acme: mouse movement for Del

If the mouse was in the tag of the old window,
it was most likely pointing at Del. If bringing up a
new window from below and not moving the mouse
somewhere else, adjust it so that it ends up pointing
at Del in the replacement window's tag too.
This makes it easy to Del a sequence of windows in
a column, from top to bottom.

http://www.youtube.com/watch?v=ET8w6RT6u5M

R=r
http://codereview.appspot.com/6558047

5 files changed, 62 insertions, 8 deletions

diff --git a/src/cmd/acme/cols.c b/src/cmd/acme/cols.c
index 424358e7..5e16c21a 100644
--- a/src/cmd/acme/cols.c
+++ b/src/cmd/acme/cols.c
@@ -157,7 +157,7 @@ void
 colclose(Column *c, Window *w, int dofree)
 {
 	Rectangle r;
-	int i;
+	int i, didmouse, up;
 
 	/* w is locked */
 	if(!c->safe)
@@ -171,7 +171,7 @@ colclose(Column *c, Window *w, int dofree)
 	w->tag.col = nil;
 	w->body.col = nil;
 	w->col = nil;
-	restoremouse(w);
+	didmouse = restoremouse(w);
 	if(dofree){
 		windelete(w);
 		winclose(w);
@@ -183,17 +183,24 @@ colclose(Column *c, Window *w, int dofree)
 		draw(screen, r, display->white, nil, ZP);
 		return;
 	}
+	up = 0;
 	if(i == c->nw){		/* extend last window down */
 		w = c->w[i-1];
 		r.min.y = w->r.min.y;
 		r.max.y = c->r.max.y;
 	}else{			/* extend next window up */
+		up = 1;
 		w = c->w[i];
 		r.max.y = w->r.max.y;
 	}
 	draw(screen, r, textcols[BACK], nil, ZP);
-	if(c->safe)
+	if(c->safe) {
+		if(!didmouse && up)
+			w->showdel = TRUE;
 		winresize(w, r, FALSE, TRUE);
+		if(!didmouse && up)
+			movetodel(w);
+	}
 }
 
 void
@@ -535,7 +542,7 @@ coldragwin(Column *c, Window *w, int but)
 		r.max.y = c->w[i+1]->r.min.y-Border;
 	winresize(w, r, c->safe, TRUE);
 	c->safe = TRUE;
-    	winmousebut(w);
+	winmousebut(w);
 }
 
 Text*
diff --git a/src/cmd/acme/dat.h b/src/cmd/acme/dat.h
index 0da2a128..0539d1ac 100644
--- a/src/cmd/acme/dat.h
+++ b/src/cmd/acme/dat.h
@@ -239,6 +239,7 @@ struct Window
 	uchar	filemenu;
 	uchar	dirty;
 	uchar	autoindent;
+	uchar	showdel;
 	int		id;
 	Range	addr;
 	Range	limit;
diff --git a/src/cmd/acme/fns.h b/src/cmd/acme/fns.h
index 8738d2d5..af063445 100644
--- a/src/cmd/acme/fns.h
+++ b/src/cmd/acme/fns.h
@@ -22,10 +22,11 @@ void	new(Text*, Text*, Text*, int, int, Rune*, int);
 void	undo(Text*, Text*, Text*, int, int, Rune*, int);
 void	scrsleep(uint);
 void	savemouse(Window*);
-void	restoremouse(Window*);
+int	restoremouse(Window*);
 void	clearmouse(void);
 void	allwindows(void(*)(Window*, void*), void*);
 uint loadfile(int, uint, int*, int(*)(void*, uint, Rune*, int), void*);
+void	movetodel(Window*);
 
 Window*	errorwin(Mntdir*, int);
 Window*	errorwinforwin(Window*);
diff --git a/src/cmd/acme/util.c b/src/cmd/acme/util.c
index 7675346a..de6cdf8c 100644
--- a/src/cmd/acme/util.c
+++ b/src/cmd/acme/util.c
@@ -383,12 +383,18 @@ savemouse(Window *w)
 	mousew = w;
 }
 
-void
+int
 restoremouse(Window *w)
 {
-	if(mousew!=nil && mousew==w)
+	int did;
+
+	did = 0;
+	if(mousew!=nil && mousew==w) {
 		moveto(mousectl, prevmouse);
+		did = 1;
+	}
 	mousew = nil;
+	return did;
 }
 
 void
diff --git a/src/cmd/acme/wind.c b/src/cmd/acme/wind.c
index bfe4beca..378c3ccb 100644
--- a/src/cmd/acme/wind.c
+++ b/src/cmd/acme/wind.c
@@ -106,6 +106,34 @@ windrawbutton(Window *w)
 	draw(screen, br, b, nil, b->r.min);
 }
 
+int
+delrunepos(Window *w)
+{
+	int n;
+	Rune rune;
+	
+	for(n=0; n<w->tag.file->b.nc; n++) {
+		bufread(&w->tag.file->b, n, &rune, 1);
+		if(rune == ' ')
+			break;
+	}
+	n += 2;
+	if(n >= w->tag.file->b.nc)
+		return -1;
+	return n;
+}
+
+void
+movetodel(Window *w)
+{
+	int n;
+	
+	n = delrunepos(w);
+	if(n < 0)
+		return;
+	moveto(mousectl, addpt(frptofchar(&w->tag.fr, n), Pt(4, w->tag.fr.font->height-4)));
+}
+
 /*
  * Compute number of tag lines required
  * to display entire tag text.
@@ -115,14 +143,25 @@ wintaglines(Window *w, Rectangle r)
 {
 	int n;
 	Rune rune;
+	Point p;
 
-	if(!w->tagexpand)
+	if(!w->tagexpand && !w->showdel)
 		return 1;
+	w->showdel = FALSE;
 	w->tag.fr.noredraw = 1;
 	textresize(&w->tag, r, TRUE);
 	w->tag.fr.noredraw = 0;
 	w->tagsafe = FALSE;
 	
+	if(!w->tagexpand) {
+		/* use just as many lines as needed to show the Del */
+		n = delrunepos(w);
+		if(n < 0)
+			return 1;
+		p = subpt(frptofchar(&w->tag.fr, n), w->tag.fr.r.min);
+		return 1 + p.y / w->tag.fr.font->height;
+	}
+		
 	/* can't use more than we have */
 	if(w->tag.fr.nlines >= w->tag.fr.maxlines)
 		return w->tag.fr.maxlines;