![[BACK]](/icons/back.gif){kind=icon}
Return to jump.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / less|
Return to jump.c CVS log | Up to [local] / src / usr.bin / less |
1.1 etheisen 1: /*
1.1.1.2 ! millert 2: * Copyright (C) 1984-2002 Mark Nudelman
1.1 etheisen 3: *
1.1.1.2 ! millert 4: * You may distribute under the terms of either the GNU General Public
! 5: * License or the Less License, as specified in the README file.
1.1 etheisen 6: *
1.1.1.2 ! millert 7: * For more information about less, or for information on how to
! 8: * contact the author, see the README file.
1.1 etheisen 9: */
10:
11:
12: /*
13: * Routines which jump to a new location in the file.
14: */
15:
16: #include "less.h"
17: #include "position.h"
18:
19: extern int hit_eof;
20: extern int jump_sline;
21: extern int squished;
22: extern int screen_trashed;
23: extern int sc_width, sc_height;
1.1.1.2 ! millert 24: extern int show_attn;
1.1 etheisen 25:
26: /*
27: * Jump to the end of the file.
28: */
29: public void
30: jump_forw()
31: {
32: POSITION pos;
33:
34: if (ch_end_seek())
35: {
36: error("Cannot seek to end of file", NULL_PARG);
37: return;
38: }
39: /*
40: * Position the last line in the file at the last screen line.
41: * Go back one line from the end of the file
42: * to get to the beginning of the last line.
43: */
44: pos = back_line(ch_tell());
45: if (pos == NULL_POSITION)
46: jump_loc((POSITION)0, sc_height-1);
47: else
48: jump_loc(pos, sc_height-1);
49: }
50:
51: /*
52: * Jump to line n in the file.
53: */
54: public void
1.1.1.2 ! millert 55: jump_back(linenum)
! 56: LINENUM linenum;
1.1 etheisen 57: {
58: POSITION pos;
59: PARG parg;
60:
61: /*
62: * Find the position of the specified line.
63: * If we can seek there, just jump to it.
64: * If we can't seek, but we're trying to go to line number 1,
65: * use ch_beg_seek() to get as close as we can.
66: */
1.1.1.2 ! millert 67: pos = find_pos(linenum);
1.1 etheisen 68: if (pos != NULL_POSITION && ch_seek(pos) == 0)
69: {
1.1.1.2 ! millert 70: if (show_attn)
! 71: set_attnpos(pos);
1.1 etheisen 72: jump_loc(pos, jump_sline);
1.1.1.2 ! millert 73: } else if (linenum <= 1 && ch_beg_seek() == 0)
1.1 etheisen 74: {
75: jump_loc(ch_tell(), jump_sline);
76: error("Cannot seek to beginning of file", NULL_PARG);
77: } else
78: {
1.1.1.2 ! millert 79: parg.p_linenum = linenum;
! 80: error("Cannot seek to line number %n", &parg);
1.1 etheisen 81: }
82: }
83:
84: /*
85: * Repaint the screen.
86: */
87: public void
88: repaint()
89: {
90: struct scrpos scrpos;
91: /*
92: * Start at the line currently at the top of the screen
93: * and redisplay the screen.
94: */
95: get_scrpos(&scrpos);
96: pos_clear();
97: jump_loc(scrpos.pos, scrpos.ln);
98: }
99:
100: /*
101: * Jump to a specified percentage into the file.
102: */
103: public void
104: jump_percent(percent)
105: int percent;
106: {
107: POSITION pos, len;
108:
109: /*
110: * Determine the position in the file
111: * (the specified percentage of the file's length).
112: */
113: if ((len = ch_length()) == NULL_POSITION)
114: {
115: ierror("Determining length of file", NULL_PARG);
116: ch_end_seek();
117: }
118: if ((len = ch_length()) == NULL_POSITION)
119: {
120: error("Don't know length of file", NULL_PARG);
121: return;
122: }
1.1.1.2 ! millert 123: pos = percent_pos(len, percent);
1.1 etheisen 124: if (pos >= len)
125: pos = len-1;
126:
127: jump_line_loc(pos, jump_sline);
128: }
129:
130: /*
131: * Jump to a specified position in the file.
132: * Like jump_loc, but the position need not be
133: * the first character in a line.
