1 /* Window definitions for GNU Emacs.
2 Copyright (C) 1985, 1986, 1993, 1995 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
6 GNU Emacs is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs; see the file COPYING. If not, write to
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* Windows are allocated as if they were vectors, but then the
23 Lisp data type is changed to Lisp_Window. They are garbage
24 collected along with the vectors.
26 All windows in use are arranged into a tree, with pointers up and down.
28 Windows that are leaves of the tree are actually displayed
29 and show the contents of buffers. Windows that are not leaves
30 are used for representing the way groups of leaf windows are
31 arranged on the frame. Leaf windows never become non-leaves.
32 They are deleted only by calling delete-window on them (but
33 this can be done implicitly). Combination windows can be created
34 and deleted at any time.
36 A leaf window has a non-nil buffer field, and also
37 has markers in its start and pointm fields. Non-leaf windows
38 have nil in these fields.
40 Non-leaf windows are either vertical or horizontal combinations.
42 A vertical combination window has children that are arranged on the frame
43 one above the next. Its vchild field points to the uppermost child.
44 The parent field of each of the children points to the vertical
45 combination window. The next field of each child points to the
46 child below it, or is nil for the lowest child. The prev field
47 of each child points to the child above it, or is nil for the
50 A horizontal combination window has children that are side by side.
51 Its hchild field points to the leftmost child. In each child
52 the next field points to the child to the right and the prev field
53 points to the child to the left.
55 The children of a vertical combination window may be leaf windows
56 or horizontal combination windows. The children of a horizontal
57 combination window may be leaf windows or vertical combination windows.
59 At the top of the tree are two windows which have nil as parent.
60 The second of these is minibuf_window. The first one manages all
61 the frame area that is not minibuffer, and is called the root window.
62 Different windows can be the root at different times;
63 initially the root window is a leaf window, but if more windows
64 are created then that leaf window ceases to be root and a newly
65 made combination window becomes root instead.
67 In any case, on screens which have an ordinary window and a
68 minibuffer, prev of the minibuf window is the root window and next of
69 the root window is the minibuf window. On minibufferless screens or
70 minibuffer-only screens, the root window and the minibuffer window are
71 one and the same, so its prev and next members are nil.
73 A dead window has its buffer, hchild, and vchild windows all nil. */
77 /* The first two fields are really the header of a vector */
78 /* The window code does not refer to them. */
80 struct Lisp_Vector
*vec_next
;
81 /* The frame this window is on. */
83 /* t if this window is a minibuffer window. */
85 /* Following child (to right or down) at same level of tree */
87 /* Preceding child (to left or up) at same level of tree */
89 /* First child of this window. */
90 /* vchild is used if this is a vertical combination,
91 hchild if this is a horizontal combination. */
92 Lisp_Object hchild
, vchild
;
93 /* The window this one is a child of. */
95 /* The upper left corner coordinates of this window,
96 as integers relative to upper left corner of frame = 0, 0 */
99 /* The size of the window */
102 /* The buffer displayed in this window */
103 /* Of the fields vchild, hchild and buffer, only one is non-nil. */
105 /* A marker pointing to where in the text to start displaying */
107 /* A marker pointing to where in the text point is in this window,
108 used only when the window is not selected.
109 This exists so that when multiple windows show one buffer
110 each one can have its own value of point. */
112 /* Non-nil means next redisplay must use the value of start
113 set up for it in advance. Set by scrolling commands. */
114 Lisp_Object force_start
;
115 /* Non-nil means we have explicitly changed the value of start,
116 but that the next redisplay is not obliged to use the new value. */
117 Lisp_Object optional_new_start
;
118 /* Number of columns display within the window is scrolled to the left. */
120 /* Number saying how recently window was selected */
121 Lisp_Object use_time
;
122 /* Unique number of window assigned when it was created */
123 Lisp_Object sequence_number
;
124 /* No permanent meaning; used by save-window-excursion's bookkeeping */
126 /* text.modified of displayed buffer as of last time display completed */
127 Lisp_Object last_modified
;
128 /* BUF_OVERLAY_MODIFIED of displayed buffer as of last complete update. */
129 Lisp_Object last_overlay_modified
;
130 /* Value of point at that time */
131 Lisp_Object last_point
;
132 /* Non-nil if the buffer was "modified" when the window
134 Lisp_Object last_had_star
;
135 /* This window's vertical scroll bar. This field is only for use
136 by the window-system-dependent code which implements the
137 scroll bars; it can store anything it likes here. If this
138 window is newly created and we haven't displayed a scroll bar in
139 it yet, or if the frame doesn't have any scroll bars, this is nil. */
140 Lisp_Object vertical_scroll_bar
;
142 /* The rest are currently not used or only half used */
143 /* Frame coords of point at that time */
144 Lisp_Object last_point_x
;
145 Lisp_Object last_point_y
;
146 /* Frame coords of mark as of last time display completed */
147 /* May be nil if mark does not exist or was not on frame */
148 Lisp_Object last_mark_x
;
149 Lisp_Object last_mark_y
;
150 /* Number of characters in buffer past bottom of window,
151 as of last redisplay that finished. */
152 Lisp_Object window_end_pos
;
153 /* t if window_end_pos is truly valid.
