text.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <cursor.h>
#include <mouse.h>
#include <keyboard.h>
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
#include <complete.h>
#include "dat.h"
#include "fns.h"

Image	*tagcols[NCOL];
Image	*textcols[NCOL];

enum{
	TABDIR = 3	/* width of tabs in directory windows */
};

void
textinit(Text *t, File *f, Rectangle r, Reffont *rf, Image *cols[NCOL])
{
	t->file = f;
	t->all = r;
	t->scrollr = r;
	t->scrollr.max.x = r.min.x+Scrollwid;
	t->lastsr = nullrect;
	r.min.x += Scrollwid+Scrollgap;
	t->eq0 = ~0;
	t->ncache = 0;
	t->reffont = rf;
	t->tabstop = maxtab;
	memmove(t->Frame.cols, cols, sizeof t->Frame.cols);
	textredraw(t, r, rf->f, screen, -1);
}

void
textredraw(Text *t, Rectangle r, Font *f, Image *b, int odx)
{
	int maxt;
	Rectangle rr;

	frinit(t, r, f, b, t->Frame.cols);
	rr = t->r;
	rr.min.x -= Scrollwid+Scrollgap;	/* back fill to scroll bar */
	draw(t->b, rr, t->cols[BACK], nil, ZP);
	/* use no wider than 3-space tabs in a directory */
	maxt = maxtab;
	if(t->what == Body){
		if(t->w->isdir)
			maxt = min(TABDIR, maxtab);
		else
			maxt = t->tabstop;
	}
	t->maxtab = maxt*stringwidth(f, "0");
	if(t->what==Body && t->w->isdir && odx!=Dx(t->all)){
		if(t->maxlines > 0){
			textreset(t);
			textcolumnate(t, t->w->dlp,  t->w->ndl);
			textshow(t, 0, 0, 1);
		}
	}else{
		textfill(t);
		textsetselect(t, t->q0, t->q1);
	}
}

int
textresize(Text *t, Rectangle r)
{
	int odx;

	if(Dy(r) > 0)
		r.max.y -= Dy(r)%t->font->height;
	else
		r.max.y = r.min.y;
	odx = Dx(t->all);
	t->all = r;
	t->scrollr = r;
	t->scrollr.max.x = r.min.x+Scrollwid;
	t->lastsr = nullrect;
	r.min.x += Scrollwid+Scrollgap;
	frclear(t, 0);
	textredraw(t, r, t->font, t->b, odx);
	return r.max.y;
}

void
textclose(Text *t)
{
	free(t->cache);
	frclear(t, 1);
	filedeltext(t->file, t);
	t->file = nil;
	rfclose(t->reffont);
	if(argtext == t)
		argtext = nil;
	if(typetext == t)
		typetext = nil;
	if(seltext == t)
		seltext = nil;
	if(mousetext == t)
		mousetext = nil;
	if(barttext == t)
		barttext = nil;
}

int
dircmp(void *a, void *b)
{
	Dirlist *da, *db;
	int i, n;

	da = *(Dirlist**)a;
	db = *(Dirlist**)b;
	n = min(da->nr, db->nr);
	i = memcmp(da->r, db->r, n*sizeof(Rune));
	if(i)
		return i;
	return da->nr - db->nr;
}

void
textcolumnate(Text *t, Dirlist **dlp, int ndl)
{
	int i, j, w, colw, mint, maxt, ncol, nrow;
	Dirlist *dl;
	uint q1;

	if(t->file->ntext > 1)
		return;
	mint = stringwidth(t->font, "0");
	/* go for narrower tabs if set more than 3 wide */
	t->maxtab = min(maxtab, TABDIR)*mint;
	maxt = t->maxtab;
	colw = 0;
	for(i=0; i<ndl; i++){
		dl = dlp[i];
		w = dl->wid;
		if(maxt-w%maxt < mint || w%maxt==0)
			w += mint;
		if(w % maxt)
			w += maxt-(w%maxt);
		if(w > colw)
			colw = w;
	}
	if(colw == 0)
		ncol = 1;
	else
		ncol = max(1, Dx(t->r)/colw);
	nrow = (ndl+ncol-1)/ncol;

