inspect: add --monitor for continguous monitoring

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

man/picom-inspect.1.adoc

@@ -19,12 +19,16 @@ DESCRIPTION
 
 OPTIONS
 -------
-*picom-inspect* accept the exact same set of options as *picom*. Naturally, most of those options will not be relevant.
+*picom-inspect* accepts all options that *picom* does. Naturally, most of those options will not be relevant.
 
 These are some of the options you might find useful (See *picom*(1) for descriptions of what they do):
 
 *--config*, *--log-level*, *--log-file*, all the options related to rules.
 
+*picom-inspect* also accepts some extra options: :::
+
+  *--monitor*:: Keep *picom-inspect* running in a loop, and dump information every time something changed about a window.
+
 NOTES
 -----
 *picom-inspect* is prototype right now. If you find any bug, for example, if rules are matched differently compared to *picom*, please submit bug reports to:

src/config.h

@@ -241,6 +241,8 @@ typedef struct options {
 	bool print_diagnostics;
 	/// Render to a separate window instead of taking over the screen
 	bool debug_mode;
+	/// For picom-inspect only, dump windows in a loop
+	bool inspect_monitor;
 	xcb_window_t inspect_win;
 	// === General ===
 	/// Use the legacy backends?

src/options.c

@@ -59,6 +59,7 @@ struct picom_option {
 	int has_arg;
 	struct picom_arg arg;
 	const char *help;
+	const char *argv0;
 };
 
 static bool set_flag(const struct picom_option * /*opt*/, const struct picom_arg *arg,
@@ -452,6 +453,8 @@ static const struct picom_option picom_options[] = {
                                                                              "window is fullscreen based only on its size and coordinates."},
     [804] = {"realtime"                 , ENABLE(use_realtime_scheduling)  , "Enable realtime scheduling. This might reduce latency, but might also cause "
                                                                              "other issues. Disable this if you see the compositor being killed."},
+    [805] = {"monitor"                  , ENABLE(inspect_monitor)          , "For picom-inspect, run in a loop and dump information every time something "
+                                                                             "changed about a window.", "picom-inspect"},
 
     // Flags that takes an argument
     ['r'] = {"shadow-radius"               , INTEGER(shadow_radius, 0, INT_MAX)             , "The blur radius for shadows. (default 12)"},
@@ -634,12 +637,19 @@ static void usage(const char *argv0, int ret) {
 		line_wrap = window_size.ws_col;
 	}
 
+	const char *basename = strrchr(argv0, '/') ? strrchr(argv0, '/') + 1 : argv0;
+
 	size_t help_indent = 0;
 	for (size_t i = 0; i < ARR_SIZE(picom_options); i++) {
 		if (picom_options[i].help == NULL) {
 			// Hide options with no help message.
 			continue;
 		}
+		if (picom_options[i].argv0 != NULL &&
+		    strcmp(picom_options[i].argv0, basename) != 0) {
+			// Hide options that are not for this program.
+			continue;
+		}
 		auto option_len = strlen(picom_options[i].long_name) + 2 + 4;
 		if (picom_options[i].arg.name) {
 			option_len += strlen(picom_options[i].arg.name) + 1;
@@ -654,6 +664,11 @@ static void usage(const char *argv0, int ret) {
 		if (picom_options[i].help == NULL) {
 			continue;
 		}
+		if (picom_options[i].argv0 != NULL &&
+		    strcmp(picom_options[i].argv0, basename) != 0) {
+			// Hide options that are not for this program.
+			continue;
+		}
 		size_t option_len = 8;
 		fprintf(f, "    ");
 		if ((i > 'a' && i < 'z') || (i > 'A' && i < 'Z')) {
@@ -943,10 +958,15 @@ bool get_cfg(options_t *opt, int argc, char *const *argv) {
 	int o = 0, longopt_idx = -1;
 	bool failed = false;
 	optind = 1;
+	const char *basename = strrchr(argv[0], '/') ? strrchr(argv[0], '/') + 1 : argv[0];
 	while (-1 != (o = getopt_long(argc, argv, shortopts, longopts, &longopt_idx))) {
 		if (o == '?' || o == ':' || picom_options[o].arg.handler == NULL) {
 			usage(argv[0], 1);
 			failed = true;
+		} else if (picom_options[o].argv0 != NULL &&
+		           strcmp(picom_options[o].argv0, basename) != 0) {
+			log_error("Invalid option %s", argv[optind - 1]);
+			failed = true;
 		} else if (!picom_options[o].arg.handler(
 		               &picom_options[o], &picom_options[o].arg, optarg, opt)) {
 			failed = true;

src/picom.c

@@ -2199,8 +2199,10 @@ static session_t *session_init(int argc, char **argv, Display *dpy,
 		ps->o.backend = backend_find("dummy");
 		ps->o.print_diagnostics = false;
 		ps->o.dbus = false;
+		if (!ps->o.inspect_monitor) {
 			ps->o.inspect_win = inspect_select_window(&ps->c);
 		}
+	}
 
 	ps->window_options_default = win_options_from_config(&ps->o);
 

src/wm/win.c

@@ -1119,10 +1119,16 @@ void win_on_factor_change(session_t *ps, struct win *w) {
 
 	if ((ps->o.inspect_win != XCB_NONE && win_id(w) == ps->o.inspect_win) ||
 	    ps->o.inspect_monitor) {
+		if (ps->o.inspect_monitor) {
+			printf("Window %#010x (Client %#010x):\n\n", win_id(w),
+			       win_client_id(w, /*fallback_to_self=*/true));
+		}
 		inspect_dump_window(ps->c2_state, &ps->o, w);
 		printf("\n");
+		if (!ps->o.inspect_monitor) {
 			quit(ps);
 		}
+	}
 }
 
 /**