Better markdown handling

This commit fixes some of the issues with markdown rendering:
- Switch to Textview instead of RecyclerView to render Markdown
- Import Spoiler renderer from Jebora
- Import Script renderer from Jebora
- Clean out markwon plugins that were specific to reddit

Closes #130 #172 #217 and #273

app/build.gradle

@@ -245,6 +245,7 @@ dependencies {
     implementation "io.noties.markwon:simple-ext:$markwonVersion"
     implementation "io.noties.markwon:inline-parser:$markwonVersion"
     implementation "io.noties.markwon:image-glide:$markwonVersion"
+    implementation "io.noties.markwon:html:$markwonVersion"
     implementation 'com.atlassian.commonmark:commonmark-ext-gfm-tables:0.14.0'
     implementation 'me.saket:better-link-movement-method:2.2.0'
 

app/src/main/java/eu/toldi/infinityforlemmy/adapters/PostDetailRecyclerViewAdapter.java

@@ -681,10 +681,7 @@ public class PostDetailRecyclerViewAdapter extends RecyclerView.Adapter<Recycler
 
             if (mPost.getSelfText() != null && !mPost.getSelfText().equals("")) {
                 ((PostDetailBaseViewHolder) holder).contentMarkdownView.setVisibility(View.VISIBLE);
-                ((PostDetailBaseViewHolder) holder).contentMarkdownView.setAdapter(mMarkwonAdapter);
+                mPostDetailMarkwon.setMarkdown(((PostDetailBaseViewHolder) holder).contentMarkdownView,mPost.getSelfText());
-                mMarkwonAdapter.setMarkdown(mPostDetailMarkwon, mPost.getSelfText());
-                // noinspection NotifyDataSetChanged
-                mMarkwonAdapter.notifyDataSetChanged();
             }
 
             if (holder instanceof PostDetailBaseVideoAutoplayViewHolder) {
@@ -1216,7 +1213,7 @@ public class PostDetailRecyclerViewAdapter extends RecyclerView.Adapter<Recycler
         CustomTextView flairTextView;
         TextView awardsTextView;
         TextView upvoteRatioTextView;
-        RecyclerView contentMarkdownView;
+        TextView contentMarkdownView;
         ConstraintLayout bottomConstraintLayout;
         MaterialButton upvoteButton;
         TextView scoreTextView;
@@ -1248,7 +1245,7 @@ public class PostDetailRecyclerViewAdapter extends RecyclerView.Adapter<Recycler
                          CustomTextView flairTextView,
                          TextView awardsTextView,
                          TextView upvoteRatioTextView,
-                         RecyclerView contentMarkdownView,
+                         TextView contentMarkdownView,
                          ConstraintLayout bottomConstraintLayout,
                          MaterialButton upvoteButton,
                          TextView scoreTextView,
@@ -1344,7 +1341,7 @@ public class PostDetailRecyclerViewAdapter extends RecyclerView.Adapter<Recycler
                 mActivity.startActivity(intent);
             });
 
-            contentMarkdownView.setLayoutManager(new SwipeLockLinearLayoutManager(mActivity, new SwipeLockInterface() {
+            /*contentMarkdownView.setLayoutManager(new SwipeLockLinearLayoutManager(mActivity, new SwipeLockInterface() {
                 @Override
                 public void lockSwipe() {
                     ((ViewPostDetailActivity) mActivity).lockSwipeRightToGoBack();
@@ -1354,7 +1351,7 @@ public class PostDetailRecyclerViewAdapter extends RecyclerView.Adapter<Recycler
                 public void unlockSwipe() {
                     ((ViewPostDetailActivity) mActivity).unlockSwipeRightToGoBack();
                 }
-            }));
+            }));*/
 
             upvoteButton.setOnClickListener(view -> {
                 if (mPost.isArchived()) {
@@ -1827,7 +1824,7 @@ public class PostDetailRecyclerViewAdapter extends RecyclerView.Adapter<Recycler
                                                      ImageView pauseButton,
                                                      ImageView playButton,
                                                      DefaultTimeBar progressBar,
-                                                     RecyclerView contentMarkdownView,
+                                                     TextView contentMarkdownView,
                                                      ConstraintLayout bottomConstraintLayout,
                                                      MaterialButton upvoteButton,
                                                      TextView scoreTextView,

