Add ConversationListModel

- This list model groups all emails by conversation in the mail list
- Also adds setting for grouping by conversation (i.e. enables this)
- The setting is overridden for SENT and DRAFT folder types (it uses the
  other per-mail list model instead)
- Adds MailSetListModel which provides a common interface for the
  MailViewModel so that additional list models can be created; it is
  used for MailListModel and the new ConversationListModel, but it can
  be extended to even more list models in the future if it is ever
  desired.

Note: This does not include actions. Any action you do (delete, archive,
etc.) will be applied to the selected email. The purpose of this commit
is to just implement the list model. See #5051 for more information.

Closes #8223

Co-authored-by: bir <[email protected]>
Co-authored-by: ivk <[email protected]>

src/common/misc/DeviceConfig.ts

@@ -22,6 +22,10 @@ export enum ListAutoSelectBehavior {
 	OLDER,
 	NEWER,
 }
+export const enum MailListDisplayMode {
+	CONVERSATIONS = "conversations",
+	MAILS = "mails",
+}
 
 export type LastExternalCalendarSyncEntry = {
 	lastSuccessfulSync: number | undefined | null
@@ -53,6 +57,7 @@ interface ConfigObject {
 	_testAssignments: PersistedAssignmentData | null
 	offlineTimeRangeDaysByUser: Record<Id, number>
 	conversationViewShowOnlySelectedMail: boolean
+	mailListDisplayMode: MailListDisplayMode
 	/** Stores each users' definition about contact synchronization */
 	syncContactsWithPhonePreference: Record<Id, boolean>
 	/** Whether mobile calendar navigation is in the "per week" or "per month" mode */
@@ -134,6 +139,7 @@ export class DeviceConfig implements UsageTestStorage, NewsItemStorage {
 			_signupToken: signupToken,
 			offlineTimeRangeDaysByUser: loadedConfig.offlineTimeRangeDaysByUser ?? {},
 			conversationViewShowOnlySelectedMail: loadedConfig.conversationViewShowOnlySelectedMail ?? false,
+			mailListDisplayMode: loadedConfig.mailListDisplayMode ?? MailListDisplayMode.CONVERSATIONS,
 			syncContactsWithPhonePreference: loadedConfig.syncContactsWithPhonePreference ?? {},
 			isCalendarDaySelectorExpanded: loadedConfig.isCalendarDaySelectorExpanded ?? false,
 			mailAutoSelectBehavior: loadedConfig.mailAutoSelectBehavior ?? (isApp() ? ListAutoSelectBehavior.NONE : ListAutoSelectBehavior.OLDER),
@@ -398,6 +404,15 @@ export class DeviceConfig implements UsageTestStorage, NewsItemStorage {
 		this.writeToStorage()
 	}
 
+	getMailListDisplayMode(): MailListDisplayMode {
+		return this.config.mailListDisplayMode
+	}
+
+	setMailListDisplayMode(setting: MailListDisplayMode) {
+		this.config.mailListDisplayMode = setting
+		this.writeToStorage()
+	}
+
 	getUserSyncContactsWithPhonePreference(id: Id): boolean | null {
 		return this.config.syncContactsWithPhonePreference[id] ?? null
 	}

src/common/misc/ListModel.ts

@@ -574,6 +574,8 @@ export class ListModel<ItemType, IdType> {
 
 	canInsertItem(entity: ItemType): boolean {
 		if (this.state.loadingStatus === ListLoadingState.Done) {
+			// If we aren't loading, it is always safe to add items, because we can assume we have the entire range
+			// loaded
 			return true
 		}
 

src/common/misc/TranslationKey.ts

@@ -1889,6 +1889,10 @@ export type TranslationKeyType =
 	| "yourMessage_label"
 	| "you_label"
 	| "emptyString_msg"
+	| "mailListGrouping_label"
+	| "mailListGroupingDontGroup_label"
+	| "mailListGroupingGroupByConversation_label"
+	| "mailListGroupingHelp_msg"
 	// Put in temporarily, will be removed soon
 	| "localAdminGroup_label"
 	| "assignAdminRightsToLocallyAdministratedUserError_msg"