:textSize="16sp"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:paddingStart="8dp"
+    android:paddingEnd="8dp"
+    android:paddingTop="4dp"
+    android:paddingBottom="4dp"
+    android:background="@color/teal_200"
+    android:textIsSelectable="false" />

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

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/text_view"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="@color/teal_200" />

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

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/text_view"
+    android:textSize="16sp"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:paddingStart="8dp"
+    android:paddingEnd="8dp"
+    android:paddingTop="4dp"
+    android:paddingBottom="4dp"
+    android:background="@color/teal_200" />

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

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/text_view"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="@color/teal_200" />

app/src/main/res/layout/gemtext_title1.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/text_view"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:textSize="30sp"
+    android:textStyle="bold"
+    android:paddingStart="8dp"
+    android:paddingEnd="8dp"
+    android:paddingTop="16dp"
+    android:paddingBottom="4dp"
+    android:background="@color/teal_700" />

app/src/main/res/layout/gemtext_title2.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/text_view"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:textSize="24sp"
+    android:textStyle="bold"
+    android:paddingStart="8dp"
+    android:paddingEnd="8dp"
+    android:paddingTop="8dp"
+    android:paddingBottom="4dp"
+    android:background="@color/teal_700" />

app/src/main/res/layout/gemtext_title3.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/text_view"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:textSize="18sp"
+    android:textStyle="bold"
+    android:paddingStart="8dp"
+    android:paddingEnd="8dp"
+    android:paddingTop="8dp"
+    android:paddingBottom="4dp"
+    android:background="@color/teal_700" />

app/src/test/java/dev/lowrespalmtree/comet/ExampleUnitTest.kt

@@ -1,17 +0,0 @@
-package dev.lowrespalmtree.comet
-
-import org.junit.Test
-
-import org.junit.Assert.*
-
-/**
- * Example local unit test, which will execute on the development machine (host).
- *
- * See [testing documentation](http://d.android.com/tools/testing).
- */
-class ExampleUnitTest {
-    @Test
-    fun addition_isCorrect() {
-        assertEquals(4, 2 + 2)
-    }
-}