6 files changed, 166 insertions(+), 2 deletions(-)

M config.def.h
A gen-rules.py
M patch/dwmc -rwxr-xr-x => -rw-r--r--
M patch/layoutmenu.sh -rwxr-xr-x => -rw-r--r--
A rules.gen.h
A rules.json

@@ 533,13 533,13 @@ static const Rule rules[] = {
 	RULE(.wintype = WTYPE "UTILITY", .isfloating = 1)
 	RULE(.wintype = WTYPE "TOOLBAR", .isfloating = 1)
 	RULE(.wintype = WTYPE "SPLASH", .isfloating = 1)
-	RULE(.class = "Gimp", .tags = 1 << 8)
+	/* App tag rules: edit rules.json (no monitor — lands on selmon). Rebuild after changes. */
+	#include "rules.gen.h"
 	#if SWALLOW_PATCH
 	RULE(.class = "St", .isterminal = 1)
 	RULE(.title = "Event Tester", .noswallow = 1)
 	RULE(.instance = "floatterm", .class = "St", .isfloating = 1, .isterminal = 1)
 	RULE(.instance = "fzfmenu", .class = "St", .isfloating = 1, .isterminal = 1)
-	RULE(.instance = "bg", .class = "St", .tags = 1 << 7, .isterminal = 1)
 	#endif // SWALLOW_PATCH
 	#if RENAMED_SCRATCHPADS_PATCH
 	RULE(.instance = "spterm", .scratchkey = 's', .isfloating = 1)

@@ 0,0 1,142 @@
+#!/usr/bin/env python3
+"""Compile rules.json into C RULE(...) macros for dwm.
+
+Tag numbers are 1-based (tag 1 .. NUMTAGS). Monitor is intentionally omitted:
+windows land on selmon (wherever you focused / put the pointer).
+
+Usage:
+  ./gen-rules.py [rules.json] > rules.gen.h
+  ./gen-rules.py rules.json rules.gen.h
+"""
+
+from __future__ import annotations
+
+import json
+import sys
+from pathlib import Path
+
+# Fields we never emit from JSON (per design).
+BLOCKED = frozenset({"monitor", "mon"})
+
+
+def c_string(s: str) -> str:
+    """Escape a Python str as a C string literal."""
+    out = []
+    for ch in s:
+        if ch == "\\":
+            out.append("\\\\")
+        elif ch == '"':
+            out.append('\\"')
+        elif ch == "\n":
+            out.append("\\n")
+        elif ch == "\t":
+            out.append("\\t")
+        elif ord(ch) < 32:
+            out.append(f"\\x{ord(ch):02x}")
+        else:
+            out.append(ch)
+    return '"' + "".join(out) + '"'
+
+
+def tag_mask(tag: int) -> str:
+    if not isinstance(tag, int) or tag < 1:
+        raise ValueError(f"tag must be integer >= 1, got {tag!r}")
+    # tag 1 => 1 << 0, tag 9 => 1 << 8
+    return f"1 << {tag - 1}"
+
+
+def rule_to_c(rule: dict, index: int) -> str:
+    if not isinstance(rule, dict):
+        raise ValueError(f"rule[{index}] must be an object")
+
+    for bad in BLOCKED:
+        if bad in rule:
+            raise ValueError(
+                f"rule[{index}]: '{bad}' is not allowed "
+                "(select the monitor yourself before launching)"
+            )
+
+    parts: list[str] = []
+
+    if "class" in rule and rule["class"] is not None:
+        parts.append(f".class = {c_string(str(rule['class']))}")
+    if "instance" in rule and rule["instance"] is not None:
+        parts.append(f".instance = {c_string(str(rule['instance']))}")
+    if "title" in rule and rule["title"] is not None:
+        parts.append(f".title = {c_string(str(rule['title']))}")
+    if "wintype" in rule and rule["wintype"] is not None:
+        # Expect short name like DIALOG, or full if already WTYPE-prefixed handling
+        wt = str(rule["wintype"])
+        if wt.startswith("WTYPE ") or wt.startswith("_NET_"):
+            parts.append(f".wintype = {c_string(wt)}")
+        else:
+            parts.append(f'.wintype = WTYPE "{wt}"')
+
+    if "tag" in rule and rule["tag"] is not None:
+        parts.append(f".tags = {tag_mask(int(rule['tag']))}")
+
+    if rule.get("floating"):
+        parts.append(".isfloating = 1")
+    if rule.get("terminal"):
+        parts.append(".isterminal = 1")
+    if rule.get("noswallow"):
+        parts.append(".noswallow = 1")
+
+    if "floatpos" in rule and rule["floatpos"] is not None:
+        parts.append(f".floatpos = {c_string(str(rule['floatpos']))}")
+
+    if not parts:
+        raise ValueError(f"rule[{index}]: empty rule (need class/instance/title/tag/...)")
+
+    comment = rule.get("comment")
+    line = "RULE(" + ", ".join(parts) + ")"
+    if comment:
+        # single-line C comment only
+        safe = str(comment).replace("*/", "* /").replace("\n", " ")
+        return f"/* {safe} */\n{line}"
+    return line
+
+
+def generate(rules_path: Path) -> str:
+    data = json.loads(rules_path.read_text(encoding="utf-8"))
+    if not isinstance(data, list):
+        raise ValueError("rules.json must be a JSON array")
+
+    lines = [
+        "/* Generated by gen-rules.py from rules.json — do not edit by hand. */",
+        "/* Edit rules.json, then rebuild dwm. Monitor is never set (selmon). */",
+        "",
+    ]
+    for i, rule in enumerate(data):
+        lines.append(rule_to_c(rule, i))
+        lines.append("")
+
+    return "\n".join(lines).rstrip() + "\n"
+
+
+def main(argv: list[str]) -> int:
+    if len(argv) >= 2 and argv[1] in ("-h", "--help"):
+        print(__doc__.strip())
+        return 0
+
+    src = Path(argv[1] if len(argv) >= 2 else "rules.json")
+    if not src.is_file():
+        print(f"gen-rules: not found: {src}", file=sys.stderr)
+        return 1
+
+    try:
+        text = generate(src)
+    except (json.JSONDecodeError, ValueError, TypeError) as e:
+        print(f"gen-rules: {e}", file=sys.stderr)
+        return 1
+
+    if len(argv) >= 3:
+        out = Path(argv[2])
+        out.write_text(text, encoding="utf-8")
+    else:
+        sys.stdout.write(text)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv))

@@ 0,0 1,8 @@
+/* Generated by gen-rules.py from rules.json — do not edit by hand. */
+/* Edit rules.json, then rebuild dwm. Monitor is never set (selmon). */
+
+/* GNU Image Manipulation Program */
+RULE(.class = "Gimp", .tags = 1 << 8)
+
+/* st -n bg (background/workspace terminal) */
+RULE(.class = "St", .instance = "bg", .tags = 1 << 7, .isterminal = 1)

@@ 0,0 1,14 @@
+[
+  {
+    "class": "Gimp",
+    "tag": 9,
+    "comment": "GNU Image Manipulation Program"
+  },
+  {
+    "class": "St",
+    "instance": "bg",
+    "tag": 8,
+    "terminal": true,
+    "comment": "st -n bg (background/workspace terminal)"
+  }
+]