Next: Menu Mouse Clicks, Previous: Clipboard, Up: Frames
Some read-only Emacs buffers include references you can follow, or commands you can activate. These include names of files, of buffers, of possible completions, of matches for a pattern, as well as the buttons in Help buffers and customization buffers. You can follow the reference or activate the command by moving point to it and typing <RET>. You can also do this with the mouse, using either Mouse-1 or Mouse-2.
Since yanking text into a read-only buffer is not allowed, these buffers generally define Mouse-2 to follow a reference or activate a command. For example, if you click Mouse-2 on a file name in a Dired buffer, you visit that file. If you click Mouse-2 on an error message in the ‘*Compilation*’ buffer, you go to the source code for that error message. If you click Mouse-2 on a completion in the ‘*Completions*’ buffer, you choose that completion.
However, most applications use Mouse-1 to do this sort of thing, so Emacs implements this too. If you click Mouse-1 quickly on a reference or button, it follows or activates. If you click slowly, it moves point as usual. Dragging, meaning moving the mouse while it is held down, also has its usual behavior of setting the region.
Normally, the Mouse-1 click behavior is performed on links in
any window. The variable mouse-1-click-in-non-selected-windows
controls whether Mouse-1 has this behavior even in non-selected
windows, or only in the selected window.
You can usually tell when Mouse-1 and Mouse-2 have this
special sort of meaning because the sensitive text highlights when you
move the mouse over it. The variable mouse-highlight
controls
whether to do this highlighting always (even when such text appears
where the mouse already is), never, or only immediately after you move
the mouse.
In Emacs versions before 22, only Mouse-2 follows links and
Mouse-1 always sets points. If you prefer this behavior, set
the variable mouse-1-click-follows-link
to nil
. This
variable also lets you choose various other alternatives for following
links with the mouse. Type C-h v mouse-1-click-follows-link <RET>
for more details.