![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to tkcvtext.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Micropolis - Activity] / micropolis / src / tk|
Return to tkcvtext.c CVS log | Up to [Micropolis - Activity] / micropolis / src / tk |
1.1 root 1: /*
2: * tkCanvText.c --
3: *
4: * This file implements text items for canvas widgets.
5: *
6: * Copyright 1991-1992 Regents of the University of California.
7: * Permission to use, copy, modify, and distribute this
8: * software and its documentation for any purpose and without
9: * fee is hereby granted, provided that the above copyright
10: * notice appear in all copies. The University of California
11: * makes no representations about the suitability of this
12: * software for any purpose. It is provided "as is" without
13: * express or implied warranty.
14: */
15:
16: #ifndef lint
17: static char rcsid[] = "$Header: /user6/ouster/wish/RCS/tkCanvText.c,v 1.12 92/08/19 08:34:12 ouster Exp $ SPRITE (Berkeley)";
18: #endif
19:
20: #include <stdio.h>
21: #include "tkint.h"
22: #include "tkcanvas.h"
23: #include "tkconfig.h"
24:
25: /*
26: * One of the following structures is kept for each line of text
27: * in a text item. It contains geometry and display information
28: * for that line.
29: */
30:
31: typedef struct TextLine {
32: char *firstChar; /* Pointer to the first character in this
33: * line (in the "text" field of enclosing
34: * text item). */
35: int numChars; /* Number of characters displayed in this
36: * line. */
37: int totalChars; /* Total number of characters included as
38: * part of this line (may include an extra
39: * space character at the end that isn't
40: * displayed). */
41: int x, y; /* Origin at which to draw line on screen
42: * (in integer pixel units, but in canvas
43: * coordinates, not screen coordinates). */
44: int x1, y1; /* Upper-left pixel that is part of text
45: * line on screen (again, in integer canvas
46: * pixel units). */
47: int x2, y2; /* Lower-left pixel that is part of text
48: * line on screen (again, in integer canvas
49: * pixel units). */
50: } TextLine;
51:
52: /*
53: * The structure below defines the record for each text item.
54: */
55:
56: typedef struct TextItem {
57: Tk_Item header; /* Generic stuff that's the same for all
58: * types. MUST BE FIRST IN STRUCTURE. */
59: char *text; /* Text for item (malloc-ed). */
60: int numChars; /* Number of non-NULL characters in text. */
61: double x, y; /* Positioning point for text. */
62: Tk_Anchor anchor; /* Where to anchor text relative to (x,y). */
63: int width; /* Width of lines for word-wrap, pixels.
64: * Zero means no word-wrap. */
65: Tk_Justify justify; /* Justification mode for text. */
66: int rightEdge; /* Pixel just to right of right edge of
67: * area of text item. Used for selecting
68: * up to end of line. */
69: XFontStruct *fontPtr; /* Font for drawing text. */
70: XColor *color; /* Color for text. */
71: Pixmap stipple; /* Stipple bitmap for text, or None. */
72: GC gc; /* Graphics context for drawing text. */
73: TextLine *linePtr; /* Pointer to array of structures describing
74: * individual lines of text item (malloc-ed). */
75: int numLines; /* Number of structs at *linePtr. */
76: int cursorPos; /* Insertion cursor is displayed just to left
77: * of character with this index. */
78: GC selTextGC; /* Graphics context for selected text. */
79: } TextItem;
80:
81: /*
82: * Information used for parsing configuration specs:
83: */
84:
85: static Tk_ConfigSpec configSpecs[] = {
86: {TK_CONFIG_ANCHOR, "-anchor", (char *) NULL, (char *) NULL,
87: "center", Tk_Offset(TextItem, anchor),
88: TK_CONFIG_DONT_SET_DEFAULT},
89: {TK_CONFIG_COLOR, "-fill", (char *) NULL, (char *) NULL,
90: "black", Tk_Offset(TextItem, color), 0},
91: {TK_CONFIG_FONT, "-font", (char *) NULL, (char *) NULL,
92: "-Adobe-Helvetica-Bold-R-Normal-*-120-*",
93: Tk_Offset(TextItem, fontPtr), 0},
94: {TK_CONFIG_JUSTIFY, "-justify", (char *) NULL, (char *) NULL,
95: "left", Tk_Offset(TextItem, justify),
96: TK_CONFIG_DONT_SET_DEFAULT},
97: {TK_CONFIG_BITMAP, "-stipple", (char *) NULL, (char *) NULL,
98: (char *) NULL, Tk_Offset(TextItem, stipple), TK_CONFIG_NULL_OK},
99: {TK_CONFIG_CUSTOM, "-tags", (char *) NULL, (char *) NULL,
100: (char *) NULL, 0, TK_CONFIG_NULL_OK, &tkCanvasTagsOption},
101: {TK_CONFIG_STRING, "-text", (char *) NULL, (char *) NULL,
102: "", Tk_Offset(TextItem, text), 0},
103: {TK_CONFIG_PIXELS, "-width", (char *) NULL, (char *) NULL,
104: "0", Tk_Offset(TextItem, width), TK_CONFIG_DONT_SET_DEFAULT},
105: {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
106: (char *) NULL, 0, 0}
107: };
108:
109: /*
110: * Prototypes for procedures defined in this file:
111: */
112:
113: static void ComputeTextBbox _ANSI_ARGS_((Tk_Canvas *canvasPtr,
114: TextItem *textPtr));
115: static int ConfigureText _ANSI_ARGS_((
116: Tk_Canvas *canvasPtr, Tk_Item *itemPtr, int argc,
117: char **argv, int flags));
118: static int CreateText _ANSI_ARGS_((Tk_Canvas *canvasPtr,
119: struct Tk_Item *itemPtr, int argc, char **argv));
120: static void DeleteText _ANSI_ARGS_((Tk_Item *itemPtr));
121: static void DisplayText _ANSI_ARGS_((Tk_Canvas *canvasPtr,
122: Tk_Item *itemPtr, Drawable dst));
123: static int GetSelText _ANSI_ARGS_((Tk_Canvas *canvasPtr,
124: Tk_Item *itemPtr, int offset, char *buffer,
125: int maxBytes));
126: static int GetTextIndex _ANSI_ARGS_((Tk_Canvas *canvasPtr,
127: Tk_Item *itemPtr, char *indexString,
128: int *indexPtr));
129: static void ScaleText _ANSI_ARGS_((Tk_Canvas *canvasPtr,
130: Tk_Item *itemPtr, double originX, double originY,
131: double scaleX, double scaleY));
132: static void SetTextCursor _ANSI_ARGS_((Tk_Canvas *canvasPtr,
133: Tk_Item *itemPtr, int index));
134: static int TextCoords _ANSI_ARGS_((Tk_Canvas *canvasPtr,
135: Tk_Item *itemPtr, int argc, char **argv));
136: static int TextDeleteChars _ANSI_ARGS_((Tk_Canvas *canvasPtr,
137: Tk_Item *itemPtr, int first, int last));
138: static int TextInsert _ANSI_ARGS_((Tk_Canvas *canvasPtr,
139: Tk_Item *itemPtr, int beforeThis, char *string));
140: static int TextToArea _ANSI_ARGS_((Tk_Canvas *canvasPtr,
141: Tk_Item *itemPtr, double *rectPtr));
142: static double TextToPoint _ANSI_ARGS_((Tk_Canvas *canvasPtr,
143: Tk_Item *itemPtr, double *pointPtr));
144: static void TranslateText _ANSI_ARGS_((Tk_Canvas *canvasPtr,
145: Tk_Item *itemPtr, double deltaX, double deltaY));
146:
147: /*
148: * The structures below defines the rectangle and oval item types
149: * by means of procedures that can be invoked by generic item code.
