Implement single-instance for panel kitten

docs/changelog.rst

@@ -100,6 +100,8 @@ Detailed list of changes
 - **Behavior change**: Now kitty does full grapheme segmentation following the
   Unicode 16 spec when splitting text into cells (:iss:`8533`)
 
+- panel kitten: Allow using :option:`kitty +kitten panel --single-instance` to create multiple panels in one process (:iss:`8549`)
+
 - launch: Allow creating desktop panels such as those created by the :doc:`panel kitten </kittens/panel>` (:iss:`8549`)
 
 - Allow configuring the mouse unhide behavior when using :opt:`mouse_hide_wait` (:pull:`8508`)

kittens/panel/main.py

@@ -4,11 +4,12 @@
 import sys
 from collections.abc import Callable
 from contextlib import suppress
-from typing import Any
+from functools import partial
+from typing import Any, Mapping, Sequence
 
 from kitty.cli import parse_args
 from kitty.cli_stub import PanelCLIOptions
-from kitty.constants import appname, is_macos, is_wayland
+from kitty.constants import appname, is_macos, is_wayland, kitten_exe
 from kitty.fast_data_types import (
     GLFW_EDGE_BOTTOM,
     GLFW_EDGE_CENTER,
@@ -28,7 +29,7 @@ from kitty.fast_data_types import (
 )
 from kitty.os_window_size import WindowSizeData, edge_spacing
 from kitty.types import LayerShellConfig
-from kitty.typing import EdgeLiteral
+from kitty.typing import BossType, EdgeLiteral
 
 OPTIONS = r'''
 --lines
@@ -147,6 +148,19 @@ On a Wayland compositor that supports the wlr layer shell protocol, override the
 This has effect only if :option:`--edge` is set to :code:`top`, :code:`left`, :code:`bottom` or :code:`right`.
 
 
+--single-instance -1
+type=bool-set
+If specified only a single instance of the panel will run. New
+invocations will instead create a new top-level window in the existing
+panel instance.
+
+
+--instance-group
+Used in combination with the :option:`--single-instance` option. All
+panel invocations with the same :option:`--instance-group` will result
+in new panels being created in the first panel instance within that group.
+
+
 --debug-rendering
 type=bool-set
 For internal debugging use.
@@ -277,6 +291,18 @@ def layer_shell_config(opts: PanelCLIOptions) -> LayerShellConfig:
                             output_name=opts.output_name or '')
 
 
+def handle_single_instance_command(boss: BossType, sys_args: Sequence[str], environ: Mapping[str, str], notify_on_os_window_death: str | None = '') -> None:
+    from kitty.tabs import SpecialWindow
+    args, items = parse_panel_args(list(sys_args[1:]))
+    items = items or [kitten_exe(), 'run-shell']
+    lsc = layer_shell_config(args)
+    os_window_id = boss.add_os_panel(lsc, args.cls, args.name)
+    if notify_on_os_window_death:
+        boss.os_window_death_actions[os_window_id] = partial(boss.notify_on_os_window_death, notify_on_os_window_death)
+    tm = boss.os_window_map[os_window_id]
+    tm.new_tab(SpecialWindow(cmd=items, env=dict(environ)))
+
+
 def main(sys_args: list[str]) -> None:
     global args
     if is_macos:
@@ -295,6 +321,8 @@ def main(sys_args: list[str]) -> None:
     for override in args.override:
         sys.argv.extend(('--override', override))
     sys.argv.append('--override=linux_display_server=auto')
+    if args.single_instance:
+        sys.argv.append('--single-instance')
     sys.argv.extend(items)
     from kitty.main import main as real_main
     from kitty.main import run_app

kitty/boss.py

@@ -841,6 +841,10 @@ class Boss:
             log_error('Malformed command received over single instance socket, ignoring')
             return None
         if isinstance(data, dict) and data.get('cmd') == 'new_instance':
+            if data['args'][0] == 'panel':
+                from kittens.panel.main import handle_single_instance_command
+                handle_single_instance_command(self, data['args'], data['environ'], data.get('notify_on_os_window_death', ''))
+                return None
             from .cli_stub import CLIOptions
             startup_id = data['environ'].get('DESKTOP_STARTUP_ID', '')
             activation_token = data['environ'].get('XDG_ACTIVATION_TOKEN', '')
@@ -864,7 +868,7 @@ class Boss:
             focused_os_window = os_window_id = 0
             for session in create_sessions(opts, args, respect_cwd=True):
                 if not session.has_non_background_processes:
-                    # background only do not create and OS Window
+                    # background only do not create an OS Window
                     from .launch import LaunchSpec, launch
                     for tab in session.tabs:
                         for window in tab.windows:

kitty/launcher/main.c

@@ -352,13 +352,6 @@ exec_kitten(int argc, char *argv[], char *exe_dir) {
     exit(1);
 }
 
