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6bf7aab6 | 1 | @c This is part of the Emacs manual. |
739a80b3 | 2 | @c Copyright (C) 1985,86,87,93,94,95,1997,2001 Free Software Foundation, Inc. |
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3 | @c See file emacs.texi for copying conditions. |
4 | @node Screen, User Input, Acknowledgments, Top | |
5 | @chapter The Organization of the Screen | |
6 | @cindex screen | |
7 | @cindex parts of the screen | |
8 | @c | |
9 | ||
10 | On a text-only terminal, the Emacs display occupies the whole screen. | |
11 | On the X Window System, Emacs creates its own X windows to use. We use | |
12 | the term @dfn{frame} to mean an entire text-only screen or an entire X | |
13 | window used by Emacs. Emacs uses both kinds of frames in the same way | |
14 | to display your editing. Emacs normally starts out with just one frame, | |
15 | but you can create additional frames if you wish. @xref{Frames}. | |
16 | ||
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17 | When you start Emacs, the entire frame except for the top and bottom |
18 | is devoted to the text you are editing. This area is called the | |
19 | @dfn{window}. At the top there is normally a @dfn{menu bar} where you | |
20 | can access a series of menus; then there may be a @dfn{tool bar}, a | |
21 | row of icons that perform editing commands if you click on them. | |
22 | Below this, the window begins. The last line is a special @dfn{echo | |
23 | area} or @dfn{minibuffer window}, where prompts appear and where you | |
ffa7d02a | 24 | enter information when Emacs asks for it. See below for more |
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25 | information about these special lines. |
26 | ||
27 | You can subdivide the large text window horizontally or vertically | |
28 | into multiple text windows, each of which can be used for a different | |
29 | file (@pxref{Windows}). In this manual, the word ``window'' always | |
30 | refers to the subdivisions of a frame within Emacs. | |
31 | ||
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32 | At any time, one window is the @dfn{selected window}; the most |
33 | prominent cursor indicates which window is selected. Most Emacs | |
34 | commands implicitly apply to the text in the selected window (though | |
35 | mouse commands generally operate on whatever window you click them in, | |
36 | whether selected or not). The other windows display text for | |
37 | reference only, unless/until you select them. If you use multiple | |
38 | frames under the X Window System, then giving the input focus to a | |
39 | particular frame selects a window in that frame. | |
6bf7aab6 | 40 | |
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41 | Each window's last line is a @dfn{mode line}, which describes what |
42 | is going on in that window. It appears in inverse video, if the | |
43 | terminal supports that; its contents normally begin with | |
44 | @w{@samp{--:-- @ *scratch*}} when Emacs starts. The mode line | |
45 | displays status information such as what buffer is being displayed | |
46 | above it in the window, what major and minor modes are in use, and | |
47 | whether the buffer contains unsaved changes. | |
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48 | |
49 | @menu | |
50 | * Point:: The place in the text where editing commands operate. | |
51 | * Echo Area:: Short messages appear at the bottom of the screen. | |
52 | * Mode Line:: Interpreting the mode line. | |
53 | * Menu Bar:: How to use the menu bar. | |
54 | @end menu | |
55 | ||
56 | @node Point | |
57 | @section Point | |
58 | @cindex point | |
59 | @cindex cursor | |
60 | ||
61 | Within Emacs, the terminal's cursor shows the location at which | |
62 | editing commands will take effect. This location is called @dfn{point}. | |
63 | Many Emacs commands move point through the text, so that you can edit at | |
64 | different places in it. You can also place point by clicking mouse | |
65 | button 1. | |
66 | ||
67 | While the cursor appears to point @emph{at} a character, you should | |
68 | think of point as @emph{between} two characters; it points @emph{before} | |
69 | the character that appears under the cursor. For example, if your text | |
70 | looks like @samp{frob} with the cursor over the @samp{b}, then point is | |
