mouse.c: Adjust clicked column if chars are concealed (#5087)

syntax.c: Added syn_get_concealed_id()

tests: Added tests for mouse clicks on concealed text.

3 files changed, 411 insertions, 0 deletions

diff --git a/src/nvim/mouse.c b/src/nvim/mouse.c
index 2f499e477c..5efac2623c 100644
--- a/src/nvim/mouse.c
+++ b/src/nvim/mouse.c
@@ -6,6 +6,7 @@
 #include "nvim/window.h"
 #include "nvim/strings.h"
 #include "nvim/screen.h"
+#include "nvim/syntax.h"
 #include "nvim/ui.h"
 #include "nvim/os_unix.h"
 #include "nvim/fold.h"
@@ -303,6 +304,10 @@ retnomove:
     mouse_past_bottom = true;
   }
 
+  if (!(flags & MOUSE_RELEASED) && which_button == MOUSE_LEFT) {
+    col = mouse_adjust_click(curwin, row, col);
+  }
+
   // Start Visual mode before coladvance(), for when 'sel' != "old"
   if ((flags & MOUSE_MAY_VIS) && !VIsual_active) {
     check_visual_highlight();
@@ -597,3 +602,74 @@ bool mouse_scroll_horiz(int dir)
 
   return leftcol_changed();
 }
+
+// Adjust the clicked column position if there are concealed characters
+// before the current column.  But only when it's absolutely necessary.
+static int mouse_adjust_click(win_T *wp, int row, int col)
+{
+  if (!(wp->w_p_cole > 0 && curbuf->b_p_smc > 0
+        && wp->w_leftcol < curbuf->b_p_smc && conceal_cursor_line(wp))) {
+    return col;
+  }
+
+  int end = (colnr_T)STRLEN(ml_get(wp->w_cursor.lnum));
+  int vend = getviscol2(end, 0);
+
+  if (col >= vend) {
+    return col;
+  }
+
+  int i = wp->w_leftcol;
+
+  if (row > 0) {
+    i += row * (wp->w_width - win_col_off(wp) - win_col_off2(wp)
+                - wp->w_leftcol) + wp->w_skipcol;
+  }
+
+  int start_col = i;
+  int matchid;
+  int last_matchid;
+  int bcol = end - (vend - col);
+
+  while (i < bcol) {
+    matchid = syn_get_concealed_id(wp, wp->w_cursor.lnum, i);
+
+    if (matchid != 0) {
+      if (wp->w_p_cole == 3) {
+        bcol++;
+      } else {
+        if (row > 0 && i == start_col) {
+          // Check if the current concealed character is actually part of
+          // the previous wrapped row's conceal group.
+          last_matchid = syn_get_concealed_id(wp, wp->w_cursor.lnum,
+                                              i - 1);
+          if (last_matchid == matchid) {
+            bcol++;
+          }
+        } else if (wp->w_p_cole == 1
+                   || (wp->w_p_cole == 2
+                       && (lcs_conceal != NUL
+                           || syn_get_sub_char() != NUL))) {
+          // At least one placeholder character will be displayed.
+          bcol--;
+        }
+
+        last_matchid = matchid;
+
+        // Adjust for concealed text that spans more than one character.
+        do {
+          i++;
+          bcol++;
+          matchid = syn_get_concealed_id(wp, wp->w_cursor.lnum, i);
+        } while (last_matchid == matchid);
+
+        continue;
+      }
+    }
+
+    i++;
+  }
+
+  return getviscol2(bcol, 0);
+}
+
diff --git a/src/nvim/syntax.c b/src/nvim/syntax.c
index 27855184df..3215f7ea14 100644
--- a/src/nvim/syntax.c
+++ b/src/nvim/syntax.c
@@ -5661,6 +5661,24 @@ int get_syntax_info(int *seqnrp)
   return current_flags;
 }
 
