add caching MessageBody in BaseTextMessageTile,use in EncryptedEventTile

missing body in EncryptedEventTile was what caused the bug

src/domain/session/room/timeline/tiles/BaseTextMessageTile.js

@@ -0,0 +1,47 @@
+/*
+Copyright 2020 Bruno Windels <bruno@windels.cloud>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {MessageTile} from "./MessageTile.js";
+import {stringAsBody} from "../MessageBody.js";
+
+export class BaseTextMessageTile extends MessageTile {
+    constructor(options) {
+        super(options);
+        this._messageBody = null;
+    }
+
+    get shape() {
+        return "message";
+    }
+
+    _parseBody(bodyString) {
+        return stringAsBody(bodyString);
+    }
+
+    get body() {
+        const body = this._getBodyAsString();
+        // body is a string, so we can check for difference by just
+        // doing an equality check
+        if (!this._messageBody || this._messageBody.sourceString !== body) {
+            // body with markup is an array of parts,
+            // so we should not recreate it for the same body string,
+            // or else the equality check in the binding will always fail.
+            // So cache it here.
+            this._messageBody = this._parseBody(body);
+        }
+        return this._messageBody;
+    }
+}

src/domain/session/room/timeline/tiles/EncryptedEventTile.js

@@ -14,10 +14,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {MessageTile} from "./MessageTile.js";
+import {BaseTextMessageTile} from "./BaseTextMessageTile.js";
 import {UpdateAction} from "../UpdateAction.js";
 
-export class EncryptedEventTile extends MessageTile {
+export class EncryptedEventTile extends BaseTextMessageTile {
     updateEntry(entry, params) {
         const parentResult = super.updateEntry(entry, params);
         // event got decrypted, recreate the tile and replace this one with it
@@ -33,7 +33,7 @@ export class EncryptedEventTile extends MessageTile {
         return "message-status"
     }
 
-    get text() {
+    _getBodyAsString() {
         const decryptionError = this._entry.decryptionError;
         const code = decryptionError?.code;
         if (code === "MEGOLM_NO_SESSION") {

src/domain/session/room/timeline/tiles/MessageTile.js

@@ -33,10 +33,6 @@ export class MessageTile extends SimpleTile {
         return this._room.mediaRepository;
     }
 
-    get shape() {
-        return "message";
-    }
-
     get displayName() {
         return this._entry.displayName || this.sender;
     }

src/domain/session/room/timeline/tiles/TextTile.js

@@ -14,12 +14,11 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import {MessageTile} from "./MessageTile.js";
-import { MessageBodyBuilder } from "../MessageBodyBuilder.js";
+import {BaseTextMessageTile} from "./BaseTextMessageTile.js";
+import {parsePlainBody} from "../MessageBody.js";
 
-export class TextTile extends MessageTile {
-
-    get _contentBody() {
+export class TextTile extends BaseTextMessageTile {
+    _getBodyAsString() {
         const content = this._getContent();
         let body = content?.body || "";
         if (content.msgtype === "m.emote") {
@@ -28,14 +27,7 @@ export class TextTile extends MessageTile {
         return body;
     }
 
-    get body() {
-        const body = this._contentBody;
-        if (body === this._body) {
-            return this._message;
-        }
-        const message = new MessageBodyBuilder();
-        message.fromText(body);
-        [this._body, this._message] = [body, message];
-        return message;
+    _parseBody(bodyString) {
+        return parsePlainBody(bodyString);
     }
 }