| blob | e8dc7293d29227df90fe09a8eb059886d1ee9955 |
2 /*******************************************************************************
3 * *
4 * textDisp.c - Display text from a text buffer *
5 * *
6 * Copyright (C) 1999 Mark Edel *
7 * *
8 * This is free software; you can redistribute it and/or modify it under the *
9 * terms of the GNU General Public License as published by the Free Software *
10 * Foundation; either version 2 of the License, or (at your option) any later *
11 * version. *
12 * *
13 * This software is distributed in the hope that it will be useful, but WITHOUT *
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or *
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License *
16 * for more details. *
17 * *
18 * You should have received a copy of the GNU General Public License along with *
19 * software; if not, write to the Free Software Foundation, Inc., 59 Temple *
20 * Place, Suite 330, Boston, MA 02111-1307 USA *
21 * *
22 * Nirvana Text Editor *
23 * June 15, 1995 *
24 * *
25 * Written by Mark Edel *
26 * *
27 *******************************************************************************/
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <limits.h>
31 #include <Xm/Xm.h>
32 #include <Xm/ScrolledW.h>
33 #include <Xm/ScrollBar.h>
37 #define TOP_MARGIN 1
38 #define BOTTOM_MARGIN 1
39 #define LEFT_MARGIN 3
40 #define RIGHT_MARGIN 3
42 /* Masks for text drawing methods. These are or'd together to form an
43 integer which describes what drawing calls to use to draw a string */
44 #define FILL_MASK 0x100
45 #define SECONDARY_MASK 0x200
46 #define PRIMARY_MASK 0x400
47 #define HIGHLIGHT_MASK 0x800
48 #define STYLE_LOOKUP_MASK 0xff
50 /* Maximum displayable line length (how many characters will fit across the
51 widest window). This amount of memory is temporarily allocated from the
52 stack in the redisplayLine routine for drawing strings */
53 #define MAX_DISP_LINE_LEN 1000
129 {
131 XGCValues gcValues;
187 /* Attach an event handler to the widget so we can know the visibility
188 (used for choosing the fastest drawing method) */
192 /* Attach the callback to the text buffer for receiving modification
193 information */
197 /* Initialize the scroll bars and attach movement callbacks */
204 }
212 }
214 /* Update the display to reflect the contents of the buffer */
218 /* Decide if the horizontal scroll bar needs to be visible */
222 }
224 /*
225 ** Free a text display and release its associated memory. Note, the text
226 ** BUFFER that the text display displays is a separate entity and is not
227 ** freed, nor are the style buffer or style table.
228 */
230 {
242 }
244 /*
245 ** Attach a text buffer to display, replacing the current buffer (if any)
246 */
248 {
249 /* If the text display is already displaying a buffer, clear it off
250 of the display and remove our callback from it */
254 }
256 /* Add the buffer to the display, and attach a callback to the buffer for
257 receiving modification information when the buffer contents change */
261 /* Update the display */
263 }
265 /*
266 ** return the displayed text buffer
267 */
269 {
271 }
273 /*
274 ** Attach (or remove) highlight information in text display and redisplay.
275 ** Highlighting information consists of a style buffer which parallels the
276 ** normal text buffer, but codes font and color information for the display;
277 ** a style table which translates style buffer codes (indexed by buffer
278 ** character - 'A') into fonts and colors; and a callback mechanism for
279 ** as-needed highlighting, triggered by a style buffer entry of
280 ** "unfinishedStyle". Style buffer can trigger additional redisplay during
281 ** a normal buffer modification if the buffer contains a primary selection
282 ** (see extendRangeForStyleMods for more information on this protocol).
283 **
284 ** Style buffers, tables and their associated memory are managed by the caller.
285 */
289 {
297 /* Call TextDSetFont to combine font information from style table and
298 primary font, adjust font-related parameters, and then redisplay */
300 }
302 /*
303 ** Change the (non highlight) font
304 */
306 {
312 XGCValues values;
315 /* If font size changes, cursor will be redrawn in a new position */
318 /* If there is a (syntax highlighting) style table in use, find the new
319 maximum font height for this text display */
325 }
329 /* If all of the current fonts are fixed and match in width, compute */
339 }
340 }
343 /* Don't let the height dip below one line, or bad things can happen */
347 /* Change the font. In most cases, this means re-allocating the
348 affected GCs (they are shared with other widgets, and if the primary
349 font changes, must be re-allocated to change it). Unfortunately,
350 this requres recovering all of the colors from the existing GCs */
373 /* Do a full resize to force recalculation of font related parameters */
379 /* Redisplay */
383 /* Clean up line number area in case spacing has changed */
385 }
388 {
397 }
398 }
399 }
401 }
404 {
413 }
414 }
415 }
417 }
419 /*
420 ** Change the size of the displayed text area
421 */
423 {
434 /* In continuous wrap mode, a change in width affects the total number of
435 lines in the buffer, and can leave the top line number incorrect, and
436 the top character no longer pointing at a valid line start */
440 True);
445 }
447 /* reallocate and update the line starts array, which may have changed
448 size and/or contents. (contents can change in continuous wrap mode
449 when the width changes, even without a change in height) */
453 }
458 /* if the window became shorter, there may be partially drawn
459 text left at the bottom edge, which must be cleaned up */
465 /* if the window became taller, there may be an opportunity to display
466 more text by scrolling down */
472 /* Update the scroll bar page increment size (as well as other scroll
473 bar parameters. If updating the horizontal range caused scrolling,
474 redraw */
479 /* If a full redraw is needed */
484 /* Decide if the horizontal scroll bar needs to be visible */
487 /* Refresh the line number display to draw more line numbers, or
488 erase extras */
490 }
492 /*
493 ** Refresh a rectangle of the text display. left and top are in coordinates of
494 ** the text drawing window
495 */
498 {
501 /* find the line number range of the display */
506 /* If the graphics contexts are shared using XtAllocateGC, their
507 clipping rectangles may have changed since the last use */
510 /* draw the lines of text */
514 /* draw the line numbers if exposed area includes them */
517 }
519 /*
520 ** Refresh all of the text between buffer positions "start" and "end"
521 ** not including the character at the position "end".
