Add support for tab expansion (because everyone else is stupid and I …

…am forced to follow along)

Tab expansion inserts spaces instead of TAB character. Number of spaces
is dependent upon your current tab stop setting, which can be changed by
running "Tab n".

As of now, it's not possible to turn it on and off during runtime. You
can however see whether it's compiled or not by executing the command
"Tabexpand". The console will show either 1 or 0. This will be taken
care of in a later commit.

src/cmd/acme/dat.h

@@ -268,6 +268,7 @@ struct Window
 	int		utflastqid;
 	int		utflastboff;
 	int		utflastq;
+	uchar	tabexpand;	/* expand tab char with space*body.tabstop */
 	int		tagsafe;		/* taglines is correct */
 	int		tagexpand;
 	int		taglines;

src/cmd/acme/exec.c

@@ -53,6 +53,7 @@ void	putall(Text*, Text*, Text*, int, int, Rune*, int);
 void	sendx(Text*, Text*, Text*, int, int, Rune*, int);
 void	sort(Text*, Text*, Text*, int, int, Rune*, int);
 void	tab(Text*, Text*, Text*, int, int, Rune*, int);
+void	tabexpand(Text*, Text*, Text*, int, int, Rune*, int);
 void	zeroxx(Text*, Text*, Text*, int, int, Rune*, int);
 
 typedef struct Exectab Exectab;
@@ -92,6 +93,7 @@ static Rune LSend[] = { 'S', 'e', 'n', 'd', 0 };
 static Rune LSnarf[] = { 'S', 'n', 'a', 'r', 'f', 0 };
 static Rune LSort[] = { 'S', 'o', 'r', 't', 0 };
 static Rune LTab[] = { 'T', 'a', 'b', 0 };
+static Rune LTabexpand[] = { 'T', 'a', 'b', 'e', 'x', 'p', 'a', 'n', 'd', 0 };
 static Rune LUndo[] = { 'U', 'n', 'd', 'o', 0 };
 static Rune LZerox[] = { 'Z', 'e', 'r', 'o', 'x', 0 };
 
@@ -123,6 +125,7 @@ Exectab exectab[] = {
 	{ LSnarf,		cut,		FALSE,	TRUE,	FALSE	},
 	{ LSort,		sort,		FALSE,	XXX,		XXX		},
 	{ LTab,		tab,		FALSE,	XXX,		XXX		},
+	{ LTabexpand,	tabexpand,	FALSE,	XXX,		XXX		},
 	{ LUndo,		undo,	FALSE,	TRUE,	XXX		},
 	{ LZerox,		zeroxx,	FALSE,	XXX,		XXX		},
 	{ nil, 			0,		0,		0,		0		}
@@ -1358,6 +1361,22 @@ tab(Text *et, Text *_0, Text *argt, int _1, int _2, Rune *arg, int narg)
 		warning(nil, "%.*S: Tab %d\n", w->body.file->nname, w->body.file->name, w->body.tabstop);
 }
 
+void
+tabexpand(Text *et, Text *_0, Text *argt, int _1, int _2, Rune *arg, int narg)
+{
+	Window *w;
+
+	USED(_0);
+	USED(_1);
+	USED(_2);
+
+	if(et==nil || et->w==nil)
+		return;
+	w = et->w;
+
+	printf("tabexpand: %d\n", w->tabexpand);
+}
+
 void
 runproc(void *argvp)
 {

src/cmd/acme/text.c

@@ -758,6 +758,14 @@ texttype(Text *t, Rune r)
 		} else
 			textshow(t, t->file->b.nc, t->file->b.nc, FALSE);
 		return;
+	case 0x09:	/* ^I (TAB) */
+		if(t->w->tabexpand == TRUE){
+			for(i=0; i < t->w->body.tabstop; i++){
+				texttype(t, ' ');
+			}
+			return;
+		}else
+			break;	/* fall through to normal code */
 	case 0x01:	/* ^A: beginning of line */
 		typecommit(t);
 		/* go to where ^U would erase, if not already at BOL */

src/cmd/acme/wind.c

@@ -80,6 +80,7 @@ wininit(Window *w, Window *clone, Rectangle r)
 	w->filemenu = TRUE;
 	w->maxlines = w->body.fr.maxlines;
 	w->autoindent = globalautoindent;
+	w->tabexpand = TRUE;
 	if(clone){
 		w->dirty = clone->dirty;
 		w->autoindent = clone->autoindent;