Merge #7082 'api: nvim_get_hl_by_name/by_id'

8 files changed, 167 insertions, 90 deletions

diff --git a/src/nvim/api/ui.c b/src/nvim/api/ui.c
index bbbd5ab2dc..afbee09c1c 100644
--- a/src/nvim/api/ui.c
+++ b/src/nvim/api/ui.c
@@ -242,39 +242,7 @@ static void push_call(UI *ui, char *name, Array args)
 static void remote_ui_highlight_set(UI *ui, HlAttrs attrs)
 {
   Array args = ARRAY_DICT_INIT;
-  Dictionary hl = ARRAY_DICT_INIT;
-
-  if (attrs.bold) {
-    PUT(hl, "bold", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.underline) {
-    PUT(hl, "underline", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.undercurl) {
-    PUT(hl, "undercurl", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.italic) {
-    PUT(hl, "italic", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.reverse) {
-    PUT(hl, "reverse", BOOLEAN_OBJ(true));
-  }
-
-  if (attrs.foreground != -1) {
-    PUT(hl, "foreground", INTEGER_OBJ(attrs.foreground));
-  }
-
-  if (attrs.background != -1) {
-    PUT(hl, "background", INTEGER_OBJ(attrs.background));
-  }
-
-  if (attrs.special != -1) {
-    PUT(hl, "special", INTEGER_OBJ(attrs.special));
-  }
+  Dictionary hl = hlattrs2dict(attrs);
 
   ADD(args, DICTIONARY_OBJ(hl));
   push_call(ui, "highlight_set", args);
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index ab893a4c0f..98f4410347 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -55,6 +55,47 @@ void nvim_command(String command, Error *err)
   try_end(err);
 }
 
+/// Gets a highlight definition by name.
+///
+/// @param name Highlight group name
+/// @param rgb Export RGB colors
+/// @param[out] err Error details, if any
+/// @return Highlight definition map
+/// @see nvim_get_hl_by_id
+Dictionary nvim_get_hl_by_name(String name, Boolean rgb, Error *err)
+  FUNC_API_SINCE(3)
+{
+  Dictionary result = ARRAY_DICT_INIT;
+  int id = syn_name2id((const char_u *)name.data);
+
+  if (id == 0) {
+    api_set_error(err, kErrorTypeException, "Invalid highlight name: %s",
+                  name.data);
+    return result;
+  }
+  result = nvim_get_hl_by_id(id, rgb, err);
+  return result;
+}
+
+/// Gets a highlight definition by id. |hlID()|
+///
+/// @param hl_id Highlight id as returned by |hlID()|
+/// @param rgb Export RGB colors
+/// @param[out] err Error details, if any
+/// @return Highlight definition map
+/// @see nvim_get_hl_by_name
+Dictionary nvim_get_hl_by_id(Integer hl_id, Boolean rgb, Error *err)
+  FUNC_API_SINCE(3)
+{
+  Dictionary dic = ARRAY_DICT_INIT;
+  if (syn_get_final_id((int)hl_id) == 0) {
+    api_set_error(err, kErrorTypeException, "Invalid highlight id: %d", hl_id);
+    return dic;
+  }
+  int attrcode = syn_id2attr((int)hl_id);
+  return hl_get_attr_by_id(attrcode, rgb, err);
+}
+
 /// Passes input keys to Nvim.
 /// On VimL error: Does not fail, but updates v:errmsg.
 ///
diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index 8de81f02df..0224b28c2a 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -42,6 +42,7 @@
 #include "nvim/ui.h"
 #include "nvim/os/os.h"
 #include "nvim/os/time.h"
+#include "nvim/api/private/helpers.h"
 
 static bool did_syntax_onoff = false;
 
