feature/syntax-checker: redesign tooltip support

Use flycheck-posframe in GUI Emacs (26+) and flycheck-popup-tip
everywhere else.

modules/feature/syntax-checker/autoload.el

@@ -0,0 +1,41 @@
+;;; feature/syntax-checker/autoload.el -*- lexical-binding: t; -*-
+
+(defun +syntax-checker-show-popup (errors)
+  "TODO"
+  (if (and EMACS26+ (display-graphic-p))
+      (flycheck-posframe-show-posframe errors)
+    (flycheck-popup-tip-show-popup errors)))
+
+(defun +syntax-checker-cleanup-popup ()
+  "TODO"
+  (when (display-graphic-p)
+    (flycheck-popup-tip-delete-popup)))
+
+;;;###autoload
+(define-minor-mode +syntax-checker-popup-mode
+  "TODO"
+  :lighter nil
+  :group 'doom
+  (let ((hooks '(post-command-hook focus-out-hook)))
+    (cond
+     ;; Use our display function and remember the old one but only if we haven't
+     ;; yet configured it, to avoid activating twice.
+     ((and +syntax-checker-popup-mode
+           (not (eq flycheck-display-errors-function
+                    #'+syntax-checker-show-popup)))
+      (setq flycheck-popup-tip-old-display-function
+            flycheck-display-errors-function
+            flycheck-display-errors-function
+            #'+syntax-checker-show-popup)
+      (dolist (hook hooks)
+        (add-hook hook #'+syntax-checker-cleanup-popup nil t)))
+     ;; Reset the display function and remove ourselves from all hooks but only
+     ;; if the mode is still active.
+     ((and (not +syntax-checker-popup-mode)
+           (eq flycheck-display-errors-function
+               #'+syntax-checker-show-popup))
+      (setq flycheck-display-errors-function
+            flycheck-popup-tip-old-display-function
+            flycheck-popup-tip-old-display-function nil)
+      (dolist (hook hooks)
+        (remove-hook hook '+syntax-checker-cleanup-popup t))))))

modules/feature/syntax-checker/config.el

@@ -10,6 +10,9 @@
   ;; Emacs feels snappier without checks on newline
   (setq flycheck-check-syntax-automatically '(save idle-change mode-enabled))
 
+  ;; Popup
+  (add-hook 'flycheck-mode-hook #'+syntax-checker-popup-mode)
+
   (after! evil
     (defun +syntax-checkers|flycheck-buffer ()
       "Flycheck buffer on ESC in normal mode."
@@ -25,26 +28,10 @@
     (delq 'idle-change flycheck-check-syntax-automatically)))
 
 
-;; Long story short, `flycheck-popup-tip' works everywhere but only looks *ok*.
-;; `flycheck-pos-tip' looks great, but only in GUI Emacs on Linux. So we want:
-;;
-;; + GUI Emacs (Linux): pos-tip
-;; + GUI Emacs (MacOS): popup-tip
-;; + tty Emacs (anywhere): popup-tip
-
-(def-package! flycheck-pos-tip
-  :unless IS-MAC
-  :after flycheck
-  :config
-  (setq flycheck-pos-tip-timeout 10
-        ;; fallback to flycheck-popup-tip in terminal Emacs
-        flycheck-pos-tip-display-errors-tty-function
-        #'flycheck-popup-tip-show-popup
-        flycheck-display-errors-delay 0.7)
-  (flycheck-pos-tip-mode))
-
 (def-package! flycheck-popup-tip
-  :commands (flycheck-popup-tip-mode flycheck-popup-tip-show-popup)
+  :commands (flycheck-popup-tip-show-popup flycheck-popup-tip-delete-popup))
-  :after flycheck
-  :config (if IS-MAC (flycheck-popup-tip-mode)))
 
+
+(def-package! flycheck-posframe
+  :when EMACS26+
+  :commands flycheck-posframe-show-posframe)

modules/feature/syntax-checker/packages.el

@@ -2,5 +2,6 @@
 ;;; feature/syntax-checker/packages.el
 
 (package! flycheck)
-(package! flycheck-pos-tip)
 (package! flycheck-popup-tip)
+(when EMACS26+
+  (package! flycheck-posframe))