Add comments for the EventHtmlRenderer file

vector/src/main/java/im/vector/app/features/html/EventHtmlRenderer.kt

@@ -14,6 +14,15 @@
  * limitations under the License.
  */
 
+/*
+ * This file renders the formatted_body of an event to a formatted Android Spannable.
+ * The core of this work is done with Markwon, a general-purpose Markdown+HTML formatter.
+ * Since formatted_body is HTML only, Markwon is configured to only handle HTML, not Markdown.
+ * The EventHtmlRenderer class is next used in the method buildFormattedTextItem
+ * in the file MessageItemFactory.kt.
+ * Effectively, this is used in the chat messages view and the room list message previews.
+ */
+
 package im.vector.app.features.html
 
 import android.content.Context
@@ -30,6 +39,7 @@ import io.noties.markwon.PrecomputedFutureTextSetterCompat
 import io.noties.markwon.ext.latex.JLatexMathPlugin
 import io.noties.markwon.ext.latex.JLatexMathTheme
 import io.noties.markwon.html.HtmlPlugin
+import io.noties.markwon.inlineparser.EntityInlineProcessor
 import io.noties.markwon.inlineparser.HtmlInlineProcessor
 import io.noties.markwon.inlineparser.MarkwonInlineParser
 import io.noties.markwon.inlineparser.MarkwonInlineParserPlugin
@@ -54,8 +64,10 @@ class EventHtmlRenderer @Inject constructor(
             .usePlugin(HtmlPlugin.create(htmlConfigure))
 
     private val markwon = if (vectorPreferences.latexMathsIsEnabled()) {
+        // If latex maths is enabled in app preferences, refomat it so Markwon recognises it
+        // It needs to be in this specific format: https://noties.io/Markwon/docs/v4/ext-latex
         builder
-                .usePlugin(object : AbstractMarkwonPlugin() { // Markwon expects maths to be in a specific format: https://noties.io/Markwon/docs/v4/ext-latex
+                .usePlugin(object : AbstractMarkwonPlugin() {
                     override fun processMarkdown(markdown: String): String {
                         return markdown
                                 .replace(Regex("""<span\s+data-mx-maths="([^"]*)">.*?</span>""")) { matchResult ->
@@ -86,6 +98,9 @@ class EventHtmlRenderer @Inject constructor(
         )
         .usePlugin(object : AbstractMarkwonPlugin() {
             override fun configureParser(builder: Parser.Builder) {
+                /* Configuring the Markwon block formatting processor.
+                 * Default settings are all Markdown blocks. Turn those off.
+                 */
                 builder.enabledBlockTypes(kotlin.collections.emptySet())
             }
         })