Use vim.on_key for mouse functionality instead of mappings

README.md

@@ -21,7 +21,8 @@ scrollview-configuration`).
 ## Requirements
 
 * `nvim>=0.6`
-* Mouse functionality requires mouse support (see `:help 'mouse'`)
+* Mouse functionality requires mouse support (see `:help 'mouse'`) and
+  `nvim>=0.11`
 * Signs require `nvim>=0.9`
 
 ## Installation

autoload/scrollview.vim

@@ -432,42 +432,6 @@ endif
 " * Mappings
 " *************************************************
 
-function! s:SetUpMouseMappings(button, primary) abort
-  if a:button isnot# v:null
-    " Create a mouse mapping only if mappings don't already exist and "!" is
-    " not used at the end of the button. For example, a mapping may already
-    " exist if the user uses swapped buttons from $VIMRUNTIME/pack/dist/opt
-    " /swapmouse/plugin/swapmouse.vim. Handling for that scenario would
-    " require modifications (e.g., possibly by updating the non-initial
-    " feedkeys calls in handle_mouse() to remap keys).
-    let l:force = v:false
-    let l:button = a:button
-    if strcharpart(l:button, strchars(l:button, 1) - 1, 1) ==# '!'
-      let l:force = v:true
-      let l:button =
-            \ strcharpart(l:button, 0, strchars(l:button, 1) - 1)
-    endif
-    " scrollview mouse handling is not supported in select-mode. #140
-    for l:mapmode in ['n', 'x', 'i']
-      execute printf(
-            \   'silent! %snoremap %s <silent> <%smouse>'
-            \   .. ' <cmd>lua require("scrollview").handle_mouse("%s", %s)<cr>',
-            \   l:mapmode,
-            \   l:force ? '' : '<unique>',
-            \   l:button,
-            \   l:button,
-            \   a:primary ? 'true' : 'false',
-            \ )
-    endfor
-  endif
-endfunction
-
-call s:SetUpMouseMappings(g:scrollview_mouse_primary, v:true)
-" :popup doesn't work for nvim<0.8.
-if has('nvim-0.8')
-  call s:SetUpMouseMappings(g:scrollview_mouse_secondary, v:false)
-endif
-
 " Additional <plug> mappings are defined for convenience of creating
 " user-defined mappings that call nvim-scrollview functionality. However,
 " since the usage of <plug> mappings requires recursive map commands, this

doc/scrollview.txt

@@ -20,7 +20,8 @@ signs. The plugin is customizable (see |scrollview-configuration|).
 1. Requirements                            *scrollview-requirements*
 
 * `nvim>=0.6`
-* Scrollbar mouse dragging requires mouse support (see |'mouse'|)
+* Scrollbar mouse functionality requires mouse support (see |'mouse'|) and
+  `nvim>=0.11`
 * Signs require `nvim>=0.9`
 
 ============================================================================
@@ -301,19 +302,15 @@ scrollview_mouse_primary                   *scrollview_mouse_primary*
                        Possible values include `'left'`, `'middle'`, `'right'`,
                        `'x1'`, and `'x2'`. These can be prepended with `'c-'` or
                        `'m-'` for the control-key and alt-key variants (e.g.,
-                       `'c-left'` for control-left). An existing mapping will
-                       not be clobbered, unless `'!'` is added at the end (e.g.,
-                       `'left!'`). Set to `v:null` to disable the functionality.
-                       Defaults to `'left'`. Considered only when the plugin is
-                       loaded.
+                       `'c-left'` for control-left). Set to `v:null` to disable
+                       the functionality. Defaults to `'left'`.
 
 scrollview_mouse_secondary                 *scrollview_mouse_secondary*
                        |String| specifying the button for secondary mouse
                        operations (clicking signs for additional information).
                        See |scrollview_mouse_primary| for the possible values,
-                       including how `'c-'`, `'m-'`, `'!'`, and `v:null` can be
-                       utilized. Defaults to `'right'`. Considered only when the
-                       plugin is loaded.
+                       including how `'c-'`, `'m-'`, and `v:null` can be utilized.
+                       Defaults to `'right'`.
 