app/src/main/java/eu/toldi/infinityforlemmy/markdown/MarkdownUtils.java

@@ -18,6 +18,8 @@ import eu.toldi.infinityforlemmy.customviews.CustomMarkwonAdapter;
 import io.noties.markwon.Markwon;
 import io.noties.markwon.MarkwonPlugin;
 import io.noties.markwon.ext.strikethrough.StrikethroughPlugin;
+import io.noties.markwon.ext.tables.TablePlugin;
+import io.noties.markwon.html.HtmlPlugin;
 import io.noties.markwon.image.glide.GlideImagesPlugin;
 import io.noties.markwon.inlineparser.BangInlineProcessor;
 import io.noties.markwon.inlineparser.HtmlInlineProcessor;
@@ -44,35 +46,27 @@ public class MarkdownUtils {
         Markwon result;
         if (dataSaverEnabled) {
             result = Markwon.builder(context)
-                    .usePlugin(MarkwonInlineParserPlugin.create(plugin -> {
-                        plugin.excludeInlineProcessor(HtmlInlineProcessor.class);
-                    }))
                     .usePlugin(miscPlugin)
-                    .usePlugin(SuperscriptPlugin.create())
+                    .usePlugin(new ScriptRewriteSupportPlugin())
-                    .usePlugin(SpoilerParserPlugin.create(markdownColor, spoilerBackgroundColor))
+                    .usePlugin(new MarkwonSpoilerPlugin(true))
-                    .usePlugin(RedditHeadingPlugin.create())
+                    .usePlugin(HtmlPlugin.create())
                     .usePlugin(StrikethroughPlugin.create())
-                    .usePlugin(MovementMethodPlugin.create(new SpoilerAwareMovementMethod()
+                    .usePlugin(TablePlugin.create(context))
-                            .setOnLinkLongClickListener(onLinkLongClickListener)))
                     .usePlugin(LinkifyPlugin.create(Linkify.WEB_URLS))
-                    .usePlugin(TableEntryPlugin.create(context))
                     .usePlugin(new MarkwonLemmyLinkPlugin())
                     .build();
         } else {
             result = Markwon.builder(context)
                     .usePlugin(GlideImagesPlugin.create(new GlideMarkdownLoader(mGlide)))
-                    .usePlugin(MarkwonInlineParserPlugin.create(plugin -> {
-                        plugin.excludeInlineProcessor(HtmlInlineProcessor.class);
-                    }))
                     .usePlugin(miscPlugin)
-                    .usePlugin(SuperscriptPlugin.create())
+                    .usePlugin(new ScriptRewriteSupportPlugin())
-                    .usePlugin(SpoilerParserPlugin.create(markdownColor, spoilerBackgroundColor))
+                    .usePlugin(new MarkwonSpoilerPlugin(true))
-                    .usePlugin(RedditHeadingPlugin.create())
+                    .usePlugin(HtmlPlugin.create())
                     .usePlugin(StrikethroughPlugin.create())
                     .usePlugin(MovementMethodPlugin.create(new SpoilerAwareMovementMethod()
                             .setOnLinkLongClickListener(onLinkLongClickListener)))
                     .usePlugin(LinkifyPlugin.create(Linkify.WEB_URLS))
-                    .usePlugin(TableEntryPlugin.create(context))
+                    .usePlugin(TablePlugin.create(context))
                     .usePlugin(ClickableGlideImagesPlugin.create(context))
                     .usePlugin(new MarkwonLemmyLinkPlugin())
                     .build();
@@ -87,32 +81,27 @@ public class MarkdownUtils {
         Markwon result;
         if (dataSaverEnabled) {
             result = Markwon.builder(context)
-                    .usePlugin(MarkwonInlineParserPlugin.create(plugin -> {
-                        plugin.excludeInlineProcessor(HtmlInlineProcessor.class);
-                    }))
                     .usePlugin(miscPlugin)
-                    .usePlugin(SuperscriptPlugin.create())
+                    .usePlugin(new ScriptRewriteSupportPlugin())
-                    .usePlugin(RedditHeadingPlugin.create())
+                    .usePlugin(new MarkwonSpoilerPlugin(true))
+                    .usePlugin(HtmlPlugin.create())
                     .usePlugin(StrikethroughPlugin.create())
                     .usePlugin(MovementMethodPlugin.create(new SpoilerAwareMovementMethod()
                             .setOnLinkLongClickListener(onLinkLongClickListener)))
                     .usePlugin(LinkifyPlugin.create(Linkify.WEB_URLS))
-                    .usePlugin(TableEntryPlugin.create(context))
+                    .usePlugin(TablePlugin.create(context))
                     .usePlugin(new MarkwonLemmyLinkPlugin())
                     .build();
         } else {
             result = Markwon.builder(context)
-                    .usePlugin(MarkwonInlineParserPlugin.create(plugin -> {
-                        plugin.excludeInlineProcessor(HtmlInlineProcessor.class);
-                    }))
                     .usePlugin(miscPlugin)
-                    .usePlugin(SuperscriptPlugin.create())
+                    .usePlugin(new ScriptRewriteSupportPlugin())
-                    .usePlugin(RedditHeadingPlugin.create())
+                    .usePlugin(new MarkwonSpoilerPlugin(true))
-                    .usePlugin(StrikethroughPlugin.create())
+                    .usePlugin(HtmlPlugin.create())
                     .usePlugin(MovementMethodPlugin.create(new SpoilerAwareMovementMethod()
                             .setOnLinkLongClickListener(onLinkLongClickListener)))
                     .usePlugin(LinkifyPlugin.create(Linkify.WEB_URLS))
-                    .usePlugin(TableEntryPlugin.create(context))
+                    .usePlugin(TablePlugin.create(context))
                     .usePlugin(GlideImagesPlugin.create(context.getApplicationContext()))
                     .usePlugin(new MarkwonLemmyLinkPlugin())
                     .build();

