1 files changed, 555 insertions, 0 deletions
diff --git a/ui/qt/widgets/syntax_line_edit.cpp b/ui/qt/widgets/syntax_line_edit.cpp
new file mode 100644
index 00000000..99ccf7bc
--- /dev/null
+++ b/ui/qt/widgets/syntax_line_edit.cpp
@@ -0,0 +1,555 @@
+/* syntax_line_edit.cpp
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+
+#include <glib.h>
+
+#include <epan/prefs.h>
+#include <epan/proto.h>
+#include <epan/dfilter/dfilter.h>
+#include <epan/column.h>
+
+#include <wsutil/utf8_entities.h>
+
+#include <ui/qt/widgets/syntax_line_edit.h>
+
+#include <ui/qt/utils/qt_ui_utils.h>
+#include <ui/qt/utils/color_utils.h>
+#include <ui/qt/utils/stock_icon.h>
+
+#include <QAbstractItemView>
+#include <QApplication>
+#include <QCompleter>
+#include <QKeyEvent>
+#include <QPainter>
+#include <QScrollBar>
+#include <QStringListModel>
+#include <QStyleOptionFrame>
+#include <limits>
+
+const int max_completion_items_ = 20;
+
+SyntaxLineEdit::SyntaxLineEdit(QWidget *parent) :
+    QLineEdit(parent),
+    completer_(NULL),
+    completion_model_(NULL),
+    completion_enabled_(false)
+{
+    setSyntaxState();
+    setMaxLength(std::numeric_limits<quint32>::max());
+}
+
+// Override setCompleter so that we don't clobber the filter text on activate.
+void SyntaxLineEdit::setCompleter(QCompleter *c)
+{
+    if (completer_)
+        QObject::disconnect(completer_, 0, this, 0);
+
+    completer_ = c;
+
+    if (!completer_)
+        return;
+
+    completer_->setWidget(this);
+    completer_->setCompletionMode(QCompleter::PopupCompletion);
+    completer_->setCaseSensitivity(Qt::CaseInsensitive);
+    // Completion items are not guaranteed to be sorted (recent filters +
+    // fields), so no setModelSorting.
+    completer_->setMaxVisibleItems(max_completion_items_);
+    QObject::connect(completer_, static_cast<void (QCompleter::*)(const QString &)>(&QCompleter::activated),
+                     this, &SyntaxLineEdit::insertFieldCompletion);
+
+    // Auto-completion is turned on.
+    completion_enabled_ = true;
+}
+
+void SyntaxLineEdit::allowCompletion(bool enabled)
+{
+    completion_enabled_ = enabled;
+}
+
+void SyntaxLineEdit::setSyntaxState(SyntaxState state) {
+    syntax_state_ = state;
+
+    // XXX Should we drop the background colors here in favor of ::paintEvent below?
+    QColor valid_bg = ColorUtils::fromColorT(&prefs.gui_text_valid);
+    QColor valid_fg = ColorUtils::contrastingTextColor(valid_bg);
+    QColor invalid_bg = ColorUtils::fromColorT(&prefs.gui_text_invalid);
+    QColor invalid_fg = ColorUtils::contrastingTextColor(invalid_bg);
+    QColor deprecated_bg = ColorUtils::fromColorT(&prefs.gui_text_deprecated);
+    QColor deprecated_fg = ColorUtils::contrastingTextColor(deprecated_bg);
+
+    // Try to matche QLineEdit's placeholder text color (which sets the
+    // alpha channel to 50%, which doesn't work in style sheets).
+    // Setting the foreground color lets us avoid yet another background
+    // color preference and should hopefully make things easier to
+    // distinguish for color blind folk.
