Allow looking up window system colors on Haiku

* lisp/help-fns.el (help-fns--editable-variable): Fix describing
variables which don't have symbol values.
* lisp/term/haiku-win.el (haiku-allowed-ui-colors): Set list of
allowed UI colors.
* src/haiku_support.cc (be_get_ui_color): New function.
* src/haiku_support.h: Update prototypes.
* src/haikufns.c (haiku_get_color): Look for defined UI color.
(syms_of_haikufns): New defvar `haiku-allowed-ui-colors'.
* src/haikuterm.c (haiku_term_init): Fix coding style.

lisp/help-fns.el

@@ -1303,8 +1303,8 @@ it is displayed along with the global value."
 
 (defun help-fns--editable-variable (start end variable value buffer)
   (when (and (readablep value)
-             (not (boundp value))
-             (not (fboundp value))
+             (not (and (symbolp value) (boundp value)))
+             (not (and (symbolp value) (fboundp value)))
              help-enable-variable-value-editing)
     (add-text-properties
      start end

lisp/term/haiku-win.el

@@ -46,6 +46,7 @@
 (defvar haiku-initialized)
 (defvar haiku-signal-invalid-refs)
 (defvar haiku-drag-track-function)
+(defvar haiku-allowed-ui-colors)
 
 (defvar haiku-dnd-selection-value nil
   "The local value of the special `XdndSelection' selection.")
@@ -74,6 +75,29 @@ content that is being put into the selection by
 `gui-set-selection'.  See the doc string of `haiku-drag-message'
 for more details on the structure of the associations.")
 
+;; This list has to be set correctly, otherwise Emacs will crash upon
+;; encountering an invalid color.
+(setq haiku-allowed-ui-colors
+      ["B_PANEL_BACKGROUND_COLOR" "B_MENU_BACKGROUND_COLOR"
+       "B_WINDOW_TAB_COLOR" "B_KEYBOARD_NAVIGATION_COLOR"
+       "B_DESKTOP_COLOR" "B_MENU_SELECTED_BACKGROUND_COLOR"
+       "B_MENU_ITEM_TEXT_COLOR" "B_MENU_SELECTED_ITEM_TEXT_COLOR"
+       "B_MENU_SELECTED_BORDER_COLOR" "B_PANEL_TEXT_COLOR"
+       "B_DOCUMENT_BACKGROUND_COLOR" "B_DOCUMENT_TEXT_COLOR"
+       "B_CONTROL_BACKGROUND_COLOR" "B_CONTROL_TEXT_COLOR"
+       "B_CONTROL_BORDER_COLOR" "B_CONTROL_HIGHLIGHT_COLOR"
+       "B_NAVIGATION_PULSE_COLOR" "B_SHINE_COLOR"
+       "B_SHADOW_COLOR" "B_TOOLTIP_BACKGROUND_COLOR"
+       "B_TOOLTIP_TEXT_COLOR" "B_WINDOW_TEXT_COLOR"
+       "B_WINDOW_INACTIVE_TAB_COLOR" "B_WINDOW_INACTIVE_TEXT_COLOR"
+       "B_WINDOW_BORDER_COLOR" "B_WINDOW_INACTIVE_BORDER_COLOR"
+       "B_CONTROL_MARK_COLOR" "B_LIST_BACKGROUND_COLOR"
+       "B_LIST_SELECTED_BACKGROUND_COLOR" "B_LIST_ITEM_TEXT_COLOR"
+       "B_LIST_SELECTED_ITEM_TEXT_COLOR" "B_SCROLL_BAR_THUMB_COLOR"
+       "B_LINK_TEXT_COLOR" "B_LINK_HOVER_COLOR"
+       "B_LINK_VISITED_COLOR" "B_LINK_ACTIVE_COLOR"
+       "B_STATUS_BAR_COLOR" "B_SUCCESS_COLOR" "B_FAILURE_COLOR"])
+
 (defun haiku-selection-bounds (value)
   "Return bounds of selection value VALUE.
 The return value is a list (BEG END BUF) if VALUE is a cons of