522 ** If end points beyond the end of the buffer, refresh the whole display
523 ** after pos, including blank lines which are not technically part of
524 ** any range of characters.
525 */
527 {
530 /* If the range is outside of the displayed text, just return */
535 /* Clean up the starting and ending values */
541 /* Get the starting and ending lines */
550 /* shouldn't happen */
552 }
553 }
555 /* Get the starting and ending positions within the lines */
562 else
565 /* Reset the clipping rectangles for the drawing GCs which are shared
566 using XtAllocateGC, and may have changed since the last use */
569 /* If the starting and ending lines are the same, redisplay the single
570 line between "start" and "end" */
574 }
576 /* Redisplay the first line from "start" */
579 /* Redisplay the lines in between at their full width */
583 /* Redisplay the last line to "end" */
585 }
587 /*
588 ** Set the scroll position of the text display vertically by line number and
589 ** horizontally by pixel offset from the left margin
590 */
592 {
595 /* Limit the requested scroll position to allowable values */
610 }
612 /*
613 ** Get the current scroll position for the text display, in terms of line
614 ** number of the top line and horizontal pixel offset from the left margin
615 */
617 {
620 }
622 /*
623 ** Set the position of the text insertion cursor for text display "textD"
624 */
626 {
627 /* make sure new position is ok, do nothing if it hasn't changed */
633 /* cursor movement cancels vertical cursor motion column */
636 /* erase the cursor at it's previous position */
639 /* draw it at its new position */
643 }
646 {
653 }
656 {
660 }
661 }
664 {
669 }
672 {
676 /* wrapping can change change the total number of lines, re-count */
679 /* changing wrap margins wrap or changing from wrapped mode to non-wrapped
680 can leave the character at the top no longer at a line start, and/or
681 change the line number */
686 /* update the line starts array */
690 /* Update the scroll bar page increment size (as well as other scroll
691 bar parameters) */
695 /* Decide if the horizontal scroll bar needs to be visible */
698 /* Do a full redraw */
701 }
704 {
706 }
708 /*
709 ** Insert "text" at the current cursor location. This has the same
710 ** effect as inserting the text into the buffer using BufInsert and
711 ** then moving the insert position after the newly inserted text, except
712 ** that it's optimized to do less redrawing.
713 */
715 {
721 }
723 /*
724 ** Insert "text" (which must not contain newlines), overstriking the current
725 ** cursor location.
726 */
728 {
736 /* determine how many displayed character positions are covered */
743 /* find which characters to remove, and if necessary generate additional
744 padding to make up for removed control characters at the end */
754 p++;
758 p++;
764 }
766 }
767 }
775 }
777 /*
778 ** Translate window coordinates to the nearest text cursor position.
779 */
781 {
783 }
785 /*
786 ** Translate window coordinates to the nearest character cell.
787 */
789 {
791 }
793 /*
794 ** Translate window coordinates to the nearest row and column number for
795 ** positioning the cursor. This, of course, makes no sense when the font
796 ** is proportional, since there are no absolute columns.
797 */
800 {
802 }
804 /*
805 ** Translate line and column to the nearest row and column number for
806 ** positioning the cursor. This, of course, makes no sense when the font
807 ** is proportional, since there are no absolute columns.
808 */
810 {
814 /* Count lines */
821 }
823 /* If line is beyond end of buffer, position at last character in buffer */
826 }
828 /* Start character index at zero */
831 /* Only have to count columns if column isn't zero (or negative) */
833 /* Count columns, expanding each character */
842 }
844 /* If the column is in the middle of an expanded character, put cursor
845 * in front of character if in first half of character, and behind
846 * character if in last half of character
847 */
849 charIndex++;
851 /* If we are beyond the end of the line, back up one space */
853 }
855 /* Position is the start of the line plus the index into line buffer */
857 }
859 /*
860 ** Translate a buffer text position to the XY location where the center
861 ** of the cursor would be positioned to point to that character. Returns
862 ** False if the position is not displayed because it is VERTICALLY out
863 ** of view. If the position is horizontally out of view, returns the
864 ** x coordinate where the position would be if it were visible.
865 */
867 {
872 /* If position is not displayed, return false */
877 /* Calculate y coordinate */
883 /* Get the text, length, and buffer position of the line. If the position
884 is beyond the end of the buffer and should be at the first position on
885 the first empty line, don't try to get or scan the text */
890 }
894 /* Step through character positions from the beginning of the line
895 to "pos" to calculate the x coordinate */
902 outIndex);
905 }
909 }
911 /*
912 ** If the text widget is maintaining a line number count appropriate to "pos"
913 ** return the line and column numbers of pos, otherwise return False. If
914 ** continuous wrap mode is on, returns the absolute line number (as opposed to
915 ** the wrapped line number which is used for scrolling). THIS ROUTINE ONLY
916 ** WORKS FOR DISPLAYED LINES AND, IN CONTINUOUS WRAP MODE, ONLY WHEN THE
917 ** ABSOLUTE LINE NUMBER IS BEING MAINTAINED. Otherwise, it returns False.
