Merge c7f0298a3d into ee7e9ef2a3

client/js/api.js

@@ -439,14 +439,18 @@ class Api extends events.EventTarget {
 
             abortFunction = () => {
                 req.abort(); // does *NOT* call the callback passed in .end()
+                if (!options.noProgress) {
                     progress.done();
+                }
                 reject(
                     new Error("The request was aborted due to user cancel.")
                 );
             };
 
             req.end((error, response) => {
+                if (!options.noProgress) {
                     progress.done();
+                }
                 abortFunction = () => {};
                 if (error) {
                     if (response && response.body) {

client/js/controllers/post_main_controller.js

@@ -41,16 +41,29 @@ class PostMainController extends BasePostController {
                     router.replace(url, ctx.state, false);
                 }
 
+                const prevPostId = aroundResponse.prev
+                        ? aroundResponse.prev.id
+                        : null;
+                const nextPostId = aroundResponse.next
+                        ? aroundResponse.next.id
+                        : null;
+
+                // preload nearby posts
+                if (prevPostId) {
+                    Post.get(prevPostId, { noProgress: true }).then(misc.preloadPostImages);
+                    PostList.getAround(prevPostId, parameters ? parameters.query : null, { noProgress: true });
+                }
+                if (nextPostId) {
+                    Post.get(nextPostId, { noProgress: true }).then(misc.preloadPostImages);
+                    PostList.getAround(nextPostId, parameters ? parameters.query : null, { noProgress: true });
+                }
+
                 this._post = post;
                 this._view = new PostMainView({
                     post: post,
                     editMode: editMode,
-                    prevPostId: aroundResponse.prev
-                        ? aroundResponse.prev.id
-                        : null,
-                    nextPostId: aroundResponse.next
-                        ? aroundResponse.next.id
-                        : null,
+                    prevPostId: prevPostId,
+                    nextPostId: nextPostId,
                     canEditPosts: api.hasPrivilege("posts:edit"),
                     canDeletePosts: api.hasPrivilege("posts:delete"),
                     canFeaturePosts: api.hasPrivilege("posts:feature"),

client/js/models/post.js

@@ -199,8 +199,8 @@ class Post extends events.EventTarget {
         return returnedPromise;
     }
 
-    static get(id) {
-        return api.get(uri.formatApiLink("post", id)).then((response) => {
+    static get(id, options) {
+        return api.get(uri.formatApiLink("post", id), options).then((response) => {
             return Promise.resolve(Post.fromResponse(response));
         });
     }

client/js/models/post_list.js

@@ -7,12 +7,13 @@ const AbstractList = require("./abstract_list.js");
 const Post = require("./post.js");
 
 class PostList extends AbstractList {
-    static getAround(id, searchQuery) {
+    static getAround(id, searchQuery, options) {
         return api.get(
             uri.formatApiLink("post", id, "around", {
                 query: PostList._decorateSearchQuery(searchQuery || ""),
                 fields: "id",
-            })
+            }),
+            options
         );
     }
 

client/js/util/misc.js

@@ -211,6 +211,15 @@ function getPrettyName(tag) {
     return tag;
 }
 
+function preloadPostImages(post) {
+    if (!["image", "animation"].includes(post.type)) {
+        return;
+    }
+    const img = new Image()
+    img.fetchPriority = "low";
+    img.src = post.contentUrl;
+}
+
 module.exports = {
     range: range,
     formatRelativeTime: formatRelativeTime,
@@ -229,4 +238,5 @@ module.exports = {
     escapeSearchTerm: escapeSearchTerm,
     dataURItoBlob: dataURItoBlob,
     getPrettyName: getPrettyName,
+    preloadPostImages: preloadPostImages,
 };