From a257d9b769f4dd86f6509110bebc16ae90877ea5 Mon Sep 17 00:00:00 2001
From: Konrad Pozniak <connyduck@users.noreply.github.com>
Date: Mon, 14 Mar 2022 14:43:00 +0100
Subject: [PATCH] correctly render whitespace in posts (#2383)

* correctly preserve whitespace in posts

* use extension function to convert from Spanned to Html

* improve comment
---
 .../tusky/json/SpannedTypeAdapter.kt          | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/app/src/main/java/com/keylesspalace/tusky/json/SpannedTypeAdapter.kt b/app/src/main/java/com/keylesspalace/tusky/json/SpannedTypeAdapter.kt
index ceb96f4a2..60af61342 100644
--- a/app/src/main/java/com/keylesspalace/tusky/json/SpannedTypeAdapter.kt
+++ b/app/src/main/java/com/keylesspalace/tusky/json/SpannedTypeAdapter.kt
@@ -19,6 +19,7 @@ import android.text.Spanned
 import android.text.SpannedString
 import androidx.core.text.HtmlCompat
 import androidx.core.text.parseAsHtml
+import androidx.core.text.toHtml
 import com.google.gson.JsonDeserializationContext
 import com.google.gson.JsonDeserializer
 import com.google.gson.JsonElement
@@ -32,12 +33,22 @@ import java.lang.reflect.Type
 class SpannedTypeAdapter : JsonDeserializer<Spanned>, JsonSerializer<Spanned?> {
     @Throws(JsonParseException::class)
     override fun deserialize(json: JsonElement, typeOfT: Type, context: JsonDeserializationContext): Spanned {
-        /* Html.fromHtml returns trailing whitespace if the html ends in a </p> tag, which
-         * all status contents do, so it should be trimmed. */
-        return json.asString?.parseAsHtml()?.trimTrailingWhitespace() ?: SpannedString("")
+        return json.asString
+            /* Mastodon uses 'white-space: pre-wrap;' so spaces are displayed as returned by the Api.
+             * We can't use CSS so we replace spaces with non-breaking-spaces to emulate the behavior.
+             */
+            ?.replace("<br> ", "<br>&nbsp;")
+            ?.replace("<br /> ", "<br />&nbsp;")
+            ?.replace("<br/> ", "<br/>&nbsp;")
+            ?.replace("  ", "&nbsp;&nbsp;")
+            ?.parseAsHtml()
+            /* Html.fromHtml returns trailing whitespace if the html ends in a </p> tag, which
+             * most status contents do, so it should be trimmed. */
+            ?.trimTrailingWhitespace()
+            ?: SpannedString("")
     }
 
     override fun serialize(src: Spanned?, typeOfSrc: Type, context: JsonSerializationContext): JsonElement {
-        return JsonPrimitive(HtmlCompat.toHtml(src!!, HtmlCompat.TO_HTML_PARAGRAPH_LINES_INDIVIDUAL))
+        return JsonPrimitive(src!!.toHtml(HtmlCompat.TO_HTML_PARAGRAPH_LINES_INDIVIDUAL))
     }
 }