918 */
920 {
923 /* In continuous wrap mode, the absolute (non-wrapped) line count is
924 maintained separately, as needed. Only return it if we're actually
925 keeping track of it and pos is in the displayed text */
934 }
936 /* Only return the data if pos is within the displayed text */
942 }
944 /*
945 ** Return True if position (x, y) is inside of the primary selection
946 */
948 {
956 }
958 /*
959 ** Correct a column number based on an unconstrained position (as returned by
960 ** TextDXYToUnconstrainedPosition) to be relative to the last actual newline
961 ** in the buffer before the row and column position given, rather than the
962 ** last line start created by line wrapping. This is an adapter
963 ** for rectangular selections and code written before continuous wrap mode,
964 ** which thinks that the unconstrained column is the number of characters
965 ** from the last newline. Obviously this is time consuming, because it
966 ** invloves character re-counting.
967 */
969 {
979 }
981 /*
982 ** Correct a row number from an unconstrained position (as returned by
983 ** TextDXYToUnconstrainedPosition) to a straight number of newlines from the
984 ** top line of the display. Because rectangular selections are based on
985 ** newlines, rather than display wrapping, and anywhere a rectangular selection
986 ** needs a row, it needs it in terms of un-wrapped lines.
987 */
989 {
994 }
996 /*
997 ** Scroll the display to bring insertion cursor into view.
998 **
999 ** Note: it would be nice to be able to do this without counting lines twice
1000 ** (setScroll counts them too) and/or to count from the most efficient
1001 ** starting point, but the efficiency of this routine is not as important to
1002 ** the overall performance of the text display.
1003 */
1005 {
1012 /* Find the new top line number */
1021 topLine++;
1025 }
1027 /* Find the new setting for horizontal offset (this is a bit ungraceful).
1028 If the line is visible, just use TextDPositionToXY to get the position
1029 to scroll to, otherwise, do the vertical scrolling first, then the
1030 horizontal */
1035 }
1041 /* Do the scroll */
1043 }
1045 /*
1046 ** Return the current preferred column along with the current
1047 ** visible line index (-1 if not visible) and the lineStartPos
1048 ** of the current insert position.
1049 */
1051 {
1054 /* Find the position of the start of the line. Use the line starts array
1055 if possible, to avoid unbounded line-counting in continuous wrap mode */
1058 }
1062 }
1064 /* Decide what column to move to, if there's a preferred column use that */
1068 }
1070 /*
1071 ** Return the insert position of the requested column given
1072 ** the lineStartPos.
1073 */
1075 {
1081 }
1083 }
1085 /*
1086 ** Cursor movement functions
1087 */
1089 {
1094 }
1097 {
1102 }
1105 {
1108 /* Find the position of the start of the line. Use the line starts array
1109 if possible, to avoid unbounded line-counting in continuous wrap mode */
1115 }
1119 /* Decide what column to move to, if there's a preferred column use that */
1123 /* count forward from the start of the previous line to reach the column */
1126 else
1132 /* move the cursor */
1135 /* if a preferred column wasn't aleady established, establish it */
1138 }
1140 {
1150 }
1160 }
1162 /*
1163 ** Same as BufCountLines, but takes in to account wrapping if wrapping is
1164 ** turned on. If the caller knows that startPos is at a line start, it
1165 ** can pass "startPosIsLineStart" as True to make the call more efficient
1166 ** by avoiding the additional step of scanning back to the last newline.
1167 */
1170 {
1173 /* If we're not wrapping use simple (and more efficient) BufCountLines */
1180 }
1182 /*
1183 ** Same as BufCountForwardNLines, but takes in to account line breaks when
1184 ** wrapping is turned on. If the caller knows that startPos is at a line start,
1185 ** it can pass "startPosIsLineStart" as True to make the call more efficient
1186 ** by avoiding the additional step of scanning back to the last newline.
1187 */
1190 {
1193 /* if we're not wrapping use more efficient BufCountForwardNLines */
1197 /* wrappedLineCounter can't handle the 0 lines case */
1201 /* use the common line counting routine to count forward */
1206 }
1208 /*
1209 ** Same as BufEndOfLine, but takes in to account line breaks when wrapping
1210 ** is turned on. If the caller knows that startPos is at a line start, it
1211 ** can pass "startPosIsLineStart" as True to make the call more efficient
1212 ** by avoiding the additional step of scanning back to the last newline.
1213 **
1214 ** Note that the definition of the end of a line is less clear when continuous
1215 ** wrap is on. With continuous wrap off, it's just a pointer to the newline
1216 ** that ends the line. When it's on, it's the character beyond the last
1217 ** DISPLAYABLE character on the line, where a whitespace character which has
1218 ** been "converted" to a newline for wrapping is not considered displayable.
1219 ** Also note that, a line can be wrapped at a non-whitespace character if the
1220 ** line had no whitespace. In this case, this routine returns a pointer to
1221 ** the start of the next line. This is also consistent with the model used by
1222 ** visLineLength.
1223 */
1225 {
1228 /* If we're not wrapping use more efficien BufEndOfLine */
1237 }
1239 /*
1240 ** Same as BufStartOfLine, but returns the character after last wrap point
1241 ** rather than the last newline.
1242 */
1244 {
1247 /* If we're not wrapping, use the more efficient BufStartOfLine */
1254 }
1256 /*
1257 ** Same as BufCountBackwardNLines, but takes in to account line breaks when
1258 ** wrapping is turned on.
