Epsilon User's Manual and Reference >
General Concepts >
Epsilon's Screen Layout
To see what
buffers and windows look like, refer to the illustration. This
shows what the screen looks like with only one window. It shows what
the screen looks like when you edit a file named screen.1.
The top section of the screen displays some of the text of the
window's buffer. Below that appears the mode line. The mode
line begins with the name of the file shown in that buffer. If the
buffer isn't associated with any file, Epsilon substitutes the buffer
name, in parentheses.
Next comes the name of the current major mode, followed by any
minor modes, all surrounded by square brackets. (See Modes in Epsilon.)
Then Epsilon shows the current column and line numbers (the first
counting from zero, the second counting from 1), and the percentage of
the buffer before the cursor. A star (*) at the end of the line means
that you have changed the buffer since the last time you saved it to
disk. (See the mode-format variable for information on
customizing the contents of the mode line.) The text area and the
mode line collectively constitute the window.
Below the mode line, on the last line of the screen, appears the
echo area. Epsilon uses this area to prompt you for information
or to display messages (in the figure it's empty). For example, the
command to read a file into a buffer uses the echo area to ask you
for the file name. Regardless of how many windows you have on the
screen, the echo area always occupies the bottommost screen line.
When Epsilon displays a message in the echo
area, it also records the message in the
(except for certain transient messages). See the
message-history-size variable to set how Epsilon keeps the
buffer from excessive size by dropping old messages.
Epsilon has an important concept called the editing
point, or simply point. While editing a buffer, the editing
point refers to the place that editing "happens", as indicated by
the cursor. Point refers not to a character position, but rather to
a character boundary, a place between characters. You can
think of point as, roughly, the leftmost edge of the cursor.
Defining the editing point as a position between characters rather
than at a particular character avoids certain ambiguities inherent in
the latter definition.
Consider, for example, the command that goes to the end of a word,
forward-word. Since point always refers to a position between
characters, point moves right after the last letter in
the word. So the cursor itself would appear underneath the first
character after the word. The command that moves to the beginning of
the word, backward-word, positions point right before
the first character in the word. In this case, the cursor itself
would appear under the first character in the word.
When you want to specify a region, this definition for point avoids
whether characters near each end belong to the region, since the ends
do not represent characters themselves, but rather character boundaries.
The illustration shows Epsilon with 3
windows. The top window and bottom window each show the buffer
"main". Notice that although these two windows display the
same buffer, they show different parts of the buffer. The mode line
of the top window says 0%, but the mode line of the bottom window
says 58%. The middle window displays a different buffer, named
"other". If the cursor appears in the middle window and
you type regular letters (the letters of your name, for example), they
go into the buffer named "other" shown in that window. As
you type the letters, the point (and so the cursor) stays to the
right of the letters.
In general, the current window refers to the window with the
cursor, or the window where the "editing happens". The current
buffer refers to the buffer displayed by the current window.
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