xref: /openbsd/gnu/usr.bin/texinfo/info/window.h (revision 1076333c)
1 /* window.h -- Structure and flags used in manipulating Info windows.
2    $Id: window.h,v 1.3 2006/07/17 16:12:36 espie Exp $
3 
4    This file is part of GNU Info, a program for reading online documentation
5    stored in Info format.
6 
7    Copyright (C) 1993, 1997, 2004 Free Software Foundation, Inc.
8 
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 2, or (at your option)
12    any later version.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 
23    Written by Brian Fox (bfox@ai.mit.edu). */
24 
25 #ifndef INFO_WINDOW_H
26 #define INFO_WINDOW_H
27 
28 #include "infomap.h"
29 #include "nodes.h"
30 
31 /* Smallest number of visible lines in a window.  The actual height is
32    always one more than this number because each window has a modeline. */
33 #define WINDOW_MIN_HEIGHT 2
34 
35 /* Smallest number of screen lines that can be used to fully present a
36    window.  This number includes the modeline of the window. */
37 #define WINDOW_MIN_SIZE (WINDOW_MIN_HEIGHT + 1)
38 
39 /* The exact same elements are used within the WINDOW_STATE structure and a
40    subsection of the WINDOW structure.  We could define a structure which
41    contains this elements, and include that structure in each of WINDOW_STATE
42    and WINDOW.  But that would lead references in the code such as
43    window->state->node which we would like to avoid.  Instead, we #define the
44    elements here, and simply include the define in both data structures. Thus,
45    if you need to change window state information, here is where you would
46    do it.  NB> The last element does NOT end with a semi-colon. */
47 #define WINDOW_STATE_DECL \
48    NODE *node;          /* The node displayed in this window. */ \
49    int pagetop;         /* LINE_STARTS[PAGETOP] is first line in WINDOW. */ \
50    long point           /* Offset within NODE of the cursor position. */
51 
52 /* Structure which defines a window.  Windows are doubly linked, next
53    and prev. The list of windows is kept on WINDOWS.  The structure member
54    window->height is the total height of the window.  The position location
55    (0, window->height + window->first_row) is the first character of this
56    windows modeline.  The number of lines that can be displayed in a window
57    is equal to window->height - 1. */
58 typedef struct window_struct
59 {
60   struct window_struct *next;      /* Next window in this chain. */
61   struct window_struct *prev;      /* Previous window in this chain. */
62   int width;            /* Width of this window. */
63   int height;           /* Height of this window. */
64   int first_row;        /* Offset of the first line in the_screen. */
65   int goal_column;      /* The column we would like the cursor to appear in. */
66   Keymap keymap;        /* Keymap used to read commands in this window. */
67   WINDOW_STATE_DECL;    /* Node, pagetop and point. */
68   char *modeline;       /* Calculated text of the modeline for this window. */
69   char **line_starts;   /* Array of printed line starts for this node. */
70   int line_count;       /* Number of lines appearing in LINE_STARTS. */
71   int flags;            /* See below for details. */
72 } WINDOW;
73 
74 typedef struct {
75   WINDOW_STATE_DECL;            /* What gets saved. */
76 } WINDOW_STATE;
77 
78 /* Structure defining the current state of an incremental search. */
79 typedef struct {
80   WINDOW_STATE_DECL;    /* The node, pagetop and point. */
81   int search_index;     /* Offset of the last char in the search string. */
82   int direction;        /* The direction that this search is heading in. */
83   int failing;          /* Whether or not this search failed. */
84 } SEARCH_STATE;
85 
86 #define W_UpdateWindow  0x01    /* WINDOW needs updating. */
87 #define W_WindowIsPerm  0x02    /* This WINDOW is a permanent object. */
88 #define W_WindowVisible 0x04    /* This WINDOW is currently visible. */
89 #define W_InhibitMode   0x08    /* This WINDOW has no modeline. */
90 #define W_NoWrap        0x10    /* Lines do not wrap in this window. */
91 #define W_InputWindow   0x20    /* Window accepts input. */
92 #define W_TempWindow    0x40    /* Window is less important. */
93 
94 extern WINDOW *windows;         /* List of visible Info windows. */
95 extern WINDOW *active_window;   /* The currently active window. */
96 extern WINDOW *the_screen;      /* The Info screen is just another window. */
97 extern WINDOW *the_echo_area;   /* THE_ECHO_AREA is a window in THE_SCREEN. */
98 
99 /* Global variable control redisplay of scrolled windows.  If non-zero, it
100    is the desired number of lines to scroll the window in order to make
101    point visible.  A user might set this to 1 for smooth scrolling.  If
102    set to zero, the line containing point is centered within the window. */
103 extern int window_scroll_step;
104 
105  /* Make the modeline member for WINDOW. */
106 extern void window_make_modeline (WINDOW *window);
107 
108 /* Initalize the window system by creating THE_SCREEN and THE_ECHO_AREA.
109    Create the first window ever, and make it permanent.
110    You pass WIDTH and HEIGHT; the dimensions of the total screen size. */
111 extern void window_initialize_windows (int width, int height);
112 
113 /* Make a new window showing NODE, and return that window structure.
