Re: [PATCH] Fix mouse click on flymake

[Ergus]

Hi Juri:

On Sun, Jan 19, 2025 at 09:47:53AM +0200, Juri Linkov wrote:
> > Flymake with fringe indicator supports an action to click in the fringe
> > and show the buffer diagnostics.
> >
> > This was only working on gui just because the map action was not
> > set. Not sure if that was intended.
>
> No, this was not intended.
>
> > The attached patch attempts to fix that; If you thing it is correct,
> > please, push it.
>
> Thanks.
>
> >  (defvar flymake-mode-map
> >    (let ((map (make-sparse-keymap)))
> > -    (define-key map `[,flymake-fringe-indicator-position mouse-1]
> > +    (define-key map `[,(pcase flymake-indicator-type
> > +                        ('fringes flymake-fringe-indicator-position)
> > +                        ('margins flymake-margin-indicator-position))
> > +                      mouse-1]
>
> What would happen when the user changes the value of flymake-indicator-type?
> The keybinding is not updated?  What if the value is nil?
> Maybe better to bind both 'fringes' and 'margins'?
> Or update keybindings when flymake-indicator-type is customized?
My first attempt for this fix was actually this patch

```
diff --git a/lisp/progmodes/flymake.el b/lisp/progmodes/flymake.el
index 9dda53713f5..25482f70b35 100644
--- a/lisp/progmodes/flymake.el
+++ b/lisp/progmodes/flymake.el
@@ -200,8 +200,20 @@ flymake-indicator-type
 See Info node `Fringes' and Info node `(elisp)Display Margins'."
   :version "30.1"
   :type '(choice (const :tag "Use Fringes" fringes)
-                 (const :tag "Use Margins "margins)
-                 (const :tag "No indicators" nil)))
+                 (const :tag "Use Margins " margins)
+                 (const :tag "No indicators" nil))
+  :set (lambda (sym val)
+         ;; TODO: Maybe add a condition here using last value of sym
+         (keymap-unset flymake-mode-map "<left-margin> <mouse-1>" t)
+         (keymap-unset flymake-mode-map "<left-fringe> <mouse-1>" t)
+         (set-default sym val)
+         (when val
+           (keymap-set flymake-mode-map
+                       (key-description `[,(pcase flymake-indicator-type
+                                   ('fringes flymake-fringe-indicator-position)
+                                   ('margins 
flymake-margin-indicator-position))
+                                         mouse-1])
+                       #'flymake-show-buffer-diagnostics))))

 (defcustom flymake-margin-indicators-string
   '((error "!!" compilation-error)
@@ -1369,11 +1381,7 @@ flymake-start
                   nil)))
              (flymake--import-foreign-diagnostics))))))

-(defvar flymake-mode-map
-  (let ((map (make-sparse-keymap)))
-    (define-key map `[,flymake-fringe-indicator-position mouse-1]
-                #'flymake-show-buffer-diagnostics)
-    map)
+(defvar flymake-mode-map (make-sparse-keymap)
   "Keymap for `flymake-mode'.")
```

But for some reason it didn't work. The entry is in the map:

```
flymake-mode-map is a keymap variable defined in ‘flymake.el’.

Documentation:
Keymap for ‘flymake-mode’.


Key             Binding

<left-margin> <mouse-1>     flymake-show-buffer-diagnostics
...
```
But the click action didn't work.

If you see my error, feel free to fix it and push.

BTW!! When I haven't seen the code yet, I was actually looking for a
property in the margin char, I thought that the char in the
fringe/margin had a 'keymap property that made it clickable.

That would give more fine grained actions and will allow a more precise
action. I tried to do that but it didn't work, apparently the action is
associated with the whole margin.

Is this also intended?

WDYT?

Best,
Ergus