src/haiku_support.cc

@@ -4323,3 +4323,21 @@ BWindow_set_z_group (void *window, enum haiku_z_group z_group)
       w->UnlockLooper ();
     }
 }
+
+int
+be_get_ui_color (const char *name, uint32_t *color)
+{
+  color_which which;
+  rgb_color rgb;
+
+  which = which_ui_color (name);
+
+  if (which == B_NO_COLOR)
+    return 1;
+
+  rgb = ui_color (which);
+  *color = (rgb.blue | rgb.green << 8
+	    | rgb.red << 16 | 255 << 24);
+
+  return 0;
+}

src/haiku_support.h

@@ -639,6 +639,7 @@ extern int be_get_display_screens (void);
 extern bool be_use_subpixel_antialiasing (void);
 extern const char *be_find_setting (const char *);
 extern haiku_font_family_or_style *be_list_font_families (size_t *);
+extern int be_get_ui_color (const char *, uint32 *);
 
 extern void BMessage_delete (void *);
 
@@ -648,7 +649,6 @@ extern bool be_drag_message (void *, void *, bool, void (*) (void),
 extern bool be_drag_and_drop_in_progress (void);
 
 extern bool be_replay_menu_bar_event (void *, struct haiku_menu_bar_click_event *);
-
 #ifdef __cplusplus
 }
 

src/haikufns.c

@@ -253,7 +253,10 @@ haiku_get_color (const char *name, Emacs_Color *color)
 {
   unsigned short r16, g16, b16;
   Lisp_Object tem, col;
-  int32 clr;
+  int32 clr, rc;
+  uint32_t ui_color;
+  ptrdiff_t size, i;
+  Lisp_Object string;
 
   if (parse_color_spec (name, &r16, &g16, &b16))
     {
@@ -283,11 +286,34 @@ haiku_get_color (const char *name, Emacs_Color *color)
 	      return 0;
 	  }
 	}
-
       unblock_input ();
     }
 
-  return 1;
+  rc = 1;
+  if (VECTORP (Vhaiku_allowed_ui_colors))
+    {
+      size = ASIZE (Vhaiku_allowed_ui_colors);
+
+      for (i = 0; i < size; ++i)
+	{
+	  string = AREF (Vhaiku_allowed_ui_colors, i);
+
+	  block_input ();
+	  if (STRINGP (string) && !strcmp (SSDATA (string), name))
+	    rc = be_get_ui_color (name, &ui_color);
+	  unblock_input ();
+	}
+    }
+
+  if (!rc)
+    {
+      color->pixel = ui_color;
+      color->red = RED_FROM_ULONG (ui_color) * 257;
+      color->green = GREEN_FROM_ULONG (ui_color) * 257;
+      color->blue = BLUE_FROM_ULONG (ui_color) * 257;
+    }
+
+  return rc;
 }
 
 static struct haiku_display_info *
@@ -2742,6 +2768,12 @@ syms_of_haikufns (void)
 	       doc: /* SKIP: real doc in xfns.c.  */);
   Vx_cursor_fore_pixel = Qnil;
 
+  DEFVAR_LISP ("haiku-allowed-ui-colors", Vhaiku_allowed_ui_colors,
+	       doc: /* Vector of UI colors that Emacs can look up from the system.
+If this is set up incorrectly, Emacs can crash when encoutering an
+invalid color.  */);
+  Vhaiku_allowed_ui_colors = Qnil;
+
 #ifdef USE_BE_CAIRO
   DEFVAR_LISP ("cairo-version-string", Vcairo_version_string,
                doc: /* Version info for cairo.  */);

src/haikuterm.c

@@ -3964,21 +3964,19 @@ haiku_term_init (void)
 
   color_file = Fexpand_file_name (build_string ("rgb.txt"),
 				  Fsymbol_value (intern ("data-directory")));
-
   color_map = Fx_load_color_file (color_file);
+
   if (NILP (color_map))
     fatal ("Could not read %s.\n", SDATA (color_file));
 
   dpyinfo->color_map = color_map;
-
   dpyinfo->display = BApplication_setup ();
-
-  BScreen_res (&dpyinfo->resx, &dpyinfo->resy);
-
   dpyinfo->next = x_display_list;
   dpyinfo->n_planes = be_get_display_planes ();
   x_display_list = dpyinfo;
 
+  BScreen_res (&dpyinfo->resx, &dpyinfo->resy);
+
   terminal = haiku_create_terminal (dpyinfo);
   if (current_kboard == initial_kboard)
     current_kboard = terminal->kboard;