How can I change the window movement key when using Unity 2D?

Question

The default window movement key (alt) conflicts with several programs that I use fairly often. I'm sure some users find this key binding useful but I really need to change it to something else so that I can be productive.

I looked in the most logical place:

System Settings > Keyboard > Shortcuts (Tab) > Windows

While there is a 'Move Window' item listed it appears to be an additional way to move windows. Where can I change the key that is bound to the following combination:

depress (and hold) alt key + left mouse button click

I'm using Unity 2D with metacity. The Compiz plugin solution referred to in similar questions will not help me.

Here is a screenshot of the old 11.04 Window Preferences illustrating what I'm trying to do:

Answer 1

I was calling it the 'window movement key' (based on the Window Preferences settings from Ubuntu 11.04). It seems in practice it's actually referred to as the 'mouse button modifier'.

Install the 'Configuration Editor' (gconf-editor) from the Ubuntu Software Center. You can use it to change the key.. or manually do it from the terminal with:

gconftool --set --type string /apps/metacity/general/mouse_button_modifier "<Super>"

The default value is <Alt>. I've changed it above to be the super (Windows) key. Other valid values are <Shift>, and <Control>.

Here's the description of the key from gnome.org:

"Clicking a window while holding down this modifier key will move the window (left click), resize the window (middle click), or show the window menu (right click). The middle and right click operations may be swapped using the "resize_with_right_button" key. Modifier is expressed as "<Alt>" or "<Super>" for example."

Answer 2

in ubuntu 15.10 this doesn't work. you can install:

sudo apt-get install compizconfig-settings-manager

then, ( e.g. use dash) to run CompizConfig Settings Manager (not sure what the command line is).

Go to Window Management, click 'MoveWindow'; click under Initiate Window Move for the mouse icon (vs. the keyboard icon) the <Alt> Button1, there, toggle the 'Super' to green, and toggle the 'Alt' to black.