1259 */
1261 {
1265 /* If we're not wrapping, use the more efficient BufCountBackwardNLines */
1276 True);
1282 }
1283 }
1285 /*
1286 ** Callback attached to the text buffer to receive modification information
1287 */
1290 {
1298 /* buffer modification cancels vertical cursor motion column */
1302 /* Count the number of lines inserted and deleted, and in the case
1303 of continuous wrap mode, how much has changed */
1311 }
1313 /* Update the line starts and topLineNum */
1322 }
1326 /* If we're counting non-wrapped lines as well, maintain the absolute
1327 (non-wrapped) line number of the text displayed */
1334 }
1336 /* Update the line count for the whole buffer */
1339 /* Update the scroll bar ranges (and value if the value changed). Note
1340 that updating the horizontal scroll bar range requires scanning the
1341 entire displayed text, however, it doesn't seem to hurt performance
1342 much. Note also, that the horizontal scroll bar update routine is
1343 allowed to re-adjust horizOffset if there is blank space to the right
1344 of all lines of text. */
1348 /* Update the cursor position */
1355 else
1357 }
1359 /* If the changes caused scrolling, re-paint everything and we're done. */
1367 }
1369 /* If the changes didn't cause scrolling, decide the range of characters
1370 that need to be re-painted. Also if the cursor position moved, be
1371 sure that the redisplay range covers the old cursor position so the
1372 old cursor gets erased, and erase the bits of the cursor which extend
1373 beyond the left and right edges of the text. */
1386 }
1392 }
1394 /* If there is a style buffer, check if the modification caused additional
1395 changes that need to be redisplayed. (Redisplaying separately would
1396 cause double-redraw on almost every modification involving styled
1397 text). Extend the redraw range to incorporate style changes */
1401 /* Redisplay computed range */
1403 }
1405 /*
1406 ** In continuous wrap mode, internal line numbers are calculated after
1407 ** wrapping. A separate non-wrapped line count is maintained when line
1408 ** numbering is turned on. There is some performance cost to maintaining this
1409 ** line count, so normally absolute line numbers are not tracked if line
1410 ** numbering is off. This routine allows callers to specify that they still
1411 ** want this line count maintained (for use via TextDPosToLineAndCol).
1412 ** More specifically, this allows the line number reported in the statistics
1413 ** line to be calibrated in absolute lines, rather than post-wrapped lines.
1414 */
1416 {
1419 }
1421 /*
1422 ** Returns the absolute (non-wrapped) line number of the first line displayed.
1423 ** Returns 0 if the absolute top line number is not being maintained.
1424 */
1426 {
1432 }
1434 /*
1435 ** Re-calculate absolute top line number for a change in scroll position.
1436 */
1438 {
1443 else
1446 }
1447 }
1449 /*
1450 ** Return true if a separate absolute top line number is being maintained
1451 ** (for displaying line numbers or showing in the statistics line).
1452 */
1454 {
1457 }
1459 /*
1460 ** Count lines from the beginning of the buffer to reestablish the
1461 ** absolute (non-wrapped) top line number. If mode is not continuous wrap,
1462 ** or the number is not being maintained, does nothing.
1463 */
1465 {
1468 }
1470 /*
1471 ** Find the line number of position "pos" relative to the first line of
1472 ** displayed text. Returns False if the line is not displayed.
1473 */
1475 {
1486 }
1491 }
1492 }
1494 }
1500 }
1501 }
1503 }
1505 /*
1506 ** Redisplay the text on a single line represented by "visLineNum" (the
1507 ** number of lines down from the top of the display), limited by
1508 ** "leftClip" and "rightClip" window coordinates and "leftCharIndex" and
1509 ** "rightCharIndex" character positions (not including the character at
1510 ** position "rightCharIndex").
1511 **
1512 ** The cursor is also drawn if it appears on the line.
1513 */
1516 {
1525 /* If line is not displayed, skip it */
1529 /* Calculate y coordinate of the string to draw */
1533 /* Get the text, length, and buffer position of the line to display */
1541 }
1543 /* Space beyond the end of the line is still counted in units of characters
1544 of a standardized character width (this is done mostly because style
1545 changes based on character position can still occur in this region due
1546 to rectangular selections). stdCharWidth must be non-zero to prevent a
1547 potential infinite loop if x does not advance */
1553 }
1555 /* Shrink the clipping range to the active display area */
1559 /* Rectangular selections are based on "real" line starts (after a newline
1560 or start of buffer). Calculate the difference between the last newline
1561 position and the line start we're using. Since scanning back to find a
1562 newline is expensive, only do so if there's actually a rectangular
1563 selection which needs it */
1574 /* Step through character positions from the beginning of the line (even if
1575 that's off the left edge of the displayed area) to find the first
1576 character position that's not clipped, and the x coordinate for drawing
1577 that character */
1593 }
1596 }
1598 /* Scan character positions from the beginning of the clipping range, and
1599 draw parts whenever the style changes (also note if the cursor is on
1600 this line, and where it should be drawn to take advantage of the x
1601 position which we've gone to so much trouble to calculate) */
1615 }
1616 }
1617 }
1632 }
1638 outPtr++;
1640 outIndex++;
1641 }
1644 }
1646 /* Draw the remaining style segment */
1649 /* Draw the cursor if part of it appeared on the redisplayed part of
1650 this line. Also check for the cases which are not caught as the
1651 line is scanned above: when the cursor appears at the very end
1652 of the redisplayed section. */
1663 }
1664 }
1665 }
1669 }
1671 /*
1672 ** Draw a string or blank area according to parameter "style", using the
1673 ** appropriate colors and drawing method for that style, with top left
1674 ** corner at x, y. If style says to draw text, use "string" as source of
1675 ** characters, and draw "nChars", if style is FILL, erase
1676 ** rectangle where text would have drawn from x to toX and from y to
1677 ** the maximum y extent of the current font(s).
1678 */
1681 {
1682 GC gc;
1683 XGCValues gcValues;
1688 /* Don't draw if widget isn't realized */
1692 /* Draw blank area rather than text, if that was the request */
1698 }
1700 /* Set font, color, and gc depending on style. For normal text, GCs
1701 for normal drawing, or drawing within a selection or highlight are
1702 pre-allocated and pre-configured. For syntax highlighting, GCs are
1703 configured here, on the fly. */
1721 else
1724 /* Draw the string using gc and font set above */
1728 /* If any space around the character remains unfilled (due to use of
1729 different sized fonts for highlighting), fill in above or below
1730 to erase previously drawn characters */
1737 /* Underline if style is secondary selection */
1741 }
1743 /*
1744 ** Clear a rectangle with the appropriate background color for "style"
1745 */
1748 {
1749 /* A width of zero means "clear to end of window" to XClearArea */
1759 else
1762 }
1765 /*
1766 ** Draw a cursor with top center at x, y.