+    QColor busy_fg = ColorUtils::alphaBlend(QApplication::palette().text(), QApplication::palette().base(), 0.5);
+
+    state_style_sheet_ = QString(
+            "SyntaxLineEdit[syntaxState=\"%1\"] {"
+            "  color: %2;"
+            "  background-color: %3;"
+            "}"
+
+            "SyntaxLineEdit[syntaxState=\"%4\"] {"
+            "  color: %5;"
+            "  background-color: %6;"
+            "}"
+
+            "SyntaxLineEdit[syntaxState=\"%7\"] {"
+            "  color: %8;"
+            "  background-color: %9;"
+            "}"
+
+            "SyntaxLineEdit[syntaxState=\"%10\"] {"
+            "  color: %11;"
+            "  background-color: %12;"
+            "}"
+            )
+
+            // CSS selector, foreground, background
+            .arg(Valid)
+            .arg(valid_fg.name())
+            .arg(valid_bg.name())
+
+            .arg(Invalid)
+            .arg(invalid_fg.name())
+            .arg(invalid_bg.name())
+
+            .arg(Deprecated)
+            .arg(deprecated_fg.name())
+            .arg(deprecated_bg.name())
+
+            .arg(Busy)
+            .arg(busy_fg.name())
+            .arg(palette().base().color().name())
+            ;
+    setStyleSheet(style_sheet_);
+}
+
+QString SyntaxLineEdit::syntaxErrorMessage()
+{
+    return syntax_error_message_;
+}
+
+QString SyntaxLineEdit::syntaxErrorMessageFull()
+{
+    return syntax_error_message_full_;
+}
+
+QString SyntaxLineEdit::createSyntaxErrorMessageFull(
+                                const QString &filter, const QString &err_msg,
+                                qsizetype loc_start, size_t loc_length)
+{
+    QString msg = tr("Invalid filter: %1").arg(err_msg);
+
+    if (loc_start >= 0 && loc_length >= 1) {
+        // Add underlined location
+        msg = QString("<p>%1<pre>  %2\n  %3^%4</pre></p>")
+            .arg(msg)
+            .arg(filter)
+            .arg(QString(' ').repeated(static_cast<int>(loc_start)))
+            .arg(QString('~').repeated(static_cast<int>(loc_length) - 1));
+    }
+    return msg;
+}
+
+QString SyntaxLineEdit::styleSheet() const {
+    return style_sheet_;
+}
+
+void SyntaxLineEdit::setStyleSheet(const QString &style_sheet) {
+    style_sheet_ = style_sheet;
+    QLineEdit::setStyleSheet(style_sheet_ + state_style_sheet_);
+}
+
+void SyntaxLineEdit::insertFilter(const QString &filter)
+{
+    QString padded_filter = filter;
+
+    if (hasSelectedText()) {
+        backspace();
+    }
+
+    int pos = cursorPosition();
+    if (pos > 0 && !text().at(pos - 1).isSpace()) {
+        padded_filter.prepend(" ");
+    }
+    if (pos < text().length() - 1 && !text().at(pos + 1).isSpace()) {
+        padded_filter.append(" ");
+    }
+    insert(padded_filter);
+}
+
+bool SyntaxLineEdit::checkDisplayFilter(QString filter)
+{
+    if (!completion_enabled_) {
+        return false;
+    }
+
+    if (filter.isEmpty()) {
+        setSyntaxState(SyntaxLineEdit::Empty);
+        return true;
+    }
+
+    dfilter_t *dfp = NULL;
+    df_error_t *df_err = NULL;
+    if (dfilter_compile(filter.toUtf8().constData(), &dfp, &df_err)) {
+        GSList *warn;
+        GPtrArray *depr = NULL;
+        if (dfp != NULL && (warn = dfilter_get_warnings(dfp)) != NULL) {
+            // FIXME Need to use a different state or rename ::Deprecated
+            setSyntaxState(SyntaxLineEdit::Deprecated);
+            /*
+            * We're being lazy and only printing the first warning.
+            * Would it be better to print all of them?
+            */
+            syntax_error_message_  = QString(static_cast<gchar *>(warn->data));
+        } else if (dfp != NULL && (depr = dfilter_deprecated_tokens(dfp)) != NULL) {
+            // You keep using that word. I do not think it means what you think it means.
