patch: add center patch

config.def.h

@@ -2,6 +2,8 @@
 /* Default settings; can be overriden by command line. */
 
 static int topbar = 1;                      /* -b  option; if 0, dmenu appears at bottom     */
+static int centered = 0;                    /* -c option; centers dmenu on screen */
+static int min_width = 500;                    /* minimum width when centered */
 /* -fn option overrides fonts[0]; default X11 font or font set */
 static const char *fonts[] = {
 	"monospace:size=10"

dmenu.1

@@ -40,6 +40,9 @@ which lists programs in the user's $PATH and runs the result in their $SHELL.
 .B \-b
 dmenu appears at the bottom of the screen.
 .TP
+.B \-c
+dmenu appears centered on the screen.
+.TP
 .B \-f
 dmenu grabs the keyboard before reading stdin if not reading from a tty. This
 is faster, but will lock up X until stdin reaches end\-of\-file.

dmenu.c

@@ -90,6 +90,15 @@ calcoffsets(void)
 			break;
 }
 
+static int
+max_textw(void)
+{
+	int len = 0;
+	for (struct item *item = items; item && item->text; item++)
+		len = MAX(TEXTW(item->text), len);
+	return len;
+}
+
 static void
 cleanup(void)
 {
@@ -612,6 +621,7 @@ setup(void)
 	bh = drw->fonts->h + 2;
 	lines = MAX(lines, 0);
 	mh = (lines + 1) * bh;
+	promptw = (prompt && *prompt) ? TEXTW(prompt) - lrpad / 4 : 0;
 #ifdef XINERAMA
 	i = 0;
 	if (parentwin == root && (info = XineramaQueryScreens(dpy, &n))) {
@@ -638,21 +648,34 @@ setup(void)
 				if (INTERSECT(x, y, 1, 1, info[i]))
 					break;
 
-		x = info[i].x_org;
-		y = info[i].y_org + (topbar ? 0 : info[i].height - mh);
-		mw = info[i].width;
+		if (centered) {
+			mw = MIN(MAX(max_textw() + promptw, min_width), info[i].width);
+			x = info[i].x_org + ((info[i].width  - mw) / 2);
+			y = info[i].y_org + ((info[i].height - mh) / 2);
+		} else {
+			x = info[i].x_org;
+			y = info[i].y_org + (topbar ? 0 : info[i].height - mh);
+			mw = info[i].width;
+		}
+
 		XFree(info);
 	} else
 #endif
 	{
 		if (!XGetWindowAttributes(dpy, parentwin, &wa))
 			die("could not get embedding window attributes: 0x%lx",
 			    parentwin);
-		x = 0;
-		y = topbar ? 0 : wa.height - mh;
-		mw = wa.width;
+
+		if (centered) {
+			mw = MIN(MAX(max_textw() + promptw, min_width), wa.width);
+			x = (wa.width  - mw) / 2;
+			y = (wa.height - mh) / 2;
+		} else {
+			x = 0;
+			y = topbar ? 0 : wa.height - mh;
+			mw = wa.width;
+		}
 	}
-	promptw = (prompt && *prompt) ? TEXTW(prompt) - lrpad / 4 : 0;
 	inputw = MIN(inputw, mw/3);
 	match();
 
@@ -711,6 +734,12 @@ main(int argc, char *argv[])
 			topbar = 0;
 		else if (!strcmp(argv[i], "-f"))   /* grabs keyboard before reading stdin */
 			fast = 1;
+		else if (!strcmp(argv[i], "-c"))   /* centers dmenu on screen */
+			centered = 1;
+		else if (!strcmp(argv[i], "-i")) { /* case-insensitive item matching */
+			fstrncmp = strncasecmp;
+			fstrstr = cistrstr;
+		}
 		else if (!strcmp(argv[i], "-s")) { /* case-sensitive item matching */
 			fstrncmp = strncmp;
 			fstrstr = strstr;