	q1 = 0;
	for(i=0; i<nrow; i++){
		for(j=i; j<ndl; j+=nrow){
			dl = dlp[j];
			fileinsert(t->file, q1, dl->r, dl->nr);
			q1 += dl->nr;
			if(j+nrow >= ndl)
				break;
			w = dl->wid;
			if(maxt-w%maxt < mint){
				fileinsert(t->file, q1, L"\t", 1);
				q1++;
				w += mint;
			}
			do{
				fileinsert(t->file, q1, L"\t", 1);
				q1++;
				w += maxt-(w%maxt);
			}while(w < colw);
		}
		fileinsert(t->file, q1, L"\n", 1);
		q1++;
	}
}

uint
textload(Text *t, uint q0, char *file, int setqid)
{
	Rune *rp;
	Dirlist *dl, **dlp;
	int fd, i, j, n, ndl, nulls;
	uint q, q1;
	Dir *d, *dbuf;
	char *tmp;
	Text *u;

	if(t->ncache!=0 || t->file->nc || t->w==nil || t!=&t->w->body)
		error("text.load");
	if(t->w->isdir && t->file->nname==0){
		warning(nil, "empty directory name\n");
		return 0;
	}
	fd = open(file, OREAD);
	if(fd < 0){
		warning(nil, "can't open %s: %r\n", file);
		return 0;
	}
	d = dirfstat(fd);
	if(d == nil){
		warning(nil, "can't fstat %s: %r\n", file);
		goto Rescue;
	}
	nulls = FALSE;
	if(d->qid.type & QTDIR){
		/* this is checked in get() but it's possible the file changed underfoot */
		if(t->file->ntext > 1){
			warning(nil, "%s is a directory; can't read with multiple windows on it\n", file);
			goto Rescue;
		}
		t->w->isdir = TRUE;
		t->w->filemenu = FALSE;
		if(t->file->name[t->file->nname-1] != '/'){
			rp = runemalloc(t->file->nname+1);
			runemove(rp, t->file->name, t->file->nname);
			rp[t->file->nname] = '/';
			winsetname(t->w, rp, t->file->nname+1);
			free(rp);
		}
		dlp = nil;
		ndl = 0;
		dbuf = nil;
		while((n=dirread(fd, &dbuf)) > 0){
			for(i=0; i<n; i++){
				dl = emalloc(sizeof(Dirlist));
				j = strlen(dbuf[i].name);
				tmp = emalloc(j+1+1);
				memmove(tmp, dbuf[i].name, j);
				if(dbuf[i].qid.type & QTDIR)
					tmp[j++] = '/';
				tmp[j] = '\0';
				dl->r = bytetorune(tmp, &dl->nr);
				dl->wid = stringwidth(t->font, tmp);
				free(tmp);
				ndl++;
				dlp = realloc(dlp, ndl*sizeof(Dirlist*));
				dlp[ndl-1] = dl;
			}
			free(dbuf);
		}
		qsort(dlp, ndl, sizeof(Dirlist*), dircmp);
		t->w->dlp = dlp;
		t->w->ndl = ndl;
		textcolumnate(t, dlp, ndl);
		q1 = t->file->nc;
	}else{
		t->w->isdir = FALSE;
		t->w->filemenu = TRUE;
		q1 = q0 + fileload(t->file, q0, fd, &nulls);
	}
	if(setqid){
		t->file->dev = d->dev;
		t->file->mtime = d->mtime;
		t->file->qidpath = d->qid.path;
	}
	close(fd);
	rp = fbufalloc();
	for(q=q0; q<q1; q+=n){
		n = q1-q;
		if(n > RBUFSIZE)
			n = RBUFSIZE;
		bufread(t->file, q, rp, n);
		if(q < t->org)
			t->org += n;
		else if(q <= t->org+t->nchars)
			frinsert(t, rp, rp+n, q-t->org);
		if(t->lastlinefull)
			break;
	}
	fbuffree(rp);
	for(i=0; i<t->file->ntext; i++){
		u = t->file->text[i];
		if(u != t){
			if(u->org > u->file->nc)	/* will be 0 because of reset(), but safety first */
				u->org = 0;
			textresize(u, u->all);
			textbacknl(u, u->org, 0);	/* go to beginning of line */
		}
		textsetselect(u, q0, q0);
	}
	if(nulls)
		warning(nil, "%s: NUL bytes elided\n", file);
	free(d);
	return q1-q0;

