[sdk] Always reserve space for three actions in header

[Tim Peeters]

Currently there is room for 3 actions directly in the header, including a back/cancel button or tabs button on the left side.

So without a button on the left, there is room for 3 actions on the right, but when there is an action on the left, only 2 actions are allowed on the right side. I think this is confusing for the users (some times you have 3 buttons, and some times 1 normal button plus an overflow button with two actions in the overflow) and not really necessary.

I propose to (on a phone) always reserve space for 3 actions on the right side in the header, even if there is an action in the left of the header.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Cris Dywan (kalikiana)]

I have been confused by this behavior before, for instance in scopes eg. "Today" where the favorite and settings buttons are hidden if you only open it from the all scopes screen. It wasn't obvious to me that they had changed places with a menu button.

[Stefano Verzegnassi (verzegnassi-stefano)]

In my opinion, it would be better to reserve space for two actions on the right.

The reason is that 4 actions on the header will use more than half of the header width, and there are some app that need that space in order to display the page title (e.g. chat name in Telegram, or document name in docviewer-app).

Also, I'd force the two actions number even when there is no action in the left of the header.
I think about Unity scopes: "Add to favourite" and "Settings" actions should always stay in a context menu, since they are secondary actions.

I took a look at the other core apps, and there will be no problem at all with this change:
Dialer, address-book, messaging-app already use the bottom edge for the main action.

Browser, terminal-app and clock-app use a custom header.

Calculator-app doesn't have an header at all.

Calendar-app: it has a left-action and it needs to show one more action on the right of the header ("New event"). However, it could be exposed by a bottom-edge component, so this is not a real issue.

Telegram: similar issue as calendar-app. It shows three actions on the right of the header, but "Compose" action could be moved on the bottom-edge (and it would be consistent with messaging-app).

[Giorgio Venturi (giorgio-venturi-deactivatedaccount)]

Hi,

The Design Guidelines say:
"The Header features a maximum of four slots that can be arranged and combined to fulfill the users' needs. When there is no back or navigation drawer, there may be three slots on the right side of the title".

https://design.ubuntu.com/apps/building-blocks/header

- On a default header, max 3 slots for actions, one for title
- On multi-select mode, 4 slots for actions

The rule is really simple and it should not confuse the user. Usability/Beta testing do not show any issues in this regards sofar.