+            // Possible alternatives: ::Troubled, or ::Problematic maybe?
+            setSyntaxState(SyntaxLineEdit::Deprecated);
+            /*
+             * We're being lazy and only printing the first "problem" token.
+             * Would it be better to print all of them?
+             */
+            QString token((const char *)g_ptr_array_index(depr, 0));
+            gchar *token_str = qstring_strdup(token.section('.', 0, 0));
+            header_field_info *hfi = proto_registrar_get_byalias(token_str);
+            if (hfi)
+                syntax_error_message_ = tr("\"%1\" is deprecated in favour of \"%2\". "
+                                           "See Help section 6.4.8 for details.").arg(token_str).arg(hfi->abbrev);
+            else
+                // The token_str is the message.
+                syntax_error_message_ = tr("%1").arg(token_str);
+            g_free(token_str);
+        } else {
+            setSyntaxState(SyntaxLineEdit::Valid);
+        }
+    } else {
+        setSyntaxState(SyntaxLineEdit::Invalid);
+        syntax_error_message_ = QString::fromUtf8(df_err->msg);
+        syntax_error_message_full_ = createSyntaxErrorMessageFull(filter, syntax_error_message_, df_err->loc.col_start, df_err->loc.col_len);
+        df_error_free(&df_err);
+    }
+    dfilter_free(dfp);
+
+    return true;
+}
+
+void SyntaxLineEdit::checkFieldName(QString field)
+{
+    if (field.isEmpty()) {
+        setSyntaxState(SyntaxLineEdit::Empty);
+        return;
+    }
+
+    char invalid_char = proto_check_field_name(field.toUtf8().constData());
+    if (invalid_char) {
+        setSyntaxState(SyntaxLineEdit::Invalid);
+    } else {
+        checkDisplayFilter(field);
+    }
+}
+
+void SyntaxLineEdit::checkCustomColumn(QString fields)
+{
+    if (fields.isEmpty()) {
+        setSyntaxState(SyntaxLineEdit::Empty);
+        return;
+    }
+
+    gchar **splitted_fields = g_regex_split_simple(COL_CUSTOM_PRIME_REGEX,
+                fields.toUtf8().constData(), G_REGEX_ANCHORED, G_REGEX_MATCH_ANCHORED);
+
+    for (guint i = 0; i < g_strv_length(splitted_fields); i++) {
+        if (splitted_fields[i] && *splitted_fields[i]) {
+            if (proto_check_field_name(splitted_fields[i]) != 0) {
+                setSyntaxState(SyntaxLineEdit::Invalid);
+                g_strfreev(splitted_fields);
+                return;
+            }
+        }
+    }
+    g_strfreev(splitted_fields);
+
+    checkDisplayFilter(fields);
+}
+
+void SyntaxLineEdit::checkInteger(QString number)
+{
+    if (number.isEmpty()) {
+        setSyntaxState(SyntaxLineEdit::Empty);
+        return;
+    }
+
+    bool ok;
+    text().toInt(&ok);
+    if (ok) {
+        setSyntaxState(SyntaxLineEdit::Valid);
+    } else {
+        setSyntaxState(SyntaxLineEdit::Invalid);
+    }
+}
+
+bool SyntaxLineEdit::isComplexFilter(const QString &filter)
+{
+    bool is_complex = false;
+    for (int i = 0; i < filter.length(); i++) {
+        if (!token_chars_.contains(filter.at(i))) {
+            is_complex = true;
+            break;
+        }
+    }
+    // Don't complete the current filter.
+    if (is_complex && filter.startsWith(text()) && filter.compare(text())) {
+        return true;
+    }
+    return false;
+}
+
+bool SyntaxLineEdit::event(QEvent *event)
+{
+    if (event->type() == QEvent::ShortcutOverride) {
+        // You can't set time display formats while the display filter edit
+        // has focus.
