ui: add highlighting

this commit implements highlighting for symbol and symbol references on
jump.

Signed-off-by: ldelossa <[email protected]>

lua/calltree.lua

@@ -63,7 +63,9 @@ M.config = {
     layout = "left",
     layout_size = 30,
     jump_mode = "invoking",
-    icons = "none"
+    icons = "none",
+    symbol_hl = "Search",
+    symbol_refs_hl = "Search"
 }
 
 -- the configured icon set after setup() is ran.
@@ -115,6 +117,7 @@ function M.setup(user_config)
    vim.cmd("command! CTFocus       lua require('calltree.ui').focus()")
    vim.cmd("command! CTJump        lua require('calltree.ui').jump()")
    vim.cmd("command! CTHover       lua require('calltree.ui').hover()")
+   vim.cmd("command! CTClearHL     lua require('calltree.ui').clear_jump_hl()")
    vim.cmd("command! CTDumpTree    lua require('calltree.tree').dump_tree()")
 end
 

lua/calltree/lsp/handlers.lua

@@ -42,7 +42,8 @@ M.ch_lsp_handler = function(direction)
              call_hierarchy_call[direction].name,
              0, -- tree.add_node will set the depth correctly.
              call_hierarchy_call[direction],
-             call_hierarchy_call[direction].kind
+             call_hierarchy_call[direction].kind,
+             call_hierarchy_call.fromRanges
           )
           table.insert(children, child)
         end

lua/calltree/tree.lua

@@ -20,14 +20,17 @@ M.Node.mt = {
 -- call hierarchy object per the LSP spec.
 --
 -- kind : string - the kind of symbol this node represents.
-function M.Node.new(name, depth, call_hierarchy_obj, kind)
+--
+-- references : array of LSP ranges
+function M.Node.new(name, depth, call_hierarchy_obj, kind, references)
     local node = {
         name=name,
         depth=depth,
         children={},
         expanded=false,
         call_hierarchy_obj=call_hierarchy_obj,
-        kind=kind
+        kind=kind,
+        references=references
     }
     setmetatable(node, M.Node.mt)
     return node

lua/calltree/ui.lua

@@ -30,6 +30,9 @@ M.direction = nil
 M.invoking_win_handle = nil
 -- the buffer switched to when the user asks for help
 M.help_buffer_handle = nil
+-- the current sighlight source, reset on jumps
+M.jump_higlight_ns = vim.api.nvim_create_namespace("calltree-jump")
+M.last_highlighted_buffer = nil
 
 -- idempotent creation and configuration of call tree's ui buffer
 local function _setup_buffer()
@@ -57,6 +60,9 @@ local function _setup_buffer()
     vim.api.nvim_buf_set_option(M.buffer_handle, 'modifiable', false)
     vim.api.nvim_buf_set_option(M.buffer_handle, 'swapfile', false)
 
+    -- au to clear highlights on window close
+    vim.cmd("au BufWinLeave <buffer=" .. M.buffer_handle .. "> lua require('calltree.ui').clear_jump_hl()")
+
     -- set buffer local keymaps
     local opts = {silent=true}
     vim.api.nvim_buf_set_keymap(M.buffer_handle, "n", "zo", ":CTExpand<CR>", opts)
@@ -366,7 +372,8 @@ M.ch_switch_handler = function(direction)
              call_hierarchy_call[direction].name,
              0, -- tree.add_node will set the depth correctly.
              call_hierarchy_call[direction],
-             call_hierarchy_call[direction].kind
+             call_hierarchy_call[direction].kind,
+             call_hierarchy_call.fromRanges
           )
           table.insert(children, child)
         end
@@ -379,10 +386,38 @@ M.ch_switch_handler = function(direction)
     end
 end
 
+local function set_jump_hl(node)
+    M.last_highlighted_buffer = vim.api.nvim_get_current_buf()
+    -- set highlght for function itself
+    local range = node.call_hierarchy_obj.range
+    vim.api.nvim_buf_add_highlight(
+        M.last_highlighted_buffer,
+        M.jump_higlight_ns,
+        ct.config.symbol_hl,
+        range["start"].line,
+        range["start"].character,
+        range["end"].character
+    )
+    -- apply it to all the references
+    if node.references ~= nil then
+        for _, ref in ipairs(node.references) do
+            vim.api.nvim_buf_add_highlight(
+                M.last_highlighted_buffer,
+                M.jump_higlight_ns,
+                ct.config.symbol_refs_hl,
+                ref["start"].line,
+                ref["start"].character,
+                ref["end"].character
+            )
+        end
+    end
+end
 
 -- jump will jump to the source code location of the
 -- symbol under the cursor.
 M.jump = function()
+    M.clear_jump_hl()
+
     local line = vim.api.nvim_get_current_line()
     local node = M.decode_line_to_node(line)
     if node == nil then
@@ -425,6 +460,18 @@ M.jump = function()
 
     ::jump::
     vim.lsp.util.jump_to_location(location)
+    set_jump_hl(node)
+end
+
+M.clear_jump_hl = function()
+    if M.last_highlighted_buffer ~= nil then
+        vim.api.nvim_buf_clear_namespace(
+            M.last_highlighted_buffer,
+            M.jump_higlight_ns,
+            0,
+            -1
+        )
+    end
 end
 
 -- hover will show LSP hover information for the symbol
@@ -469,7 +516,8 @@ M.ch_expand_handler = function(node, linenr, direction)
                 call_hierarchy_call[direction].name,
                 0, -- tree.add_node will compute depth for us
                 call_hierarchy_call[direction],
-                call_hierarchy_call[direction].kind
+                call_hierarchy_call[direction].kind,
+                call_hierarchy_call.fromRanges
             )
             table.insert(children, child)
         end