154 This is nil if nontrivial redisplay is preempted
155 since in that case the frame image that window_end_pos
156 did not get onto the frame. */
157 Lisp_Object window_end_valid
;
158 /* Vertical position (relative to window top) of that buffer position
159 of the first of those characters */
160 Lisp_Object window_end_vpos
;
161 /* Non-nil means must regenerate mode line of this window */
162 Lisp_Object update_mode_line
;
163 /* Non-nil means current value of `start'
164 was the beginning of a line when it was chosen. */
165 Lisp_Object start_at_line_beg
;
166 /* Display-table to use for displaying chars in this window.
167 Nil means use the buffer's own display-table. */
168 Lisp_Object display_table
;
169 /* Non-nil means window is marked as dedicated. */
170 Lisp_Object dedicated
;
171 /* Line number and position of a line somewhere above the
172 top of the screen. */
173 /* If this field is nil, it means we don't have a base line. */
174 Lisp_Object base_line_number
;
175 /* If this field is nil, it means we don't have a base line.
176 If it is a buffer, it means don't display the line number
177 as long as the window shows that buffer. */
178 Lisp_Object base_line_pos
;
179 /* If we have highlighted the region (or any part of it),
180 this is the mark position that we used, as an integer. */
181 Lisp_Object region_showing
;
182 /* The column number currently displayed in this window's mode line,
183 or nil if column numbers are not being displayed. */
184 Lisp_Object column_number_displayed
;
185 /* If redisplay in this window goes beyond this buffer position,
186 must run the redisplay-end-trigger-hook. */
187 Lisp_Object redisplay_end_trigger
;
190 /* 1 if W is a minibuffer window. */
192 #define MINI_WINDOW_P(W) (!EQ ((W)->mini_p, Qnil))
194 /* Return the frame column at which the text in window W starts.
195 This is different from the `left' field because it does not include
196 a left-hand scroll bar if any. */
198 #define WINDOW_LEFT_MARGIN(W) \
199 (XFASTINT ((W)->left) \
200 + FRAME_LEFT_SCROLL_BAR_WIDTH (XFRAME (WINDOW_FRAME (W))))
202 /* Return the frame column before window W ends.
203 This includes a right-hand scroll bar, if any. */
205 #define WINDOW_RIGHT_EDGE(W) \
206 (XFASTINT ((W)->left) + XFASTINT ((W)->width))
208 /* Return the frame column before which the text in window W ends.
209 This is different from WINDOW_RIGHT_EDGE because it does not include
210 a scroll bar or window-separating line on the right edge. */
212 #define WINDOW_RIGHT_MARGIN(W) \
213 (WINDOW_RIGHT_EDGE (W) \
214 - (! FRAME_HAS_VERTICAL_SCROLL_BARS (XFRAME (WINDOW_FRAME (W))) \
215 ? ((WINDOW_RIGHTMOST_P (W)) ? 0 : 1) \
216 : FRAME_HAS_VERTICAL_SCROLL_BARS_ON_RIGHT (XFRAME (WINDOW_FRAME (W))) \
217 ? FRAME_SCROLL_BAR_COLS (XFRAME (WINDOW_FRAME (W))) \
220 /* 1 if window W takes up the full width of its frame. */
222 #define WINDOW_FULL_WIDTH_P(W) \
223 (XFASTINT ((W)->width) == FRAME_WINDOW_WIDTH (XFRAME (WINDOW_FRAME (W))))
225 /* 1 if window W's has no other windows to its right in its frame. */
227 #define WINDOW_RIGHTMOST_P(W) \
228 (WINDOW_RIGHT_EDGE (W) == FRAME_WINDOW_WIDTH (XFRAME (WINDOW_FRAME (W))))
230 /* This is the window in which the terminal's cursor should
231 be left when nothing is being done with it. This must
232 always be a leaf window, and its buffer is selected by
233 the top level editing loop at the end of each command.