71 | between the @samp{o} and the @samp{b}. If you insert the character | |
72 | @samp{!} at that position, the result is @samp{fro!b}, with point | |
73 | between the @samp{!} and the @samp{b}. Thus, the cursor remains over | |
74 | the @samp{b}, as before. | |
75 | ||
76 | Sometimes people speak of ``the cursor'' when they mean ``point,'' or | |
77 | speak of commands that move point as ``cursor motion'' commands. | |
78 | ||
6bf7aab6 | 79 | If you are editing several files in Emacs, each in its own buffer, |
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80 | each buffer has its own point location. A buffer that is not |
81 | currently displayed remembers its point location in case you display | |
82 | it again later. When Emacs displays multiple windows, each window has | |
83 | its own point location. If the same buffer appears in more than one | |
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84 | window, each window has its own position for point in that buffer, and |
85 | (when possible) its own cursor. | |
86 | ||
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87 | A text-only terminal has just one cursor, so Emacs puts it |
88 | in the selected window. The other windows do not show a cursor, even | |
89 | though they do have a location of point. When Emacs updates the | |
90 | screen on a text-only terminal, it has to put the cursor temporarily | |
91 | at the place the output goes. This doesn't mean point is there, | |
92 | though. Once display updating finishes, Emacs puts the cursor where | |
93 | point is. | |
94 | ||
95 | On graphical terminals, Emacs shows a cursor in each window; the | |
96 | selected window's cursor is solid or blinking, and the other cursors | |
97 | are just hollow. Thus, the most striking cursor always shows you | |
98 | the selected window, on all kinds of terminals. | |
99 | ||
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100 | @xref{Cursor Display}, for customization options that control display |
101 | of the cursor or cursors. | |
6bf7aab6 | 102 | |
2684ed46 | 103 | The term ``point'' comes from the character @samp{.}, which was the |
6bf7aab6 | 104 | command in TECO (the language in which the original Emacs was written) |
2684ed46 | 105 | for accessing the value now called ``point.'' |
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106 | |
107 | @node Echo Area | |
108 | @section The Echo Area | |
109 | @cindex echo area | |
177c0ea7 | 110 | @c |
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111 | |
112 | The line at the bottom of the frame (below the mode line) is the | |
113 | @dfn{echo area}. It is used to display small amounts of text for | |
114 | several purposes. | |
115 | ||
116 | @dfn{Echoing} means displaying the characters that you type. Outside | |
117 | Emacs, the operating system normally echoes all your input. Emacs | |
118 | handles echoing differently. | |
119 | ||
120 | Single-character commands do not echo in Emacs, and multi-character | |
121 | commands echo only if you pause while typing them. As soon as you pause | |
122 | for more than a second in the middle of a command, Emacs echoes all the | |
123 | characters of the command so far. This is to @dfn{prompt} you for the | |
124 | rest of the command. Once echoing has started, the rest of the command | |
125 | echoes immediately as you type it. This behavior is designed to give | |
126 | confident users fast response, while giving hesitant users maximum | |
127 | feedback. You can change this behavior by setting a variable | |
af6eba70 | 128 | (@pxref{Display Custom}). |
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129 | |
130 | @cindex error message in the echo area | |
1ba2ce68 | 131 | If a command cannot be executed, it may display an @dfn{error message} |
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132 | in the echo area. Error messages are accompanied by beeping or by |
133 | flashing the screen. The error also discards any input you have typed | |
134 | ahead. | |
6bf7aab6 | 135 | |
1ba2ce68 | 136 | Some commands display informative messages in the echo area. These |
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137 | messages look much like error messages, but they are not announced |
138 | with a beep and do not throw away input. Sometimes the message tells | |