app/src/main/kotlin/eu/toldi/infinityforlemmy/markdown/MarkwonSpoilerPlugin.kt

@@ -0,0 +1,158 @@
+package eu.toldi.infinityforlemmy.markdown
+
+import android.text.SpannableStringBuilder
+import android.text.Spanned
+import android.text.TextPaint
+import android.text.style.ClickableSpan
+import android.util.Log
+import android.view.View
+import android.widget.TextView
+import io.noties.markwon.AbstractMarkwonPlugin
+import io.noties.markwon.MarkwonPlugin
+import io.noties.markwon.MarkwonVisitor
+import io.noties.markwon.core.CorePlugin
+import io.noties.markwon.image.AsyncDrawableScheduler
+
+// Source copied from https://github.com/LemmyNet/jerboa/blob/main/app/src/main/java/com/jerboa/util/markwon/MarkwonSpoilerPlugin.kt
+
+data class SpoilerTitleSpan(
+    val title: CharSequence,
+)
+
+class SpoilerCloseSpan
+
+class MarkwonSpoilerPlugin(
+    val enableInteraction: Boolean,
+) : AbstractMarkwonPlugin() {
+    override fun configure(registry: MarkwonPlugin.Registry) {
+        registry.require(CorePlugin::class.java) {
+            it.addOnTextAddedListener(
+                SpoilerTextAddedListener(),
+            )
+        }
+    }
+
+    private class SpoilerTextAddedListener : CorePlugin.OnTextAddedListener {
+        override fun onTextAdded(
+            visitor: MarkwonVisitor,
+            text: String,
+            start: Int,
+        ) {
+            val spoilerTitleRegex = Regex("(:::\\s+spoiler\\s+)(.*)")
+            // Find all spoiler "start" lines
+            val spoilerTitles = spoilerTitleRegex.findAll(text)
+
+            for (match in spoilerTitles) {
+                val spoilerTitle = match.groups[2]!!.value
+                visitor.builder().setSpan(
+                    SpoilerTitleSpan(spoilerTitle),
+                    start,
+                    start + match.groups[2]!!.range.last,
+                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE,
+                )
+            }
+
+            val spoilerCloseRegex = Regex("^(?!.*spoiler).*:::")
+            // Find all spoiler "end" lines
+            val spoilerCloses = spoilerCloseRegex.findAll(text)
+            for (match in spoilerCloses) {
+                visitor
+                    .builder()
+                    .setSpan(SpoilerCloseSpan(), start, start + 3, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)
+            }
+        }
+    }
+
+    override fun afterSetText(textView: TextView) {
+        try {
+            val spanned = SpannableStringBuilder(textView.text)
+            val spoilerTitleSpans =
+                spanned.getSpans(0, spanned.length, SpoilerTitleSpan::class.java)
+            val spoilerCloseSpans =
+                spanned.getSpans(0, spanned.length, SpoilerCloseSpan::class.java)
+
+            spoilerTitleSpans.sortBy { spanned.getSpanStart(it) }
+            spoilerCloseSpans.sortBy { spanned.getSpanStart(it) }
+
+            spoilerTitleSpans.forEachIndexed { index, spoilerTitleSpan ->
+                val spoilerStart = spanned.getSpanStart(spoilerTitleSpan)
+
+                var spoilerEnd = spanned.length
+                if (index < spoilerCloseSpans.size) {
+                    val spoilerCloseSpan = spoilerCloseSpans[index]
+                    spoilerEnd = spanned.getSpanEnd(spoilerCloseSpan)
+                }
+
+                var open = false
+                // The space at the end is necessary for the lengths to be the same
+                // This reduces complexity as else it would need complex logic to determine the replacement length
+                val getSpoilerTitle = { openParam: Boolean ->
+                    if (openParam) "▼ ${spoilerTitleSpan.title}\n" else "▶ ${spoilerTitleSpan.title}\u200B"
+                }
+
+                val spoilerTitle = getSpoilerTitle(false)
+
+                val spoilerContent =
