using async call in sidepanel

README.md

@@ -755,6 +755,9 @@ Treesitter outline and Diagnostics
 <img width="708" alt="image" src="https://user-images.githubusercontent.com/1681295/174791609-0023e68f-f1f4-4335-9ea2-d2360e9f0bfd.png">
 <img width="733" alt="image" src="https://user-images.githubusercontent.com/1681295/174804579-26f87fbf-426b-46d0-a7a3-a5aab69c032f.png">
 
+The side panel is vim buffer. You can toggle folds with za/zo/zc
+
+
 Calltree (Expandable LSP call hierarchy)
 <img width="769" alt="image" src="https://user-images.githubusercontent.com/1681295/176998572-e39fc968-4c8c-475d-b3b8-fb7991663646.png">
 
@@ -914,6 +917,53 @@ end
 
 [known issues I am working on](https://github.com/ray-x/navigator.lua/issues/1)
 
+
+## API and extensions
+The plugin built on top of guihua, you can extend the plugin based on your requirements.
+e.g. A side pannel of lsp symbols and lsp diagnostics:
+
+
+```lua
+local function treesitter_and_diag_panel()
+  local Panel = require('guihua.panel')
+
+  local diag = require('navigator.diagnostics')
+  local ft = vim.bo.filetype
+  local results = diag.diagnostic_list[ft]
+  log(diag.diagnostic_list, ft)
+
+  local bufnr = api.nvim_get_current_buf()
+  local p = Panel:new({
+    header = 'treesitter',
+    render = function(b)
+      log('render for ', bufnr, b)
+      return require('navigator.treesitter').all_ts_nodes(b)
+    end,
+  })
+  p:add_section({
+    header = 'diagnostic',
+    render = function(buf)
+      log(buf, diagnostic)
+      if diag.diagnostic_list[ft] ~= nil then
+        local display_items = {}
+        for _, client_items in pairs(results) do
+          for _, items in pairs(client_items) do
+            for _, it in pairs(items) do
+              log(it)
+              table.insert(display_items, it)
+            end
+          end
+        end
+        return display_items
+      else
+        return {}
+      end
+    end,
+  })
+  p:open(true)
+end
+```
+
 ## Todo
 
 - The project is in the early phase, bugs expected, PRs and suggestions are welcome

lua/navigator/sidepanel.lua

@@ -1,4 +1,3 @@
-local gui = require('navigator.gui')
 local diagnostic = vim.diagnostic or vim.lsp.diagnostic
 local util = require('navigator.util')
 local log = util.log
@@ -57,18 +56,31 @@ function M.lsp_and_diag_panel()
   if ft == 'nofile' or ft == 'guihua' or ft == 'prompt' then
     return
   end
+  local lsp
   local p = Panel:new({
     header = 'symbols',
     render = function(bufnr)
       bufnr = bufnr or api.nvim_get_current_buf()
       local params = vim.lsp.util.make_range_params()
-      local sync_req = require('navigator.lspwrapper').call_sync
-      local lsp = sync_req(
-        'textDocument/documentSymbol',
-        params,
-        { timeout = 2000, bufnr = bufnr, no_show = true },
-        vim.lsp.with(require('navigator.symbols').document_symbol_handler, { no_show = true })
-      )
+      local lsp_call = require('navigator.lspwrapper').call_sync
+      if not Panel:is_open() or vim.fn.empty(lsp) == 1 then
+        lsp = lsp_call(
+          'textDocument/documentSymbol',
+          params,
+          { timeout = 2000, bufnr = bufnr, no_show = true },
+          vim.lsp.with(require('navigator.symbols').document_symbol_handler, { no_show = true })
+        )
+      else
+        lsp_call = require('navigator.lspwrapper').call_async
+        local f = function(err, result, ctx)
+          -- log(result, ctx)
+          ctx = ctx or {}
+          ctx.no_show = true
+          lsp = require('navigator.symbols').document_symbol_handler(err, result, ctx)
+          return lsp
+        end
+        lsp_call('textDocument/documentSymbol', params, f, bufnr)
+      end
       return lsp
     end,
   })

lua/navigator/symbols.lua

@@ -26,7 +26,7 @@ function M.document_symbols(opts)
     api = ' ',
   }
 
-  local bufnr = vim.api.nvim_get_current_buf()
+  local bufnr = opts.bufnr or vim.api.nvim_get_current_buf()
   vim.list_extend(lspopts, opts)
   local params = vim.lsp.util.make_position_params()
   params.context = { includeDeclaration = true }