Merge pull request #8806 from bfredl/bce

tui: fix resize and use BCE more often

src/nvim/tui/tui.c

@@ -88,6 +88,7 @@ typedef struct {
   bool cont_received;
   UGrid grid;
   kvec_t(Rect) invalid_regions;
+  bool did_resize;
   int row, col;
   int out_fd;
   bool scroll_region_is_full_screen;
@@ -95,6 +96,7 @@ typedef struct {
   bool can_set_lr_margin;
   bool can_set_left_right_margin;
   bool immediate_wrap_after_last_column;
+  bool bce;
   bool mouse_enabled;
   bool busy, is_invisible;
   bool cork, overflow;
@@ -236,6 +238,7 @@ static void terminfo_start(UI *ui)
   data->immediate_wrap_after_last_column =
     terminfo_is_term_family(term, "cygwin")
     || terminfo_is_term_family(term, "interix");
+  data->bce = unibi_get_bool(data->ut, unibi_back_color_erase);
   data->normlen = unibi_pre_fmt_str(data, unibi_cursor_normal,
                                     data->norm, sizeof data->norm);
   data->invislen = unibi_pre_fmt_str(data, unibi_cursor_invisible,
@@ -435,6 +438,12 @@ static bool attrs_differ(HlAttrs a1, HlAttrs a2, bool rgb)
   }
 }
 
+static bool no_bg(UI *ui, HlAttrs attrs)
+{
+  return  ui->rgb ? attrs.rgb_bg_color == -1
+                  : attrs.cterm_bg_color == 0;
+}
+
 static void update_attrs(UI *ui, HlAttrs attrs)
 {
   TUIData *data = ui->data;
@@ -597,8 +606,6 @@ static void cursor_goto(UI *ui, int row, int col)
   if (row == grid->row && col == grid->col) {
     return;
   }
-  grid->row = row;
-  grid->col = col;
   if (0 == row && 0 == col) {
     unibi_out(ui, unibi_cursor_home);
     ugrid_goto(grid, row, col);
@@ -693,10 +700,11 @@ static void clear_region(UI *ui, int top, int bot, int left, int right,
   UGrid *grid = &data->grid;
 
   bool cleared = false;
-  // TODO(bfredl): support BCE for non-default background
-  bool nobg = ui->rgb ? attrs.rgb_bg_color == -1
-                      : attrs.cterm_bg_color == 0;
-  if (nobg && right == ui->width -1) {
+
+  // non-BCE terminals can't clear with non-default background color
+  bool can_clear = data->bce || no_bg(ui, attrs);
+
+  if (can_clear && 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.
     update_attrs(ui, attrs);
@@ -729,6 +737,14 @@ static void clear_region(UI *ui, int top, int bot, int left, int right,
       cursor_goto(ui, row, col);
       print_cell(ui, cell);
     });
+
+    if (data->did_resize && top == 0) {
+      // TODO(bfredl): the first line of the screen doesn't gets properly
+      // cleared after resize by the loop above, so redraw the final state
+      // after the next flush.
+      invalidate(ui, 0, bot, left, right);
+      data->did_resize = false;
+    }
   }
 
   // restore cursor
@@ -804,6 +820,7 @@ static void tui_grid_resize(UI *ui, Integer g, Integer width, Integer height)
   TUIData *data = ui->data;
   UGrid *grid = &data->grid;
   ugrid_resize(grid, (int)width, (int)height);
+  data->did_resize = true;
 
   // resize might not always be followed by a clear before flush
   // so clip the invalid region
@@ -984,18 +1001,13 @@ static void tui_grid_scroll(UI *ui, Integer g, Integer top, Integer bot,
   ugrid_scroll(grid, (int)rows, &clear_top, &clear_bot);
 
   if (can_use_scroll(ui)) {
-    bool scroll_clears_to_current_colour =
-      unibi_get_bool(data->ut, unibi_back_color_erase);
-
     // Change terminal scroll region and move cursor to the top
     if (!data->scroll_region_is_full_screen) {
       set_scroll_region(ui);
     }
     cursor_goto(ui, grid->top, grid->left);
     // also set default color attributes or some terminals can become funny
-    if (scroll_clears_to_current_colour) {
-      update_attrs(ui, data->clear_attrs);
-    }
+    update_attrs(ui, data->clear_attrs);
 
     if (rows > 0) {
       if (rows == 1) {
@@ -1019,7 +1031,7 @@ static void tui_grid_scroll(UI *ui, Integer g, Integer top, Integer bot,
     }
     cursor_goto(ui, data->row, data->col);
 
-    if (!scroll_clears_to_current_colour) {
+    if (!(data->bce || no_bg(ui, data->clear_attrs))) {
       // Scrolling will leave wrong background in the cleared area on non-BCE
       // terminals. Update the cleared area.
       clear_region(ui, clear_top, clear_bot, grid->left, grid->right,
@@ -1382,6 +1394,7 @@ static void patch_terminfo_bugs(TUIData *data, const char *term,
   bool roxterm = !!os_getenv("ROXTERM_ID");
 #endif
   bool xterm = terminfo_is_term_family(term, "xterm");
+  bool kitty = terminfo_is_term_family(term, "xterm-kitty");
   bool linuxvt = terminfo_is_term_family(term, "linux");
   bool rxvt = terminfo_is_term_family(term, "rxvt");
   bool teraterm = terminfo_is_term_family(term, "teraterm");
@@ -1437,8 +1450,8 @@ static void patch_terminfo_bugs(TUIData *data, const char *term,
     }
   }
 
-  if (!true_xterm) {
-    // Cannot trust terminfo; safer to disable BCE. #7624
+  if (tmux || screen || kitty) {
+    // Disable BCE in some cases we know it is not working. #8806
     unibi_set_bool(ut, unibi_back_color_erase, false);
   }