150: */
151:
152: Tk_ItemType TkTextType = {
153: "text", /* name */
154: sizeof(TextItem), /* itemSize */
155: CreateText, /* createProc */
156: configSpecs, /* configSpecs */
157: ConfigureText, /* configureProc */
158: TextCoords, /* coordProc */
159: DeleteText, /* deleteProc */
160: DisplayText, /* displayProc */
161: 0, /* alwaysRedraw */
162: TextToPoint, /* pointProc */
163: TextToArea, /* areaProc */
164: (Tk_ItemPostscriptProc *) NULL, /* postscriptProc */
165: ScaleText, /* scaleProc */
166: TranslateText, /* translateProc */
167: GetTextIndex, /* indexProc */
168: SetTextCursor, /* cursorProc */
169: GetSelText, /* selectionProc */
170: TextInsert, /* insertProc */
171: TextDeleteChars, /* dTextProc */
172: (Tk_ItemType *) NULL /* nextPtr */
173: };
174:
175: /*
176: *--------------------------------------------------------------
177: *
178: * CreateText --
179: *
180: * This procedure is invoked to create a new text item
181: * in a canvas.
182: *
183: * Results:
184: * A standard Tcl return value. If an error occurred in
185: * creating the item then an error message is left in
186: * canvasPtr->interp->result; in this case itemPtr is
187: * left uninitialized so it can be safely freed by the
188: * caller.
189: *
190: * Side effects:
191: * A new text item is created.
192: *
193: *--------------------------------------------------------------
194: */
195:
196: static int
197: CreateText(canvasPtr, itemPtr, argc, argv)
198: register Tk_Canvas *canvasPtr; /* Canvas to hold new item. */
199: Tk_Item *itemPtr; /* Record to hold new item; header
200: * has been initialized by caller. */
201: int argc; /* Number of arguments in argv. */
202: char **argv; /* Arguments describing rectangle. */
203: {
204: register TextItem *textPtr = (TextItem *) itemPtr;
205:
206: if (argc < 2) {
207: Tcl_AppendResult(canvasPtr->interp, "wrong # args: should be \"",
208: Tk_PathName(canvasPtr->tkwin),
209: "\" create text x y [options]", (char *) NULL);
210: return TCL_ERROR;
211: }
212:
213: /*
214: * Carry out initialization that is needed in order to clean
215: * up after errors during the the remainder of this procedure.
216: */
217:
218: textPtr->text = NULL;
219: textPtr->anchor = TK_ANCHOR_CENTER;
220: textPtr->width = 0;
221: textPtr->justify = TK_JUSTIFY_LEFT;
222: textPtr->fontPtr = NULL;
223: textPtr->color = NULL;
224: textPtr->stipple = None;
225: textPtr->gc = None;
226: textPtr->linePtr = NULL;
227: textPtr->numLines = 0;
228: textPtr->cursorPos = 0;
229: textPtr->selTextGC = None;
230:
231: /*
232: * Process the arguments to fill in the item record.
233: */
234:
235: if ((TkGetCanvasCoord(canvasPtr, argv[0], &textPtr->x) != TCL_OK)
236: || (TkGetCanvasCoord(canvasPtr, argv[1], &textPtr->y) != TCL_OK)) {
237: return TCL_ERROR;
238: }
239:
240: if (ConfigureText(canvasPtr, itemPtr, argc-2, argv+2, 0) != TCL_OK) {
241: DeleteText(itemPtr);
242: return TCL_ERROR;
243: }
244: return TCL_OK;
245: }
246:
247: /*
248: *--------------------------------------------------------------
249: *
250: * TextCoords --
251: *
252: * This procedure is invoked to process the "coords" widget
253: * command on text items. See the user documentation for
254: * details on what it does.
255: *
256: * Results:
257: * Returns TCL_OK or TCL_ERROR, and sets canvasPtr->interp->result.
258: *
259: * Side effects:
260: * The coordinates for the given item may be changed.
261: *
262: *--------------------------------------------------------------
263: */
264:
265: static int
266: TextCoords(canvasPtr, itemPtr, argc, argv)
267: register Tk_Canvas *canvasPtr; /* Canvas containing item. */
268: Tk_Item *itemPtr; /* Item whose coordinates are to be
269: * read or modified. */
270: int argc; /* Number of coordinates supplied in
271: * argv. */
272: char **argv; /* Array of coordinates: x1, y1,
273: * x2, y2, ... */
274: {
275: register TextItem *textPtr = (TextItem *) itemPtr;
276:
277: if (argc == 0) {
278: sprintf(canvasPtr->interp->result, "%g %g", textPtr->x, textPtr->y);
279: } else if (argc == 2) {
280: if ((TkGetCanvasCoord(canvasPtr, argv[0], &textPtr->x) != TCL_OK)
281: || (TkGetCanvasCoord(canvasPtr, argv[1],
282: &textPtr->y) != TCL_OK)) {
283: return TCL_ERROR;
284: }
285: ComputeTextBbox(canvasPtr, textPtr);
286: } else {
287: sprintf(canvasPtr->interp->result,
288: "wrong # coordinates: expected 0 or 2, got %d",
289: argc);
290: return TCL_ERROR;
291: }
292: return TCL_OK;
293: }
294:
295: /*
296: *--------------------------------------------------------------
297: *
298: * ConfigureText --
299: *
300: * This procedure is invoked to configure various aspects
301: * of a text item, such as its border and background colors.