139 | you what the command has done, when this is not obvious from looking | |
140 | at the text being edited. Sometimes the sole purpose of a command is | |
141 | to show you a message giving you specific information---for example, | |
142 | @kbd{C-x =} (hold down @key{CTRL} and type @kbd{x}, then let go of | |
143 | @key{CTRL} and type @kbd{=}) displays a message describing the | |
144 | character position of point in the text and its current column in the | |
145 | window. Commands that take a long time often display messages ending | |
146 | in @samp{...} while they are working, and add @samp{done} at the end | |
147 | when they are finished. | |
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148 | |
149 | @cindex @samp{*Messages*} buffer | |
150 | @cindex saved echo area messages | |
151 | @cindex messages saved from echo area | |
152 | Echo-area informative messages are saved in an editor buffer named | |
153 | @samp{*Messages*}. (We have not explained buffers yet; see | |
154 | @ref{Buffers}, for more information about them.) If you miss a message | |
155 | that appears briefly on the screen, you can switch to the | |
156 | @samp{*Messages*} buffer to see it again. (Successive progress messages | |
157 | are often collapsed into one in that buffer.) | |
158 | ||
159 | @vindex message-log-max | |
160 | The size of @samp{*Messages*} is limited to a certain number of lines. | |
161 | The variable @code{message-log-max} specifies how many lines. Once the | |
162 | buffer has that many lines, each line added at the end deletes one line | |
163 | from the beginning. @xref{Variables}, for how to set variables such as | |
164 | @code{message-log-max}. | |
165 | ||
166 | The echo area is also used to display the @dfn{minibuffer}, a window that | |
167 | is used for reading arguments to commands, such as the name of a file to be | |
168 | edited. When the minibuffer is in use, the echo area begins with a prompt | |
169 | string that usually ends with a colon; also, the cursor appears in that line | |
170 | because it is the selected window. You can always get out of the | |
171 | minibuffer by typing @kbd{C-g}. @xref{Minibuffer}. | |
172 | ||
173 | @node Mode Line | |
174 | @section The Mode Line | |
175 | @cindex mode line | |
176 | @cindex top level | |
177 | @c | |
178 | ||
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179 | Each text window's last line is a @dfn{mode line}, which describes |
180 | what is going on in that window. When there is only one text window, | |
181 | the mode line appears right above the echo area; it is the | |
8858fc50 | 182 | next-to-last line in the frame. The mode line starts and ends with |
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183 | dashes. On a text-mode display, the mode line is in inverse video if |
184 | the terminal supports that; on a graphics display, the mode line has a | |
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185 | 3D box appearance to help it stand out. The mode line of the |
186 | selected window has a slightly different appearance than those of | |
187 | other windows; see @ref{Optional Mode Line}, for more about this. | |
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188 | |
189 | Normally, the mode line looks like this: | |
190 | ||
191 | @example | |
778a11ff | 192 | -@var{cs}:@var{ch} @var{buf} @var{line} @var{pos} (@var{major} @var{minor})------ |
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193 | @end example |
194 | ||
195 | @noindent | |
196 | This gives information about the buffer being displayed in the window: the | |
197 | buffer's name, what major and minor modes are in use, whether the buffer's | |
198 | text has been changed, and how far down the buffer you are currently | |
199 | looking. | |
200 | ||
201 | @var{ch} contains two stars @samp{**} if the text in the buffer has | |
202 | been edited (the buffer is ``modified''), or @samp{--} if the buffer has | |
203 | not been edited. For a read-only buffer, it is @samp{%*} if the buffer | |
204 | is modified, and @samp{%%} otherwise. | |
205 | ||
206 | @var{buf} is the name of the window's @dfn{buffer}. In most cases | |
207 | this is the same as the name of a file you are editing. @xref{Buffers}. | |
208 | ||
209 | The buffer displayed in the selected window (the window that the | |