+
+        // Keep shortcuts in the main window from stealing keyPressEvents
+        // with Ctrl+Alt modifiers from us. This is a problem for many AltGr
+        // combinations since they are delivered with Ctrl+Alt modifiers
+        // instead of Qt::Key_AltGr and they tend to match the time display
+        // format shortcuts.
+
+        // Uncommenting the qDebug line below prints the following here:
+        //
+        // US Keyboard:
+        // Ctrl+o: 79 QFlags<Qt::KeyboardModifiers>(ControlModifier) "\u000F"
+        // Ctrl+Alt+2: 50 QFlags<Qt::KeyboardModifiers>(ControlModifier|AltModifier) "2"
+        //
+        // Swedish (Sweden) Keyboard:
+        // Ctrl+o: 79 QFlags<Qt::KeyboardModifiers>(ControlModifier) "\u000F"
+        // Ctrl+Alt+2: 64 QFlags<Qt::KeyboardModifiers>(ControlModifier|AltModifier) "@"
+        // AltGr+{: 123 QFlags<Qt::KeyboardModifiers>(ControlModifier|AltModifier) "{"
+
+        QKeyEvent* key_event = static_cast<QKeyEvent*>(event);
+        // qDebug() << "=so" << key_event->key() << key_event->modifiers() << key_event->text();
+
+        if (key_event->modifiers() == Qt::KeyboardModifiers(Qt::ControlModifier|Qt::AltModifier)) {
+            event->accept();
+            return true;
+        }
+    }
+    return QLineEdit::event(event);
+}
+
+void SyntaxLineEdit::completionKeyPressEvent(QKeyEvent *event)
+{
+    // Forward to the completer if needed...
+    if (completer_ && completer_->popup()->isVisible()) {
+        switch (event->key()) {
+        case Qt::Key_Enter:
+        case Qt::Key_Return:
+            break;
+        case Qt::Key_Tab:
+            focusNextChild();
+            break;
+        case Qt::Key_Escape:
+        case Qt::Key_Backtab:
+            event->ignore();
+            return;
+        default:
+            break;
+        }
+    }
+
+    // ...otherwise process the key ourselves.
+    SyntaxLineEdit::keyPressEvent(event);
+
+    if (!completion_enabled_ || !completer_ || !completion_model_ || !prefs.gui_autocomplete_filter) return;
+
+    // Do nothing on bare shift.
+    if ((event->modifiers() & Qt::ShiftModifier) && event->text().isEmpty()) return;
+
+    if (event->modifiers() & (Qt::ControlModifier | Qt::AltModifier | Qt::MetaModifier)) {
+        completer_->popup()->hide();
+        return;
+    }
+
+    QStringList sentence(splitLineUnderCursor());
+    Q_ASSERT(sentence.size() == 2);     // (preamble, token)
+    buildCompletionList(sentence[1] /* token */, sentence[0] /* preamble */);
+
+    if (completion_model_->stringList().length() < 1) {
+        completer_->popup()->hide();
+        return;
+    }
+
+    QRect cr = cursorRect();
+    cr.setWidth(completer_->popup()->sizeHintForColumn(0)
+                + completer_->popup()->verticalScrollBar()->sizeHint().width());
+    completer_->complete(cr);
+}
+
+void SyntaxLineEdit::completionFocusInEvent(QFocusEvent *event)
+{
+    if (completer_)
+        completer_->setWidget(this);
+    SyntaxLineEdit::focusInEvent(event);
+}
+
+void SyntaxLineEdit::focusOutEvent(QFocusEvent *event)
+{
+    if (completer_ && completer_->popup()->isVisible() && event->reason() == Qt::PopupFocusReason) {
+        // Pretend we still have focus so that we'll draw our cursor.
+        // If cursorRect() were more precise we could just draw the cursor
+        // during a paintEvent.