302: *
303: * Results:
304: * A standard Tcl result code. If an error occurs, then
305: * an error message is left in canvasPtr->interp->result.
306: *
307: * Side effects:
308: * Configuration information, such as colors and stipple
309: * patterns, may be set for itemPtr.
310: *
311: *--------------------------------------------------------------
312: */
313:
314: static int
315: ConfigureText(canvasPtr, itemPtr, argc, argv, flags)
316: Tk_Canvas *canvasPtr; /* Canvas containing itemPtr. */
317: Tk_Item *itemPtr; /* Rectangle item to reconfigure. */
318: int argc; /* Number of elements in argv. */
319: char **argv; /* Arguments describing things to configure. */
320: int flags; /* Flags to pass to Tk_ConfigureWidget. */
321: {
322: register TextItem *textPtr = (TextItem *) itemPtr;
323: XGCValues gcValues;
324: GC newGC, newSelGC;
325: unsigned long mask;
326:
327: if (Tk_ConfigureWidget(canvasPtr->interp, canvasPtr->tkwin,
328: configSpecs, argc, argv, (char *) textPtr, flags) != TCL_OK) {
329: return TCL_ERROR;
330: }
331:
332: /*
333: * A few of the options require additional processing, such as
334: * graphics contexts.
335: */
336:
337: textPtr->numChars = strlen(textPtr->text);
338: newGC = newSelGC = None;
339: if ((textPtr->color != NULL) && (textPtr->fontPtr != NULL)) {
340: gcValues.foreground = textPtr->color->pixel;
341: gcValues.font = textPtr->fontPtr->fid;
342: mask = GCForeground|GCFont;
343: if (textPtr->stipple != None) {
344: gcValues.stipple = textPtr->stipple;
345: gcValues.fill_style = FillStippled;
346: mask |= GCForeground|GCStipple|GCFillStyle;
347: }
348: newGC = Tk_GetGC(canvasPtr->tkwin, mask, &gcValues);
349: gcValues.foreground = canvasPtr->selFgColorPtr->pixel;
350: newSelGC = Tk_GetGC(canvasPtr->tkwin, mask, &gcValues);
351: }
352: if (textPtr->gc != None) {
353: Tk_FreeGC(textPtr->gc);
354: }
355: textPtr->gc = newGC;
356: if (textPtr->selTextGC != None) {
357: Tk_FreeGC(textPtr->selTextGC);
358: }
359: textPtr->selTextGC = newSelGC;
360:
361: /*
362: * If the text was changed, move the selection and insertion indices
363: * to keep them inside the item.
364: */
365:
366: if (canvasPtr->selItemPtr == itemPtr) {
367: if (canvasPtr->selectFirst >= textPtr->numChars) {
368: canvasPtr->selItemPtr = NULL;
369: } else {
370: if (canvasPtr->selectLast >= textPtr->numChars) {
371: canvasPtr->selectLast = textPtr->numChars-1;
372: }
373: if ((canvasPtr->anchorItemPtr == itemPtr)
374: && (canvasPtr->selectAnchor >= textPtr->numChars)) {
375: canvasPtr->selectAnchor = textPtr->numChars-1;
376: }
377: }
378: }
379: if (textPtr->cursorPos >= textPtr->numChars) {
380: textPtr->cursorPos = textPtr->numChars;
381: }
382:
383: ComputeTextBbox(canvasPtr, textPtr);
384: return TCL_OK;
385: }
386:
387: /*
388: *--------------------------------------------------------------
389: *
390: * DeleteText --
391: *
392: * This procedure is called to clean up the data structure
393: * associated with a text item.
394: *
395: * Results:
396: * None.
397: *
398: * Side effects:
399: * Resources associated with itemPtr are released.
400: *
401: *--------------------------------------------------------------
402: */
403:
404: static void
405: DeleteText(itemPtr)
406: Tk_Item *itemPtr; /* Item that is being deleted. */
407: {
408: register TextItem *textPtr = (TextItem *) itemPtr;
409:
410: if (textPtr->text != NULL) {
411: ckfree(textPtr->text);
412: }
413: if (textPtr->fontPtr != NULL) {
414: Tk_FreeFontStruct(textPtr->fontPtr);
415: }
416: if (textPtr->color != NULL) {
417: Tk_FreeColor(textPtr->color);
418: }
419: if (textPtr->stipple != None) {
420: Tk_FreeBitmap(textPtr->stipple);
421: }
422: if (textPtr->gc != None) {
423: Tk_FreeGC(textPtr->gc);
424: }
425: if (textPtr->linePtr != NULL) {
426: ckfree((char *) textPtr->linePtr);
427: }
428: if (textPtr->selTextGC != None) {
429: Tk_FreeGC(textPtr->selTextGC);
430: }
431: }
432:
433: /*
434: *--------------------------------------------------------------
435: *
436: * ComputeTextBbox --
437: *
438: * This procedure is invoked to compute the bounding box of
439: * all the pixels that may be drawn as part of a text item.
440: * In addition, it recomputes all of the geometry information
441: * used to display a text item or check for mouse hits.
442: *
443: * Results:
444: * None.
445: *
446: * Side effects:
447: * The fields x1, y1, x2, and y2 are updated in the header
448: * for itemPtr, and the linePtr structure is regenerated
449: * for itemPtr.
450: *
451: *--------------------------------------------------------------
452: */
453:
454: static void
455: ComputeTextBbox(canvasPtr, textPtr)
456: register Tk_Canvas *canvasPtr; /* Canvas that contains item. */
457: register TextItem *textPtr; /* Item whose bbos is to be
458: * recomputed. */
459: {
460: register TextLine *linePtr;
461: #define MAX_LINES 100
462: char *lineStart[MAX_LINES];
463: int lineChars[MAX_LINES];
464: int linePixels[MAX_LINES];
465: int numLines, wrapPixels, maxLinePixels, leftX, topY, y;
466: int lineHeight, i, fudge;
467: char *p;
468: XCharStruct *maxBoundsPtr = &textPtr->fontPtr->max_bounds;
469:
470: if (textPtr->linePtr != NULL) {
471: ckfree((char *) textPtr->linePtr);
472: textPtr->linePtr = NULL;
473: }
474:
475: /*
476: * Work through the text computing the starting point, number of
477: * characters, and number of pixels in each line.
