Qt: Add syntax line edit feedback symbols.

Draw a circle+backslash or a warning triangle in the far right of the
line edit entry for invalid and deprecated filters respectively. This
should provide an additional clue for color blind users.

Bug: 15326
Change-Id: I55a1e214834a340ccda3bfe8880bba12c5e274e9
Reviewed-on: https://code.wireshark.org/review/30936
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 47 insertions, 4 deletions

diff --git a/ui/qt/widgets/syntax_line_edit.cpp b/ui/qt/widgets/syntax_line_edit.cpp
index ae4e082548..feee60a8fe 100644
--- a/ui/qt/widgets/syntax_line_edit.cpp
+++ b/ui/qt/widgets/syntax_line_edit.cpp
@@ -16,21 +16,22 @@
 #include <epan/dfilter/dfilter.h>
 #include <epan/column-info.h>
 
+#include <wsutil/utf8_entities.h>
+
 #include <ui/qt/widgets/syntax_line_edit.h>
 
 #include <ui/qt/utils/color_utils.h>
+#include <ui/qt/utils/stock_icon.h>
 
 #include <QAbstractItemView>
 #include <QCompleter>
 #include <QKeyEvent>
+#include <QPainter>
 #include <QScrollBar>
 #include <QStringListModel>
+#include <QStyleOptionFrame>
 #include <limits>
 
-// To do:
-// - Add indicator icons for syntax states to make things more clear for
-//   color blind people?
-
 const int max_completion_items_ = 20;
 
 SyntaxLineEdit::SyntaxLineEdit(QWidget *parent) :
@@ -350,6 +351,48 @@ void SyntaxLineEdit::focusOutEvent(QFocusEvent *event)
     QLineEdit::focusOutEvent(event);
 }
 
+// Add indicator icons for syntax states in order to make things more clear for
+// color blind people.
+void SyntaxLineEdit::paintEvent(QPaintEvent *event)
+{
+    QLineEdit::paintEvent(event);
+
+    QString si_name;
+
+    switch (syntax_state_) {
+    case Invalid:
+        si_name = "x-filter-invalid";
+        break;
+    case Deprecated:
+        si_name = "x-filter-deprecated";
+        break;
+    default:
+        return;
+    }
+
+    QStyleOptionFrame opt;
+    initStyleOption(&opt);
+    QRect cr = style()->subElementRect(QStyle::SE_LineEditContents, &opt, this);
+    QRect sir = QRect(0, 0, 14, 14); // QIcon::paint scales, which is not what we want.
+
+    if (fontMetrics().width(text()) + cr.height() > cr.width() || cr.height() < sir.height()) {
+        // No space to draw
+        return;
+    }
+
+    QIcon state_icon = StockIcon(si_name);
+    if (state_icon.isNull()) {
+        return;
+    }
+
+    int si_off = (cr.height() - sir.height()) / 2;
+    sir.moveTop(si_off);
+    sir.moveRight(cr.right() - si_off);
+    QPainter painter(this);
+    painter.setOpacity(0.25);
+    state_icon.paint(&painter, sir);
+}
+
 void SyntaxLineEdit::insertFieldCompletion(const QString &completion_text)
 {
     if (!completer_) return;