feat(ui): allow conceal to be defined in decorations

bfredl · bfredl · commit 6eca9b69c4a1 · 2022-03-20T18:02:41.000+01:00
Unlike syntax conceal, change highlight of concealed char

Can be used in tree-sitter using "conceal" metadata.
diff --git a/runtime/lua/vim/treesitter/highlighter.lua b/runtime/lua/vim/treesitter/highlighter.lua
@@ -274,7 +274,8 @@ local function on_line_impl(self, buf, line)
                                { end_line = end_row, end_col = end_col,
                                  hl_group = hl,
                                  ephemeral = true,
-                                 priority = tonumber(metadata.priority) or 100 -- Low but leaves room below
+                                 priority = tonumber(metadata.priority) or 100, -- Low but leaves room below
+                                 conceal = metadata.conceal,
                                 })
       end
       if start_row > line then
diff --git a/src/nvim/api/extmark.c b/src/nvim/api/extmark.c
@@ -467,6 +467,11 @@ Array nvim_buf_get_extmarks(Buffer buffer, Integer ns_id, Object start, Object e
 ///                   as the mark and 'cursorline' is enabled.
 ///                   Note: ranges are unsupported and decorations are only
 ///                   applied to start_row
+///               - conceal: string which should be either empty or a single
+///                   character. Enable concealing similar to |:syn-conceal|.
+///                   When a character is supplied it is used as |:syn-cchar|.
+///                   "hl_group" is used as highlight for the cchar if provided,
+///                   otherwise it defaults to |hl-Conceal|.
 ///
 /// @param[out]  err   Error details, if any
 /// @return Id of the created/updated extmark
@@ -563,6 +568,17 @@ Integer nvim_buf_set_extmark(Buffer buffer, Integer ns_id, Integer line, Integer
     }
   }
 
+  if (opts->conceal.type == kObjectTypeString) {
+    String c = opts->conceal.data.string;
+    decor.conceal = true;
+    if (c.size) {
+      decor.conceal_char = utf_ptr2char((const char_u *)c.data);
+    }
+  } else if (HAS_KEY(opts->conceal)) {
+    api_set_error(err, kErrorTypeValidation, "conceal is not a String");
+    goto error;
+  }
+
   if (opts->virt_text.type == kObjectTypeArray) {
     decor.virt_text = parse_virt_text(opts->virt_text.data.array, err,
                                       &decor.virt_text_width);
diff --git a/src/nvim/api/keysets.lua b/src/nvim/api/keysets.lua
@@ -27,6 +27,7 @@ return {
     "number_hl_group";
     "line_hl_group";
     "cursorline_hl_group";
+    "conceal";
   };
   keymap = {
     "noremap";
diff --git a/src/nvim/decoration.c b/src/nvim/decoration.c
@@ -312,6 +312,10 @@ int decor_redraw_col(buf_T *buf, int col, int win_col, bool hidden, DecorState *
 
   int attr = 0;
   size_t j = 0;
+  bool conceal = 0;
+  int conceal_char = 0;
+  int conceal_attr = 0;
+
   for (size_t i = 0; i < kv_size(state->active); i++) {
     DecorRange item = kv_A(state->active, i);
     bool active = false, keep = true;
@@ -336,6 +340,14 @@ int decor_redraw_col(buf_T *buf, int col, int win_col, bool hidden, DecorState *
     if (active && item.attr_id > 0) {
       attr = hl_combine_attr(attr, item.attr_id);
     }
+    if (active && item.decor.conceal) {
+      conceal = true;
+      if (item.start_row == state->row && item.start_col == col && item.decor.conceal_char) {
+        conceal_char = item.decor.conceal_char;
+        state->col_until = MIN(state->col_until, item.start_col);
+        conceal_attr = item.attr_id;
+      }
+    }
     if ((item.start_row == state->row && item.start_col <= col)
         && kv_size(item.decor.virt_text)
         && item.decor.virt_text_pos == kVTOverlay && item.win_col == -1) {
@@ -349,6 +361,9 @@ int decor_redraw_col(buf_T *buf, int col, int win_col, bool hidden, DecorState *
   }
   kv_size(state->active) = j;
   state->current = attr;
+  state->conceal = conceal;
+  state->conceal_char = conceal_char;
+  state->conceal_attr = conceal_attr;
   return attr;
 }
 
diff --git a/src/nvim/decoration.h b/src/nvim/decoration.h
@@ -47,6 +47,7 @@ struct Decoration {
   bool virt_text_hide;
   bool hl_eol;
   bool virt_lines_above;
+  bool conceal;
   // TODO(bfredl): style, etc
   DecorPriority priority;
   int col;  // fixed col value, like win_col
@@ -56,9 +57,13 @@ struct Decoration {
   int number_hl_id;
   int line_hl_id;
   int cursorline_hl_id;
+  // TODO(bfredl): in principle this should be a schar_T, but we
+  // probably want some kind of glyph cache for that..
+  int conceal_char;
 };
-#define DECORATION_INIT { KV_INITIAL_VALUE, KV_INITIAL_VALUE, 0, kVTEndOfLine, kHlModeUnknown, \
-                          false, false, false, DECOR_PRIORITY_BASE, 0, 0, NULL, 0, 0, 0, 0 }
+#define DECORATION_INIT { KV_INITIAL_VALUE, KV_INITIAL_VALUE, 0, kVTEndOfLine, \
+                          kHlModeUnknown, false, false, false, false, DECOR_PRIORITY_BASE, \
+                          0, 0, NULL, 0, 0, 0, 0, 0 }
 