478: */
479:
480: p = textPtr->text;
481: if (textPtr->width > 0) {
482: wrapPixels = maxLinePixels = textPtr->width;
483: } else {
484: wrapPixels = 10000000;
485: maxLinePixels = 0;
486: }
487: for (numLines = 0; (numLines < MAX_LINES) && (*p != 0);
488: numLines++) {
489: int numChars, numPixels;
490: numChars = TkMeasureChars(textPtr->fontPtr, p,
491: (textPtr->text + textPtr->numChars) - p, 0,
492: wrapPixels, TK_WHOLE_WORDS|TK_AT_LEAST_ONE, &numPixels);
493: if (numPixels > maxLinePixels) {
494: maxLinePixels = numPixels;
495: }
496: lineStart[numLines] = p;
497: lineChars[numLines] = numChars;
498: linePixels[numLines] = numPixels;
499: p += numChars;
500:
501: /*
502: * Skip space character that terminates a line, if there is one.
503: * In the case of multiple spaces, all but one will be displayed.
504: * This is important to make sure the insertion cursor gets
505: * displayed when it is in the middle of a multi-space.
506: */
507:
508: if (isspace(*p)) {
509: p++;
510: }
511: }
512:
513: /*
514: * Use overall geometry information to compute the top-left corner
515: * of the bounding box for the text item.
516: */
517:
518: leftX = textPtr->x + 0.5;
519: topY = textPtr->y + 0.5;
520: lineHeight = textPtr->fontPtr->ascent + textPtr->fontPtr->descent;
521: switch (textPtr->anchor) {
522: case TK_ANCHOR_NW:
523: case TK_ANCHOR_N:
524: case TK_ANCHOR_NE:
525: break;
526:
527: case TK_ANCHOR_W:
528: case TK_ANCHOR_CENTER:
529: case TK_ANCHOR_E:
530: topY -= (lineHeight * numLines)/2;
531: break;
532:
533: case TK_ANCHOR_SW:
534: case TK_ANCHOR_S:
535: case TK_ANCHOR_SE:
536: topY -= lineHeight * numLines;
537: break;
538: }
539: switch (textPtr->anchor) {
540: case TK_ANCHOR_NW:
541: case TK_ANCHOR_W:
542: case TK_ANCHOR_SW:
543: break;
544:
545: case TK_ANCHOR_N:
546: case TK_ANCHOR_CENTER:
547: case TK_ANCHOR_S:
548: leftX -= maxLinePixels/2;
549: break;
550:
551: case TK_ANCHOR_NE:
552: case TK_ANCHOR_E:
553: case TK_ANCHOR_SE:
554: leftX -= maxLinePixels;
555: break;
556: }
557: textPtr->rightEdge = leftX + maxLinePixels;
558:
559: /*
560: * Create the new TextLine array and fill it in using the geometry
561: * information gathered already.
562: */
563:
564: if (numLines > 0) {
565: textPtr->linePtr = (TextLine *) ckalloc((unsigned)
566: (numLines * sizeof(TextLine)));
567: } else {
568: textPtr->linePtr = NULL;
569: }
570: textPtr->numLines = numLines;
571: for (i = 0, linePtr = textPtr->linePtr, y = topY;
572: i < numLines; i++, linePtr++, y += lineHeight) {
573: linePtr->firstChar = lineStart[i];
574: linePtr->numChars = lineChars[i];
575: if (i == (numLines-1)) {
576: linePtr->totalChars = linePtr->numChars;
577: } else {
578: linePtr->totalChars = lineStart[i+1] - lineStart[i];
579: }
580: switch (textPtr->justify) {
581: case TK_JUSTIFY_LEFT:
582: case TK_JUSTIFY_FILL:
583: linePtr->x = leftX;
584: break;
585: case TK_JUSTIFY_CENTER:
586: linePtr->x = leftX + maxLinePixels/2 - linePixels[i]/2;
587: break;
588: case TK_JUSTIFY_RIGHT:
589: linePtr->x = leftX + maxLinePixels - linePixels[i];
590: break;
591: }
592: linePtr->y = y + textPtr->fontPtr->ascent;
593: linePtr->x1 = linePtr->x - maxBoundsPtr->lbearing;
594: linePtr->y1 = y;
595: linePtr->x2 = linePtr->x + linePixels[i] + maxBoundsPtr->rbearing
596: - textPtr->fontPtr->min_bounds.rbearing;
597: linePtr->y2 = linePtr->y + textPtr->fontPtr->descent - 1;
598: }
599:
600: /*
601: * Last of all, update the bounding box for the item. The item's
602: * bounding box includes the bounding box of all its lines, plus
603: * an extra fudge factor for the cursor border (which could
604: * potentially be quite large).
605: */
606:
607: linePtr = textPtr->linePtr;
608: textPtr->header.x1 = textPtr->header.x2 = leftX;
609: textPtr->header.y1 = topY;
610: textPtr->header.y2 = topY + numLines*lineHeight;
611: for (linePtr = textPtr->linePtr, i = textPtr->numLines; i > 0;
612: i--, linePtr++) {
613: if (linePtr->x1 < textPtr->header.x1) {
614: textPtr->header.x1 = linePtr->x1;
615: }
616: if (linePtr->x2 >= textPtr->header.x2) {
617: textPtr->header.x2 = linePtr->x2 + 1;
618: }
619: }
620:
621: fudge = canvasPtr->cursorWidth/2;
622: if (canvasPtr->selBorderWidth > fudge) {
623: fudge = canvasPtr->selBorderWidth;
624: }
625: textPtr->header.x1 -= fudge;
626: textPtr->header.x2 += fudge;
627: }
628:
629: /*
630: *--------------------------------------------------------------
631: *
632: * DisplayText --
633: *
634: * This procedure is invoked to draw a text item in a given
635: * drawable.
636: *
637: * Results:
638: * None.
639: *
640: * Side effects:
641: * ItemPtr is drawn in drawable using the transformation
642: * information in canvasPtr.
