By default, Emacs supports all the normal mouse actions like setting the cursor by clicking on the left mouse button, and selecting an area by dragging the mouse pointer. All mouse actions can be used to bind commands in the same way you bind them to keyboard events (see Keys). This section provides a general overview of using the mouse in Emacs; see Mouse Commands for Editing, and the sections that follow it, for more details about mouse commands in Emacs.
When you click the left mouse button, Emacs receives a
mouse-1 event. To see what command is bound to that event, you
can type C-h c and then press the left mouse button. Similarly,
the middle mouse button is mouse-2 and the right mouse button is
mouse-3. If you have a mouse with a wheel, the wheel events
are commonly bound to either wheel-down or wheel-up, or
mouse-4 and mouse-5, but that depends on the operating
system configuration.
In general, legacy X systems and terminals (see Using a Mouse in Text Terminals)
will report mouse-4 and mouse-5, while all other systems
will report wheel-down and wheel-up.
Some mice also have a horizontal scroll wheel, and touchpads usually
support scrolling horizontally as well. These events are reported as
wheel-left and wheel-right on all systems other than
terminals and legacy X systems, where they are mouse-6 and
mouse-7.
You can also combine keyboard modifiers with mouse events, so you
can bind a special command that triggers when you, for instance, holds
down the Meta key and then uses the middle mouse button. In that
case, the event name will be M-mouse-2.
On some systems, you can also bind commands for handling touch
screen events. In that case, the events are called
touchscreen-update and touchscreen-end.