66e46e19 | 210 | cursor is in) is also Emacs's current buffer, the one that editing |
6bf7aab6 | 211 | takes place in. When we speak of what some command does to ``the |
66e46e19 | 212 | buffer,'' we are talking about the current buffer. |
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213 | |
214 | @var{line} is @samp{L} followed by the current line number of point. | |
215 | This is present when Line Number mode is enabled (which it normally is). | |
216 | You can optionally display the current column number too, by turning on | |
217 | Column Number mode (which is not enabled by default because it is | |
218 | somewhat slower). @xref{Optional Mode Line}. | |
219 | ||
220 | @var{pos} tells you whether there is additional text above the top of | |
221 | the window, or below the bottom. If your buffer is small and it is all | |
222 | visible in the window, @var{pos} is @samp{All}. Otherwise, it is | |
223 | @samp{Top} if you are looking at the beginning of the buffer, @samp{Bot} | |
224 | if you are looking at the end of the buffer, or @samp{@var{nn}%}, where | |
225 | @var{nn} is the percentage of the buffer above the top of the | |
226 | window.@refill | |
227 | ||
228 | @var{major} is the name of the @dfn{major mode} in effect in the | |
229 | buffer. At any time, each buffer is in one and only one of the possible | |
230 | major modes. The major modes available include Fundamental mode (the | |
231 | least specialized), Text mode, Lisp mode, C mode, Texinfo mode, and many | |
232 | others. @xref{Major Modes}, for details of how the modes differ and how | |
233 | to select one.@refill | |
234 | ||
235 | Some major modes display additional information after the major mode | |
236 | name. For example, Rmail buffers display the current message number and | |
237 | the total number of messages. Compilation buffers and Shell buffers | |
238 | display the status of the subprocess. | |
239 | ||
240 | @var{minor} is a list of some of the @dfn{minor modes} that are turned | |
241 | on at the moment in the window's chosen buffer. For example, | |
242 | @samp{Fill} means that Auto Fill mode is on. @samp{Abbrev} means that | |
243 | Word Abbrev mode is on. @samp{Ovwrt} means that Overwrite mode is on. | |
244 | @xref{Minor Modes}, for more information. @samp{Narrow} means that the | |
245 | buffer being displayed has editing restricted to only a portion of its | |
246 | text. This is not really a minor mode, but is like one. | |
247 | @xref{Narrowing}. @samp{Def} means that a keyboard macro is being | |
248 | defined. @xref{Keyboard Macros}. | |
249 | ||
250 | In addition, if Emacs is currently inside a recursive editing level, | |
251 | square brackets (@samp{[@dots{}]}) appear around the parentheses that | |
252 | surround the modes. If Emacs is in one recursive editing level within | |
253 | another, double square brackets appear, and so on. Since recursive | |
254 | editing levels affect Emacs globally, not just one buffer, the square | |
255 | brackets appear in every window's mode line or not in any of them. | |
256 | @xref{Recursive Edit}.@refill | |
257 | ||
258 | Non-windowing terminals can only show a single Emacs frame at a time | |
259 | (@pxref{Frames}). On such terminals, the mode line displays the name of | |
260 | the selected frame, after @var{ch}. The initial frame's name is | |
261 | @samp{F1}. | |
262 | ||
263 | @var{cs} states the coding system used for the file you are editing. | |
264 | A dash indicates the default state of affairs: no code conversion, | |
265 | except for end-of-line translation if the file contents call for that. | |
266 | @samp{=} means no conversion whatsoever. Nontrivial code conversions | |
267 | are represented by various letters---for example, @samp{1} refers to ISO | |
268 | Latin-1. @xref{Coding Systems}, for more information. If you are using | |
269 | an input method, a string of the form @samp{@var{i}>} is added to the | |
270 | beginning of @var{cs}; @var{i} identifies the input method. (Some input | |
271 | methods show @samp{+} or @samp{@@} instead of @samp{>}.) @xref{Input | |
272 | Methods}. | |
273 | ||
274 | When you are using a character-only terminal (not a window system), | |
275 | @var{cs} uses three characters to describe, respectively, the coding | |