+
+/// Get the sequence number of the concealed file position.
+///
+/// @return seqnr if the file position is concealed, 0 otherwise.
+int syn_get_concealed_id(win_T *wp, linenr_T lnum, colnr_T col)
+{
+  int seqnr;
+  int syntax_flags;
+
+  (void)syn_get_id(wp, lnum, col, false, NULL, false);
+  syntax_flags = get_syntax_info(&seqnr);
+
+  if (syntax_flags & HL_CONCEAL) {
+    return seqnr;
+  }
+  return 0;
+}
+
 /*
  * Return conceal substitution character
  */
diff --git a/test/functional/ui/mouse_spec.lua b/test/functional/ui/mouse_spec.lua
index a433143266..7b820347ac 100644
--- a/test/functional/ui/mouse_spec.lua
+++ b/test/functional/ui/mouse_spec.lua
@@ -462,4 +462,321 @@ describe('Mouse input', function()
                                |
     ]])
   end)
+
+  describe('on concealed text', function()
+    -- Helpful for reading the test expectations:
+    -- :match Error /\^/
+    local concealed = {
+      c = { foreground = Screen.colors.LightGrey, background = Screen.colors.DarkGray }
+    }
+
+    before_each(function()
+      screen:try_resize(25, 7)
+      feed('ggdG')
+
+      execute('set concealcursor=n')
+      execute('set nowrap')
+      execute('syntax match NonText "\\<amet\\>" conceal')
+      execute('syntax match NonText "\\cs\\|g." conceal cchar=X')
+      execute('syntax match NonText "\\%(lo\\|cl\\)." conceal')
+      execute('syntax match NonText "Lo" conceal cchar=Y')
+
+      insert([[
+      Lorem ipsum dolor sit amet, consetetur sadipscing elitr.
+      Stet clita kasd gubergren, no sea takimata sanctus est.
+      ]])
+
+      feed('gg')
+    end)
+
+    it('(level 1) click on non-wrapped lines', function()
+      execute('let &conceallevel=1', 'echo')
+
+      feed('<esc><LeftMouse><0,0>')
+      screen:expect([[
+        {c:^Y}rem ip{c:X}um do{c: } {c:X}it {c: }, con|
+        {c:X}tet {c: }ta ka{c:X}d {c:X}ber{c:X}en, no|
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><1,0>')
+      screen:expect([[
+        {c:Y}^rem ip{c:X}um do{c: } {c:X}it {c: }, con|
+        {c:X}tet {c: }ta ka{c:X}d {c:X}ber{c:X}en, no|
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,0>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do{c: } {c:^X}it {c: }, con|
+        {c:X}tet {c: }ta ka{c:X}d {c:X}ber{c:X}en, no|
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,1>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do{c: } {c:X}it {c: }, con|
+        {c:X}tet {c: }ta ka{c:X}d {c:X}^ber{c:X}en, no|
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+    end) -- level 1 - non wrapped
+
+    it('(level 1) click on wrapped lines', function()
+      execute('let &conceallevel=1', 'let &wrap=1', 'echo')
+
+      feed('<esc><LeftMouse><0,0>')
+      screen:expect([[
+        {c:^Y}rem ip{c:X}um do{c: } {c:X}it {c: }     |
+        , con{c:X}etetur {c:X}adip{c:X}cin{c:X}  |
+        elitr.                   |
+        {c:X}tet {c: }ta ka{c:X}d {c:X}ber{c:X}en    |
+        , no {c:X}ea takimata {c:X}anctu{c:X}|
+         e{c:X}t.                    |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><6,1>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do{c: } {c:X}it {c: }     |
+        , con{c:X}^etetur {c:X}adip{c:X}cin{c:X}  |
+        elitr.                   |
+        {c:X}tet {c: }ta ka{c:X}d {c:X}ber{c:X}en    |
+        , no {c:X}ea takimata {c:X}anctu{c:X}|
+         e{c:X}t.                    |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,1>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do{c: } {c:X}it {c: }     |
+        , con{c:X}etetur {c:X}a^dip{c:X}cin{c:X}  |
+        elitr.                   |
+        {c:X}tet {c: }ta ka{c:X}d {c:X}ber{c:X}en    |
+        , no {c:X}ea takimata {c:X}anctu{c:X}|
+         e{c:X}t.                    |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,3>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do{c: } {c:X}it {c: }     |
+        , con{c:X}etetur {c:X}adip{c:X}cin{c:X}  |
+        elitr.                   |
+        {c:X}tet {c: }ta ka{c:X}d {c:X}^ber{c:X}en    |
+        , no {c:X}ea takimata {c:X}anctu{c:X}|
+         e{c:X}t.                    |
+                                 |
+      ]], concealed)
+    end) -- level 1 - wrapped
+
+
+    it('(level 2) click on non-wrapped lines', function()
+      execute('let &conceallevel=2', 'echo')
+
+      feed('<esc><LeftMouse><0,0>')
+      screen:expect([[
+        {c:^Y}rem ip{c:X}um do {c:X}it , con{c:X}e|
+        {c:X}tet ta ka{c:X}d {c:X}ber{c:X}en, no |
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><1,0>')
+      screen:expect([[
