Mouse chording is the capability of performing actions when multiple mouse buttons are held down, much like a chorded keyboard.
Plan 9 heavily makes use of mouse chording. It behaves on text in the following manner
- the left (button 1) selects
- holding the left and clicking the middle (button 2) cuts
- holding the left and clicking the right (button 3) pastes
Copying is effected by holding the left, then clicking the middle and right in succession (X under UNIX systems has chording-like capability similar to Plan 9's, but functions with single buttons and not multiple ones). This behavior is common to all text windows under Plan 9, but can have different capability under different contexts. In Plan 9's acme editor, the following happens:
- button 1 selects as normally
- button 2 performs an action
- button 3 performs context-based actions