Fix Fl_Terminal::handle_unknown_char() for plot_char() (#948)

- Add 'int Fl_Terminal::handle_unknown_char(int drow, int dcol)'
  to write the "unknown" character to the intended display position.

- Define Fl_Terminal::unknown_char as a static variable to avoid
  redundancy. In the future this might be overridden by users.

1 files changed, 4 insertions, 0 deletions

diff --git a/FL/Fl_Terminal.H b/FL/Fl_Terminal.H
index 3b9b39a86..d6580a106 100644
--- a/FL/Fl_Terminal.H
+++ b/FL/Fl_Terminal.H
@@ -1027,6 +1027,7 @@ public:
   void append(const char *s, int len=-1);
 protected:
   int handle_unknown_char(void);
+  int handle_unknown_char(int drow, int dcol);
   // Drawing
   void draw_row_bg(int grow, int X, int Y) const;
   void draw_row(int grow, int Y) const;
@@ -1170,6 +1171,9 @@ public:
   // API: Show unknown/unprintable chars
   bool  show_unknown(void) const;
   void  show_unknown(bool val);
+protected:
+  static const char *unknown_char; ///< "unknown" replacement character
+public:
   // API: ANSI sequences
   bool  ansi(void) const;
   void  ansi(bool val);