Application Switcher Auto-Selects Based on Mouse Hover

[Cerin]

In Ubuntu ~17 and earlier, when using Gnome-Shell, switching applications via the standard alt+tab would bring up a display of all the running gui applications, allowing one to be selected via mouse or keyboard.

You could select an application by hovering over the application's icon in this view, but the select required that you to first move your cursor.

By default, the next to last used application would be selected, even if the mouse was placed in an area of the screen that caused it to be hovering over another application when the application switcher display was shown.

In Ubuntu 18, this behavior has regressed. Now, if the mouse is placed in an area where the application switcher renders its display, the switcher will auto-select whatever application is beneath it.

This is immensely frustrating as it breaks the application switcher's ordering heuristic. The switcher orders applications in the list based on recency of use, so you can select the most recently used applications by pressing alt+tab a few times. This makes sense, as the probability of a user selecting an application is related to how long ago they last used an application.

However, now that the application switcher immediately selects the application beneath the mouse, this breaks this functionality. The user now has to tab over or use the mouse or arrow keys to scroll through a long list of applications to get to the one they want.

As the application switcher occupies between 1/5 and 1/3 of the screen space in the vertical center of the screen (depending on resolution and number of applications running) and the user usually places their cursor near the center of the screen, there's a good chance that the cursor will be placed in an area that will cause it to auto-select the wrong application when the application switcher activates.

The preferred behavior would be in that the application switcher ignores mouse cursor position when initially rendering and selecting the default application, until an explicit mouse movement is made. This was the functionality prior to Ubuntu 18.

[Daniel van Vugt (vanvugt)]

We're already discussing this problem upstream:
https://gitlab.gnome.org/GNOME/gnome-shell/issues/1506