643: *
644: *--------------------------------------------------------------
645: */
646:
647: static void
648: DisplayText(canvasPtr, itemPtr, drawable)
649: register Tk_Canvas *canvasPtr; /* Canvas that contains item. */
650: Tk_Item *itemPtr; /* Item to be displayed. */
651: Drawable drawable; /* Pixmap or window in which to draw
652: * item. */
653: {
654: register TextItem *textPtr = (TextItem *) itemPtr;
655: Display *display = Tk_Display(canvasPtr->tkwin);
656: register TextLine *linePtr;
657: int i, focusHere, cursorX, cursorIndex, lineIndex;
658: int beforeSelect, inSelect, afterSelect, selStartX, selEndX;
659:
660: if (textPtr->gc == None) {
661: return;
662: }
663: focusHere = (canvasPtr->focusItemPtr == itemPtr) &&
664: (canvasPtr->flags & GOT_FOCUS);
665: for (linePtr = textPtr->linePtr, i = textPtr->numLines;
666: i > 0; linePtr++, i--) {
667:
668: /*
669: * If part or all of this line is selected, then draw a special
670: * background under the selected part of the line.
671: */
672:
673: lineIndex = linePtr->firstChar - textPtr->text;
674: if ((canvasPtr->selItemPtr != itemPtr)
675: || (canvasPtr->selectLast < lineIndex)
676: || (canvasPtr->selectFirst >= (lineIndex
677: + linePtr->totalChars))) {
678: beforeSelect = linePtr->numChars;
679: inSelect = 0;
680: } else {
681: beforeSelect = canvasPtr->selectFirst - lineIndex;
682: if (beforeSelect <= 0) {
683: beforeSelect = 0;
684: selStartX = linePtr->x;
685: } else {
686: (void) TkMeasureChars(textPtr->fontPtr,
687: linePtr->firstChar, beforeSelect, 0,
688: (int) 1000000, TK_PARTIAL_OK, &selStartX);
689: selStartX += linePtr->x;
690: }
691: inSelect = canvasPtr->selectLast + 1 - (lineIndex + beforeSelect);
692:
693: /*
694: * If the selection spans the end of this line, then display
695: * selection background all the way to the end of the line.
696: * However, for the last line we only want to display up to
697: * the last character, not the end of the line, hence the
698: * "i != 1" check.
699: */
700:
701: if (inSelect >= (linePtr->totalChars - beforeSelect)) {
702: inSelect = linePtr->numChars - beforeSelect;
703: if (i != 1) {
704: selEndX = textPtr->rightEdge;
705: goto fillSelectBackground;
706: }
707: }
708: (void) TkMeasureChars(textPtr->fontPtr,
709: linePtr->firstChar + beforeSelect, inSelect,
710: selStartX-linePtr->x, (int) 1000000, TK_PARTIAL_OK,
711: &selEndX);
712: selEndX += linePtr->x;
713: fillSelectBackground:
714: Tk_Fill3DRectangle(display, drawable, canvasPtr->selBorder,
715: selStartX - canvasPtr->drawableXOrigin
716: - canvasPtr->selBorderWidth,
717: linePtr->y - canvasPtr->drawableYOrigin
718: - textPtr->fontPtr->ascent,
719: selEndX - selStartX + 2*canvasPtr->selBorderWidth,
720: textPtr->fontPtr->ascent + textPtr->fontPtr->descent,
721: canvasPtr->selBorderWidth, TK_RELIEF_RAISED);
722: }
723:
724: /*
725: * If the insertion cursor is in this line, then draw a special
726: * background for the cursor before drawing the text. Note:
727: * if we're the cursor item but the cursor is turned off, then
728: * redraw background over the area of the cursor. This guarantees
729: * that the selection won't make the cursor invisible on mono
730: * displays, where both are drawn in the same color.
731: */
732:
733: if (focusHere) {
734: cursorIndex = textPtr->cursorPos
735: - (linePtr->firstChar - textPtr->text);
736: if ((cursorIndex >= 0) && (cursorIndex <= linePtr->numChars)) {
737: (void) TkMeasureChars(textPtr->fontPtr, linePtr->firstChar,
738: cursorIndex, 0, (int) 1000000, TK_PARTIAL_OK, &cursorX);
739: if (canvasPtr->flags & CURSOR_ON) {
740: Tk_Fill3DRectangle(display, drawable,
741: canvasPtr->cursorBorder,
742: linePtr->x - canvasPtr->drawableXOrigin
743: + cursorX - (canvasPtr->cursorWidth)/2,
744: linePtr->y - canvasPtr->drawableYOrigin
745: - textPtr->fontPtr->ascent,
746: canvasPtr->cursorWidth,
747: textPtr->fontPtr->ascent
748: + textPtr->fontPtr->descent,
749: canvasPtr->cursorBorderWidth, TK_RELIEF_RAISED);
750: } else if (Tk_DefaultDepth(
751: Tk_Screen(canvasPtr->tkwin)) == 1){
752: Tk_Fill3DRectangle(display, drawable,
753: canvasPtr->bgBorder,
754: linePtr->x - canvasPtr->drawableXOrigin
755: + cursorX - (canvasPtr->cursorWidth)/2,
756: linePtr->y - canvasPtr->drawableYOrigin
757: - textPtr->fontPtr->ascent,
758: canvasPtr->cursorWidth,
759: textPtr->fontPtr->ascent
760: + textPtr->fontPtr->descent,
761: 0, TK_RELIEF_FLAT);
762: }
763: }
764: }
765:
766: /*
767: * Display the text in three pieces: the part before the
768: * selection, the selected part (which needs a different graphics
769: * context), and the part after the selection.
770: */
771:
772: if (beforeSelect != 0) {
773: TkDisplayChars(display, drawable, textPtr->gc, textPtr->fontPtr,
774: linePtr->firstChar, beforeSelect,
775: linePtr->x - canvasPtr->drawableXOrigin,
776: linePtr->y - canvasPtr->drawableYOrigin, 0);
777: }
778: if (inSelect != 0) {
779: TkDisplayChars(display, drawable, textPtr->selTextGC,
780: textPtr->fontPtr, linePtr->firstChar + beforeSelect,
781: inSelect, selStartX - canvasPtr->drawableXOrigin,
782: linePtr->y - canvasPtr->drawableYOrigin, 0);
783: }
784: afterSelect = linePtr->numChars - beforeSelect - inSelect;
785: if (afterSelect > 0) {
786: TkDisplayChars(display, drawable, textPtr->gc, textPtr->fontPtr,
787: linePtr->firstChar + beforeSelect + inSelect,
788: afterSelect, selEndX - canvasPtr->drawableXOrigin,
789: linePtr->y - canvasPtr->drawableYOrigin, 0);
790: }
791: }
792: }
793:
794: /*
795: *--------------------------------------------------------------
796: *
797: * TextInsert --
798: *
799: * Insert characters into a text item at a given position.
800: *
801: * Results:
802: * Always returns TCL_OK.
803: *
804: * Side effects:
805: * The text in the given item is modified. The cursor and
806: * selection positions are also modified to reflect the
807: * insertion.