235 This value is always the same as
236 FRAME_SELECTED_WINDOW (selected_frame). */
238 extern Lisp_Object selected_window
;
240 /* This is a time stamp for window selection, so we can find the least
241 recently used window. Its only users are Fselect_window,
242 init_window_once, and make_frame. */
244 extern int window_select_count
;
246 /* The minibuffer window of the selected frame.
247 Note that you cannot test for minibufferness of an arbitrary window
248 by comparing against this; use the MINI_WINDOW_P macro instead. */
250 extern Lisp_Object minibuf_window
;
252 /* Non-nil => window to for C-M-v to scroll
253 when the minibuffer is selected. */
254 extern Lisp_Object Vminibuf_scroll_window
;
256 /* nil or a symbol naming the window system
257 under which emacs is running
258 ('x is the only current possibility) */
259 extern Lisp_Object Vwindow_system
;
261 /* Version number of X windows: 10, 11 or nil. */
262 extern Lisp_Object Vwindow_system_version
;
264 /* Window that the mouse is over (nil if no mouse support). */
265 extern Lisp_Object Vmouse_window
;
267 /* Last mouse-click event (nil if no mouse support). */
268 extern Lisp_Object Vmouse_event
;
270 EXFUN (Fnext_window
, 3);
271 EXFUN (Fselect_window
, 1);
272 EXFUN (Fdisplay_buffer
, 3);
273 EXFUN (Fset_window_buffer
, 2);
274 extern Lisp_Object make_window
P_ ((void));
275 extern void delete_window
P_ ((Lisp_Object
));
276 extern Lisp_Object window_from_coordinates
P_ ((struct frame
*, int, int, int *));
277 EXFUN (Fwindow_dedicated_p
, 1);
278 extern int window_height
P_ ((Lisp_Object
));
279 extern int window_width
P_ ((Lisp_Object
));
280 extern void set_window_height
P_ ((Lisp_Object
, int, int));
281 extern void set_window_width
P_ ((Lisp_Object
, int, int));
282 extern void change_window_height
P_ ((int, int));
283 extern void delete_all_subwindows
P_ ((struct window
*));
285 /* Prompt to display in front of the minibuffer contents. */
286 extern Lisp_Object minibuf_prompt
;
288 /* The visual width of the above. */
289 extern int minibuf_prompt_width
;
291 /* Message to display instead of minibuffer contents.
292 This is what the functions error and message make,
293 and command echoing uses it as well. It overrides the
294 minibuf_prompt as well as the buffer. */
295 extern char *echo_area_glyphs
;
297 /* This is the length of the message in echo_area_glyphs. */
298 extern int echo_area_glyphs_length
;
300 /* Value of echo_area_glyphs when it was last acted on.
301 If this is nonzero, there is a message on the frame
302 in the minibuffer and it should be erased as soon
303 as it is no longer requested to appear. */
304 extern char *previous_echo_glyphs
;
306 /* This is the window where the echo area message was displayed.
307 It is always a minibuffer window, but it may not be the
308 same window currently active as a minibuffer. */
309 extern Lisp_Object echo_area_window
;
311 /* Depth in recursive edits. */
312 extern int command_loop_level
;
314 /* Depth in minibuffer invocations. */
315 extern int minibuf_level
;
317 /* true iff we should redraw the mode lines on the next redisplay. */
318 extern int update_mode_lines
;
320 /* Minimum value of GPT - BEG since last redisplay that finished. */
322 extern int beg_unchanged
;
324 /* Minimum value of Z - GPT since last redisplay that finished. */
326 extern int end_unchanged
;
328 /* MODIFF as of last redisplay that finished;
329 if it matches MODIFF, beg_unchanged and end_unchanged
330 contain no useful information. */
331 extern int unchanged_modified
;
333 /* BUF_OVERLAY_MODIFF of current buffer, as of last redisplay that finished;
334 if it matches BUF_OVERLAY_MODIFF, beg_unchanged and end_unchanged
335 contain no useful information. */
336 extern int overlay_unchanged_modified
;
338 /* Nonzero if BEGV - BEG or Z - ZV of current buffer has changed
339 since last redisplay that finished. */
340 extern int clip_changed
;
342 /* Nonzero if window sizes or contents have changed
343 since last redisplay that finished */
344 extern int windows_or_buffers_changed
;
346 /* Number of windows displaying the selected buffer.
347 Normally this is 1, but it can be more. */
348 extern int buffer_shared
;
350 /* If *ROWS or *COLS are too small a size for FRAME, set them to the
351 minimum allowable size. */
352 extern void check_frame_size
P_ ((struct frame
*frame
, int *rows
, int *cols
));