statusbar: print ellipsis when text is truncated (#501)HEADmaster

currently, there's no feedback on when the statusbar text is
getting truncated due to insufficient space. this prints an
ellipsis if the text wouldn't be able to fit inside the given
width to indicate truncation.

Reviewed-on: https://codeberg.org/nsxiv/nsxiv/pulls/501
Reviewed-by: eylles <eylles@noreply.codeberg.org>

1 files changed, 22 insertions, 1 deletions

diff --git a/window.c b/window.c
index 3c8b3f0..42c3f2b 100644
--- a/window.c
+++ b/window.c
@@ -67,6 +67,11 @@ static struct {
 #if HAVE_LIBFONTS
 static XftFont *font;
 static double fontsize;
+/* utf8 ellipsis "…". the buffer must be at least 4 bytes for utf8_decode() */
+enum { ELLIPSIS_LEN = 3 };
+static const unsigned char ellipsis[4] = { 0xe2, 0x80, 0xa6, 0x0 };
+static int ellipsis_w;
+static int win_draw_text(win_t *, XftDraw *, const XftColor *, int, int, char *, int, int);
 #endif
 
 #if HAVE_LIBFONTS
@@ -156,6 +161,7 @@ void win_init(win_t *win)
 
 	f = win_res(db, BAR_FONT[0], BAR_FONT[1] ? BAR_FONT[1] : "monospace-8");
 	win_init_font(e, f);
+	ellipsis_w = TEXTWIDTH(win, (char *)ellipsis, ELLIPSIS_LEN);
 
 	win->bar.l.buf = lbuf;
 	win->bar.r.buf = rbuf;
@@ -410,7 +416,7 @@ void win_clear(win_t *win)
 static int win_draw_text(win_t *win, XftDraw *d, const XftColor *color,
                          int x, int y, char *text, int len, int w)
 {
-	int err, tw = 0, warned = 0;
+	int err, tw = 0, warned = 0, danger_zone = w - ellipsis_w;
 	char *t, *next;
 	uint32_t rune;
 	XftFont *f;
@@ -437,6 +443,21 @@ static int win_draw_text(win_t *win, XftDraw *d, const XftColor *color,
 			FcCharSetDestroy(fccharset);
 		}
 		XftTextExtentsUtf8(win->env.dpy, f, (XftChar8 *)t, next - t, &ext);
+		if (d != NULL && tw + ext.xOff >= danger_zone) {
+			int remaining_width = TEXTWIDTH(win, t, (text + len) - t);
+			if (tw + remaining_width > w) { /* overflow, print ellipsis */
+				if (tw + ellipsis_w <= w) {
+					win_draw_text(win, d, color, x, y, (char *)ellipsis,
+					              ELLIPSIS_LEN, ellipsis_w);
+					tw += ellipsis_w;
+				}
+				if (f != font)
+					XftFontClose(win->env.dpy, f);
+				return tw;
+			}
+			/* text will fit, no need to check again on next iterations */
+			danger_zone = INT_MAX;
+		}
 		tw += ext.xOff;
 		if (tw <= w) {
 			XftDrawStringUtf8(d, color, f, x, y, (XftChar8 *)t, next - t);