1767 */
1769 {
1780 /* For cursors other than the block, make them around 2/3 of a character
1781 width, rounded to an even number of pixels so that X will draw an
1782 odd number centered on the stem at x. */
1787 /* Create segments and draw cursor */
1820 }
1824 /* Save the last position drawn */
1827 }
1829 /*
1830 ** Determine the drawing method to use to draw a specific character from "buf".
1831 ** "lineStartPos" gives the character index where the line begins, "lineIndex",
1832 ** the number of characters past the beginning of the line, and "dispIndex",
1833 ** the number of displayed characters past the beginning of the line. Passing
1834 ** lineStartPos of -1 returns the drawing style for "no text".
1835 **
1836 ** Why not just: styleOfPos(textD, pos)? Because style applies to blank areas
1837 ** of the window beyond the text boundaries, and because this routine must also
1838 ** decide whether a position is inside of a rectangular selection, and do so
1839 ** efficiently, without re-counting character positions from the start of the
1840 ** line.
1841 **
1842 ** Note that style is a somewhat incorrect name, drawing method would
1843 ** be more appropriate.
1844 */
1847 {
1862 /* encountered "unfinished" style, trigger parsing */
1865 }
1866 }
1874 }
1876 /*
1877 ** Find the width of a string in the font of a particular style
1878 */
1880 {
1885 else
1888 }
1890 /*
1891 ** Return true if position "pos" with indentation "dispIndex" is in
1892 ** selection "sel"
1893 */
1895 {
1902 }
1904 /*
1905 ** Translate window coordinates to the nearest (insert cursor or character
1906 ** cell) text position. The parameter posType specifies how to interpret the
1907 ** position: CURSOR_POS means translate the coordinates to the nearest cursor
1908 ** position, and CHARACTER_POS means return the position of the character
1909 ** closest to (x, y).
1910 */
1912 {
1917 /* Find the visible line number corresponding to the y coordinate */
1925 /* Find the position at the start of the line */
1928 /* If the line start was empty, return the last position in the buffer */
1932 /* Get the line text and its length */
1936 /* Step through character positions from the beginning of the line
1937 to find the character position corresponding to the x coordinate */
1948 }
1951 }
1953 /* If the x position was beyond the end of the line, return the position
1954 of the newline at the end of the line */
1957 }
1959 /*
1960 ** Translate window coordinates to the nearest row and column number for
1961 ** positioning the cursor. This, of course, makes no sense when the font is
1962 ** proportional, since there are no absolute columns. The parameter posType
1963 ** specifies how to interpret the position: CURSOR_POS means translate the
1964 ** coordinates to the nearest position between characters, and CHARACTER_POS
1965 ** means translate the position to the nearest character cell.
1966 */
1969 {
1973 /* Find the visible line number corresponding to the y coordinate */
1980 }
1982 /*
1983 ** Offset the line starts array, topLineNum, firstChar and lastChar, for a new
1984 ** vertical scroll position given by newTopLineNum. If any currently displayed
1985 ** lines will still be visible, salvage the line starts values, otherwise,
1986 ** count lines from the nearest known line start (start or end of buffer, or
1987 ** the closest value in the lineStarts array)
1988 */
1990 {
1999 /* If there was no offset, nothing needs to be changed */
2003 /* { int i;
2004 printf("Scroll, lineDelta %d\n", lineDelta);
2005 printf("lineStarts Before: ");
2006 for(i=0; i<nVisLines; i++) printf("%d ", lineStarts[i]);
2007 printf("\n");
2008 } */
2010 /* Find the new value for firstChar by counting lines from the nearest
2011 known line start (start or end of buffer, or the closest value in the
2012 lineStarts array) */
2016 True);
2017 /* printf("counting forward %d lines from start\n", newTopLineNum-1);*/
2021 /* printf("counting backward %d lines from firstChar\n", -lineDelta);*/
2024 /* printf("taking new start from lineStarts[%d]\n",
2025 newTopLineNum - oldTopLineNum); */
2029 /* printf("counting forward %d lines from start of last line\n",
2030 newTopLineNum - lastLineNum); */
2034 /* printf("counting backward %d lines from end\n",
2035 textD->nBufferLines - newTopLineNum + 1); */
2036 }
2038 /* Fill in the line starts array */
2050 /* Set lastChar and topLineNum */
2054 /* If we're numbering lines or being asked to maintain an absolute line
2055 number, re-calculate the absolute line number */
2058 /* { int i;
2059 printf("lineStarts After: ");
2060 for(i=0; i<nVisLines; i++) printf("%d ", lineStarts[i]);
2061 printf("\n");
2062 } */
2063 }
2065 /*
2066 ** Update the line starts array, topLineNum, firstChar and lastChar for text
2067 ** display "textD" after a modification to the text buffer, given by the
2068 ** position where the change began "pos", and the nmubers of characters
2069 ** and lines inserted and deleted.
