Speedup generating folderlist

dev/Model/FolderCollection.js

@@ -297,7 +297,7 @@ export class FolderModel extends AbstractModel {
 
 				visible: () => folder.hasSubscriptions() | !SettingsUserStore.hideUnsubscribed(),
 
-				isSystemFolder: () => FolderType.User !== folder.type() || !!folder.kolabType(),
+				isSystemFolder: () => FolderType.User !== folder.type() | !!folder.kolabType(),
 
 				hidden: () => {
 					let hasSubFolders = folder.hasSubscribedSubfolders();
@@ -354,9 +354,7 @@ export class FolderModel extends AbstractModel {
 				},
 
 				collapsed: {
-					read: () => folder.isInbox() && FolderUserStore.singleRootFolder()
-						? false
-						: !folder.hidden() && folder.collapsedPrivate(),
+					read: () => !folder.hidden() && folder.collapsedPrivate(),
 					write: value => folder.collapsedPrivate(value)
 				},
 

dev/Settings/User/Folders.js

@@ -22,6 +22,8 @@ import { showScreenPopup } from 'Knoin/Knoin';
 import { FolderCreatePopupView } from 'View/Popup/FolderCreate';
 import { FolderSystemPopupView } from 'View/Popup/FolderSystem';
 
+const folderForDeletion = ko.observable(null).deleteAccessHelper();
+
 export class FoldersUserSettings /*extends AbstractViewSettings*/ {
 	constructor() {
 		this.showKolab = Settings.capa(Capa.Kolab) && FolderUserStore.metadataSupported();
@@ -56,7 +58,7 @@ export class FoldersUserSettings /*extends AbstractViewSettings*/ {
 			return loading || creating || deleting || renaming;
 		});
 
-		this.folderForDeletion = ko.observable(null).deleteAccessHelper();
+		this.folderForDeletion = folderForDeletion;
 
 		this.folderForEdit = ko.observable(null).extend({ toggleSubscribeProperty: [this, 'edited'] });
 
@@ -111,7 +113,7 @@ export class FoldersUserSettings /*extends AbstractViewSettings*/ {
 			folderToRemove.deleteAccess() &&
 			0 === folderToRemove.privateMessageCountAll()
 		) {
-			this.folderForDeletion(null);
+			folderForDeletion(null);
 
 			if (folderToRemove) {
 				Local.set(ClientSideKeyName.FoldersLashHash, '');
@@ -123,6 +125,7 @@ export class FoldersUserSettings /*extends AbstractViewSettings*/ {
 						() => {
 							folderToRemove.selectable(false)
 							removeFolderFromCacheList(folderToRemove.fullNameRaw);
+							FolderUserStore.folderList(FolderUserStore.folderList.filter(folder => folder !== folderToRemove));
 						},
 						error => {
 							FolderUserStore.folderListError(

dev/Stores/User/Folder.js

@@ -57,18 +57,6 @@ export const FolderUserStore = new class {
 
 			draftFolderNotEnabled: () => !this.draftFolder() || UNUSED_OPTION_VALUE === this.draftFolder(),
 
-			// foldersListWithSingleInboxRootFolder
-			/** returns true when there are no non-system folders in the root of the folders tree */
-			singleRootFolder: () => {
-				let multiple = false;
-				this.folderList.forEach(folder => {
-					let subscribed = folder.subscribed(),
-						hasSub = folder.hasSubscribedSubfolders();
-					multiple |= (!folder.isSystemFolder() || (hasSub && !folder.isInbox())) && (subscribed || hasSub)
-				});
-				return !multiple;
-			},
-
 			currentFolderFullNameRaw: () => (this.currentFolder() ? this.currentFolder().fullNameRaw : ''),
 
 			currentFolderFullName: () => (this.currentFolder() ? this.currentFolder().fullName : ''),

dev/View/User/MailBox/FolderList.js

@@ -33,7 +33,7 @@ export class MailFolderList extends AbstractViewLeft {
 
 		this.moveAction = moveAction;
 
-		this.foldersListWithSingleInboxRootFolder = FolderUserStore.singleRootFolder;
+		this.foldersListWithSingleInboxRootFolder = ko.observable(false);
 
 		this.leftPanelDisabled = leftPanelDisabled;
 
@@ -42,7 +42,24 @@ export class MailFolderList extends AbstractViewLeft {
 		addComputablesTo(this, {
 			folderListFocused: () => Scope.FolderList === AppUserStore.focusedState(),
 
-			folderListVisible: () => FolderUserStore.folderList().filter(v => !(v.hidden() || v.kolabType()))
+			folderListVisible: () => {
+				let multiple = false,
+					inbox, subscribed, hasSub,
+					result = FolderUserStore.folderList().filter(folder => {
+						if (folder.isInbox()) {
+							inbox = folder;
+						}
+						subscribed = folder.subscribed();
+						hasSub = folder.hasSubscribedSubfolders();
+						multiple |= (!folder.isSystemFolder() || (hasSub && !folder.isInbox())) && (subscribed || hasSub)
+						return !(folder.hidden() | folder.kolabType());
+					});
+				if (inbox && !multiple) {
+					inbox.collapsedPrivate(false);
+				}
+				this.foldersListWithSingleInboxRootFolder(!multiple);
+				return result;
+			}
 		});
 	}
 

snappymail/v/0.0.0/app/templates/Views/User/MailFolderListItem.html

@@ -1,4 +1,5 @@
-<li data-bind="visible: visible">
+<!-- ko if: visible -->
+<li>
 	<a data-bind="dropmessages: $data,
 	   css: { 'selected': selected() && !isSystemFolder(), 'system': isSystemFolder, 'selectable': canBeSelected, 'hidden' : hidden, 'unread-sub': hasSubscribedUnreadMessagesSubfolders, 'anim-action-class': actionBlink },
 	   attr: { 'data-unread': printableUnreadCount }">
@@ -9,3 +10,4 @@
 	<ul data-bind="template: { name: 'MailFolderListItem', foreach: subFolders }, css: { 'collapsed': collapsed() }"></ul>
 	<!-- /ko -->
 </li>
+<!-- /ko -->