-static void
-delegate_to_kitten_if_possible(int argc, char *argv[], char* exe_dir) {
-    if (argc > 1 && argv[1][0] == '@') exec_kitten(argc, argv, exe_dir);
-    if (argc > 2 && strcmp(argv[1], "+kitten") == 0 && is_wrapped_kitten(argv[2])) exec_kitten(argc - 1, argv + 1, exe_dir);
-    if (argc > 3 && strcmp(argv[1], "+") == 0 && strcmp(argv[2], "kitten") == 0 && is_wrapped_kitten(argv[3])) exec_kitten(argc - 2, argv + 2, exe_dir);
-}
-
 static bool
 is_boolean_flag(const char *x) {
     static const char *all_boolean_options = KITTY_CLI_BOOL_OPTIONS;
@@ -368,7 +361,7 @@ is_boolean_flag(const char *x) {
 }
 
 static void
-handle_fast_commandline(int argc, char *argv[]) {
+handle_fast_commandline(int argc, char *argv[], const char *instance_group_prefix) {
     char current_option_expecting_argument[128] = {0};
     CLIOptions opts = {0};
     int first_arg = 1;
@@ -436,7 +429,36 @@ handle_option_value:
         exit(0);
     }
     unsetenv("KITTY_SI_DATA");
-    if (opts.single_instance) single_instance_main(argc, argv, &opts);
+    if (opts.single_instance) {
+        char igbuf[256];
+        if (instance_group_prefix && instance_group_prefix[0]) {
+            if (opts.instance_group && opts.instance_group[0]) {
+                snprintf(igbuf, sizeof(igbuf), "%s-%s", instance_group_prefix, opts.instance_group ? opts.instance_group : "");
+                opts.instance_group = igbuf;
+            } opts.instance_group = instance_group_prefix;
+        }
+        single_instance_main(argc, argv, &opts);
+    }
+}
+
+static bool
+delegate_to_kitten_if_possible(int argc, char *argv[], char* exe_dir) {
+    if (argc > 1 && argv[1][0] == '@') exec_kitten(argc, argv, exe_dir);
+    if (argc > 2 && strcmp(argv[1], "+kitten") == 0) {
+        if (is_wrapped_kitten(argv[2])) exec_kitten(argc - 1, argv + 1, exe_dir);
+        if (strcmp(argv[2], "panel") == 0) {
+            handle_fast_commandline(argc - 2, argv + 2, "panel");
+            return true;
+        }
+    }
+    if (argc > 3 && strcmp(argv[1], "+") == 0 && strcmp(argv[2], "kitten") == 0) {
+        if (is_wrapped_kitten(argv[3])) exec_kitten(argc - 2, argv + 2, exe_dir);
+        if (strcmp(argv[3], "panel") == 0) {
+            handle_fast_commandline(argc - 3, argv + 3, "panel");
+            return true;
+        }
+    }
+    return false;
 }
 
 int main(int argc, char *argv[], char* envp[]) {
@@ -452,8 +474,7 @@ int main(int argc, char *argv[], char* envp[]) {
     if (!read_exe_path(exe, sizeof(exe))) return 1;
     strncpy(exe_dir_buf, exe, sizeof(exe_dir_buf));
     char *exe_dir = dirname(exe_dir_buf);
-    delegate_to_kitten_if_possible(argc, argv, exe_dir);
-    handle_fast_commandline(argc, argv);
+    if (!delegate_to_kitten_if_possible(argc, argv, exe_dir)) handle_fast_commandline(argc, argv, NULL);
     int num, ret=0;
     char lib[PATH_MAX+1] = {0};
     if (KITTY_LIB_PATH[0] == '/') {