    Rescue:
	close(fd);
	return 0;
}

uint
textbsinsert(Text *t, uint q0, Rune *r, uint n, int tofile, int *nrp)
{
	Rune *bp, *tp, *up;
	int i, initial;

	if(t->what == Tag){	/* can't happen but safety first: mustn't backspace over file name */
    Err:
		textinsert(t, q0, r, n, tofile);
		*nrp = n;
		return q0;
	}
	bp = r;
	for(i=0; i<n; i++)
		if(*bp++ == '\b'){
			--bp;
			initial = 0;
			tp = runemalloc(n);
			runemove(tp, r, i);
			up = tp+i;
			for(; i<n; i++){
				*up = *bp++;
				if(*up == '\b')
					if(up == tp)
						initial++;
					else
						--up;
				else
					up++;
			}
			if(initial){
				if(initial > q0)
					initial = q0;
				q0 -= initial;
				textdelete(t, q0, q0+initial, tofile);
			}
			n = up-tp;
			textinsert(t, q0, tp, n, tofile);
			free(tp);
			*nrp = n;
			return q0;
		}
	goto Err;
}

void
textinsert(Text *t, uint q0, Rune *r, uint n, int tofile)
{
	int c, i;
	Text *u;

	if(tofile && t->ncache != 0)
		error("text.insert");
	if(n == 0)
		return;
	if(tofile){
		fileinsert(t->file, q0, r, n);
		if(t->what == Body){
			t->w->dirty = TRUE;
			t->w->utflastqid = -1;
		}
		if(t->file->ntext > 1)
			for(i=0; i<t->file->ntext; i++){
				u = t->file->text[i];
				if(u != t){
					u->w->dirty = TRUE;	/* always a body */
					textinsert(u, q0, r, n, FALSE);
					textsetselect(u, u->q0, u->q1);
					textscrdraw(u);
				}
			}
					
	}
	if(q0 < t->q1)
		t->q1 += n;
	if(q0 < t->q0)
		t->q0 += n;
	if(q0 < t->org)
		t->org += n;
	else if(q0 <= t->org+t->nchars)
		frinsert(t, r, r+n, q0-t->org);
	if(t->w){
		c = 'i';
		if(t->what == Body)
			c = 'I';
		if(n <= EVENTSIZE)
			winevent(t->w, "%c%d %d 0 %d %.*S\n", c, q0, q0+n, n, n, r);
		else
			winevent(t->w, "%c%d %d 0 0 \n", c, q0, q0+n, n);
	}
}

void
typecommit(Text *t)
{
	if(t->w != nil)
		wincommit(t->w, t);
	else
		textcommit(t, TRUE);
}

void
textfill(Text *t)
{
	Rune *rp;
	int i, n, m, nl;

	if(t->lastlinefull || t->nofill)
		return;
	if(t->ncache > 0)
		typecommit(t);
	rp = fbufalloc();
	do{
		n = t->file->nc-(t->org+t->nchars);
		if(n == 0)
			break;
		if(n > 2000)	/* educated guess at reasonable amount */
			n = 2000;
		bufread(t->file, t->org+t->nchars, rp, n);
		/*
		 * it's expensive to frinsert more than we need, so
		 * count newlines.
		 */
		nl = t->maxlines-t->nlines;
		m = 0;
		for(i=0; i<n; ){
			if(rp[i++] == '\n'){
				m++;
				if(m >= nl)
					break;
			}
		}
		frinsert(t, rp, rp+i, t->nchars);
	}while(t->lastlinefull == FALSE);
	fbuffree(rp);
}

