Lightbox: Added Button to jump to current image within the conversation

Author: findus

_locales/en/messages.json

@@ -8343,5 +8343,9 @@
   "icu:WhatsNew__v7.50--0": {
     "messageformat": "If you link a new Desktop on Signal Android and choose to transfer your message history, now you can also selectively transfer old attachments from your primary device too. Bring the past into the present by scrolling back in time and clicking on the download icon. As always, the transfer process is end-to-end encrypted and secure.",
     "description": "Release notes for version 7.49"
+  },
+  "icu:jumpto": {
+    "messageformat": "Jump to",
+    "description": "Jumps to the medias position in the conversation"
   }
 }

stylesheets/components/Lightbox.scss

@@ -360,6 +360,15 @@
       }
     }
 
+    &--jump {
+      &::before {
+        @include mixins.color-svg(
+          '../images/icons/v3/chat/chat.svg',
+          variables.$color-gray-15
+        );
+      }
+    }
+
     &--close {
       &::before {
         @include mixins.color-svg(

ts/components/Lightbox.tsx

@@ -13,6 +13,7 @@ import type {
   ConversationType,
   SaveAttachmentActionCreatorType,
 } from '../state/ducks/conversations';
+import { useConversationsActions } from '../state/ducks/conversations';
 import type { LocalizerType } from '../types/Util';
 import type { MediaItemType } from '../types/MediaItem';
 import * as GoogleChrome from '../util/GoogleChrome';
@@ -99,6 +100,7 @@ export function Lightbox({
   hasNextMessage,
   hasPrevMessage,
 }: PropsType): JSX.Element | null {
+  const { scrollToMessage } = useConversationsActions();
   const hasThumbnails = media.length > 1;
   const messageId = media.at(0)?.message.id;
   const prevMessageId = usePrevious(messageId, messageId);
@@ -243,6 +245,21 @@ export function Lightbox({
     [isViewOnce, media, saveAttachment, selectedIndex]
   );
 
+  const handleJumpToConversation = useCallback(
+    (
+      event: KeyboardEvent | React.MouseEvent<HTMLButtonElement, MouseEvent>
+    ) => {
+      if (isViewOnce) {
+        return;
+      }
+      const mediaItem = media[selectedIndex];
+      const { message } = mediaItem;
+      const { conversationId, id } = message;
+      scrollToMessage(conversationId, id);
+    },
+    [isViewOnce, media, selectedIndex, scrollToMessage]
+  );
+
   const handleForward = (
     event: React.MouseEvent<HTMLButtonElement, MouseEvent>
   ) => {
@@ -726,6 +743,14 @@ export function Lightbox({
                   <div />
                 )}
                 <div className="Lightbox__controls">
+                  {!isViewOnce ? (
+                    <button
+                      aria-label={i18n('icu:jumpto')}
+                      className="Lightbox__button Lightbox__button--jump"
+                      onClick={handleJumpToConversation}
+                      type="button"
+                    />
+                  ) : null}
                   {!isViewOnce ? (
                     <button
                       aria-label={i18n('icu:forwardMessage')}