+                    spanned.subSequence(
+                        spanned.getSpanEnd(spoilerTitleSpan) + 1,
+                        spoilerEnd - 3,
+                    ) as SpannableStringBuilder
+
+                // Remove spoiler content from span
+                spanned.replace(spoilerStart, spoilerEnd, spoilerTitle)
+                // Set span block title
+                spanned.setSpan(
+                    spoilerTitle,
+                    spoilerStart,
+                    spoilerStart + spoilerTitle.length,
+                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE,
+                )
+
+                val wrapper =
+                    object : ClickableSpan() {
+                        override fun onClick(p0: View) {
+                            if (enableInteraction) {
+                                textView.cancelPendingInputEvents()
+                                open = !open
+
+                                val spoilerStartCurrent = spanned.getSpanStart(spoilerTitle)
+
+                                spanned.replace(
+                                    spoilerStartCurrent,
+                                    spoilerStartCurrent + spoilerTitle.length,
+                                    getSpoilerTitle(open),
+                                )
+                                if (open) {
+                                    spanned.insert(spoilerStartCurrent + spoilerTitle.length, spoilerContent)
+                                } else {
+                                    spanned.replace(
+                                        spoilerStartCurrent + spoilerTitle.length,
+                                        spoilerStartCurrent + spoilerTitle.length + spoilerContent.length,
+                                        "",
+                                    )
+                                }
+
+                                textView.text = spanned
+                                AsyncDrawableScheduler.schedule(textView)
+                            }
+                        }
+
+                        override fun updateDrawState(ds: TextPaint) {
+                        }
+                    }
+
+                // Set spoiler block type as ClickableSpan
+                spanned.setSpan(
+                    wrapper,
+                    spoilerStart,
+                    spoilerStart + spoilerTitle.length,
+                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE,
+                )
+
+                textView.text = spanned
+            }
+        } catch (e: Exception) {
+            Log.w("jerboa", "Failed to parse spoiler tag. Format incorrect")
+        }
+    }
+}

app/src/main/kotlin/eu/toldi/infinityforlemmy/markdown/ScriptRewriteSupportPlugin.kt

@@ -0,0 +1,26 @@
+package eu.toldi.infinityforlemmy.markdown
+
+import io.noties.markwon.AbstractMarkwonPlugin
+
+// Source copied from https://github.com/LemmyNet/jerboa/blob/main/app/src/main/java/com/jerboa/util/markwon/ScriptRewriteSupportPlugin.kt
+
+class ScriptRewriteSupportPlugin : AbstractMarkwonPlugin() {
+    override fun processMarkdown(markdown: String): String =
+        super.processMarkdown(
+            if (markdown.contains("^") || markdown.contains("~")) {
+                rewriteLemmyScriptToMarkwonScript(markdown)
+            } else { // Fast path: if there are no markdown characters, we don't need to do anything
+                markdown
+            },
+        )
+
+    companion object {
+        val SUPERSCRIPT_RGX = Regex("""\^([^\n^]+)\^""")
+        val SUBSCRIPT_RGX = Regex("""(?<!~)~([^\n~]+)~""")
+
+        fun rewriteLemmyScriptToMarkwonScript(text: String): String =
+            text
+                .replace(SUPERSCRIPT_RGX, "<sup>$1</sup>")
+                .replace(SUBSCRIPT_RGX, "<sub>$1</sub>")
+    }
+}

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

@@ -256,13 +256,13 @@
         android:src="@drawable/ic_link"
         android:visibility="gone" />
 
-    <androidx.recyclerview.widget.RecyclerView
+    <TextView
         android:id="@+id/content_markdown_view_item_post_detail_gallery"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="8dp"
-        android:layout_marginStart="8dp"
+        android:layout_marginStart="16dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="16dp"
         android:visibility="gone"
         android:nestedScrollingEnabled="false" />
 

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

@@ -262,13 +262,13 @@
 
     </RelativeLayout>
 
-    <androidx.recyclerview.widget.RecyclerView
+    <TextView
         android:id="@+id/content_markdown_view_item_post_detail_image_and_gif_autoplay"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="8dp"
-        android:layout_marginStart="8dp"
+        android:layout_marginStart="16dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="16dp"
         android:visibility="gone"
         android:nestedScrollingEnabled="false" />
 

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

@@ -271,13 +271,13 @@
 
     </RelativeLayout>
 
-    <androidx.recyclerview.widget.RecyclerView
+    <TextView
         android:id="@+id/content_markdown_view_item_post_detail_link"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="8dp"
-        android:layout_marginStart="8dp"
+        android:layout_marginStart="16dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="16dp"
         android:visibility="gone"
         android:nestedScrollingEnabled="false" />
 

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

@@ -106,17 +106,17 @@
         android:focusable="true"
         android:longClickable="true" />
 
-    <androidx.recyclerview.widget.RecyclerView
+    <TextView
         android:id="@+id/content_markdown_view_item_post_detail_no_preview"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="8dp"
-        android:layout_marginStart="8dp"
+        android:layout_marginStart="16dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="16dp"
         android:visibility="gone"
         android:nestedScrollingEnabled="false" >
 
-    </androidx.recyclerview.widget.RecyclerView>
+    </TextView>
 
     <androidx.constraintlayout.widget.ConstraintLayout
         android:layout_width="match_parent"

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

@@ -106,17 +106,17 @@
         android:textIsSelectable="true"
         android:textSize="?attr/title_font_18" />
 
-    <androidx.recyclerview.widget.RecyclerView
+    <TextView
         android:id="@+id/content_markdown_view_item_post_detail_text"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="8dp"
-        android:layout_marginStart="8dp"
+        android:layout_marginStart="16dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="16dp"
         android:visibility="gone"
         android:nestedScrollingEnabled="false" >
 
-    </androidx.recyclerview.widget.RecyclerView>
+    </TextView>
 
     <androidx.constraintlayout.widget.ConstraintLayout
         android:layout_width="match_parent"

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

@@ -274,13 +274,13 @@
 
     </RelativeLayout>
 
-    <androidx.recyclerview.widget.RecyclerView
+    <TextView
         android:id="@+id/content_markdown_view_item_post_detail_video_and_gif_preview"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="8dp"
-        android:layout_marginStart="8dp"
+        android:layout_marginStart="16dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="16dp"
         android:visibility="gone"
         android:nestedScrollingEnabled="false" />
 

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

@@ -255,13 +255,13 @@
 
     </com.google.android.exoplayer2.ui.AspectRatioFrameLayout>
 
-    <androidx.recyclerview.widget.RecyclerView
+    <TextView
         android:id="@+id/content_markdown_view_item_post_detail_video_autoplay"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="8dp"
-        android:layout_marginStart="8dp"
+        android:layout_marginStart="16dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="16dp"
         android:visibility="gone"
         android:nestedScrollingEnabled="false" />
 

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

@@ -258,13 +258,13 @@
 
     </com.google.android.exoplayer2.ui.AspectRatioFrameLayout>
 
-    <androidx.recyclerview.widget.RecyclerView
+    <TextView
         android:id="@+id/content_markdown_view_item_post_detail_video_autoplay"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="8dp"
-        android:layout_marginStart="8dp"
+        android:layout_marginStart="16dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="16dp"
         android:visibility="gone"
         android:nestedScrollingEnabled="false" />