Ubuntu – How to disable ‘Activities’ hot corner in GNOME shell

For 11.10

The location of this was changed for 11.04, for 11.04 look below. You can do this with a quick edit of the file /usr/share/gnome-shell/js/ui/layout.js If you find the code:

this._corner = new Clutter.Rectangle({ name: 'hot-corner',
                                       width: 1,
                                       height: 1,
                                       opacity: 0,
                                       reactive: true });

Change reactive: true to reactive: false and it will disable the hot corner but still allow to activate the overview screen by clicking the Activities button or by pressing the Super (Windows) key.

I'm going to look into making an extension to modify this behaviour instead of direct modification of the panel.js file as it will be overwritten with updates.

For 11.04

Same as above but edit the file /usr/share/gnome-shell/js/ui/panel.js:

this._corner = new Clutter.Rectangle({ width: 1,
                                       height: 1,
                                       opacity: 0,
                                       reactive: true });

The button next to "Activities" is called "App Menu".

App Menu can be designed to contain not just "close" option, but other options related to the corresponding application, e.g. Preferences/Settings, Help, About etc. But almost all the third-party applications (if not all) are not yet designed to contain any options other than close. If you run native GNOME applications like Files (aka Nautilus), Text Editor (aka Gedit) etc. you'll find there are options other than close.

To remove App Menu from the top-bar you may use (GNOME) Tweaks. First install it by running

sudo apt install gnome-tweak-tool

Then launch Tweaks, go to "Top Bar" section and toggle off the "Application Menu" option.