276 | system for keyboard input, the coding system for terminal output, and | |
277 | the coding system used for the file you are editing. | |
278 | ||
279 | When multibyte characters are not enabled, @var{cs} does not appear at | |
280 | all. @xref{Enabling Multibyte}. | |
281 | ||
282 | @cindex end-of-line conversion, mode-line indication | |
283 | The colon after @var{cs} can change to another string in certain | |
ad4a78d6 | 284 | circumstances. Emacs uses newline characters to separate lines in the buffer. |
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285 | Some files use different conventions for separating lines: either |
286 | carriage-return linefeed (the MS-DOS convention) or just carriage-return | |
287 | (the Macintosh convention). If the buffer's file uses carriage-return | |
288 | linefeed, the colon changes to either a backslash (@samp{\}) or | |
289 | @samp{(DOS)}, depending on the operating system. If the file uses just | |
290 | carriage-return, the colon indicator changes to either a forward slash | |
291 | (@samp{/}) or @samp{(Mac)}. On some systems, Emacs displays | |
292 | @samp{(Unix)} instead of the colon even for files that use newline to | |
293 | separate lines. | |
294 | ||
295 | @vindex eol-mnemonic-unix | |
296 | @vindex eol-mnemonic-dos | |
297 | @vindex eol-mnemonic-mac | |
298 | @vindex eol-mnemonic-undecided | |
299 | You can customize the mode line display for each of the end-of-line | |
300 | formats by setting each of the variables @code{eol-mnemonic-unix}, | |
301 | @code{eol-mnemonic-dos}, @code{eol-mnemonic-mac}, and | |
302 | @code{eol-mnemonic-undecided} to any string you find appropriate. | |
4e3a22f8 | 303 | @xref{Variables}, for an explanation of how to set variables. |
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304 | |
305 | @xref{Optional Mode Line}, for features that add other handy | |
306 | information to the mode line, such as the current column number of | |
307 | point, the current time, and whether new mail for you has arrived. | |
308 | ||
446809ab RS |
309 | The mode line is mouse-sensitive; when you move the mouse across |
310 | various parts of it, Emacs displays help text to say what a click in | |
311 | that place will do. @xref{Mode Line Mouse}. | |
ad4a78d6 | 312 | |
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313 | @node Menu Bar |
314 | @section The Menu Bar | |
315 | @cindex menu bar | |
316 | ||
317 | Each Emacs frame normally has a @dfn{menu bar} at the top which you | |
318 | can use to perform certain common operations. There's no need to list | |
319 | them here, as you can more easily see for yourself. | |
320 | ||
321 | @kindex M-` | |
322 | @kindex F10 | |
323 | @findex tmm-menubar | |
324 | When you are using a window system, you can use the mouse to choose a | |
325 | command from the menu bar. An arrow pointing right, after the menu | |
326 | item, indicates that the item leads to a subsidiary menu; @samp{...} at | |
327 | the end means that the command will read arguments from the keyboard | |
328 | before it actually does anything. | |
329 | ||
330 | To view the full command name and documentation for a menu item, type | |
331 | @kbd{C-h k}, and then select the menu bar with the mouse in the usual | |
332 | way (@pxref{Key Help}). | |
333 | ||
334 | On text-only terminals with no mouse, you can use the menu bar by | |
335 | typing @kbd{M-`} or @key{F10} (these run the command | |
336 | @code{tmm-menubar}). This command enters a mode in which you can select | |
337 | a menu item from the keyboard. A provisional choice appears in the echo | |
338 | area. You can use the left and right arrow keys to move through the | |
339 | menu to different choices. When you have found the choice you want, | |
340 | type @key{RET} to select it. | |
341 | ||
342 | Each menu item also has an assigned letter or digit which designates | |
343 | that item; it is usually the initial of some word in the item's name. | |
344 | This letter or digit is separated from the item name by @samp{=>}. You | |
345 | can type the item's letter or digit to select the item. | |
346 | ||
347 | Some of the commands in the menu bar have ordinary key bindings as | |
348 | well; if so, the menu lists one equivalent key binding in parentheses | |
349 | after the item itself. |