2070 */
2073 {
2079 /* { int i;
2080 printf("linesDeleted %d, linesInserted %d, charsInserted %d, charsDeleted %d\n",
2081 linesDeleted, linesInserted, charsInserted, charsDeleted);
2082 printf("lineStarts Before: ");
2083 for(i=0; i<nVisLines; i++) printf("%d ", lineStarts[i]);
2084 printf("\n");
2085 } */
2086 /* If all of the changes were before the displayed text, the display
2087 doesn't change, just update the top line num and offset the line
2088 start entries and first and last characters */
2093 /* { int i;
2094 printf("lineStarts after delete doesn't touch: ");
2095 for(i=0; i<nVisLines; i++) printf("%d ", lineStarts[i]);
2096 printf("\n");
2097 } */
2102 }
2104 /* The change began before the beginning of the displayed text, but
2105 part or all of the displayed text was deleted */
2107 /* If some text remains in the window, anchor on that */
2113 /* Otherwise anchor on original line number and recount everything */
2121 }
2123 /* { int i;
2124 printf("lineStarts after delete encroaches: ");
2125 for(i=0; i<nVisLines; i++) printf("%d ", lineStarts[i]);
2126 printf("\n");
2127 } */
2128 /* calculate lastChar by finding the end of the last displayed line */
2132 }
2134 /* If the change was in the middle of the displayed text (it usually is),
2135 salvage as much of the line starts array as possible by moving and
2136 offsetting the entries after the changed area, and re-counting the
2137 added lines or the lines beyond the salvaged part of the line starts
2138 array */
2140 /* find line on which the change began */
2142 /* salvage line starts after the changed area */
2154 }
2155 /* { int i;
2156 printf("lineStarts after salvage: ");
2157 for(i=0; i<nVisLines; i++) printf("%d ", lineStarts[i]);
2158 printf("\n");
2159 } */
2160 /* fill in the missing line starts */
2165 /* { int i;
2166 printf("lineStarts after recalculation: ");
2167 for(i=0; i<nVisLines; i++) printf("%d ", lineStarts[i]);
2168 printf("\n");
2169 } */
2170 /* calculate lastChar by finding the end of the last displayed line */
2174 }
2176 /* Change was past the end of the displayed text, but displayable by virtue
2177 of being an insert at the end of the buffer into visible blank lines */
2182 /* { int i;
2183 printf("lineStarts after insert at end: ");
2184 for(i=0; i<nVisLines; i++) printf("%d ", lineStarts[i]);
2185 printf("\n");
2186 } */
2189 }
2191 /* Change was beyond the end of the buffer and not visible, do nothing */
2193 }
2195 /*
2196 ** Scan through the text in the "textD"'s buffer and recalculate the line
2197 ** starts array values beginning at index "startLine" and continuing through
2198 ** (including) "endLine". It assumes that the line starts entry preceding
2199 ** "startLine" (or textD->firstChar if startLine is 0) is good, and re-counts
2200 ** newlines to fill in the requested entries. Out of range values for
2201 ** "startLine" and "endLine" are acceptable.
2202 */
2204 {
2209 /* Clean up (possibly) messy input parameters */
2217 /* Find the last known good line number -> position mapping */
2221 }
2224 /* If the starting position is already past the end of the text,
2225 fill in -1's (means no text on line) and return */
2230 }
2232 /* Loop searching for ends of lines and storing the positions of the
2233 start of the next line in lineStarts */
2238 /* If the buffer ends with a newline or line break, put
2239 buf->length in the next line start position (instead of
2240 a -1 which is the normal marker for an empty line) to
2241 indicate that the cursor may safely be displayed there */
2245 line++;
2246 }
2248 }
2250 }
2252 /* Set any entries beyond the end of the text to -1 */
2255 }
2257 /*
2258 ** Given a textDisp with a complete, up-to-date lineStarts array, update
2259 ** the lastChar entry to point to the last buffer position displayed.
2260 */
2262 {
2268 }
2272 {
2280 /* Do nothing if scroll position hasn't actually changed or there's no
2281 window to draw in yet */
2286 /* If part of the cursor is protruding beyond the text clipping region,
2287 clear it off */
2290 /* If the vertical scroll position has changed, update the line
2291 starts array and related counters in the text display */
2294 /* Just setting textD->horizOffset is enough information for redisplay */
2297 /* Update the scroll bar positions if requested, note: updating the
2298 horizontal scroll bars can have the further side-effect of changing
2299 the horizontal scroll position, textD->horizOffset */
2304 }
2306 /* Redisplay everything if the window is partially obscured (since
2307 it's too hard to tell what displayed areas are salvageable) or
2308 if there's nothing to recover because the scroll distance is large */
2316 /* If the window is not obscured, paint most of the window using XCopyArea
2317 from existing displayed text, and redraw only what's necessary */
2319 /* Recover the useable window areas by moving to the proper location */
2329 /* redraw the un-recoverable parts */
2342 /* Restore protruding parts of the cursor */
2344 }
2346 /* Refresh line number display if its up and we've scrolled vertically */
2349 }
2351 /*
2352 ** Update the minimum, maximum, slider size, page increment, and value
2353 ** for vertical scroll bar.
2354 */
2356 {
2362 /* The Vert. scroll bar value and slider size directly represent the top
2363 line number, and the number of visible lines respectively. The scroll
2364 bar maximum value is chosen to generally represent the size of the whole
2365 buffer, with minor adjustments to keep the scroll bar widget happy */
2374 }
2376 /*
2377 ** Update the minimum, maximum, slider size, page increment, and value
2378 ** for the horizontal scroll bar. If scroll position is such that there
2379 ** is blank space to the right of all lines of text, scroll back (adjust
2380 ** horizOffset but don't redraw) to take up the slack and position the
2381 ** right edge of the text at the right edge of the display.
2382 **
2383 ** Note, there is some cost to this routine, since it scans the whole range
2384 ** of displayed text, particularly since it's usually called for each typed
2385 ** character!
