Saved Desks

Saved Desks refers to any features which involve saving the active desk with all its applications and then launching the saved desk via a UI in overview mode with all its applications in their saved states. There are two such features; Desk Templates and Save and Recall. They have a few differences but both involve saving a desk and launching it at a later time. Save and Recall is available for all users while Desk Templates has to be turned on via policy or a flag: "enable-desks-templates".

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User Journey

Overview Mode

The user starts off in overview mode - ash/wm/overview/. There are two buttons named "Save desk as a template" and "Save desk for later". Both buttons will save the active desk and its applications; "Save desk for later", which is Save and Recall will additionally close the active desk and all its windows. The button will be disabled or hidden if the active desk cannot be saved.

Desk Storage Model

Saving a desk triggers a call to the model which serializes and stores the desk. The model logic is in components/desks_storage/. There are two ways to store the desk:

1. Using DeskSyncBridge which stores it in the cloud via Chrome Sync.
2. Using LocalDeskDataManager which writes it to a file.

Both models support the same functionalities and are interchangeable from code in ash/ standpoint.

Library Page

This is the main UI the user interacts with. It is a page within overview mode accessed by pressing the "Library" button on the desks bar. It contains grids of items with each item representing one saved desk. The item gives information such as time, name and a visual representation of what applications and tabs are saved in the form of application icons and tab favicons. Additionally, users can use buttons and a textfield on the item to launch, delete or update the corresponding saved desks. There are also dialogs and toasts to assist users with using the features.

Launching Applications

Launching applications is done via ChromeDesksTemplatesDelegate, which lives in chrome/. Launching applications requires dependencies which are forbidden in ash/, such as app service, profiles and browser code.

Launching applications code is shared with the full restore feature. There are a couple differences, including:

1. Support to move applications which only support a single instance and are already open.
2. Browser windows are created from scratch; full restore uses session restore to relaunch browser windows.

Launched templates have an associated SavedDesk object, which contains the info necessary to launch the associated applications. The info is parsed by the model into a app_restore::RestoreData object, which is part of the components/app_restore library. This library is also used by full restore and contains the logic to create the application widgets with the correct bounds. Just like full restore, additional ash/ logic like MRU order and window states will be handled in WindowRestoreController.

Differences

Though the two features are closely related and share a lot of code, they have a couple differences. Desk templates is aimed towards reducing manual setup for repetitive tasks, and templates created by an admin. Desks and templates are not automatically deleted when using this feature. Save and recall is aimed towards picking up where a user left off. Desks are deleted once saved, and templates are deleted once launched. This reduces the number of user interactions when dealing with the virtual desks limit and the saved desks limit.