Fix caret position after selected suggestion and media upload (#7595)

* Fix media upload reseting caret position to last inserted emoji

* Fix caret position after inserting suggestions (fixes #6089)

3 files changed, 11 insertions, 7 deletions

diff --git a/app/javascript/mastodon/features/compose/components/compose_form.js b/app/javascript/mastodon/features/compose/components/compose_form.js
index 9cd39be8b..6cc594c88 100644
--- a/app/javascript/mastodon/features/compose/components/compose_form.js
+++ b/app/javascript/mastodon/features/compose/components/compose_form.js
@@ -40,6 +40,7 @@ export default class ComposeForm extends ImmutablePureComponent {
     privacy: PropTypes.string,
     spoiler_text: PropTypes.string,
     focusDate: PropTypes.instanceOf(Date),
+    caretPosition: PropTypes.number,
     preselectDate: PropTypes.instanceOf(Date),
     is_submitting: PropTypes.bool,
     is_uploading: PropTypes.bool,
@@ -96,7 +97,6 @@ export default class ComposeForm extends ImmutablePureComponent {
   }
 
   onSuggestionSelected = (tokenStart, token, value) => {
-    this._restoreCaret = null;
     this.props.onSuggestionSelected(tokenStart, token, value);
   }
 
@@ -116,9 +116,9 @@ export default class ComposeForm extends ImmutablePureComponent {
       if (this.props.preselectDate !== prevProps.preselectDate) {
         selectionEnd   = this.props.text.length;
         selectionStart = this.props.text.search(/\s/) + 1;
-      } else if (typeof this._restoreCaret === 'number') {
-        selectionStart = this._restoreCaret;
-        selectionEnd   = this._restoreCaret;
+      } else if (typeof this.props.caretPosition === 'number') {
+        selectionStart = this.props.caretPosition;
+        selectionEnd   = this.props.caretPosition;
       } else {
         selectionEnd   = this.props.text.length;
         selectionStart = selectionEnd;
@@ -138,10 +138,8 @@ export default class ComposeForm extends ImmutablePureComponent {
   handleEmojiPick = (data) => {
     const { text }     = this.props;
     const position     = this.autosuggestTextarea.textarea.selectionStart;
-    const emojiChar    = data.native;
     const needsSpace   = data.custom && position > 0 && !allowedAroundShortCode.includes(text[position - 1]);
 
-    this._restoreCaret = position + emojiChar.length + 1 + (needsSpace ? 1 : 0);
     this.props.onPickEmoji(position, data, needsSpace);
   }
 
diff --git a/app/javascript/mastodon/features/compose/containers/compose_form_container.js b/app/javascript/mastodon/features/compose/containers/compose_form_container.js
index c3aa580ee..3822dd711 100644
--- a/app/javascript/mastodon/features/compose/containers/compose_form_container.js
+++ b/app/javascript/mastodon/features/compose/containers/compose_form_container.js
@@ -19,6 +19,7 @@ const mapStateToProps = state => ({
   spoiler_text: state.getIn(['compose', 'spoiler_text']),
   privacy: state.getIn(['compose', 'privacy']),
   focusDate: state.getIn(['compose', 'focusDate']),
+  caretPosition: state.getIn(['compose', 'caretPosition']),
   preselectDate: state.getIn(['compose', 'preselectDate']),
   is_submitting: state.getIn(['compose', 'is_submitting']),
   is_uploading: state.getIn(['compose', 'is_uploading']),
diff --git a/app/javascript/mastodon/reducers/compose.js b/app/javascript/mastodon/reducers/compose.js
index 46d9d6c8e..62461d1a7 100644
--- a/app/javascript/mastodon/reducers/compose.js
+++ b/app/javascript/mastodon/reducers/compose.js
@@ -44,6 +44,7 @@ const initialState = ImmutableMap({
   privacy: null,
   text: '',
   focusDate: null,
+  caretPosition: null,
   preselectDate: null,
   in_reply_to: null,
   is_composing: false,
@@ -91,7 +92,6 @@ function appendMedia(state, media) {
     map.update('media_attachments', list => list.push(media));
     map.set('is_uploading', false);
     map.set('resetFileKey', Math.floor((Math.random() * 0x10000)));
-    map.set('focusDate', new Date());
     map.set('idempotencyKey', uuid());
 
     if (prevSize === 0 && (state.get('default_sensitive') || state.get('spoiler'))) {
@@ -119,6 +119,7 @@ const insertSuggestion = (state, position, token, completion) => {
     map.set('suggestion_token', null);
     map.update('suggestions', ImmutableList(), list => list.clear());
     map.set('focusDate', new Date());
+    map.set('caretPosition', position + completion.length + 1);
     map.set('idempotencyKey', uuid());
   });
 };
@@ -142,6 +143,7 @@ const insertEmoji = (state, position, emojiData, needsSpace) => {
   return state.merge({
     text: `${oldText.slice(0, position)}${emoji} ${oldText.slice(position)}`,
     focusDate: new Date(),
+    caretPosition: position + emoji.length + 1,
     idempotencyKey: uuid(),
   });
 };
@@ -216,6 +218,7 @@ export default function compose(state = initialState, action) {
       map.set('text', statusToTextMentions(state, action.status));
       map.set('privacy', privacyPreference(action.status.get('visibility'), state.get('default_privacy')));
       map.set('focusDate', new Date());
+      map.set('caretPosition', null);
       map.set('preselectDate', new Date());
       map.set('idempotencyKey', uuid());
 
@@ -259,6 +262,7 @@ export default function compose(state = initialState, action) {
     return state.withMutations(map => {
       map.update('text', text => [text.trim(), `@${action.account.get('acct')} `].filter((str) => str.length !== 0).join(' '));
       map.set('focusDate', new Date());
+      map.set('caretPosition', null);
       map.set('idempotencyKey', uuid());
     });
   case COMPOSE_DIRECT:
@@ -266,6 +270,7 @@ export default function compose(state = initialState, action) {
       map.update('text', text => [text.trim(), `@${action.account.get('acct')} `].filter((str) => str.length !== 0).join(' '));
       map.set('privacy', 'direct');
       map.set('focusDate', new Date());
+      map.set('caretPosition', null);
       map.set('idempotencyKey', uuid());
     });
   case COMPOSE_SUGGESTIONS_CLEAR: