Bugfix/lens check if supported (#2389)

* lsp-lens: only enable if supported

`lsp--auto-configure': add `lsp-lens--enable' instead of
`lsp-lens-mode', since the former checks for lens support. This way, the
mode won't be enabled for servers that don't support lenses.

* `lsp-lens-mode': disabling now works

Now disabling `lsp-lens-mode' actually works, and the lenses don't
reappear after a short delay. The issue was that the wrong lambdas were
being removed from the various hooks in `lsp-lens-mode' and because
`lsp-lens--refresh-timer' was not cancelled.

To fix this, extract `(lsp--lens-schedule-refresh t)' to a new function
instead, since they are much less fragile in hooks. At the end of the
disable part of `lsp-lens-mode', cancel `lsp-lens--refresh-timer'.

* `lsp-lens-mode': check if timer is non-nil

`lsp-lens--refresh-timer' could be nil if `lsp-lens-mode' is disabled
within `lsp-idle-delay' afterwards.

* `lsp-lens-mode': dont configure globally

`lsp-lens-mode' is not responsible for globally configuring lenses, so
it shouldn't modify `lsp-configure-hook' and `lsp-unconfigure-hook'.

Author: nbfalcon

lsp-lens.el

@@ -125,9 +125,10 @@ Results are meaningful only if FROM and TO are on the same line."
   "Handler for `after-save-hook' for lens mode."
   (lsp-lens--schedule-refresh t))
 
-(defun lsp-lens--schedule-refresh (buffer-modified?)
+(defun lsp-lens--schedule-refresh (&optional buffer-modified?)
   "Call each of the backend.
-BUFFER-MODIFIED? determines whether the buffer is modified or not."
+BUFFER-MODIFIED? determines whether the buffer was modified or
+not."
   (-some-> lsp-lens--refresh-timer cancel-timer)
 
   (setq lsp-lens--page (cons (window-start) (window-end)))
@@ -138,6 +139,11 @@ BUFFER-MODIFIED? determines whether the buffer is modified or not."
                         (or lsp-lens--modified? buffer-modified?)
                         (current-buffer))))
 
+(defun lsp-lens--schedule-refresh-modified ()
+  "Schedule a lens refresh due to a buffer-modification.
+See `lsp-lens--schedule-refresh' for details."
+  (lsp-lens--schedule-refresh t))
+
 (defun lsp-lens--keymap (command)
   "Build the lens keymap for COMMAND."
   (-doto (make-sparse-keymap)
@@ -344,21 +350,20 @@ CALLBACK - callback for the lenses."
   :lighter "Lens"
   (cond
    (lsp-lens-mode
-    (add-hook 'lsp-configure-hook #'lsp-lens--enable nil t)
-    (add-hook 'lsp-unconfigure-hook #'lsp-lens--disable nil t)
     (add-hook 'lsp-on-idle-hook #'lsp-lens--idle-function nil t)
-    (add-hook 'lsp-on-change-hook (lambda () (lsp-lens--schedule-refresh t)) nil t)
-    (add-hook 'after-save-hook (lambda () (lsp-lens--schedule-refresh t)) nil t)
+    (add-hook 'lsp-on-change-hook #'lsp-lens--schedule-refresh-modified nil t)
+    (add-hook 'after-save-hook #'lsp-lens--schedule-refresh nil t)
     (add-hook 'before-revert-hook #'lsp-lens-hide nil t)
     (lsp-lens-refresh t))
    (t
-    (lsp-lens-hide)
-    (remove-hook 'lsp-configure-hook #'lsp-lens--enable t)
-    (remove-hook 'lsp-unconfigure-hook #'lsp-lens--disable t)
     (remove-hook 'lsp-on-idle-hook #'lsp-lens--idle-function t)
-    (remove-hook 'lsp-on-change-hook (lambda () (lsp-lens--schedule-refresh nil)) t)
-    (remove-hook 'after-save-hook (lambda () (lsp-lens--schedule-refresh t)) t)
+    (remove-hook 'lsp-on-change-hook #'lsp-lens--schedule-refresh-modified t)
+    (remove-hook 'after-save-hook #'lsp-lens--schedule-refresh t)
     (remove-hook 'before-revert-hook #'lsp-lens-hide t)
+    (when lsp-lens--refresh-timer
+      (cancel-timer lsp-lens--refresh-timer))
+    (setq lsp-lens--refresh-timer nil)
+    (lsp-lens-hide)
     (setq lsp-lens--last-count nil)
     (setq lsp-lens--backend-cache nil))))
 

lsp-mode.el

@@ -6732,7 +6732,7 @@ returns the command to execute."
   (when lsp-modeline-workspace-status-enable
     (add-hook 'lsp-configure-hook 'lsp-modeline-workspace-status-mode))
   (when lsp-lens-enable
-    (add-hook 'lsp-configure-hook 'lsp-lens-mode))
+    (add-hook 'lsp-configure-hook 'lsp-lens--enable))
 
   ;; yas-snippet config
   (setq-local yas-inhibit-overlay-modification-protection t))