Pre-process media for `LightboxGallery`

js/views/conversation_view.js

@@ -603,13 +603,14 @@
         .loadWithObjectURL(Signal.Migrations.loadMessage);
       const media = await loadMessages(rawMedia);
 
+      const { getAbsoluteAttachmentPath } = Signal.Migrations;
       const saveAttachment = async ({ message } = {}) => {
         const attachment = message.attachments[0];
         const timestamp = message.received_at;
         Signal.Types.Attachment.save({
           attachment,
           document,
-          getAbsolutePath: Signal.Migrations.getAbsoluteAttachmentPath,
+          getAbsolutePath: getAbsoluteAttachmentPath,
           timestamp,
         });
       };
@@ -622,14 +623,18 @@
           }
 
           case 'media': {
+            const mediaWithObjectURL = media.map(mediaMessage =>
+              Object.assign(
+                {},
+                mediaMessage,
+                { objectURL: getAbsoluteAttachmentPath(mediaMessage.attachments[0].path) }
+              ));
             const selectedIndex = media.findIndex(mediaMessage =>
               mediaMessage.id === message.id);
-            const { getAbsoluteAttachmentPath } = Signal.Migrations;
             this.lightboxGalleryView = new Whisper.ReactWrapperView({
               Component: Signal.Components.LightboxGallery,
               props: {
-                getAbsoluteAttachmentPath,
-                messages: media,
+                messages: mediaWithObjectURL,
                 onSave: () => saveAttachment({ message }),
                 selectedIndex,
               },

ts/components/LightboxGallery.tsx

@@ -14,7 +14,6 @@ interface Item {
 
 interface Props {
   close: () => void;
-  getAbsoluteAttachmentPath: (relativePath: string) => string;
   messages: Array<Message>;
   onSave?: ({ message }: { message: Message }) => void;
   selectedIndex: number;
@@ -25,7 +24,7 @@ interface State {
 }
 
 const messageToItem = (message: Message): Item => ({
-  objectURL: message.attachments[0].path,
+  objectURL: message.objectURL,
   contentType: message.attachments[0].contentType,
 });
 
@@ -43,7 +42,7 @@ export class LightboxGallery extends React.Component<Props, State> {
   }
 
   public render() {
-    const { close, getAbsoluteAttachmentPath, messages, onSave } = this.props;
+    const { close, messages, onSave } = this.props;
     const { selectedIndex } = this.state;
 
     const selectedMessage: Message = messages[selectedIndex];
@@ -56,9 +55,7 @@ export class LightboxGallery extends React.Component<Props, State> {
     const lastIndex = messages.length - 1;
     const onNext = selectedIndex < lastIndex ? this.handleNext : undefined;
 
-    const objectURL = selectedItem.objectURL
-      ? getAbsoluteAttachmentPath(selectedItem.objectURL)
-      : 'images/video.svg';
+    const objectURL = selectedItem.objectURL || 'images/alert-outline.svg';
 
     return (
       <Lightbox