808: *
809: *--------------------------------------------------------------
810: */
811:
812: static int
813: TextInsert(canvasPtr, itemPtr, beforeThis, string)
814: Tk_Canvas *canvasPtr; /* Canvas containing text item. */
815: Tk_Item *itemPtr; /* Text item to be modified. */
816: int beforeThis; /* Index of character before which text is
817: * to be inserted. */
818: char *string; /* New characters to be inserted. */
819: {
820: register TextItem *textPtr = (TextItem *) itemPtr;
821: int length;
822: char *new;
823:
824: length = strlen(string);
825: if (length == 0) {
826: return TCL_OK;
827: }
828: if (beforeThis < 0) {
829: beforeThis = 0;
830: }
831: if (beforeThis > textPtr->numChars) {
832: beforeThis = textPtr->numChars;
833: }
834:
835: new = (char *) ckalloc((unsigned) (textPtr->numChars + length + 1));
836: strncpy(new, textPtr->text, beforeThis);
837: strcpy(new+beforeThis, string);
838: strcpy(new+beforeThis+length, textPtr->text+beforeThis);
839: ckfree(textPtr->text);
840: textPtr->text = new;
841: textPtr->numChars += length;
842:
843: /*
844: * Inserting characters invalidates indices such as those for the
845: * selection and cursor. Update the indices appropriately.
846: */
847:
848: if (canvasPtr->selItemPtr == itemPtr) {
849: if (canvasPtr->selectFirst >= beforeThis) {
850: canvasPtr->selectFirst += length;
851: }
852: if (canvasPtr->selectLast >= beforeThis) {
853: canvasPtr->selectLast += length;
854: }
855: if ((canvasPtr->anchorItemPtr == itemPtr)
856: && (canvasPtr->selectAnchor >= beforeThis)) {
857: canvasPtr->selectAnchor += length;
858: }
859: }
860: if (textPtr->cursorPos >= beforeThis) {
861: textPtr->cursorPos += length;
862: }
863: ComputeTextBbox(canvasPtr, textPtr);
864: return TCL_OK;
865: }
866:
867: /*
868: *--------------------------------------------------------------
869: *
870: * TextDeleteChars --
871: *
872: * Delete one or more characters from a text item.
873: *
874: * Results:
875: * Always returns TCL_OK.
876: *
877: * Side effects:
878: * Characters between "first" and "last", inclusive, get
879: * deleted from itemPtr, and things like the selection
880: * position get updated.
881: *
882: *--------------------------------------------------------------
883: */
884:
885: static int
886: TextDeleteChars(canvasPtr, itemPtr, first, last)
887: Tk_Canvas *canvasPtr; /* Canvas containing itemPtr. */
888: Tk_Item *itemPtr; /* Item in which to delete characters. */
889: int first; /* Index of first character to delete. */
890: int last; /* Index of last character to delete. */
891: {
892: register TextItem *textPtr = (TextItem *) itemPtr;
893: int count;
894: char *new;
895:
896: if (first < 0) {
897: first = 0;
898: }
899: if (last >= textPtr->numChars) {
900: last = textPtr->numChars-1;
901: }
902: if (first > last) {
903: return TCL_OK;
904: }
905: count = last + 1 - first;
906:
907: new = ckalloc((unsigned) (textPtr->numChars + 1 - count));
908: strncpy(new, textPtr->text, first);
909: strcpy(new+first, textPtr->text+last+1);
910: ckfree(textPtr->text);
911: textPtr->text = new;
912: textPtr->numChars -= count;
913:
914: /*
915: * Update indexes for the selection and cursor to reflect the
916: * renumbering of the remaining characters.
917: */
918:
919: if (canvasPtr->selItemPtr == itemPtr) {
920: if (canvasPtr->selectFirst > first) {
921: canvasPtr->selectFirst -= count;
922: if (canvasPtr->selectFirst < first) {
923: canvasPtr->selectFirst = first;
924: }
925: }
926: if (canvasPtr->selectLast >= first) {
927: canvasPtr->selectLast -= count;
928: if (canvasPtr->selectLast < (first-1)) {
929: canvasPtr->selectLast = (first-1);
930: }
931: }
932: if (canvasPtr->selectFirst > canvasPtr->selectLast) {
933: canvasPtr->selItemPtr = NULL;
934: }
935: if ((canvasPtr->anchorItemPtr == itemPtr)
936: && (canvasPtr->selectAnchor > first)) {
937: canvasPtr->selectAnchor -= count;
938: if (canvasPtr->selectAnchor < first) {
939: canvasPtr->selectAnchor = first;
940: }
941: }
942: }
943: if (textPtr->cursorPos > first) {
944: textPtr->cursorPos -= count;
945: if (textPtr->cursorPos < first) {
946: textPtr->cursorPos = first;
947: }
948: }
949: ComputeTextBbox(canvasPtr, textPtr);
950: return TCL_OK;
951: }
952:
953: /*
954: *--------------------------------------------------------------
955: *
956: * TextToPoint --
957: *
958: * Computes the distance from a given point to a given
959: * text item, in canvas units.
960: *
961: * Results:
962: * The return value is 0 if the point whose x and y coordinates
963: * are pointPtr[0] and pointPtr[1] is inside the arc. If the
964: * point isn't inside the arc then the return value is the
965: * distance from the point to the arc.
966: *
967: * Side effects:
968: * None.
969: *
970: *--------------------------------------------------------------
971: */
972:
973: /* ARGSUSED */
974: static double
975: TextToPoint(canvasPtr, itemPtr, pointPtr)
976: Tk_Canvas *canvasPtr; /* Canvas containing itemPtr. */
977: Tk_Item *itemPtr; /* Item to check against point. */
978: double *pointPtr; /* Pointer to x and y coordinates. */
979: {
980: TextItem *textPtr = (TextItem *) itemPtr;
981: register TextLine *linePtr;
982: int i;
983: double xDiff, yDiff, dist, minDist;
984:
985: /*
986: * Treat each line in the text item as a rectangle, compute the
987: * distance to that rectangle, and take the minimum of these
988: * distances. Perform most of the calculations in integer pixel
989: * units, since that's how the dimensions of the text are defined.
990: */
991:
992: minDist = -1.0;
993: for (linePtr = textPtr->linePtr, i = textPtr->numLines;
994: i > 0; linePtr++, i--) {
995:
996: /*
997: * If the point is inside the line's rectangle, then can
998: * return immediately.