@@ -6644,7 +6645,6 @@ do_highlight(char_u *line, int forceit, int init) {
     syn_unadd_group();
   } else {
     if (is_normal_group) {
-      HL_TABLE()[idx].sg_attr = 0;
       // Need to update all groups, because they might be using "bg" and/or
       // "fg", which have been changed now.
       highlight_attr_set_all();
@@ -6879,6 +6879,7 @@ int hl_combine_attr(int char_attr, int prim_attr)
 
 /// \note this function does not apply exclusively to cterm attr contrary
 /// to what its name implies
+/// \warn don't call it with attr 0 (i.e., the null attribute)
 attrentry_T *syn_cterm_attr2entry(int attr)
 {
   attr -= ATTR_OFF;
@@ -7123,22 +7124,14 @@ syn_list_header(int did_header, int outlen, int id)
   return newline;
 }
 
-/*
- * Set the attribute numbers for a highlight group.
- * Called after one of the attributes has changed.
- */
-static void 
-set_hl_attr (
-    int idx                    /* index in array */
-)
+/// Set the attribute numbers for a highlight group.
+/// Called after one of the attributes has changed.
+/// @param idx corrected highlight index
+static void set_hl_attr(int idx)
 {
   attrentry_T at_en = ATTRENTRY_INIT;
   struct hl_group     *sgp = HL_TABLE() + idx;
 
-  // The "Normal" group doesn't need an attribute number
-  if (sgp->sg_name_u != NULL && STRCMP(sgp->sg_name_u, "NORMAL") == 0) {
-    return;
-  }
 
   at_en.cterm_ae_attr = sgp->sg_cterm;
   at_en.cterm_fg_color = sgp->sg_cterm_fg;
@@ -8247,6 +8240,30 @@ RgbValue name_to_color(const uint8_t *name)
   return -1;
 }
 
+/// Gets highlight description for id `attr_id` as a map.
+Dictionary hl_get_attr_by_id(Integer attr_id, Boolean rgb, Error *err)
+{
+  HlAttrs attrs = HLATTRS_INIT;
+  Dictionary dic = ARRAY_DICT_INIT;
+
+  if (attr_id == 0) {
+    goto end;
+  }
+
+  attrentry_T *aep = syn_cterm_attr2entry((int)attr_id);
+  if (!aep) {
+    api_set_error(err, kErrorTypeException,
+                  "Invalid attribute id: %d", attr_id);
+    return dic;
+  }
+
+  attrs = attrentry2hlattrs(aep, rgb);
+
+end:
+  return hlattrs2dict(attrs);
+}
+
+
 /**************************************
 *  End of Highlighting stuff	      *
 **************************************/
diff --git a/src/nvim/tui/tui.c b/src/nvim/tui/tui.c
index 256772489d..8e0e905bcd 100644
--- a/src/nvim/tui/tui.c
+++ b/src/nvim/tui/tui.c
@@ -288,7 +288,7 @@ static void terminfo_stop(UI *ui)
 static void tui_terminal_start(UI *ui)
 {
   TUIData *data = ui->data;
-  data->print_attrs = EMPTY_ATTRS;
+  data->print_attrs = HLATTRS_INIT;
   ugrid_init(&data->grid);
   terminfo_start(ui);
   update_size(ui);
@@ -628,7 +628,7 @@ static void clear_region(UI *ui, int top, int bot, int left, int right)
   if (grid->bg == -1 && right == ui->width -1) {
     // Background is set to the default color and the right edge matches the
     // screen end, try to use terminal codes for clearing the requested area.
-    HlAttrs clear_attrs = EMPTY_ATTRS;
+    HlAttrs clear_attrs = HLATTRS_INIT;
     clear_attrs.foreground = grid->fg;
     clear_attrs.background = grid->bg;
     update_attrs(ui, clear_attrs);
@@ -926,7 +926,7 @@ static void tui_scroll(UI *ui, Integer count)
     cursor_goto(ui, grid->top, grid->left);
     // also set default color attributes or some terminals can become funny
     if (scroll_clears_to_current_colour) {
-      HlAttrs clear_attrs = EMPTY_ATTRS;
+      HlAttrs clear_attrs = HLATTRS_INIT;
       clear_attrs.foreground = grid->fg;
       clear_attrs.background = grid->bg;
       update_attrs(ui, clear_attrs);
diff --git a/src/nvim/ugrid.c b/src/nvim/ugrid.c
index 7a0a16687e..2b5e96ee60 100644
--- a/src/nvim/ugrid.c
+++ b/src/nvim/ugrid.c
@@ -16,7 +16,7 @@
 