114    The new window is made to be the active window.  If NODE is passed
115    as NULL, then show the node showing in the active window.  If the
116    window could not be made return a NULL pointer.  The active window
117    is not changed.*/
118 extern WINDOW *window_make_window (NODE *node);
119 
120 /* Delete WINDOW from the list of known windows.  If this window was the
121    active window, make the next window in the chain be the active window,
122    or the previous window in the chain if there is no next window. */
123 extern void window_delete_window (WINDOW *window);
124 
125 /* A function to call when the screen changes size, and some windows have
126    to get deleted.  The function is called with the window to be deleted
127    as an argument, and it can't do anything about the window getting deleted;
128    it can only clean up dangling references to that window. */
129 extern VFunction *window_deletion_notifier;
130 
131 /* Set WINDOW to display NODE. */
132 extern void window_set_node_of_window (WINDOW *window, NODE *node);
133 
134 /* Tell the window system that the size of the screen has changed.  This
135    causes lots of interesting things to happen.  The permanent windows
136    are resized, as well as every visible window.  You pass WIDTH and HEIGHT;
137    the dimensions of the total screen size. */
138 extern void window_new_screen_size (int width, int height);
139 
140 /* Change the height of WINDOW by AMOUNT.  This also automagically adjusts
141    the previous and next windows in the chain.  If there is only one user
142    window, then no change takes place. */
143 extern void window_change_window_height (WINDOW *window, int amount);
144 
145 /* Adjust the pagetop of WINDOW such that the cursor point will be visible. */
146 extern void window_adjust_pagetop (WINDOW *window);
147 
148 /* Tile all of the windows currently displayed in the global variable
149    WINDOWS.  If argument DO_INTERNALS is non-zero, tile windows displaying
150    internal nodes as well. */
151 #define DONT_TILE_INTERNALS 0
152 #define TILE_INTERNALS      1
153 extern void window_tile_windows (int style);
154 
155 /* Toggle the state of line wrapping in WINDOW.  This can do a bit of fancy
156    redisplay. */
157 extern void window_toggle_wrap (WINDOW *window);
158 
159 /* For every window in CHAIN, set the flags member to have FLAG set. */
160 extern void window_mark_chain (WINDOW *chain, int flag);
161 
162 /* For every window in CHAIN, clear the flags member of FLAG. */
163 extern void window_unmark_chain (WINDOW *chain, int flag);
164 
165 /* Make WINDOW start displaying at PERCENT percentage of its node. */
166 extern void window_goto_percentage (WINDOW *window, int percent);
167 
168 /* Build a new node which has FORMAT printed with ARG1 and ARG2 as the
169    contents. */
170 extern NODE *build_message_node (char *format, void *arg1, void *arg2);
171 
172 /* Useful functions can be called from outside of window.c. */
173 extern void initialize_message_buffer (void);
174 
175 /* Print FORMAT with ARG1,2 to the end of the current message buffer. */
176 extern void printf_to_message_buffer (char *format, void *arg1, void *arg2,
177     void *arg3);
178 
179 /* Convert the contents of the message buffer to a node. */
180 extern NODE *message_buffer_to_node (void);
181 
182 /* Return the length of the most recently printed line in message buffer. */
183 extern int message_buffer_length_this_line (void);
184 
185 /* Pad STRING to COUNT characters by inserting blanks. */
186 extern int pad_to (int count, char *string);
187 
188 /* Make a message appear in the echo area, built from FORMAT, ARG1 and ARG2.
189    The arguments are treated similar to printf () arguments, but not all of
190    printf () hair is present.  The message appears immediately.  If there was
191    already a message appearing in the echo area, it is removed. */
192 extern void window_message_in_echo_area (char *format, void *arg1, void *arg2);
193 
194 /* Place a temporary message in the echo area built from FORMAT, ARG1
195    and ARG2.  The message appears immediately, but does not destroy
196    any existing message.  A future call to unmessage_in_echo_area ()
197    restores the old contents. */
198 extern void message_in_echo_area (char *format, void *arg1, void *arg2);
199 extern void unmessage_in_echo_area (void);
200 
201 /* Clear the echo area, removing any message that is already present.
202    The echo area is cleared immediately. */
203 extern void window_clear_echo_area (void);
204 
205 /* Quickly guess the approximate number of lines to that NODE would
206    take to display.  This really only counts carriage returns. */
207 extern int window_physical_lines (NODE *node);
208 
209 /* Calculate a list of line starts for the node belonging to WINDOW.  The line
210    starts are pointers to the actual text within WINDOW->NODE. */
211 extern void calculate_line_starts (WINDOW *window);
212 
213 /* Given WINDOW, recalculate the line starts for the node it displays. */
214 extern void recalculate_line_starts (WINDOW *window);
215 
216 /* Return the number of characters it takes to display CHARACTER on the
217    screen at HPOS. */
218 extern int character_width (int character, int hpos);
219 
220 /* Return the number of characters it takes to display STRING on the
221    screen at HPOS. */
222 extern int string_width (char *string, int hpos);
223 
224 /* Return the index of the line containing point. */
225 extern int window_line_of_point (WINDOW *window);
226 
227 /* Get and return the goal column for this window. */
228 extern int window_get_goal_column (WINDOW *window);
229 
230 /* Get and return the printed column offset of the cursor in this window. */
231 extern int window_get_cursor_column (WINDOW *window);
232 
233 /* Get and Set the node, pagetop, and point of WINDOW. */
234 extern void window_get_state (WINDOW *window, SEARCH_STATE *state);
235 extern void window_set_state (WINDOW *window, SEARCH_STATE *state);
236 
237 /* Count the number of characters in LINE that precede the printed column
238    offset of GOAL. */
239 extern int window_chars_to_goal (char *line, int goal);
240 
241 #endif /* not INFO_WINDOW_H */
242