999: */
1000:
1001: if ((pointPtr[0] >= linePtr->x1)
1002: && (pointPtr[0] <= linePtr->x2)
1003: && (pointPtr[1] >= linePtr->y1)
1004: && (pointPtr[1] <= linePtr->y2)) {
1005: return 0.0;
1006: }
1007:
1008: /*
1009: * Point is outside line's rectangle; compute distance to nearest
1010: * side.
1011: */
1012:
1013: if (pointPtr[0] < linePtr->x1) {
1014: xDiff = linePtr->x1 - pointPtr[0];
1015: } else if (pointPtr[0] > linePtr->x2) {
1016: xDiff = pointPtr[0] - linePtr->x2;
1017: } else {
1018: xDiff = 0;
1019: }
1020:
1021: if (pointPtr[1] < linePtr->y1) {
1022: yDiff = linePtr->y1 - pointPtr[1];
1023: } else if (pointPtr[1] > linePtr->y2) {
1024: yDiff = pointPtr[1] - linePtr->y2;
1025: } else {
1026: yDiff = 0;
1027: }
1028:
1029: dist = hypot((float) xDiff, (float) yDiff);
1030: if ((dist < minDist) || (minDist < 0.0)) {
1031: minDist = dist;
1032: }
1033: }
1034: return minDist;
1035: }
1036:
1037: /*
1038: *--------------------------------------------------------------
1039: *
1040: * TextToArea --
1041: *
1042: * This procedure is called to determine whether an item
1043: * lies entirely inside, entirely outside, or overlapping
1044: * a given rectangle.
1045: *
1046: * Results:
1047: * -1 is returned if the item is entirely outside the area
1048: * given by rectPtr, 0 if it overlaps, and 1 if it is entirely
1049: * inside the given area.
1050: *
1051: * Side effects:
1052: * None.
1053: *
1054: *--------------------------------------------------------------
1055: */
1056:
1057: /* ARGSUSED */
1058: static int
1059: TextToArea(canvasPtr, itemPtr, rectPtr)
1060: Tk_Canvas *canvasPtr; /* Canvas containing itemPtr. */
1061: Tk_Item *itemPtr; /* Item to check against rectangle. */
1062: double *rectPtr; /* Pointer to array of four coordinates
1063: * (x1, y1, x2, y2) describing rectangular
1064: * area. */
1065: {
1066: TextItem *textPtr = (TextItem *) itemPtr;
1067: register TextLine *linePtr;
1068: int i, result;
1069:
1070: /*
1071: * Scan the lines one at a time, seeing whether each line is
1072: * entirely in, entirely out, or overlapping the rectangle. If
1073: * an overlap is detected, return immediately; otherwise wait
1074: * until all lines have been processed and see if they were all
1075: * inside or all outside.
1076: */
1077:
1078: result = 0;
1079: for (linePtr = textPtr->linePtr, i = textPtr->numLines;
1080: i > 0; linePtr++, i--) {
1081: if ((rectPtr[2] < linePtr->x1) || (rectPtr[0] > linePtr->x2)
1082: || (rectPtr[3] < linePtr->y1) || (rectPtr[1] > linePtr->y2)) {
1083: if (result == 1) {
1084: return 0;
1085: }
1086: result = -1;
1087: continue;
1088: }
1089: if ((linePtr->x1 < rectPtr[0]) || (linePtr->x2 > rectPtr[2])
1090: || (linePtr->y1 < rectPtr[1]) || (linePtr->y2 > rectPtr[3])) {
1091: return 0;
1092: }
1093: if (result == -1) {
1094: return 0;
1095: }
1096: result = 1;
1097: }
1098: return result;
1099: }
1100:
1101: /*
1102: *--------------------------------------------------------------
1103: *
1104: * ScaleText --
1105: *
1106: * This procedure is invoked to rescale a text item.
1107: *
1108: * Results:
1109: * None.
1110: *
1111: * Side effects:
1112: * Scales the position of the text, but not the size
1113: * of the font for the text.
1114: *
1115: *--------------------------------------------------------------
1116: */
1117:
1118: /* ARGSUSED */
1119: static void
1120: ScaleText(canvasPtr, itemPtr, originX, originY, scaleX, scaleY)
1121: Tk_Canvas *canvasPtr; /* Canvas containing rectangle. */
1122: Tk_Item *itemPtr; /* Rectangle to be scaled. */
1123: double originX, originY; /* Origin about which to scale rect. */
1124: double scaleX; /* Amount to scale in X direction. */
1125: double scaleY; /* Amount to scale in Y direction. */
1126: {
1127: register TextItem *textPtr = (TextItem *) itemPtr;
1128:
1129: textPtr->x = originX + scaleX*(textPtr->x - originX);
1130: textPtr->y = originY + scaleY*(textPtr->y - originY);
1131: ComputeTextBbox(canvasPtr, textPtr);
1132: return;
1133: }
1134:
1135: /*
1136: *--------------------------------------------------------------
1137: *
1138: * TranslateText --
1139: *
1140: * This procedure is called to move a text item by a
1141: * given amount.
1142: *
1143: * Results:
1144: * None.
1145: *
1146: * Side effects:
1147: * The position of the text item is offset by (xDelta, yDelta),
1148: * and the bounding box is updated in the generic part of the
1149: * item structure.
1150: *
1151: *--------------------------------------------------------------
1152: */
1153:
1154: static void
1155: TranslateText(canvasPtr, itemPtr, deltaX, deltaY)
1156: Tk_Canvas *canvasPtr; /* Canvas containing item. */
1157: Tk_Item *itemPtr; /* Item that is being moved. */
1158: double deltaX, deltaY; /* Amount by which item is to be
1159: * moved. */
1160: {
1161: register TextItem *textPtr = (TextItem *) itemPtr;
1162:
1163: textPtr->x += deltaX;
1164: textPtr->y += deltaY;
1165: ComputeTextBbox(canvasPtr, textPtr);
1166: }
1167:
1168: /*
1169: *--------------------------------------------------------------
1170: *
1171: * GetTextIndex --
1172: *
1173: * Parse an index into a text item and return either its value
1174: * or an error.
1175: *
1176: * Results:
1177: * A standard Tcl result. If all went well, then *indexPtr is
1178: * filled in with the index (into itemPtr) corresponding to
1179: * string. Otherwise an error message is left in
1180: * canvasPtr->interp->result.
1181: *
1182: * Side effects:
1183: * None.