                                            *scrollview_on_startup*
 scrollview_on_startup  |Boolean| specifying whether scrollbars are enabled on

lua/scrollview.lua

@@ -138,6 +138,20 @@ local BORDER_RIGHT = 4
 local BORDER_BOTTOM = 6
 local BORDER_LEFT = 8
 
+-- Maps mouse buttons (e.g., 'left') to the Neovim key representation.
+local MOUSE_LOOKUP = (function()
+  local valid_buttons = {
+    'left', 'middle', 'right', 'x1', 'x2',
+    'c-left', 'c-middle', 'c-right', 'c-x1', 'c-x2',
+    'm-left', 'm-middle', 'm-right', 'm-x1', 'm-x2',
+  }
+  local result = {}
+  for _, button in ipairs(valid_buttons) do
+    result[button] = t('<' .. button .. 'mouse>')
+  end
+  return result
+end)()
+
 -- *************************************************
 -- * Memoization
 -- *************************************************
@@ -2962,9 +2976,14 @@ local handle_mouse = function(button, primary)
   local mousedown = t('<' .. button .. 'mouse>')
   local mouseup = t('<' .. button .. 'release>')
   if not vim.g.scrollview_enabled then
-    -- nvim-scrollview is disabled. Process the click as it would ordinarily be
-    -- processed, by re-sending the click and returning.
+    -- We have to temporarily set handling_mouse to true so that the on_key
+    -- handler doesn't call handle_mouse. Setting it back to false is deferred
+    -- (a later comment explains why, where the same type of handling is used).
+    handling_mouse = true
     fn.feedkeys(mousedown, 'ni')
+    vim.defer_fn(function()
+      handling_mouse = false
+    end, 0)
     return
   end
   local state = init()
@@ -3312,7 +3331,45 @@ local handle_mouse = function(button, primary)
     reset_memoize()
   end
   restore(state)
-  handling_mouse = false
+  -- The processing of feedkeys calls initiated above (that aren't consumed by
+  -- read_input_stream) does not happen immediately. Defer the setting of
+  -- handling_mouse to false, to prevent an infinite loop of calls to
+  -- handle_mouse (e.g., for an ordinary click not on a sign or scrollbar).
+  vim.defer_fn(function()
+    handling_mouse = false
+  end, 0)
+end
+
+-- pcall is not necessary here to avoid an error in some cases (Neovim
+-- #17273), since that would be necessary for nvim<0.8, where this code would
+-- not execute (the on_key handling for the mouse requires nvim==0.11, for the
+-- ability to ignore the key by returning the empty string).
+if to_bool(fn.has('nvim-0.11')) then  -- Neovim 0.11 for ignoring keys
+  vim.on_key(function(str)
+    local normalize = function(button)
+      if button == vim.NIL then
+        button = nil
+      elseif button:sub(-1) == '!' then
+        -- Remove a trailing "!", which was supported in older versions of the
+        -- plugin for clobbering mappings.
+        button = button:sub(1, -2)
+      end
+      return button
+    end
+    local primary = normalize(vim.g.scrollview_mouse_primary)
+    local secondary = normalize(vim.g.scrollview_mouse_secondary)
+    if primary ~= nil
+        and not handling_mouse
+        and str == MOUSE_LOOKUP[primary] then
+      handle_mouse(primary, true)
+      return ''  -- ignore the mousedown
+    elseif secondary ~= nil
+        and not handling_mouse
+        and str == MOUSE_LOOKUP[secondary] then
+      handle_mouse(secondary, false)
+      return ''  -- ignore the mousedown
+    end
+  end)
 end
 
 -- A convenience function for setting global options with