move inline formatting code out of react component

src/editor/operations.js

@@ -0,0 +1,38 @@
+/*
+Copyright 2019 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
+
+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.
+*/
+
+/**
+ * Some common queries and transformations on the editor model
+ */
+
+export function replaceRangeAndExpandSelection(model, range, newParts) {
+    model.transform(() => {
+        const oldLen = range.length;
+        const addedLen = range.replace(newParts);
+        const firstOffset = range.start.asOffset(model);
+        const lastOffset = firstOffset.add(oldLen + addedLen);
+        return model.startRange(firstOffset.asPosition(model), lastOffset.asPosition(model));
+    });
+}
+
+export function formatInline(range, prefix, suffix = prefix) {
+    const {model, parts} = range;
+    const {partCreator} = model;
+    parts.unshift(partCreator.plain(prefix));
+    parts.push(partCreator.plain(suffix));
+    replaceRangeAndExpandSelection(model, range, parts);
+}