Add explicit use of timer in example
#include <ncurses.h>
#include <stdbool.h>
#include <stdlib.h>
+#include <unistd.h>
typedef struct {
chtype* buffer;
@@ -116,6 +117,10 @@ int main() {
keypad(stdscr, TRUE);
// Hide the terminal cursor
curs_set(0);
+ // Don't block on calls like getch() -- have it ERR immediately if the user
+ // hasn't typed anything. That way we can mix other timers in our code,
+ // instead of being a slave only to terminal input.
+ nodelay(stdscr, TRUE);
view_state vs;
init_view_state(&vs);
@@ -128,18 +133,27 @@ int main() {
refresh();
for (;;) {
- chtype ch = getch();
+ int ch = getch();
if (ch == 'q')
break;
+ // ncurses gives us ERR if there was no user input. We'll sleep for 0
+ // seconds, so that we'll yield CPU time to the OS instead of looping as
+ // fast as possible. This avoids battery drain/excessive CPU usage. There
+ // are better ways to do this that waste less CPU, but they require doing a
+ // little more work on each individual platform (Linux, Mac, etc.)
+ if (ch == ERR) {
+ sleep(0);
+ continue;
+ }
// ncurses gives us the special value KEY_RESIZE if the user didn't
// actually type anything, but the terminal resized. If that happens to us,
// just re-use the fill character from last time.
- if (ch == KEY_RESIZE)
+ if (ch < CHAR_MIN || ch > CHAR_MAX || ch == KEY_RESIZE)
ch = vs.fill_char;
int term_height = getmaxy(stdscr);
int term_width = getmaxx(stdscr);
assert(term_height >= 0 && term_width >= 0);
- update_view_state(&vs, term_height, term_width, ch);
+ update_view_state(&vs, term_height, term_width, (chtype)ch);
draw_view_state(&vs);
refresh();
}
