add feature flag

src/components/views/messages/MessageActionBar.js

@@ -103,6 +103,10 @@ export default class MessageActionBar extends React.PureComponent {
         return SettingsStore.isFeatureEnabled("feature_reactions");
     }
 
+    isEditingEnabled() {
+        return SettingsStore.isFeatureEnabled("feature_message_editing");
+    }
+
     renderAgreeDimension() {
         if (!this.isReactionsEnabled()) {
             return null;
@@ -144,10 +148,12 @@ export default class MessageActionBar extends React.PureComponent {
                 title={_t("Reply")}
                 onClick={this.onReplyClick}
             />;
-            editButton = <span className="mx_MessageActionBar_maskButton mx_MessageActionBar_editButton"
-                title={_t("Edit")}
-                onClick={this.onEditClick}
-            />;
+            if (this.isEditingEnabled()) {
+                editButton = <span className="mx_MessageActionBar_maskButton mx_MessageActionBar_editButton"
+                    title={_t("Edit")}
+                    onClick={this.onEditClick}
+                />;
+            }
         }
 
         return <div className="mx_MessageActionBar">

src/i18n/strings/en_EN.json

@@ -300,6 +300,7 @@
     "Show recent room avatars above the room list": "Show recent room avatars above the room list",
     "Group & filter rooms by custom tags (refresh to apply changes)": "Group & filter rooms by custom tags (refresh to apply changes)",
     "Render simple counters in room header": "Render simple counters in room header",
+    "Edit messages after they have been sent": "Edit messages after they have been sent",
     "React to messages with emoji (refresh to apply changes)": "React to messages with emoji (refresh to apply changes)",
     "Enable Emoji suggestions while typing": "Enable Emoji suggestions while typing",
     "Use compact timeline layout": "Use compact timeline layout",
@@ -897,6 +898,7 @@
     "Agree or Disagree": "Agree or Disagree",
     "Like or Dislike": "Like or Dislike",
     "Reply": "Reply",
+    "Edit": "Edit",
     "Options": "Options",
     "Attachment": "Attachment",
     "Error decrypting attachment": "Error decrypting attachment",
@@ -973,7 +975,6 @@
     "Reload widget": "Reload widget",
     "Popout widget": "Popout widget",
     "Picture": "Picture",
-    "Edit": "Edit",
     "Revoke widget access": "Revoke widget access",
     "Create new room": "Create new room",
     "Unblacklist": "Unblacklist",

src/settings/Settings.js

@@ -118,6 +118,12 @@ export const SETTINGS = {
         supportedLevels: LEVELS_FEATURE,
         default: false,
     },
+    "feature_message_editing": {
+        isFeature: true,
+        displayName: _td("Edit messages after they have been sent"),
+        supportedLevels: LEVELS_FEATURE,
+        default: false,
+    },
     "feature_reactions": {
         isFeature: true,
         displayName: _td("React to messages with emoji (refresh to apply changes)"),