2386 */
2388 {
2395 /* Scan all the displayed lines to find the width of the longest line */
2399 /* If the scroll position is beyond what's necessary to keep all lines
2400 in view, scroll to the left to bring the end of the longest line to
2401 the right margin */
2405 /* Readjust the scroll bar */
2414 /* Return True if scroll position was changed */
2416 }
2418 /*
2419 ** Define area for drawing line numbers. A width of 0 disables line
2420 ** number drawing.
2421 */
2424 {
2433 }
2435 /*
2436 ** Refresh the line number area. If clearAll is False, writes only over
2437 ** the character cell areas. Setting clearAll to True will clear out any
2438 ** stray marks outside of the character cell area, which might have been
2439 ** left from before a resize or font change.
2440 */
2442 {
2448 /* Don't draw if lineNumWidth == 0 (line numbers are hidden), or widget is
2449 not yet realized */
2453 /* GC is allocated on demand, since not everyone will use line numbering */
2455 XGCValues values;
2461 }
2463 /* Erase the previous contents of the line number area, if requested */
2468 /* Draw the line numbers, aligned to the text */
2480 line++;
2486 line++;
2487 }
2489 }
2490 }
2492 /*
2493 ** Callbacks for drag or valueChanged on scroll bars
2494 */
2496 {
2504 }
2506 {
2513 }
2517 {
2518 /* Record whether the window is fully visible or not. This information
2519 is used for choosing the scrolling methodology for optimal performance,
2520 if the window is partially obscured, XCopyArea may not work */
2522 }
2525 {
2527 }
2530 {
2532 }
2534 /*
2535 ** Count the number of newlines in a null-terminated text string;
2536 */
2538 {
2547 }
2549 /*
2550 ** Return the width in pixels of the displayed line pointed to by "visLineNum"
2551 */
2553 {
2564 }
2572 len);
2574 }
2575 }
2577 }
2579 /*
2580 ** Return true if there are lines visible with no corresponding buffer text
2581 */
2583 {
2586 }
2588 /*
2589 ** When the cursor is at the left or right edge of the text, part of it
2590 ** sticks off into the clipped region beyond the text. Normal redrawing
2591 ** can not overwrite this protruding part of the cursor, so it must be
2592 ** erased independently by calling this routine.
2593 */
2595 {
2613 }
2615 /*
2616 ** Allocate shared graphics contexts used by the widget, which must be
2617 ** re-allocated on a font change.
2618 */
2622 {
2627 GCArcMode);
2632 GCArcMode);
2635 }
2637 /*
2638 ** X11R4 does not have the XtAllocateGC function for sharing graphics contexts
2639 ** with changeable fields. Unfortunately the R4 call for creating shared
2640 ** graphics contexts (XtGetGC) is rarely useful because most widgets need
2641 ** to be able to set and change clipping, and that makes the GC unshareable.
2642 **
2643 ** This function allocates and returns a gc, using XtAllocateGC if possible,
2644 ** or XCreateGC on X11R4 systems where XtAllocateGC is not available.
2645 */
2649 {
2650 XGCValues gcValues;
2655 #if defined(XlibSpecificationRelease) && XlibSpecificationRelease > 4
2657 dontCareMask);
2658 #else
2661 #endif
2662 }
2664 /*
2665 ** Release a gc allocated with allocateGC above
2666 */
2668 {
2669 #if defined(XlibSpecificationRelease) && XlibSpecificationRelease > 4
2671 #else
2673 #endif
2674 }
2676 /*
2677 ** resetClipRectangles sets the clipping rectangles for GCs which clip
2678 ** at the text boundary (as opposed to the window boundary). These GCs
2679 ** are shared such that the drawing styles are constant, but the clipping
2680 ** rectangles are allowed to change among different users of the GCs (the
2681 ** GCs were created with XtAllocGC). This routine resets them so the clipping
2682 ** rectangles are correct for this text display.
2683 */
2685 {
2686 XRectangle clipRect;
2707 }
2709 /*
2710 ** Return the length of a line (number of displayable characters) by examining
2711 ** entries in the line starts array rather than by scanning for newlines
2712 */
2714 {
2727 }
2729 /*
2730 ** When continuous wrap is on, and the user inserts or deletes characters,
2731 ** wrapping can happen before and beyond the changed position. This routine
2732 ** finds the extent of the changes, and counts the deleted and inserted lines
2733 ** over that range. It also attempts to minimize the size of the range to
2734 ** what has to be counted and re-displayed, so the results can be useful
2735 ** both for delimiting where the line starts need to be recalculated, and
2736 ** for deciding what part of the text to redisplay.
2737 */
2741 {
2749 /*
2750 ** Determine where to begin searching: either the previous newline, or
2751 ** if possible, limit to the start of the (original) previous displayed
2752 ** line, using information from the existing line starts array
2753 */
2767 /*
2768 ** Move forward through the (new) text one line at a time, counting
2769 ** displayed lines, and looking for either a real newline, or for the
2770 ** line starts to re-sync with the original line starts array
2771 */
2776 /* advance to the next line. If the line ended in a real newline
2777 or the end of the buffer, that's far enough */
2784 nLines++;
2788 nLines++;
2794 }
2796 /* check for synchronization with the original line starts array
2797 before pos, if so, the modified range can begin later */
2800 visLineNum++;
2806 else
2810 }
2812 /* check for synchronization with the original line starts array
2813 after pos, if so, the modified range can end early */
2817 visLineNum++;
2823 }
2824 }
2825 }
2829 /* Count deleted lines between countFrom and countTo as the text existed
2830 before the modification (that is, as if the text between pos and
2831 pos+nInserted were replaced by "deletedText"). This extra context is
2832 necessary because wrapping can occur outside of the modified region
2833 as a result of adding or deleting text in the region. This is done by
2834 creating a textBuffer containing the deleted text and the necessary
2835 additional context, and calling the wrappedLineCounter on it. */
2847 }
2849 /*
2850 ** Count forward from startPos to either maxPos or maxLines (whichever is
2851 ** reached first), and return all relevant positions and line count.
