scroll patch

1 files changed, 169 insertions, 0 deletions

diff --git a/drw.c b/drw.c
index a58a2b4..fa23260 100644
--- a/drw.c
+++ b/drw.c
@@ -384,6 +384,175 @@ no_match:
 	return x + (render ? w : 0);
 }
 
+int
+utf8nextchar(const char *str, int len, int i, int inc)
+{
+	int n;
+
+	for (n = i + inc; n + inc >= 0 && n + inc <= len
+	  && (str[n] & 0xc0) == 0x80; n += inc)
+		;
+	return n;
+}
+
+int
+drw_text_align(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *text, int textlen, int align)
+{
+	int ty;
+	unsigned int ew;
+	XftDraw *d = NULL;
+	Fnt *usedfont, *curfont, *nextfont;
+	size_t len;
+	int utf8strlen, utf8charlen, render = x || y || w || h;
+	long utf8codepoint = 0;
+	const char *utf8str;
+	FcCharSet *fccharset;
+	FcPattern *fcpattern;
+	FcPattern *match;
+	XftResult result;
+	int charexists = 0;
+	int i, n;
+
+	if (!drw || (render && !drw->scheme) || !text || !drw->fonts || textlen <= 0
+	  || (align != AlignL && align != AlignR))
+		return 0;
+
+	if (!render) {
+		w = ~w;
+	} else {
+		XSetForeground(drw->dpy, drw->gc, drw->scheme[ColBg].pixel);
+		XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
+		d = XftDrawCreate(drw->dpy, drw->drawable,
+		                  DefaultVisual(drw->dpy, drw->screen),
+		                  DefaultColormap(drw->dpy, drw->screen));
+	}
+
+	usedfont = drw->fonts;
+	i = align == AlignL ? 0 : textlen;
+	x = align == AlignL ? x : x + w;
+	while (1) {
+		utf8strlen = 0;
+		nextfont = NULL;
+		/* if (align == AlignL) */
+		utf8str = text + i;
+
+		while ((align == AlignL && i < textlen) || (align == AlignR && i > 0)) {
+			if (align == AlignL) {
+				utf8charlen = utf8decode(text + i, &utf8codepoint, MIN(textlen - i, UTF_SIZ));
+				if (!utf8charlen) {
+					textlen = i;
+					break;
+				}
+			} else {
+				n = utf8nextchar(text, textlen, i, -1);
+				utf8charlen = utf8decode(text + n, &utf8codepoint, MIN(textlen - n, UTF_SIZ));
+				if (!utf8charlen) {
+					textlen -= i;
+					text += i;
+					i = 0;
+					break;
+				}
+			}
+			for (curfont = drw->fonts; curfont; curfont = curfont->next) {
+				charexists = charexists || XftCharExists(drw->dpy, curfont->xfont, utf8codepoint);
+				if (charexists) {
+					if (curfont == usedfont) {
+						utf8strlen += utf8charlen;
+						i += align == AlignL ? utf8charlen : -utf8charlen;
+					} else {
+						nextfont = curfont;
+					}
+					break;
+				}
+			}
+
+			if (!charexists || nextfont)
+				break;
+			else
+				charexists = 0;
+		}
+
+		if (align == AlignR)
+			utf8str = text + i;
+
+		if (utf8strlen) {
+			drw_font_getexts(usedfont, utf8str, utf8strlen, &ew, NULL);
+			/* shorten text if necessary */
+			if (align == AlignL) {
+				for (len = utf8strlen; len && ew > w; ) {
+					len = utf8nextchar(utf8str, len, len, -1);
+					drw_font_getexts(usedfont, utf8str, len, &ew, NULL);
+				}
+			} else {
+				for (len = utf8strlen; len && ew > w; ) {
+					n = utf8nextchar(utf8str, len, 0, +1);
+					utf8str += n;
+					len -= n;
+					drw_font_getexts(usedfont, utf8str, len, &ew, NULL);
+				}
+			}
+
+			if (len) {
+				if (render) {
+					ty = y + (h - usedfont->h) / 2 + usedfont->xfont->ascent;
+					XftDrawStringUtf8(d, &drw->scheme[ColFg],
+					                  usedfont->xfont, align == AlignL ? x : x - ew, ty, (XftChar8 *)utf8str, len);
+				}
+				x += align == AlignL ? ew : -ew;
+				w -= ew;
+			}
+			if (len < utf8strlen)
+				break;
+		}
+
+		if ((align == AlignR && i <= 0) || (align == AlignL && i >= textlen)) {
+			break;
+		} else if (nextfont) {
+			charexists = 0;
+			usedfont = nextfont;
+		} else {
+			/* Regardless of whether or not a fallback font is found, the
+			 * character must be drawn. */
+			charexists = 1;
+
+			fccharset = FcCharSetCreate();
+			FcCharSetAddChar(fccharset, utf8codepoint);
+
+			if (!drw->fonts->pattern) {
+				/* Refer to the comment in xfont_create for more information. */
+				die("the first font in the cache must be loaded from a font string.");
+			}
+
+			fcpattern = FcPatternDuplicate(drw->fonts->pattern);
+			FcPatternAddCharSet(fcpattern, FC_CHARSET, fccharset);
+			FcPatternAddBool(fcpattern, FC_SCALABLE, FcTrue);
+
+			FcConfigSubstitute(NULL, fcpattern, FcMatchPattern);
+			FcDefaultSubstitute(fcpattern);
+			match = XftFontMatch(drw->dpy, drw->screen, fcpattern, &result);
+
+			FcCharSetDestroy(fccharset);
+			FcPatternDestroy(fcpattern);
+
+			if (match) {
+				usedfont = xfont_create(drw, NULL, match);
+				if (usedfont && XftCharExists(drw->dpy, usedfont->xfont, utf8codepoint)) {
+					for (curfont = drw->fonts; curfont->next; curfont = curfont->next)
+						; /* NOP */
+					curfont->next = usedfont;
+				} else {
+					xfont_free(usedfont);
+					usedfont = drw->fonts;
+				}
+			}
+		}
+	}
+	if (d)
+		XftDrawDestroy(d);
+
+	return x;
+}
+
 void
 drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h)
 {