void
textdelete(Text *t, uint q0, uint q1, int tofile)
{
	uint n, p0, p1;
	int i, c;
	Text *u;

	if(tofile && t->ncache != 0)
		error("text.delete");
	n = q1-q0;
	if(n == 0)
		return;
	if(tofile){
		filedelete(t->file, q0, q1);
		if(t->what == Body){
			t->w->dirty = TRUE;
			t->w->utflastqid = -1;
		}
		if(t->file->ntext > 1)
			for(i=0; i<t->file->ntext; i++){
				u = t->file->text[i];
				if(u != t){
					u->w->dirty = TRUE;	/* always a body */
					textdelete(u, q0, q1, FALSE);
					textsetselect(u, u->q0, u->q1);
					textscrdraw(u);
				}
			}
	}
	if(q0 < t->q0)
		t->q0 -= min(n, t->q0-q0);
	if(q0 < t->q1)
		t->q1 -= min(n, t->q1-q0);
	if(q1 <= t->org)
		t->org -= n;
	else if(q0 < t->org+t->nchars){
		p1 = q1 - t->org;
		if(p1 > t->nchars)
			p1 = t->nchars;
		if(q0 < t->org){
			t->org = q0;
			p0 = 0;
		}else
			p0 = q0 - t->org;
		frdelete(t, p0, p1);
		textfill(t);
	}
	if(t->w){
		c = 'd';
		if(t->what == Body)
			c = 'D';
		winevent(t->w, "%c%d %d 0 0 \n", c, q0, q1);
	}
}

void
textconstrain(Text *t, uint q0, uint q1, uint *p0, uint *p1)
{
	*p0 = min(q0, t->file->nc);
	*p1 = min(q1, t->file->nc);
}

Rune
textreadc(Text *t, uint q)
{
	Rune r;

	if(t->cq0<=q && q<t->cq0+t->ncache)
		r = t->cache[q-t->cq0];
	else
		bufread(t->file, q, &r, 1);
	return r;
}

int
textbswidth(Text *t, Rune c)
{
	uint q, eq;
	Rune r;
	int skipping;

	/* there is known to be at least one character to erase */
	if(c == 0x08)	/* ^H: erase character */
		return 1;
	q = t->q0;
	skipping = TRUE;
	while(q > 0){
		r = textreadc(t, q-1);
		if(r == '\n'){		/* eat at most one more character */
			if(q == t->q0)	/* eat the newline */
				--q;
			break; 
		}
		if(c == 0x17){
			eq = isalnum(r);
			if(eq && skipping)	/* found one; stop skipping */
				skipping = FALSE;
			else if(!eq && !skipping)
				break;
		}
		--q;
	}
	return t->q0-q;
}

int
textfilewidth(Text *t, uint q0, int oneelement)
{
	uint q;
	Rune r;

	q = q0;
	while(q > 0){
		r = textreadc(t, q-1);
		if(r <= ' ')
			break;
		if(oneelement && r=='/')
			break;
		--q;
	}
	return q0-q;
}

Rune*
textcomplete(Text *t)
{
	int i, nstr, npath;
	uint q;
	Rune tmp[200];
	Rune *str, *path;
	Rune *rp;
	Completion *c;
	char *s, *dirs;
	Runestr dir;

