fixed displaying of control characters in the "info" line (and window title)

 * this relied on Curses' control character drawing on Curses.
   However it treats tab and line feed differently than other
   control characters, so registers like "^Mfoo" could not be displayed
   properly.
   Even if we can configure Curses to display them correctly, we need
   a "canonicalized", flat form of strings for other purposes (like setting
   window titles. This is form is different from the formatting used
   for command lines which may change anyway once we introduce Scintilla
   mini buffers.
 * therefore String::canonicalize_ctl() was introduced
 * also set window title on PDCurses

4 files changed, 60 insertions, 4 deletions

diff --git a/src/interface-curses.cpp b/src/interface-curses.cpp
index 9060a0b..a9bb466 100644
--- a/src/interface-curses.cpp
+++ b/src/interface-curses.cpp
@@ -38,6 +38,7 @@
 #endif
 
 #include "sciteco.h"
+#include "string-utils.h"
 #include "cmdline.h"
 #include "qregisters.h"
 #include "ring.h"
@@ -226,14 +227,27 @@ InterfaceCurses::draw_info(void)
 	wbkgdset(info_window, ' ' | SCI_COLOR_ATTR(COLOR_BLACK, COLOR_WHITE));
 	waddstr(info_window, info_current);
 	wclrtoeol(info_window);
+
+#ifdef PDCURSES
+	PDC_set_title(info_current);
+#endif
 }
 
 void
 InterfaceCurses::info_update_impl(const QRegister *reg)
 {
+	/*
+	 * We cannot rely on Curses' control character drawing
+	 * and we need the info_current string for other purposes
+	 * (like PDC_set_title()), so we "canonicalize" the
+	 * register name here:
+	 */
+	gchar *name = String::canonicalize_ctl(reg->name);
+
 	g_free(info_current);
-	info_current = g_strdup_printf("%s - <QRegister> %s", PACKAGE_NAME,
-				       reg->name);
+	info_current = g_strdup_printf("%s - <QRegister> %s",
+	                               PACKAGE_NAME, name);
+	g_free(name);
 
 	draw_info();
 }
diff --git a/src/interface-gtk.cpp b/src/interface-gtk.cpp
index 14dfafd..c8c96f5 100644
--- a/src/interface-gtk.cpp
+++ b/src/interface-gtk.cpp
@@ -36,6 +36,7 @@
 #include <ScintillaWidget.h>
 
 #include "sciteco.h"
+#include "string-utils.h"
 #include "cmdline.h"
 #include "qregisters.h"
 #include "ring.h"
@@ -168,10 +169,13 @@ InterfaceGtk::show_view_impl(ViewGtk *view)
 void
 InterfaceGtk::info_update_impl(const QRegister *reg)
 {
+	gchar *name = String::canonicalize_ctl(reg->name);
 	gchar buf[255];
 
-	g_snprintf(buf, sizeof(buf), "%s - <QRegister> %s", PACKAGE_NAME,
-		   reg->name);
+	g_snprintf(buf, sizeof(buf), "%s - <QRegister> %s",
+		   PACKAGE_NAME, name);
+	g_free(name);
+
 	gtk_window_set_title(GTK_WINDOW(window), buf);
 }
 
diff --git a/src/string-utils.cpp b/src/string-utils.cpp
index 6481765..7da9875 100644
--- a/src/string-utils.cpp
+++ b/src/string-utils.cpp
@@ -21,10 +21,46 @@
 
 #include <glib.h>
 
+#include "sciteco.h"
 #include "string-utils.h"
 
 namespace SciTECO {
 
+/**
+ * Canonicalize control characters in str.
+ * This converts all control characters to printable
+ * characters without tabs, line feeds, etc.
+ * Useful for displaying Q-Register names and
+ * TECO code.
+ */
+gchar *
+String::canonicalize_ctl(const gchar *str)
+{
+	gsize ret_len = 1; /* for trailing 0 */
+	gchar *ret, *p;
+
+	/*
+	 * Instead of approximating size with strlen()
+	 * we can just as well calculate it exactly:
+	 */
+	for (const gchar *p = str; *p; p++)
+		ret_len += IS_CTL(*p) ? 2 : 1;
+
+	p = ret = (gchar *)g_malloc(ret_len);
+
+	while (*str) {
+		if (IS_CTL(*str)) {
+			*p++ = '^';
+			*p++ = CTL_ECHO(*str++);
+		} else {
+			*p++ = *str++;
+		}
+	}
+	*p = '\0';
+
+	return ret;
+}
+
 void
 String::get_coord(const gchar *str, gint pos,
                   gint &line, gint &column)
diff --git a/src/string-utils.h b/src/string-utils.h
index e2f7be3..aa646d6 100644
--- a/src/string-utils.h
+++ b/src/string-utils.h
@@ -75,6 +75,8 @@ append(gchar *&str, gchar chr)
 	append(str, buf);
 }
 
+gchar *canonicalize_ctl(const gchar *str);
+
 void get_coord(const gchar *str, gint pos,
 	       gint &line, gint &column);