feat(health): support show health in floating window

Problem: health can not shown in a floating window
Solution: add g:health variable

runtime/doc/health.txt

@@ -21,6 +21,16 @@ To run all healthchecks, use: >vim
 <
 Plugin authors are encouraged to write new healthchecks. |health-dev|
 
+                                                                    *g:health*
+g:health  This global variable controls the behavior and appearance of the
+          `health` floating window. It should be a dictionary containing the
+          following optional keys:
+          - `style`: string? Determines the display style of the `health` window.
+                            Set to `'float'` to enable a floating window. Other
+                            styles are not currently supported.
+          Example: >vim
+            let g:health = { 'style': 'float' }
+
 Commands                                                     *health-commands*
 
                                                            *:che* *:checkhealth*

runtime/doc/lsp.txt

@@ -1755,7 +1755,8 @@ Lua module: vim.lsp.util                                            *lsp-util*
       • {zindex}?        (`integer`) override `zindex`, defaults to 50
       • {title}?         (`string`)
       • {title_pos}?     (`'left'|'center'|'right'`)
-      • {relative}?      (`'mouse'|'cursor'`) (default: `'cursor'`)
+      • {pos}?           (`'center'`)
+      • {relative}?      (`'mouse'|'cursor'|'editor'`) (default: `'cursor'`)
       • {anchor_bias}?   (`'auto'|'above'|'below'`, default: `'auto'`) -
                          "auto": place window based on which side of the
                          cursor has more lines

runtime/doc/news.txt

@@ -287,8 +287,9 @@ UI
   |hl-PmenuSel| and |hl-PmenuMatch| both inherit from |hl-Pmenu|, and
   |hl-PmenuMatchSel| inherits highlights from both |hl-PmenuSel| and
   |hl-PmenuMatch|.
-
 • |ui-messages| content chunks now also contain the highlight group ID.
+• |health| can be displayed in a floating window and controlled by
+  the |g:health| variable.
 
 ==============================================================================
 CHANGED FEATURES                                                 *news-changed*

runtime/lua/vim/health.lua

@@ -11,6 +11,16 @@
 --- <
 --- Plugin authors are encouraged to write new healthchecks. |health-dev|
 ---
+---                                                              *g:health*
+--- g:health  This global variable controls the behavior and appearance of the
+---           `health` floating window. It should be a dictionary containing the
+---           following optional keys:
+---           - `style`: string? Determines the display style of the `health` window.
+---                             Set to `'float'` to enable a floating window. Other
+---                             styles are not currently supported.
+---           Example: >vim
+---             let g:health = { 'style': 'float' }
+---
 --- Commands                                *health-commands*
 ---
 ---                                                              *:che* *:checkhealth*
@@ -331,13 +341,28 @@ function M._check(mods, plugin_names)
 
   local emptybuf = vim.fn.bufnr('$') == 1 and vim.fn.getline(1) == '' and 1 == vim.fn.line('$')
 
+  local bufnr = vim.api.nvim_create_buf(true, true)
+  if
+    vim.g.health
+    and type(vim.g.health) == 'table'
+    and vim.tbl_get(vim.g.health, 'style') == 'float'
+  then
+    local float_bufnr, float_winid = vim.lsp.util.open_floating_preview({}, '', {
+      height = math.floor(vim.o.lines * 0.8),
+      width = math.floor(vim.o.columns * 0.8),
+      pos = 'center',
+      relative = 'editor',
+    })
+    vim.api.nvim_set_current_win(float_winid)
+    vim.bo[float_bufnr].modifiable = true
+    vim.wo[float_winid].list = false
+  else
     -- When no command modifiers are used:
     -- - If the current buffer is empty, open healthcheck directly.
     -- - If not specified otherwise open healthcheck in a tab.
     local buf_cmd = #mods > 0 and (mods .. ' sbuffer') or emptybuf and 'buffer' or 'tab sbuffer'
-
-  local bufnr = vim.api.nvim_create_buf(true, true)
     vim.cmd(buf_cmd .. ' ' .. bufnr)
+  end
 
   if vim.fn.bufexists('health://') == 1 then
     vim.cmd.bwipe('health://')

runtime/lua/vim/lsp/util.lua

@@ -875,13 +875,16 @@ function M.make_floating_popup_options(width, height, opts)
     title_pos = opts.title_pos or 'center'
   end
 
+  local in_center = opts.pos == 'center'
   return {
     anchor = anchor,
-    col = col + (opts.offset_x or 0),
+    row = in_center and math.floor((vim.o.lines - height) / 2) or row + (opts.offset_y or 0),
+    col = in_center and math.floor((vim.o.columns - width) / 2) or col + (opts.offset_x or 0),
     height = height,
     focusable = opts.focusable,
-    relative = opts.relative == 'mouse' and 'mouse' or 'cursor',
-    row = row + (opts.offset_y or 0),
+    relative = opts.relative == 'mouse' and 'mouse'
+      or opts.relative == 'editor' and 'editor'
+      or 'cursor',
     style = 'minimal',
     width = width,
     border = opts.border or default_border,
@@ -1491,9 +1494,10 @@ end
 --- @field zindex? integer override `zindex`, defaults to 50
 --- @field title? string
 --- @field title_pos? 'left'|'center'|'right'
+--- @field pos? 'center'
 ---
 --- (default: `'cursor'`)
---- @field relative? 'mouse'|'cursor'
+--- @field relative? 'mouse'|'cursor'|'editor'
 ---
 --- - "auto": place window based on which side of the cursor has more lines
 --- - "above": place the window above the cursor unless there are not enough lines