26.1.4 Secondary Selection

The secondary selection is another way of selecting text using the X Window System. It does not use point or the mark, so you can use it to kill text without setting point or the mark.

M-Drag-Mouse-1

Set the secondary selection, with one end at the place where you press down the button, and the other end at the place where you release it (mouse-set-secondary). The highlighting appears and changes as you drag. You can control the appearance of the highlighting by customizing the secondary-selection face (see section Customizing Faces).

If you move the mouse off the top or bottom of the window while dragging, the window scrolls at a steady rate until you move the mouse back into the window. This way, you can mark regions that don't fit entirely on the screen.

This way of setting the secondary selection does not alter the kill ring.

M-Mouse-1

Set one endpoint for the secondary selection (mouse-start-secondary).

M-Mouse-3

Make a secondary selection, using the place specified with M-Mouse-1 as the other end (mouse-secondary-save-then-kill). This also puts the selected text in the kill ring. A second click at the same place kills the secondary selection just made.

M-Mouse-2

Insert the secondary selection where you click (mouse-yank-secondary). This places point at the end of the yanked text.

Double or triple clicking of M-Mouse-1 operates on words and lines, much like Mouse-1.

If mouse-yank-at-point is non-nil, M-Mouse-2 yanks at point. Then it does not matter precisely where you click, or even which of the frame's windows you click on. See section Mouse Commands for Editing.