Try to match a fallback font if needed

Fixes #276

Instead of rendering the entire filename at once, Xft will let us do it
character by character. This will allow sxiv to query fontconfig for
a font that can provide any missing codepoints, if needed.

A known issue of this patch is that the "..." dots rendering will not
work properly for very long multibyte filenames. That is because we
cannot easily predict the final width of the rendered filename before
drawing it. I couldn't figure out a clean way to deal with this, so I
ended up just truncating the offending filenames.

1 files changed, 2 insertions, 1 deletions

diff --git a/sxiv.h b/sxiv.h
index 25443ea..2d026b1 100644
--- a/sxiv.h
+++ b/sxiv.h
@@ -362,6 +362,7 @@ int r_opendir(r_dir_t*, const char*, bool);
 int r_closedir(r_dir_t*);
 char* r_readdir(r_dir_t*);
 int r_mkdir(char*);
+void* utf8codepoint(const void * __restrict__ str, long * __restrict__ out_codepoint);
 
 
 /* window.c */
@@ -442,7 +443,7 @@ void win_toggle_bar(win_t*);
 void win_clear(win_t*);
 void win_draw(win_t*);
 void win_draw_rect(win_t*, int, int, int, int, bool, int, unsigned long);
-int win_textwidth(const win_env_t*, const char*, unsigned int, bool);
+int win_textwidth(const win_env_t*, const char*, unsigned int, bool, XftFont*);
 void win_set_title(win_t*, const char*);
 void win_set_cursor(win_t*, cursor_t);
 void win_cursor_pos(win_t*, int*, int*);