2020-12-07 22:12:27 (UTC-03:00)

Marcel Rodrigues <marcelgmr@gmail.com>

term: use no-op SIGWINCH handler to trigger redraw

diff --git a/seqt.c b/seqt.c
index 8b4da05..9a75de7 100644
--- a/seqt.c
+++ b/seqt.c
@@ -6,7 +6,6 @@
 int ntracks;
 char map[MAPSIZE][RECSIZE];
 unsigned char matrix[MAXINDEX][MAXTRACK][MAXVOICE];
-struct winsize term_size;
 
 void
 print_blank()
@@ -102,6 +101,7 @@ main(int argc, char *argv[])
     FILE *fin;
     char *fname;
     struct termios term_prev;
+    struct winsize term_size;
     int running;
     char key;
     if (argc < 2) {
@@ -115,11 +115,12 @@ main(int argc, char *argv[])
         return 1;
     }
     fclose(fin);
-    setup_terminal(&term_prev, &term_size);
-    /* printf("%hux%hu\n", term_size.ws_col, term_size.ws_row); */
+    setup_terminal(&term_prev);
     print_tracks(0, 10, 0, 3);
     running = 1;
     while (running) {
+        get_terminal_size(&term_size);
+        printf("%hux%hu      \r", term_size.ws_col, term_size.ws_row);
         key = getchar();
         switch (key) {
         case 'q':

diff --git a/seqt.h b/seqt.h
index 81a5f21..21d21e8 100644
--- a/seqt.h
+++ b/seqt.h
@@ -58,8 +58,8 @@ int save_txt(FILE *fp);
 
 /* ============================ terminal =======]==================== */
 
-extern struct winsize term_size;
-void setup_terminal(struct termios *term_prev, struct winsize *term_size);
+#define get_terminal_size(WS)   ioctl(0, TIOCGWINSZ, (WS))
+void setup_terminal(struct termios *term_prev);
 void restore_terminal(struct termios *term_prev);
 
 /* ====================[=====+=====  =====+=====]==================== */

diff --git a/term.c b/term.c
index f3281c0..ab01eee 100644
--- a/term.c
+++ b/term.c
@@ -3,23 +3,18 @@
 #include <string.h>
 #include <signal.h>
 
-#define get_terminal_size(TS)   ioctl(0, TIOCGWINSZ, (TS))
-
 #ifndef SIGWINCH
 #define SIGWINCH  28
 #endif
 
-volatile sig_atomic_t pending_winch;
-
-void
-handle_winch(int sig)
-{
-    (void) sig;
-    pending_winch = 1;
-}
+/* When a UNIX terminal is resized, it sends a SIGWINCH signal to clients.
+ * Normally, seqt's mainloop remains blocked on user input upon SIGWINCH.
+ * Setting up any signal handler seems to send EOF to stdin upon SIGWINCH.
+ * This allows seqt to redraw the screen immediately. */
+void handle_winch(int sig) { (void) sig; }
 
 void
-setup_terminal(struct termios *term_prev, struct winsize *term_size)
+setup_terminal(struct termios *term_prev)
 {
     struct termios term_raw;
     struct sigaction sa;
@@ -38,8 +33,6 @@ setup_terminal(struct termios *term_prev, struct winsize *term_size)
     term_raw.c_cc[VMIN] = 1;
     term_raw.c_cc[VTIME] = 0;
     tcsetattr(0, TCSAFLUSH, &term_raw);
-    /* get terminal size */
-    get_terminal_size(term_size);
 }
 
 void