+        {c:Y}^rem ip{c:X}um do {c:X}it , con{c:X}e|
+        {c:X}tet ta ka{c:X}d {c:X}ber{c:X}en, no |
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,0>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do {c:X}^it , con{c:X}e|
+        {c:X}tet ta ka{c:X}d {c:X}ber{c:X}en, no |
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,1>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do {c:X}it , con{c:X}e|
+        {c:X}tet ta ka{c:X}d {c:X}b^er{c:X}en, no |
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+    end) -- level 2 - non wrapped
+
+    it('(level 2) click on wrapped lines', function()
+      execute('let &conceallevel=2', 'let &wrap=1', 'echo')
+
+      feed('<esc><LeftMouse><0,0>')
+      screen:expect([[
+        {c:^Y}rem ip{c:X}um do {c:X}it        |
+        , con{c:X}etetur {c:X}adip{c:X}cin{c:X}  |
+        elitr.                   |
+        {c:X}tet ta ka{c:X}d {c:X}ber{c:X}en     |
+        , no {c:X}ea takimata {c:X}anctu{c:X}|
+         e{c:X}t.                    |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><6,1>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do {c:X}it        |
+        , con{c:X}^etetur {c:X}adip{c:X}cin{c:X}  |
+        elitr.                   |
+        {c:X}tet ta ka{c:X}d {c:X}ber{c:X}en     |
+        , no {c:X}ea takimata {c:X}anctu{c:X}|
+         e{c:X}t.                    |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,1>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do {c:X}it        |
+        , con{c:X}etetur {c:X}a^dip{c:X}cin{c:X}  |
+        elitr.                   |
+        {c:X}tet ta ka{c:X}d {c:X}ber{c:X}en     |
+        , no {c:X}ea takimata {c:X}anctu{c:X}|
+         e{c:X}t.                    |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,3>')
+      screen:expect([[
+        {c:Y}rem ip{c:X}um do {c:X}it        |
+        , con{c:X}etetur {c:X}adip{c:X}cin{c:X}  |
+        elitr.                   |
+        {c:X}tet ta ka{c:X}d {c:X}b^er{c:X}en     |
+        , no {c:X}ea takimata {c:X}anctu{c:X}|
+         e{c:X}t.                    |
+                                 |
+      ]], concealed)
+    end) -- level 2 - wrapped
+
+
+    it('(level 3) click on non-wrapped lines', function()
+      execute('let &conceallevel=3', 'echo')
+
+      feed('<esc><LeftMouse><0,0>')
+      screen:expect([[
+        ^rem ipum do it , conetetu|
+        tet ta kad beren, no ea t|
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><1,0>')
+      screen:expect([[
+        r^em ipum do it , conetetu|
+        tet ta kad beren, no ea t|
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,0>')
+      screen:expect([[
+        rem ipum do it ^, conetetu|
+        tet ta kad beren, no ea t|
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,1>')
+      screen:expect([[
+        rem ipum do it , conetetu|
+        tet ta kad bere^n, no ea t|
+                                 |
+        ~                        |
+        ~                        |
+        ~                        |
+                                 |
+      ]], concealed)
+    end) -- level 3 - non wrapped
+
+    it('(level 3) click on wrapped lines', function()
+      execute('let &conceallevel=3', 'let &wrap=1', 'echo')
+
+      feed('<esc><LeftMouse><0,0>')
+      screen:expect([[
+        ^rem ipum do it           |
+        , conetetur adipcin      |
+        elitr.                   |
+        tet ta kad beren         |
+        , no ea takimata anctu   |
+         et.                     |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><6,1>')
+      screen:expect([[
+        rem ipum do it           |
+        , cone^tetur adipcin      |
+        elitr.                   |
+        tet ta kad beren         |
+        , no ea takimata anctu   |
+         et.                     |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,1>')
+      screen:expect([[
+        rem ipum do it           |
+        , conetetur adi^pcin      |
+        elitr.                   |
+        tet ta kad beren         |
+        , no ea takimata anctu   |
+         et.                     |
+                                 |
+      ]], concealed)
+
+      feed('<esc><LeftMouse><15,3>')
+      screen:expect([[
+        rem ipum do it           |
+        , conetetur adipcin      |
+        elitr.                   |
+        tet ta kad bere^n         |
+        , no ea takimata anctu   |
+         et.                     |
+                                 |
+      ]], concealed)
+    end) -- level 3 - wrapped
+  end)
 end)