+        return;
+    }
+    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)
+{
+    QStyleOptionFrame opt;
+    initStyleOption(&opt);
+    QRect cr = style()->subElementRect(QStyle::SE_LineEditContents, &opt, this);
+    QPainter painter(this);
+
+    // In my (gcc) testing here, if I add "background: yellow;" to the DisplayFilterCombo
+    // stylesheet, when building with Qt 5.15.2 the combobox background is yellow and the
+    // text entry area (between the bookmark and apply button) is drawn in the correct
+    // base color (white for light mode and black for dark mode), and the correct syntax
+    // color otherwise. When building with Qt 6.2.4 and 6.3.1, the combobox background is
+    // yellow and the text entry area is always yellow, i.e. QLineEdit isn't painting its
+    // background for some reason.
+    //
+    // It's not clear if this is a bug or just how things work under Qt6. Either way, it's
+    // easy to work around.
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    // Must match CaptureFilterEdit and DisplayFilterEdit stylesheets.
+    int pad = style()->pixelMetric(QStyle::PM_DefaultFrameWidth) + 1;
+    QRect full_cr = cr.adjusted(-pad, 0, -1, 0);
+    QBrush bg;
+
+    switch (syntax_state_) {
+    case Valid:
+        bg = ColorUtils::fromColorT(&prefs.gui_text_valid);
+        break;
+    case Invalid:
+        bg = ColorUtils::fromColorT(&prefs.gui_text_invalid);
+        break;
+    case Deprecated:
+        bg = ColorUtils::fromColorT(&prefs.gui_text_deprecated);
+        break;
+    default:
+        bg = palette().base();
+        break;
+    }
+
+    painter.fillRect(full_cr, bg);
+#endif
+
+    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;
+    }
+
+    QRect sir = QRect(0, 0, 14, 14); // QIcon::paint scales, which is not what we want.
+    int textWidth = fontMetrics().boundingRect(text()).width();
+    // Qt always adds a margin of 6px between the border and text, see
+    // QLineEditPrivate::effectiveLeftTextMargin and
+    // QLineEditPrivate::sideWidgetParameters.
+    int margin = 2 * 6 + 1;
+
+    if (cr.width() - margin - textWidth < sir.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(cr.top() + si_off);
+    sir.moveRight(cr.right() - si_off);
+    painter.save();
+    painter.setOpacity(0.25);
+    state_icon.paint(&painter, sir);
+    painter.restore();
+}
+
+void SyntaxLineEdit::insertFieldCompletion(const QString &completion_text)
+{
+    if (!completer_) return;
+
+    QPoint field_coords(getTokenUnderCursor());
+
+    // Insert only if we have a matching field or if the entry is empty
+    if (field_coords.y() < 1 && !text().isEmpty()) {
+        completer_->popup()->hide();
+        return;
+    }
+
+    QString new_text = text().replace(field_coords.x(), field_coords.y(), completion_text);
+    setText(new_text);
+    setCursorPosition(field_coords.x() + static_cast<int>(completion_text.length()));
+    emit textEdited(new_text);
+}
+
+QPoint SyntaxLineEdit::getTokenUnderCursor()
+{
+    if (selectionStart() >= 0) return (QPoint(0,0));
+
+    int pos = cursorPosition();
+    int start = pos;
+    int len = 0;
+
+    while (start > 0 && token_chars_.contains(text().at(start -1))) {
+        start--;
+        len++;
+    }
+    while (pos < text().length() && token_chars_.contains(text().at(pos))) {
+        pos++;
+        len++;
+    }
+
+    return QPoint(start, len);
+}
+
+QStringList SyntaxLineEdit::splitLineUnderCursor()
+{
+    QPoint token_coords(getTokenUnderCursor());
+
+    // Split line into preamble and word under cursor.
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+    QString preamble = text().first(token_coords.x()).trimmed();
+#else
+    QString preamble = text().mid(0, token_coords.x()).trimmed();
+#endif
+    // This should be trimmed already
+    QString token_word = text().mid(token_coords.x(), token_coords.y());
+
+    return QStringList{ preamble, token_word };
+}