 void ugrid_init(UGrid *grid)
 {
-  grid->attrs = EMPTY_ATTRS;
+  grid->attrs = HLATTRS_INIT;
   grid->fg = grid->bg = -1;
   grid->cells = NULL;
 }
@@ -118,7 +118,7 @@ UCell *ugrid_put(UGrid *grid, uint8_t *text, size_t size)
 
 static void clear_region(UGrid *grid, int top, int bot, int left, int right)
 {
-  HlAttrs clear_attrs = EMPTY_ATTRS;
+  HlAttrs clear_attrs = HLATTRS_INIT;
   clear_attrs.foreground = grid->fg;
   clear_attrs.background = grid->bg;
   UGRID_FOREACH_CELL(grid, top, bot, left, right, {
diff --git a/src/nvim/ugrid.h b/src/nvim/ugrid.h
index 268362bf1b..1cf047502d 100644
--- a/src/nvim/ugrid.h
+++ b/src/nvim/ugrid.h
@@ -21,8 +21,6 @@ struct ugrid {
   UCell **cells;
 };
 
-#define EMPTY_ATTRS ((HlAttrs){ false, false, false, false, false, -1, -1, -1 })
-
 #define UGRID_FOREACH_CELL(grid, top, bot, left, right, code) \
   do { \
     for (int row = top; row <= bot; row++) { \
diff --git a/src/nvim/ui.c b/src/nvim/ui.c
index 01d3604159..afe7a51d43 100644
--- a/src/nvim/ui.c
+++ b/src/nvim/ui.c
@@ -166,6 +166,90 @@ void ui_event(char *name, Array args)
   }
 }
 
+
+/// Converts an attrentry_T into an HlAttrs
+///
+/// @param[in] aep data to convert
+/// @param use_rgb use 'gui*' settings if true, else resorts to 'cterm*'
+HlAttrs attrentry2hlattrs(const attrentry_T *aep, bool use_rgb)
+{
+  assert(aep);
+
+  HlAttrs attrs = HLATTRS_INIT;
+  int mask = 0;
+
+  mask = use_rgb ? aep->rgb_ae_attr : aep->cterm_ae_attr;
+
+  attrs.bold = mask & HL_BOLD;
+  attrs.underline = mask & HL_UNDERLINE;
+  attrs.undercurl = mask & HL_UNDERCURL;
+  attrs.italic = mask & HL_ITALIC;
+  attrs.reverse = mask & (HL_INVERSE | HL_STANDOUT);
+
+  if (use_rgb) {
+    if (aep->rgb_fg_color != -1) {
+      attrs.foreground = aep->rgb_fg_color;
+    }
+
+    if (aep->rgb_bg_color != -1) {
+      attrs.background = aep->rgb_bg_color;
+    }
+
+    if (aep->rgb_sp_color != -1) {
+      attrs.special = aep->rgb_sp_color;
+    }
+  } else {
+    if (cterm_normal_fg_color != aep->cterm_fg_color) {
+      attrs.foreground = aep->cterm_fg_color - 1;
+    }
+
+    if (cterm_normal_bg_color != aep->cterm_bg_color) {
+        attrs.background = aep->cterm_bg_color - 1;
+    }
+  }
+
+  return attrs;
+}
+
+Dictionary hlattrs2dict(HlAttrs attrs)
+{
+  Dictionary hl = ARRAY_DICT_INIT;
+
+  if (attrs.bold) {
+    PUT(hl, "bold", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.underline) {
+    PUT(hl, "underline", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.undercurl) {
+    PUT(hl, "undercurl", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.italic) {
+    PUT(hl, "italic", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.reverse) {
+    PUT(hl, "reverse", BOOLEAN_OBJ(true));
+  }
+
+  if (attrs.foreground != -1) {
+    PUT(hl, "foreground", INTEGER_OBJ(attrs.foreground));
+  }
+
+  if (attrs.background != -1) {
+    PUT(hl, "background", INTEGER_OBJ(attrs.background));
+  }
+
+  if (attrs.special != -1) {
+    PUT(hl, "special", INTEGER_OBJ(attrs.special));
+  }
+
+  return hl;
+}
+
 void ui_refresh(void)
 {
   if (!ui_active()) {
@@ -405,54 +489,20 @@ void ui_flush(void)
 