2852 **
2853 ** Returned values:
2854 **
2855 ** retPos: Position where counting ended. When counting lines, the
2856 ** position returned is the start of the line "maxLines"
2857 ** lines beyond "startPos".
2858 ** retLines: Number of line breaks counted
2859 ** retLineStart: Start of the line where counting ended
2860 ** retLineEnd: End position of the last line traversed
2861 */
2865 {
2872 /* If the font is fixed, or there's a wrap margin set, it's more efficient
2873 to measure in columns, than to count pixels. Determine if we can count
2874 in columns (countPixels == False) or must count pixels (countPixels ==
2875 True), and set the wrap target for either pixels or columns */
2885 }
2887 /* Find the start of the line if the start pos is not marked as a
2888 line start. */
2891 else
2894 /*
2895 ** Loop until position exceeds maxPos or line count exceeds maxLines.
2896 ** (actually, contines beyond maxPos to end of line containing maxPos,
2897 ** in case later characters cause a word wrap back before maxPos)
2898 */
2904 /* If the character was a newline, count the line and start over,
2905 otherwise, add it to the width and column counts */
2913 }
2914 nLines++;
2921 }
2929 }
2931 /* If character exceeded wrap margin, find the break point
2932 and wrap there */
2945 colNum++;
2946 }
2951 }
2952 }
2958 }
2963 newLineStart;
2966 }
2967 nLines++;
2974 }
2976 }
2977 }
2979 /* reached end of buffer before reaching pos or line target */
2984 }
2986 /*
2987 ** Measure the width in pixels of a character "c" at a particular column
2988 ** "colNum" and buffer position "pos". This is for measuring characters in
2989 ** proportional or mixed-width highlighting fonts.
2990 **
2991 ** A note about proportional and mixed-width fonts: the mixed width and
2992 ** proportional font code in nedit does not get much use in general editing,
2993 ** because nedit doesn't allow per-language-mode fonts, and editing programs
2994 ** in a proportional font is usually a bad idea, so very few users would
2995 ** choose a proportional font as a default. There are still probably mixed-
2996 ** width syntax highlighting cases where things don't redraw properly for
2997 ** insertion/deletion, though static display and wrapping and resizing
2998 ** should now be solid because they are now used for online help display.
2999 */
3001 {
3013 /* encountered "unfinished" style, trigger parsing */
3016 }
3017 }
3019 }
3021 /*
3022 ** Finds both the end of the current line and the start of the next line. Why?
3023 ** In continuous wrap mode, if you need to know both, figuring out one from the
3024 ** other can be expensive or error prone. The problem comes when there's a
3025 ** trailing space or tab just before the end of the buffer. To translate an
3026 ** end of line value to or from the next lines start value, you need to know
3027 ** whether the trailing space or tab is being used as a line break or just a
3028 ** normal character, and to find that out would otherwise require counting all
3029 ** the way back to the beginning of the line.
3030 */
3033 {
3036 /* if we're not wrapping use more efficient BufEndOfLine */
3041 }
3043 /* use the wrapped line counter routine to count forward one line */
3048 }
3050 /*
3051 ** Line breaks in continuous wrap mode usually happen at newlines or
3052 ** whitespace. This line-terminating character is not included in line
3053 ** width measurements and has a special status as a non-visible character.
3054 ** However, lines with no whitespace are wrapped without the benefit of a
3055 ** line terminating character, and this distinction causes endless trouble
3056 ** with all of the text display code which was originally written without
3057 ** continuous wrap mode and always expects to wrap at a newline character.
3058 **
3059 ** Given the position of the end of the line, as returned by TextDEndOfLine
3060 ** or BufEndOfLine, this returns true if there is a line terminating
3061 ** character, and false if there's not. On the last character in the
3062 ** buffer, this function can't tell for certain whether a trailing space was
3063 ** used as a wrap point, and just guesses that it wasn't. So if an exact
3064 ** accounting is necessary, don't use this function.
3065 */
3067 {
3076 }
3078 /*
3079 ** Decide whether the user needs (or may need) a horizontal scroll bar,
3080 ** and manage or unmanage the scroll bar widget accordingly. The H.
3081 ** scroll bar is only hidden in continuous wrap mode when it's absolutely
3082 ** certain that the user will not need it: when wrapping is set
3083 ** to the window edge, or when the wrap margin is strictly less than
3084 ** the longest possible line.
3085 */
3087 {
3091 else
3093 }
3095 /*
3096 ** Return true if the selection "sel" is rectangular, and touches a
3097 ** buffer position withing "rangeStart" to "rangeEnd"
3098 */
3100 {
3103 }
3105 /*
3106 ** Extend the range of a redraw request (from *start to *end) with additional
3107 ** redraw requests resulting from changes to the attached style buffer (which
3108 ** contains auxiliary information for coloring or styling text).
3109 */
3111 {
3115 /* The peculiar protocol used here is that modifications to the style
3116 buffer are marked by selecting them with the buffer's primary selection.
3117 The style buffer is usually modified in response to a modify callback on
3118 the text buffer BEFORE textDisp.c's modify callback, so that it can keep
3119 the style buffer in step with the text buffer. The style-update
3120 callback can't just call for a redraw, because textDisp hasn't processed
3121 the original text changes yet. Anyhow, to minimize redrawing and to
3122 avoid the complexity of scheduling redraws later, this simple protocol
3123 tells the text display's buffer modify callback to extend it's redraw
3124 range to show the text color/and font changes as well. */
3129 }
3133 }
3134 }
3136 /* If the selection was extended due to a style change, and some of the
3137 fonts don't match in spacing, extend redraw area to end of line to
3138 redraw characters exposed by possible font size changes */
3141 }