further improved monochrome terminal support: fixed reverse text on reverse backgrounds

* Unfortunately we cannot use `wbkgdset(win, A_REVERSE)` if we plan to
  use reverse text on this background, i.e. if we want to cancel out the background A_REVERSE.
* SciTECO therefore no longer uses background attributes, but only foreground attributes.
  When setting a reverse text, we XOR A_REVERSE into the previous attributes.
* This fixes control characters especially in the info line and popups, as well as rendering
  of the popup scroll bars.
* The command-line should now be rendered properly even on a dark-on-bright color theme
  (which does not yet exist).

1 files changed, 13 insertions, 4 deletions

diff --git a/src/interface-curses/curses-info-popup.c b/src/interface-curses/curses-info-popup.c
index dffbcf8..332d434 100644
--- a/src/interface-curses/curses-info-popup.c
+++ b/src/interface-curses/curses-info-popup.c
@@ -98,7 +98,13 @@ teco_curses_info_popup_init_pad(teco_curses_info_popup_t *ctx, attr_t attr)
 	 */
 	ctx->pad = newpad(pad_lines, cols - 2);
 
-	wbkgd(ctx->pad, ' ' | attr);
+	/*
+	 * NOTE: attr could contain A_REVERSE on monochrome terminals,
+	 * so we use foreground attributes instead of background attributes.
+	 * This way, we can cancel out the A_REVERSE if necessary.
+	 */
+	wattrset(ctx->pad, attr);
+	teco_curses_clrtobot(ctx->pad);
 
 	/*
 	 * cur_col is the row currently written.
@@ -113,7 +119,8 @@ teco_curses_info_popup_init_pad(teco_curses_info_popup_t *ctx, attr_t attr)
 		wmove(ctx->pad, cur_line-1,
 		      (cur_col % pad_cols)*pad_colwidth);
 
-		wattrset(ctx->pad, entry->highlight ? A_BOLD : A_NORMAL);
+		if (entry->highlight)
+			wattron(ctx->pad, A_BOLD);
 
 		switch (entry->type) {
 		case TECO_POPUP_FILE:
@@ -137,6 +144,8 @@ teco_curses_info_popup_init_pad(teco_curses_info_popup_t *ctx, attr_t attr)
 			break;
 		}
 
+		wattroff(ctx->pad, A_BOLD);
+
 		cur_col++;
 	}
 }
@@ -167,7 +176,7 @@ teco_curses_info_popup_show(teco_curses_info_popup_t *ctx, attr_t attr)
 	/* window covers message, scintilla and info windows */
 	ctx->window = newwin(popup_lines, 0, lines - 1 - popup_lines, 0);
 
-	wbkgdset(ctx->window, ' ' | attr);
+	wattrset(ctx->window, attr);
 
 	wborder(ctx->window,
 	        ACS_VLINE,
@@ -198,7 +207,7 @@ teco_curses_info_popup_show(teco_curses_info_popup_t *ctx, attr_t attr)
 	 * Instead, simply draw reverse blanks.
 	 */
 	wmove(ctx->window, bar_y, cols-1);
-	wattron(ctx->window, A_REVERSE);
+	wattrset(ctx->window, attr ^ A_REVERSE);
 	wvline(ctx->window, ' ', bar_height);
 }