Qt: Lighten non-printable byte view characters.

Draw non-printable characters using a lighter foreground color in the
byte view.

Change-Id: Ib97a1f9f897fa6f78e33ff80c7efea21f68ef2d5
Reviewed-on: https://code.wireshark.org/review/24935
Reviewed-by: Roland Knall <rknall@gmail.com>

2 files changed, 22 insertions, 2 deletions

diff --git a/ui/qt/widgets/byte_view_text.cpp b/ui/qt/widgets/byte_view_text.cpp
index f6eddd4397..8f637fabc9 100644
--- a/ui/qt/widgets/byte_view_text.cpp
+++ b/ui/qt/widgets/byte_view_text.cpp
@@ -363,6 +363,9 @@ void ByteViewText::drawLine(QPainter *painter, const int offset, const int row_y
 
     // ASCII
     if (show_ascii_) {
+        bool in_non_printable = false;
+        int np_start;
+        int np_len;
         for (int tvb_pos = offset; tvb_pos <= max_tvb_pos; tvb_pos++) {
             /* insert a space every separator_interval_ bytes */
             if ((tvb_pos != offset) && ((tvb_pos % separator_interval_) == 0)) {
@@ -378,14 +381,27 @@ void ByteViewText::drawLine(QPainter *painter, const int offset, const int row_y
 
             if (g_ascii_isprint(c)) {
                 line += c;
+                if (in_non_printable) {
+                    in_non_printable = false;
+                    addAsciiFormatRange(fmt_list, np_start, np_len, offset, max_tvb_pos, ModeNonPrintable);
+                }
             } else {
-                // XXX Should we soften the text color as well?
                 line += UTF8_MIDDLE_DOT;
+                if (!in_non_printable) {
+                    in_non_printable = true;
+                    np_start = tvb_pos;
+                    np_len = 1;
+                } else {
+                    np_len++;
+                }
             }
             if (build_x_pos) {
                 x_pos_to_column_ += QVector<int>().fill(tvb_pos - offset, fontMetrics().width(line) - x_pos_to_column_.size());
             }
         }
+        if (in_non_printable) {
+            addAsciiFormatRange(fmt_list, np_start, np_len, offset, max_tvb_pos, ModeNonPrintable);
+        }
         addAsciiFormatRange(fmt_list, proto_start_, proto_len_, offset, max_tvb_pos, ModeProtocol);
         if (addAsciiFormatRange(fmt_list, field_start_, field_len_, offset, max_tvb_pos, ModeField)) {
             offset_mode = ModeOffsetField;
@@ -451,6 +467,9 @@ bool ByteViewText::addFormatRange(QList<QTextLayout::FormatRange> &fmt_list, int
         format_range.format.setForeground(ColorUtils::byteViewMarkColor(false));
         format_range.format.setBackground(ColorUtils::byteViewMarkColor(true));
         break;
+    case ModeNonPrintable:
+        format_range.format.setForeground(offset_normal_fg_);
+        break;
     }
     fmt_list << format_range;
     return true;
diff --git a/ui/qt/widgets/byte_view_text.h b/ui/qt/widgets/byte_view_text.h
index 73f58cb51d..4da15e919f 100644
--- a/ui/qt/widgets/byte_view_text.h
+++ b/ui/qt/widgets/byte_view_text.h
@@ -72,7 +72,8 @@ private:
         ModeOffsetNormal,
         ModeOffsetField,
         ModeHover,
-        ModeMarked
+        ModeMarked,
+        ModeNonPrintable
     } HighlightMode;
 
     QTextLayout *layout_;