134: */
135: public void
136: jump_line_loc(pos, sline)
137: POSITION pos;
138: int sline;
139: {
140: int c;
141:
142: if (ch_seek(pos) == 0)
143: {
144: /*
145: * Back up to the beginning of the line.
146: */
147: while ((c = ch_back_get()) != '\n' && c != EOI)
148: ;
149: if (c == '\n')
150: (void) ch_forw_get();
151: pos = ch_tell();
152: }
1.1.1.2 ! millert 153: if (show_attn)
! 154: set_attnpos(pos);
1.1 etheisen 155: jump_loc(pos, sline);
156: }
157:
158: /*
159: * Jump to a specified position in the file.
160: * The position must be the first character in a line.
161: * Place the target line on a specified line on the screen.
162: */
163: public void
164: jump_loc(pos, sline)
165: POSITION pos;
166: int sline;
167: {
168: register int nline;
169: POSITION tpos;
170: POSITION bpos;
171:
172: /*
173: * Normalize sline.
174: */
175: sline = adjsline(sline);
176:
177: if ((nline = onscreen(pos)) >= 0)
178: {
179: /*
180: * The line is currently displayed.
181: * Just scroll there.
182: */
183: nline -= sline;
184: if (nline > 0)
185: forw(nline, position(BOTTOM_PLUS_ONE), 1, 0, 0);
186: else
187: back(-nline, position(TOP), 1, 0);
1.1.1.2 ! millert 188: if (show_attn)
! 189: repaint_hilite(1);
1.1 etheisen 190: return;
191: }
192:
193: /*
194: * Line is not on screen.
195: * Seek to the desired location.
196: */
197: if (ch_seek(pos))
198: {
199: error("Cannot seek to that file position", NULL_PARG);
200: return;
201: }
202:
203: /*
204: * See if the desired line is before or after
205: * the currently displayed screen.
206: */
207: tpos = position(TOP);
208: bpos = position(BOTTOM_PLUS_ONE);
209: if (tpos == NULL_POSITION || pos >= tpos)
210: {
211: /*
212: * The desired line is after the current screen.
213: * Move back in the file far enough so that we can
214: * call forw() and put the desired line at the
215: * sline-th line on the screen.
216: */
217: for (nline = 0; nline < sline; nline++)
218: {
219: if (bpos != NULL_POSITION && pos <= bpos)
220: {
221: /*
222: * Surprise! The desired line is
223: * close enough to the current screen
224: * that we can just scroll there after all.
225: */
226: forw(sc_height-sline+nline-1, bpos, 1, 0, 0);
1.1.1.2 ! millert 227: if (show_attn)
! 228: repaint_hilite(1);
1.1 etheisen 229: return;
230: }
231: pos = back_line(pos);
232: if (pos == NULL_POSITION)
233: {
234: /*
235: * Oops. Ran into the beginning of the file.
236: * Exit the loop here and rely on forw()
237: * below to draw the required number of
238: * blank lines at the top of the screen.
239: */
240: break;
241: }
242: }
243: lastmark();
244: hit_eof = 0;
245: squished = 0;
246: screen_trashed = 0;
247: forw(sc_height-1, pos, 1, 0, sline-nline);
248: } else
249: {
250: /*
251: * The desired line is before the current screen.
252: * Move forward in the file far enough so that we
253: * can call back() and put the desired line at the
254: * sline-th line on the screen.
255: */
256: for (nline = sline; nline < sc_height - 1; nline++)
257: {
258: pos = forw_line(pos);
259: if (pos == NULL_POSITION)
260: {
261: /*
262: * Ran into end of file.
263: * This shouldn't normally happen,
264: * but may if there is some kind of read error.
265: */
266: break;
267: }
268: if (pos >= tpos)
269: {
270: /*
271: * Surprise! The desired line is
272: * close enough to the current screen
273: * that we can just scroll there after all.
274: */
275: back(nline+1, tpos, 1, 0);
1.1.1.2 ! millert 276: if (show_attn)
! 277: repaint_hilite(1);
1.1 etheisen 278: return;
279: }
280: }
281: lastmark();
282: clear();
283: screen_trashed = 0;
284: add_back_pos(pos);
285: back(sc_height-1, pos, 1, 0);
286: }
287: }