fix toots showing too much whitespace (#1761)

* fix toots showing too much whitespace

* use isWhitespace extension function

app/src/main/java/com/keylesspalace/tusky/db/Converters.kt

@@ -136,7 +136,7 @@ class Converters {
         if(spannedString == null) {
             return null
         }
-        return HtmlUtils.fromHtml(spannedString)
+        return spannedString.parseAsHtml().trimTrailingWhitespace()
     }
 
     @TypeConverter
@@ -149,4 +149,4 @@ class Converters {
         return gson.fromJson(pollJson, Poll::class.java)
     }
 
-}
+}

app/src/main/java/com/keylesspalace/tusky/json/SpannedTypeAdapter.kt

@@ -0,0 +1,37 @@
+/* Copyright 2020 Tusky Contributors
+ *
+ * This file is a part of Tusky.
+ *
+ * This program is free software; you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * Tusky is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with Tusky; if not,
+ * see <http://www.gnu.org/licenses>. */
+
+package com.keylesspalace.tusky.json
+
+import android.text.Spanned
+import android.text.SpannedString
+import androidx.core.text.HtmlCompat
+import androidx.core.text.parseAsHtml
+import com.google.gson.*
+import com.keylesspalace.tusky.util.trimTrailingWhitespace
+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("")
+    }
+
+    override fun serialize(src: Spanned?, typeOfSrc: Type, context: JsonSerializationContext): JsonElement {
+        return JsonPrimitive(HtmlCompat.toHtml(src!!, HtmlCompat.TO_HTML_PARAGRAPH_LINES_INDIVIDUAL))
+    }
+}

app/src/main/java/com/keylesspalace/tusky/repository/TimelineRepository.kt

@@ -1,5 +1,6 @@
 package com.keylesspalace.tusky.repository
 
+import android.text.Spanned
 import android.text.SpannedString
 import com.google.gson.Gson
 import com.google.gson.reflect.TypeToken
@@ -12,6 +13,7 @@ import com.keylesspalace.tusky.util.Either
 import com.keylesspalace.tusky.util.HtmlConverter
 import com.keylesspalace.tusky.util.dec
 import com.keylesspalace.tusky.util.inc
+import com.keylesspalace.tusky.util.trimTrailingWhitespace
 import io.reactivex.Single
 import io.reactivex.schedulers.Schedulers
 import java.io.IOException
@@ -215,7 +217,7 @@ class TimelineRepositoryImpl(
                     inReplyToId = status.inReplyToId,
                     inReplyToAccountId = status.inReplyToAccountId,
                     reblog = null,
-                    content = status.content?.let(htmlConverter::fromHtml) ?: SpannedString(""),
+                    content = status.content?.parseAsHtml()?.trimTrailingWhitespace() ?: SpannedString(""),
                     createdAt = Date(status.createdAt),
                     emojis = emojis,
                     reblogsCount = status.reblogsCount,
@@ -268,7 +270,7 @@ class TimelineRepositoryImpl(
                     inReplyToId = status.inReplyToId,
                     inReplyToAccountId = status.inReplyToAccountId,
                     reblog = null,
-                    content = status.content?.let(htmlConverter::fromHtml) ?: SpannedString(""),
+                    content = status.content?.parseAsHtml()?.trimTrailingWhitespace() ?: SpannedString(""),
                     createdAt = Date(status.createdAt),
                     emojis = emojis,
                     reblogsCount = status.reblogsCount,

app/src/main/java/com/keylesspalace/tusky/util/StringUtils.kt

@@ -2,7 +2,8 @@
 
 package com.keylesspalace.tusky.util
 
-import java.util.Random
+import android.text.Spanned
+import java.util.*
 
 
 private const val POSSIBLE_CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@@ -71,3 +72,11 @@ fun String.isLessThan(other: String): Boolean {
         else -> this < other
     }
 }
+
+fun Spanned.trimTrailingWhitespace(): Spanned {
+    var i = length
+    do {
+        i--
+    } while (i >= 0 && get(i).isWhitespace())
+    return subSequence(0, i + 1) as Spanned
+}