	/* control-f: filename completion; works back to white space or / */
	if(t->q0<t->file->nc && textreadc(t, t->q0)>' ')	/* must be at end of word */
		return nil;
	nstr = textfilewidth(t, t->q0, TRUE);
	str = runemalloc(nstr);
	npath = textfilewidth(t, t->q0-nstr, FALSE);
	path = runemalloc(npath);

	c = nil;
	rp = nil;
	dirs = nil;

	q = t->q0-nstr;
	for(i=0; i<nstr; i++)
		str[i] = textreadc(t, q++);
	q = t->q0-nstr-npath;
	for(i=0; i<npath; i++)
		path[i] = textreadc(t, q++);
	/* is path rooted? if not, we need to make it relative to window path */
	if(npath>0 && path[0]=='/')
		dir = (Runestr){path, npath};
	else{
		dir = dirname(t, nil, 0);
		if(dir.nr + 1 + npath > nelem(tmp)){
			free(dir.r);
			goto Return;
		}
		if(dir.nr == 0){
			dir.nr = 1;
			dir.r = runestrdup(L".");
		}
		runemove(tmp, dir.r, dir.nr);
		tmp[dir.nr] = '/';
		runemove(tmp+dir.nr+1, path, npath);
		free(dir.r);
		dir.r = tmp;
		dir.nr += 1+npath;
		dir = cleanrname(dir);
	}

	s = smprint("%.*S", nstr, str);
	dirs = smprint("%.*S", dir.nr, dir.r);
	c = complete(dirs, s);
	free(s);
	if(c == nil){
		warning(nil, "error attempting completion: %r\n");
		goto Return;
	}

	if(!c->advance){
		warning(nil, "%.*S%s%.*S*%s\n",
			dir.nr, dir.r,
			dir.nr>0 && dir.r[dir.nr-1]!='/' ? "/" : "",
			nstr, str,
			c->nmatch? "" : ": no matches in:");
		for(i=0; i<c->nfile; i++)
			warning(nil, " %s\n", c->filename[i]);
	}

	if(c->advance)
		rp = runesmprint("%s", c->string);
	else
		rp = nil;
  Return:
	freecompletion(c);
	free(dirs);
	free(str);
	free(path);
	return rp;
}

void
texttype(Text *t, Rune r)
{
	uint q0, q1;
	int nnb, nb, n, i;
	int nr;
	Rune *rp;
	Text *u;

	if(t->what!=Body && r=='\n')
		return;
	nr = 1;
	rp = &r;
	switch(r){
	case Kleft:
		if(t->q0 > 0){
			typecommit(t);
			textshow(t, t->q0-1, t->q0-1, TRUE);
		}
		return;
	case Kright:
		if(t->q1 < t->file->nc){
			typecommit(t);
			textshow(t, t->q1+1, t->q1+1, TRUE);
		}
		return;
	case Kdown:
		n = t->maxlines/3;
		goto case_Down;
	case Kscrollonedown:
		n = mousescrollsize(t->maxlines);
		if(n <= 0)
			n = 1;
		goto case_Down;
	case Kpgdown:
		n = 2*t->maxlines/3;
	case_Down:
		q0 = t->org+frcharofpt(t, Pt(t->r.min.x, t->r.min.y+n*t->font->height));
		textsetorigin(t, q0, TRUE);
		return;
	case Kup:
		n = t->maxlines/3;
		goto case_Up;
	case Kscrolloneup:
		n = mousescrollsize(t->maxlines);
		goto case_Up;
	case Kpgup:
		n = 2*t->maxlines/3;
	case_Up:
		q0 = textbacknl(t, t->org, n);
		textsetorigin(t, q0, TRUE);
		return;
	case Khome:
		typecommit(t);
		textshow(t, 0, 0, FALSE);
		return;
	case Kend:
		typecommit(t);
		textshow(t, t->file->nc, t->file->nc, FALSE);
		return;
	case 0x01:	/* ^A: beginning of line */
		typecommit(t);
		/* go to where ^U would erase, if not already at BOL */
		nnb = 0;
		if(t->q0>0 && textreadc(t, t->q0-1)!='\n')
			nnb = textbswidth(t, 0x15);
		textshow(t, t->q0-nnb, t->q0-nnb, TRUE);
		return;