lsp-ui-doc childframe does not respect altered lsp-ui-doc-background

[svenssonaxel]

To reproduce:

• Open with emacs -Q

• Evaluate:

  (progn
  (defvar bootstrap-version)
  (let ((bootstrap-file
   (expand-file-name "straight/repos/straight.el/bootstrap.el" user-emacs-directory))
  (bootstrap-version 5))
  (unless (file-exists-p bootstrap-file)
    (with-current-buffer
        (url-retrieve-synchronously
         "https://raw.githubusercontent.com/raxod502/straight.el/develop/install.el"
         'silent 'inhibit-cookies)
  (goto-char (point-max))
  (eval-print-last-sexp)))
  (load bootstrap-file nil 'nomessage))
  (straight-use-package 'lsp-mode)
  (straight-use-package 'lsp-ui)
  (require 'lsp-mode)
  (require 'lsp-ui)
  (setq 
  lsp-ui-doc-enable t
  lsp-ui-doc-header t
  lsp-ui-doc-include-signature t
  lsp-ui-doc-position 'bottom
  lsp-ui-doc-alignment 'window
  lsp-ui-doc-use-childframe t
  lsp-ui-doc-use-webkit nil
  lsp-ui-doc-delay 0.2
  
  lsp-ui-sideline-enable nil
  lsp-ui-imenu-enable t)
  (custom-set-faces
  '(lsp-ui-doc-background ((t :background "#ff00ff")))
  '(lsp-ui-doc-header ((t :foreground "#ff8000" :background "#00ff00")))
  '(lsp-ui-doc-url ((t :inherit link))))
  )

• Open a new file ~/test.js
• M-x lsp
• Write document.activeelement and wait for the info-box.
• It is magenta, as expected.
• Evaluate:

  (custom-set-faces
  '(lsp-ui-doc-background ((t :background "#0000ff")))
  '(lsp-ui-doc-header ((t :foreground "#00ff80" :background "#808080")))
  '(lsp-ui-doc-url ((t :inherit link))))

• Activate the documentation frame again.
• It seems that the changed lsp-ui-doc-header is respected, but not the new value for lsp-ui-doc-background.

[svenssonaxel]

The following diff is a first attempt to fix it. It works both inline and with childframe. Note that

• It is not tested with webkit.
• In inline mode, it will allow other features than :background to be used if set.

diff --git a/lsp-ui-doc.el b/lsp-ui-doc.el
index 210f5c8..118c7dd 100644
--- a/lsp-ui-doc.el
+++ b/lsp-ui-doc.el
@@ -313,8 +313,7 @@ We don't extract the string that `lps-line' is already displaying."
   "Set background color of the WebKit widget."
   (lsp-ui-doc--webkit-execute-script
    (format "document.body.style.background = '%s';"
-           "#fdfdfd"
-           ;; (face-attribute 'lsp-ui-doc-background :background)
+           (face-attribute 'lsp-ui-doc-background :background)
            )))

 (defun lsp-ui-doc--webkit-set-foreground ()
@@ -530,7 +529,7 @@ FN is the function to call on click."

 (defun lsp-ui-doc--inline-padding (string len)
   (let ((string (concat " " string (make-string (- len (string-width string)) ?\s) " ")))
-    (add-face-text-property 0 (length string) (list :background (face-background 'lsp-ui-doc-background nil t)) t string)
+    (add-face-text-property 0 (length string) 'lsp-ui-doc-background t string)
     string))

 (defun lsp-ui-doc--inline-faking-frame (doc-strings)
@@ -783,5 +782,15 @@ It is supposed to be called from `lsp-ui--toggle'"
   (lsp-ui-doc-show)
   (add-hook 'pre-command-hook 'lsp-ui-doc--glance-hide-frame))

+(defun lsp-ui-doc-update-frame-background (&rest _ignore)
+  (if-let (frame (lsp-ui-doc--get-frame))
+      (if  lsp-ui-doc-use-webkit
+          (lsp-ui-doc--webkit-set-background)
+        (set-frame-parameter
+         frame
+         'background-color
+         (face-background 'lsp-ui-doc-background nil t)))))
+(advice-add 'custom-set-faces :after #'lsp-ui-doc-update-frame-background)
+
 (provide 'lsp-ui-doc)
 ;;; lsp-ui-doc.el ends here

[danielmartin]

Thanks for the patch. Could you create a separate PR with it so that we can review/test it and eventually merge it?

[svenssonaxel]

@danielmartin PR created.