Option for changing macOS titlebar color

Note that the actual implementation is still needed, this is just the
option definition/parsing code.

kitty/cocoa_window.m

@@ -6,7 +6,7 @@
  */
 
 
-#include "data-types.h"
+#include "state.h"
 #include <Cocoa/Cocoa.h>
 
 #include <AvailabilityMacros.h>
@@ -23,6 +23,9 @@ typedef void* rusage_info_t;  // needed for libproc.h
 #endif
 
 static NSMenuItem* title_menu = NULL;
+static bool change_titlebar_color = false;
+static color_type titlebar_color = 0;
+
 
 static NSString*
 find_app_name(void) {
@@ -154,7 +157,7 @@ cocoa_make_window_resizable(void *w) {
     return true;
 }
 
-PyObject*
+static PyObject*
 cocoa_get_lang(PyObject UNUSED *self) {
     NSString* locale = nil;
     NSString* lang_code = [[NSLocale currentLocale] objectForKey:NSLocaleLanguageCode];
@@ -168,7 +171,7 @@ cocoa_get_lang(PyObject UNUSED *self) {
     return Py_BuildValue("s", [locale UTF8String]);
 }
 
-PyObject*
+static PyObject*
 cwd_of_process(PyObject *self UNUSED, PyObject *pid_) {
     long pid = PyLong_AsLong(pid_);
     struct proc_vnodepathinfo vpi;
@@ -177,10 +180,30 @@ cwd_of_process(PyObject *self UNUSED, PyObject *pid_) {
     return PyUnicode_FromString(vpi.pvi_cdir.vip_path);
 }
 
+static inline color_type
+color_as_int(PyObject *color) {
+#define I(n, s) ((PyLong_AsUnsignedLong(PyTuple_GET_ITEM(color, n)) & 0xff) << s)
+    return (I(0, 16) | I(1, 8) | I(2, 0)) & 0xffffff;
+#undef I
+}
+
+static PyObject*
+macos_change_titlebar_color(PyObject *self UNUSED, PyObject *val) {
+    if (val == Py_None) change_titlebar_color = false;
+    else if (val == Py_True) {
+        change_titlebar_color = true;
+        titlebar_color = OPT(background);
+    } else {
+        if (!PyTuple_Check(val)) { PyErr_SetString(PyExc_TypeError, "Not a color tuple"); return NULL; }
+        titlebar_color = color_as_int(val);
+    }
+    Py_RETURN_NONE;
+}
 
 static PyMethodDef module_methods[] = {
     {"cocoa_get_lang", (PyCFunction)cocoa_get_lang, METH_NOARGS, ""},
     {"cwd_of_process", (PyCFunction)cwd_of_process, METH_O, ""},
+    {"macos_change_titlebar_color", (PyCFunction)macos_change_titlebar_color, METH_O, ""},
     {NULL, NULL, 0, NULL}        /* Sentinel */
 };
 

kitty/config.py

@@ -220,6 +220,15 @@ def adjust_line_height(x):
     return int(x)
 
 
+def macos_titlebar_color(x):
+    x = x.strip('"')
+    if x == 'system':
+        return
+    if x == 'background':
+        return True
+    return to_color(x)
+
+
 def box_drawing_scale(x):
     ans = tuple(float(x.strip()) for x in x.split(','))
     if len(ans) != 4:
@@ -288,6 +297,7 @@ type_map = {
     'initial_window_height': positive_int,
     'macos_hide_titlebar': to_bool,
     'macos_option_as_alt': to_bool,
+    'macos_titlebar_color': macos_titlebar_color,
     'box_drawing_scale': box_drawing_scale,
     'x11_bell_volume': int,
     'background_opacity': unit_float,

kitty/kitty.conf

@@ -386,6 +386,12 @@ map ctrl+shift+e        run_simple_kitten text url_hints
 # browser can read the contents of the clipboard.
 copy_on_select no
 
+# Change the color of the kitty window's titlebar on macOS. A value of "system"
+# means to use the default system color, a value of "background" means to use
+# the default background color and finally you can use an arbitrary color, such
+# as #12af59 or "red".
+macos_titlebar_color system
+
 # Hide the kitty window's title bar on macOS.
 macos_hide_titlebar no
 

kitty/main.py

@@ -40,6 +40,9 @@ def init_graphics():
 def run_app(opts, args):
     set_scale(opts.box_drawing_scale)
     set_options(opts, is_wayland, args.debug_gl)
+    if is_macos:
+        from .fast_data_types import macos_change_titlebar_color
+        macos_change_titlebar_color(opts.macos_titlebar_color)
     with cached_values_for('main') as cached_values:
         w, h = initial_window_size(opts, cached_values)
         window_id = create_os_window(w, h, appname, args.name or args.cls or appname, args.cls or appname, load_all_shaders)