 static void set_highlight_args(int attr_code)
 {
-  HlAttrs rgb_attrs = { false, false, false, false, false, -1, -1, -1 };
+  HlAttrs rgb_attrs = HLATTRS_INIT;
   HlAttrs cterm_attrs = rgb_attrs;
 
   if (attr_code == HL_NORMAL) {
     goto end;
   }
-
-  int rgb_mask = 0;
-  int cterm_mask = 0;
   attrentry_T *aep = syn_cterm_attr2entry(attr_code);
 
   if (!aep) {
     goto end;
   }
 
-  rgb_mask = aep->rgb_ae_attr;
-  cterm_mask = aep->cterm_ae_attr;
-
-  rgb_attrs.bold = rgb_mask & HL_BOLD;
-  rgb_attrs.underline = rgb_mask & HL_UNDERLINE;
-  rgb_attrs.undercurl = rgb_mask & HL_UNDERCURL;
-  rgb_attrs.italic = rgb_mask & HL_ITALIC;
-  rgb_attrs.reverse = rgb_mask & (HL_INVERSE | HL_STANDOUT);
-  cterm_attrs.bold = cterm_mask & HL_BOLD;
-  cterm_attrs.underline = cterm_mask & HL_UNDERLINE;
-  cterm_attrs.undercurl = cterm_mask & HL_UNDERCURL;
-  cterm_attrs.italic = cterm_mask & HL_ITALIC;
-  cterm_attrs.reverse = cterm_mask & (HL_INVERSE | HL_STANDOUT);
-
-  if (aep->rgb_fg_color != normal_fg) {
-    rgb_attrs.foreground = aep->rgb_fg_color;
-  }
-
-  if (aep->rgb_bg_color != normal_bg) {
-    rgb_attrs.background = aep->rgb_bg_color;
-  }
-
-  if (aep->rgb_sp_color != normal_sp) {
-    rgb_attrs.special = aep->rgb_sp_color;
-  }
-
-  if (cterm_normal_fg_color != aep->cterm_fg_color) {
-    cterm_attrs.foreground = aep->cterm_fg_color - 1;
-  }
-
-  if (cterm_normal_bg_color != aep->cterm_bg_color) {
-    cterm_attrs.background = aep->cterm_bg_color - 1;
-  }
+  rgb_attrs = attrentry2hlattrs(aep, true);
+  cterm_attrs = attrentry2hlattrs(aep, false);
 
 end:
   UI_CALL(highlight_set, (ui->rgb ? rgb_attrs : cterm_attrs));
diff --git a/src/nvim/ui.h b/src/nvim/ui.h
index 064f77fee1..f1ea0716e6 100644
--- a/src/nvim/ui.h
+++ b/src/nvim/ui.h
@@ -21,6 +21,9 @@ typedef struct {
   int foreground, background, special;
 } HlAttrs;
 
+#define HLATTRS_INIT \
+  ((HlAttrs){ false, false, false, false, false, -1, -1, -1 })
+
 typedef struct ui_t UI;
 
 struct ui_t {