Alternative content types (#516)

* Akkoma content types

* Default content type preference

* per-account content types, compatible with glitch

* disable content types by default, change icon

* persist content type to state

* update string

* fall back to plain text if formatting enabled

---------

Co-authored-by: sk <sk22@mailbox.org>

mastodon/src/main/java/org/joinmastodon/android/model/ContentType.java

@@ -0,0 +1,40 @@
+package org.joinmastodon.android.model;
+
+import android.view.Menu;
+
+import androidx.annotation.Nullable;
+
+import com.google.gson.annotations.SerializedName;
+
+import org.joinmastodon.android.R;
+
+public enum ContentType {
+	@SerializedName("text/plain")
+	PLAIN,
+	@SerializedName("text/html")
+	HTML,
+	@SerializedName("text/markdown")
+	MARKDOWN,
+	@SerializedName("text/bbcode")
+	BBCODE, // akkoma
+	@SerializedName("text/x.misskeymarkdown")
+	MISSKEY_MARKDOWN; // akkoma/*key
+
+	public static int getContentTypeRes(@Nullable ContentType contentType) {
+		return contentType == null ? R.id.content_type_null : switch(contentType) {
+			case PLAIN -> R.id.content_type_plain;
+			case HTML -> R.id.content_type_html;
+			case MARKDOWN -> R.id.content_type_markdown;
+			case BBCODE -> R.id.content_type_bbcode;
+			case MISSKEY_MARKDOWN -> R.id.content_type_misskey_markdown;
+		};
+	}
+
+	public static void adaptMenuToInstance(Menu m, Instance i) {
+		if (i.pleroma == null) {
+			// memo: change this if glitch or another mastodon fork supports bbcode or mfm
+			m.findItem(R.id.content_type_bbcode).setVisible(false);
+			m.findItem(R.id.content_type_misskey_markdown).setVisible(false);
+		}
+	}
+}

mastodon/src/main/java/org/joinmastodon/android/model/ScheduledStatus.java

@@ -39,6 +39,7 @@ public class ScheduledStatus extends BaseModel implements DisplayItemsParent{
         public String idempotency;
         public String applicationId;
         public List<String> mediaIds;
+        public ContentType contentType;
     }
 
     @Parcel