1184: *
1185: *--------------------------------------------------------------
1186: */
1187:
1188: static int
1189: GetTextIndex(canvasPtr, itemPtr, string, indexPtr)
1190: Tk_Canvas *canvasPtr; /* Canvas containing item. */
1191: Tk_Item *itemPtr; /* Item for which the index is being
1192: * specified. */
1193: char *string; /* Specification of a particular character
1194: * in itemPtr's text. */
1195: int *indexPtr; /* Where to store converted index. */
1196: {
1197: register TextItem *textPtr = (TextItem *) itemPtr;
1198: int length;
1199:
1200: length = strlen(string);
1201:
1202: if (string[0] == 'e') {
1203: if (strncmp(string, "end", length) == 0) {
1204: *indexPtr = textPtr->numChars;
1205: } else {
1206: badIndex:
1207:
1208: /*
1209: * Some of the paths here leave messages in
1210: * canvasPtr->interp->result, so we have to clear it out
1211: * before storing our own message.
1212: */
1213:
1214: Tcl_SetResult(canvasPtr->interp, (char *) NULL, TCL_STATIC);
1215: Tcl_AppendResult(canvasPtr->interp, "bad index \"", string,
1216: "\"", (char *) NULL);
1217: return TCL_ERROR;
1218: }
1219: } else if (string[0] == 'c') {
1220: if (strncmp(string, "cursor", length) == 0) {
1221: *indexPtr = textPtr->cursorPos;
1222: } else {
1223: goto badIndex;
1224: }
1225: } else if (string[0] == 's') {
1226: if (canvasPtr->selItemPtr != itemPtr) {
1227: canvasPtr->interp->result = "selection isn't in item";
1228: return TCL_ERROR;
1229: }
1230: if (length < 5) {
1231: goto badIndex;
1232: }
1233: if (strncmp(string, "sel.first", length) == 0) {
1234: *indexPtr = canvasPtr->selectFirst;
1235: } else if (strncmp(string, "sel.last", length) == 0) {
1236: *indexPtr = canvasPtr->selectLast;
1237: } else {
1238: goto badIndex;
1239: }
1240: } else if (string[0] == '@') {
1241: int x, y, dummy, i;
1242: char *end, *p;
1243: register TextLine *linePtr;
1244:
1245: p = string+1;
1246: x = strtol(p, &end, 0);
1247: if ((end == p) || (*end != ',')) {
1248: goto badIndex;
1249: }
1250: p = end+1;
1251: y = strtol(p, &end, 0);
1252: if ((end == p) || (*end != 0)) {
1253: goto badIndex;
1254: }
1255: if ((textPtr->numChars == 0) || (y < textPtr->linePtr[0].y1)) {
1256: *indexPtr = 0;
1257: return TCL_OK;
1258: }
1259: for (i = 0, linePtr = textPtr->linePtr; ; i++, linePtr++) {
1260: if (i >= textPtr->numLines) {
1261: *indexPtr = textPtr->numChars;
1262: return TCL_OK;
1263: }
1264: if (y <= linePtr->y2) {
1265: break;
1266: }
1267: }
1268: *indexPtr = TkMeasureChars(textPtr->fontPtr, linePtr->firstChar,
1269: linePtr->numChars, linePtr->x, x, 0, &dummy);
1270: *indexPtr += linePtr->firstChar - textPtr->text;
1271: } else {
1272: if (Tcl_GetInt(canvasPtr->interp, string, indexPtr) != TCL_OK) {
1273: goto badIndex;
1274: }
1275: if (*indexPtr < 0){
1276: *indexPtr = 0;
1277: } else if (*indexPtr > textPtr->numChars) {
1278: *indexPtr = textPtr->numChars;
1279: }
1280: }
1281: return TCL_OK;
1282: }
1283:
1284: /*
1285: *--------------------------------------------------------------
1286: *
1287: * SetTextCursor --
1288: *
1289: * Set the position of the insertion cursor in this item.
1290: *
1291: * Results:
1292: * None.
1293: *
1294: * Side effects:
1295: * The cursor position will change.
1296: *
1297: *--------------------------------------------------------------
1298: */
1299:
1300: /* ARGSUSED */
1301: static void
1302: SetTextCursor(canvasPtr, itemPtr, index)
1303: Tk_Canvas *canvasPtr; /* Record describing canvas widget. */
1304: Tk_Item *itemPtr; /* Text item in which cursor position
1305: * is to be set. */
1306: int index; /* Index of character just before which
1307: * cursor is to be positioned. */
1308: {
1309: register TextItem *textPtr = (TextItem *) itemPtr;
1310:
1311: if (index < 0) {
1312: textPtr->cursorPos = 0;
1313: } else if (index > textPtr->numChars) {
1314: textPtr->cursorPos = textPtr->numChars;
1315: } else {
1316: textPtr->cursorPos = index;
1317: }
1318: }
1319:
1320: /*
1321: *--------------------------------------------------------------
1322: *
1323: * GetSelText --
1324: *
1325: * This procedure is invoked to return the selected portion
1326: * of a text item. It is only called when this item has
1327: * the selection.
1328: *
1329: * Results:
1330: * The return value is the number of non-NULL bytes stored
1331: * at buffer. Buffer is filled (or partially filled) with a
1332: * NULL-terminated string containing part or all of the selection,
1333: * as given by offset and maxBytes.
1334: *
1335: * Side effects:
1336: * None.
1337: *
1338: *--------------------------------------------------------------
1339: */
1340:
1341: static int
1342: GetSelText(canvasPtr, itemPtr, offset, buffer, maxBytes)
1343: Tk_Canvas *canvasPtr; /* Canvas containing selection. */
1344: Tk_Item *itemPtr; /* Text item containing selection. */
1345: int offset; /* Offset within selection of first
1346: * character to be returned. */
1347: char *buffer; /* Location in which to place
1348: * selection. */
1349: int maxBytes; /* Maximum number of bytes to place
1350: * at buffer, not including terminating
1351: * NULL character. */
1352: {
1353: TextItem *textPtr = (TextItem *) itemPtr;
1354: int count;
1355:
1356: count = canvasPtr->selectLast + 1 - canvasPtr->selectFirst - offset;
1357: if (canvasPtr->selectLast == textPtr->numChars) {
1358: count -= 1;
1359: }
1360: if (count > maxBytes) {
1361: count = maxBytes;
1362: }
1363: if (count <= 0) {
1364: return 0;
1365: }
1366: strncpy(buffer, textPtr->text + canvasPtr->selectFirst + offset, count);
1367: buffer[count] = '\0';
1368: return count;
1369: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.