centralize script handling logic (#477)

currently the logic of when to open/close script is scattered around the
entire code-base which is both ugly and error-prone.

this patch centralizes script handling by remembering the relevant
information on each redraw and then comparing it with the previous
information to figure out whether something changed or not.

this also fixes a bug where scripts weren't being called in thumbnail
mode when mouse was used for selecting a different image.

Closes: https://codeberg.org/nsxiv/nsxiv/issues/475

Reviewed-on: https://codeberg.org/nsxiv/nsxiv/pulls/477
Reviewed-by: eylles <eylles@noreply.codeberg.org>

commands.c

@@ -83,9 +83,6 @@ bool cg_switch_mode(arg_t _)
 		load_image(fileidx);
 		mode = MODE_IMAGE;
 	}
-	close_info();
-	open_info();
-	title_dirty = true;
 	return true;
 }
 
@@ -415,12 +412,7 @@ bool ci_slideshow(arg_t _)
 
 bool ct_move_sel(arg_t dir)
 {
-	bool dirty = tns_move_selection(&tns, dir, prefix);
-	if (dirty) {
-		close_info();
-		open_info();
-	}
-	return dirty;
+	return tns_move_selection(&tns, dir, prefix);
 }
 
 bool ct_reload_all(arg_t _)

image.c

@@ -717,7 +717,7 @@ static bool img_fit(img_t *img)
 
 	if (ABS(img->zoom - z) > 1.0 / MAX(img->w, img->h)) {
 		img->zoom = z;
-		img->dirty = title_dirty = true;
+		img->dirty = true;
 		return true;
 	} else {
 		return false;
@@ -852,7 +852,7 @@ bool img_zoom_to(img_t *img, float z)
 		img->y = y - (y - img->y) * z / img->zoom;
 		img->zoom = z;
 		img->scalemode = SCALE_ZOOM;
-		img->dirty = img->checkpan = title_dirty = true;
+		img->dirty = img->checkpan = true;
 		return true;
 	} else {
 		return false;

main.c

@@ -70,7 +70,6 @@ int alternate;
 int markcnt;
 int markidx;
 int prefix;
-bool title_dirty;
 const XButtonEvent *xbutton_ev;
 
 static void autoreload(void);
@@ -316,7 +315,7 @@ static void open_title(void)
 	char *argv[8];
 	char w[12] = "", h[12] = "", z[12] = "", fidx[12], fcnt[12];
 
-	if (wintitle.f.err || !title_dirty)
+	if (wintitle.f.err)
 		return;
 
 	close_title();
@@ -331,7 +330,6 @@ static void open_title(void)
 	               fidx, fcnt, w, h, z, NULL);
 	if ((wintitle.pid = spawn(&wintitle.fd, NULL, argv)) > 0)
 		fcntl(wintitle.fd, F_SETFL, O_NONBLOCK);
-	title_dirty = false;
 }
 
 void close_info(void)
@@ -402,10 +400,7 @@ void load_image(int new)
 	files[new].flags &= ~FF_WARN;
 	fileidx = current = new;
 
-	close_info();
-	open_info();
 	arl_add(&arl, files[fileidx].path);
-	title_dirty = true;
 
 	if (img.multi.cnt > 0 && img.multi.animate)
 		set_timeout(animate, img.multi.frames[img.multi.sel].delay, true);
@@ -443,9 +438,33 @@ static void update_info(void)
 	const char *mark;
 	win_bar_t *l = &win.bar.l, *r = &win.bar.r;
 
+	static struct {
+		const char *filepath;
+		int fileidx;
+		float zoom;
+		appmode_t mode;
+	} prev;
+
+	if (prev.fileidx != fileidx || prev.mode != mode ||
+	    (prev.filepath == NULL || !STREQ(prev.filepath, files[fileidx].path)))
+	{
+		close_info();
+		open_info();
+		open_title();
+	} else if (mode == MODE_IMAGE && prev.zoom != img.zoom) {
+		open_title();
+	}
+
 	/* update bar contents */
 	if (win.bar.h == 0 || extprefix)
 		return;
+
+	free((char *)prev.filepath);
+	prev.filepath = estrdup(files[fileidx].path);
+	prev.fileidx = fileidx;
+	prev.zoom = img.zoom;
+	prev.mode = mode;
+
 	for (fw = 0, i = filecnt; i > 0; fw++, i /= 10)
 		;
 	mark = files[fileidx].flags & FF_MARK ? "* " : "";
@@ -520,7 +539,6 @@ void redraw(void)
 		tns_render(&tns);
 	}
 	update_info();
-	open_title();
 	win_draw(&win);
 	reset_timeout(redraw);
 	reset_cursor();
@@ -669,8 +687,6 @@ static bool run_key_handler(const char *key, unsigned int mask)
 	if (mode == MODE_IMAGE && changed) {
 		img_close(&img, true);
 		load_image(fileidx);
-	} else {
-		open_info();
 	}
 	free(oldst);
 	reset_cursor();

nsxiv.h

@@ -468,6 +468,5 @@ extern int alternate;
 extern int markcnt;
 extern int markidx;
 extern int prefix;
-extern bool title_dirty;
 
 #endif /* NSXIV_H */

thumbs.c

@@ -447,7 +447,6 @@ void tns_render(tns_t *tns)
 	}
 	tns->dirty = false;
 	tns_highlight(tns, *tns->sel, true);
-	title_dirty = true;
 }
 
 void tns_mark(tns_t *tns, int n, bool mark)
@@ -516,7 +515,6 @@ bool tns_move_selection(tns_t *tns, direction_t dir, int cnt)
 		tns_check_view(tns, false);
 		if (!tns->dirty)
 			tns_highlight(tns, *tns->sel, true);
-		title_dirty = true;
 	}
 	return *tns->sel != old;
 }