Message Tray Drawer

A concept for notifications in GNOME 3.

When a new notification arrives, a banner is shown at the bottom of the screen. This hides after 2 seconds if the user is active.
If no mouse movement or keyboard input is detected, the user is considered idle and the timeout isn’t triggered and the banner stays visible.
- If no pointer device is present, banners always hide after the 2 second time out.
If the pointer is in the location where the banner would normally pop up, the banner only peeks - banners should never appear under the cursor.
Banners include the notification title and one line of the body (if the "Show Details in Banners" option is enabled).
The image is 32x32px.
Actions for banners:
- Pointer - hovering over the banner highlights the banner and expands it.
- On touch - tap or drag up expands the banner
- Super+N keyboard shortcut expands the banner.
Only one banner is shown at a time. Notifications that arrive while a banner is being displayed are queued in the background.
Queued notifications are played back in sequence.

Expanded banners include the notification title, up to three lines of the body, action buttons and a close button.
The main area of the notification highlights on hover, to indicate that it can be selected (buttons use the same hover effect).
Actions for expanded banners:
- Click the main area: performs the default action.
- Clicking outside of the notification or swipe down on touch closes the banner but leaves it in the Message Tray.
- Action buttons can be clicked while the pointer is resting on the bottom screen edge.
- Only the core chat app is able to have a text entry in its expanded banners.

Urgent notifications are displayed in expanded mode and must be explicitly dismissed to be hidden. They are never shown in banner mode.
Banners are queued in the background while an urgent notification is displayed.
The Message Tray can be open while an urgent notification is displayed (although this isn't possible with a pointer).

When the pointer is hovered over or pushed against the bottom screen edge, the top of the Message Tray peeks up from the bottom of the screen. A counter with the number of notifications in the tray is also displayed.
Clicking the banner or counter opens the tray. Super+M keybard shortcut also opens the tray.
On touch, dragging up and over the bottom screen edge opens the tray.

The peeking tray and counter are permanently displayed in the Activities Overview.
Regular notification banners are displayed over the peeking tray and counter.

Hovering over the area around the counter, or against the bottom screen edge, shows the Message Tray banner.
Clicking the banner opens the tray as usual.

Notifications are listed in time/date order, with most recent at the top.
Music is always positioned at the top of the list.
Urgent notifications are positioned at the top of the list, below music.
Notifications show the icon, title, one line of the body, action buttons and a close button.
There is a hard limit of five notifications per application.
The bottom of the tray includes buttons for clearing all notifications, opening notification settings, system tray items and for closing the tray.
If the number of notifications exceeds the visible area, the list scrolls (the close tray, clear, settings and system tray elements are always visible while scrolling).
Esc or Super+M keyboard combination closes the tray.