 typedef struct {
   int start_row;
@@ -80,6 +85,10 @@ typedef struct {
   int col_until;
   int current;
   int eol_col;
+
+  bool conceal;
+  int conceal_char;
+  int conceal_attr;
 } DecorState;
 
 EXTERN DecorState decor_state INIT(= { 0 });
diff --git a/src/nvim/screen.c b/src/nvim/screen.c
@@ -2682,6 +2682,8 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool noc
   // Repeat for the whole displayed line.
   for (;;) {
     int has_match_conc = 0;  ///< match wants to conceal
+    int decor_conceal = 0;
+
     bool did_decrement_ptr = false;
 
     // Skip this quickly when working on the text.
@@ -3506,6 +3508,11 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool noc
               char_attr = hl_combine_attr(extmark_attr, char_attr);
             }
           }
+
+          decor_conceal = decor_state.conceal;
+          if (decor_conceal && decor_state.conceal_char) {
+            decor_conceal = 2;  // really??
+          }
         }
 
         // Found last space before word: check for line break.
@@ -3809,19 +3816,25 @@ static int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool noc
       if (wp->w_p_cole > 0
           && (wp != curwin || lnum != wp->w_cursor.lnum
               || conceal_cursor_line(wp))
-          && ((syntax_flags & HL_CONCEAL) != 0 || has_match_conc > 0)
+          && ((syntax_flags & HL_CONCEAL) != 0 || has_match_conc > 0 || decor_conceal > 0)
           && !(lnum_in_visual_area
                && vim_strchr(wp->w_p_cocu, 'v') == NULL)) {
         char_attr = conceal_attr;
-        if ((prev_syntax_id != syntax_seqnr || has_match_conc > 1)
+        if ((prev_syntax_id != syntax_seqnr || has_match_conc > 1 || decor_conceal > 1)
             && (syn_get_sub_char() != NUL
                 || (has_match_conc && match_conc)
+                || (decor_conceal && decor_state.conceal_char)
                 || wp->w_p_cole == 1)
             && wp->w_p_cole != 3) {
           // First time at this concealed item: display one
           // character.
           if (has_match_conc && match_conc) {
             c = match_conc;
+          } else if (decor_conceal && decor_state.conceal_char) {
+            c = decor_state.conceal_char;
+            if (decor_state.conceal_attr) {
+              char_attr = decor_state.conceal_attr;
+            }
           } else if (syn_get_sub_char() != NUL) {
             c = syn_get_sub_char();
           } else if (wp->w_p_lcs_chars.conceal != NUL) {
diff --git a/test/functional/treesitter/highlight_spec.lua b/test/functional/treesitter/highlight_spec.lua
@@ -672,6 +672,46 @@ describe('treesitter highlighting', function()
     ]]}
   end)
 
+  it("supports conceal attribute", function()
+    if pending_c_parser(pending) then return end
+    insert(hl_text)
+
+    -- conceal can be empty or a single cchar.
+    exec_lua [=[
+      vim.opt.cole = 2
+      local parser = vim.treesitter.get_parser(0, "c")
+      test_hl = vim.treesitter.highlighter.new(parser, {queries = {c = [[
+        ("static" @keyword
+         (set! conceal "R"))
+
+        ((identifier) @Identifier
+         (set! conceal "")
+         (eq? @Identifier "lstate"))
+      ]]}})
+    ]=]
+
+    screen:expect{grid=[[
+      /// Schedule Lua callback on main loop's event queue             |
+      {4:R} int nlua_schedule(lua_State *const )                           |
+      {                                                                |
+        if (lua_type(, 1) != LUA_TFUNCTION                             |
+            ||  != ) {                                                 |
+          lua_pushliteral(, "vim.schedule: expected function");        |
+          return lua_error();                                          |
+        }                                                              |
+                                                                       |
+        LuaRef cb = nlua_ref(, 1);                                     |
+                                                                       |
+        multiqueue_put(main_loop.events, nlua_schedule_event,          |
+                       1, (void *)(ptrdiff_t)cb);                      |
+        return 0;                                                      |
+      ^}                                                                |
+      {1:~                                                                }|
+      {1:~                                                                }|
+                                                                       |
+    ]]}
+  end)
+
   it("hl_map has the correct fallback behavior", function()
     exec_lua [[
       local hl_map = vim.treesitter.highlighter.hl_map
