diff --git a/.gitignore b/.gitignore
index 97283cc..04fe903 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,5 @@
 /qtads.pro.user*
 /qrc_resources.cpp
 /.qmake.stash
+.cache
+compile_commands.json
diff --git a/src/confdialog.cc b/src/confdialog.cc
index 196b8ac..e2cd02d 100644
--- a/src/confdialog.cc
+++ b/src/confdialog.cc
@@ -2,6 +2,7 @@
 #include "confdialog.h"
 
 #include "globals.h"
+#include "qstringconverter_base.h"
 #include "settings.h"
 #include "sysframe.h"
 #include "syswingroup.h"
@@ -10,7 +11,9 @@
 #include <QCheckBox>
 #include <QColorDialog>
 #include <QPushButton>
-#include <QTextCodec>
+#include <QStringConverter>
+#include <QStringDecoder>
+#include <QStringEncoder>
 #include <algorithm>
 #include <vector>
 
@@ -40,27 +43,20 @@ ConfDialog::ConfDialog(CHtmlSysWinGroupQt* const parent)
     ui->linkClickedColorButton->setFixedSize(macSize);
 #endif
 
-    const auto aliases = QTextCodec::availableCodecs();
-    std::vector<QByteArray> codecs;
-    for (const auto& alias : aliases) {
-        auto codecName = QTextCodec::codecForName(alias)->name();
-        // Only allow some of the possible sets, otherwise we would get a big
-        // list with most of the encodings being irrelevant.  The only Unicode
-        // encoding we allow is UTF-8, since it's a single-byte character set
-        // and therefore can be used by TADS 2 games (though I'm not aware of
-        // any that actually use UTF-8.)
-        if (codecName == "UTF-8" or codecName.startsWith("windows-") or codecName.startsWith("ISO-")
-            or codecName.startsWith("KOI8-") or codecName.startsWith("IBM")
-            or codecName.startsWith("EUC-") or codecName.startsWith("jisx020")
-            or codecName.startsWith("cp949"))
-        {
-            codecs.emplace_back(std::move(codecName));
-        }
-    }
-    std::sort(codecs.begin(), codecs.end());
+    const QStringConverter::Encoding codecs[9]{
+        QStringConverter::Encoding::System,  QStringConverter::Encoding::Latin1,
+        QStringConverter::Encoding::Utf16,   QStringConverter::Encoding::Utf16BE,
+        QStringConverter::Encoding::Utf16LE, QStringConverter::Encoding::Utf32,
+        QStringConverter::Encoding::Utf32BE, QStringConverter::Encoding::Utf32LE,
+        QStringConverter::Encoding::Utf8,
+    };
     for (const auto& codec : codecs) {
-        if (ui->encodingComboBox->findText(QString::fromLatin1(codec)) == -1) {
-            ui->encodingComboBox->addItem(QString::fromLatin1(codec));
+        if (ui->encodingComboBox->findText(
+                QString::fromLatin1(QStringConverter::nameForEncoding(codec)))
+            == -1)
+        {
+            ui->encodingComboBox->addItem(
+                QString::fromLatin1(QStringConverter::nameForEncoding(codec)));
         }
     }
 
diff --git a/src/kcolorbutton.cc b/src/kcolorbutton.cc
index 88e4a18..cf403eb 100644
--- a/src/kcolorbutton.cc
+++ b/src/kcolorbutton.cc
@@ -232,9 +232,9 @@ void KColorButton::paintEvent(QPaintEvent *)
     if (hasFocus()) {
         QRect focusRect = style->subElementRect(QStyle::SE_PushButtonFocusRect, &butOpt, this);
         QStyleOptionFocusRect focusOpt;
-        focusOpt.init(this);
+        focusOpt.initFrom(this);
         focusOpt.rect            = focusRect;
-        focusOpt.backgroundColor = palette().background().color();
+        focusOpt.backgroundColor = palette().window().color();
         style->drawPrimitive(QStyle::PE_FrameFocusRect, &focusOpt, &painter, this);
     }
 }
@@ -243,16 +243,14 @@ QSize KColorButton::sizeHint() const
 {
     QStyleOptionButton opt;
     d->initStyleOption(&opt);
-    return style()->sizeFromContents(QStyle::CT_PushButton, &opt, QSize(40, 15), this).
-           expandedTo(QApplication::globalStrut());
+    return style()->sizeFromContents(QStyle::CT_PushButton, &opt, QSize(40, 15), this);
 }
 
 QSize KColorButton::minimumSizeHint() const
 {
     QStyleOptionButton opt;
     d->initStyleOption(&opt);
-    return style()->sizeFromContents(QStyle::CT_PushButton, &opt, QSize(3, 3), this).
-           expandedTo(QApplication::globalStrut());
+    return style()->sizeFromContents(QStyle::CT_PushButton, &opt, QSize(3, 3), this);
 }
 
 void KColorButton::dragEnterEvent(QDragEnterEvent *event)
@@ -294,7 +292,7 @@ void KColorButton::mouseMoveEvent(QMouseEvent *e)
 {
     if ((e->buttons() & Qt::LeftButton) &&
             (e->pos() - d->mPos).manhattanLength() > QApplication::startDragDistance()) {
-        _k_createDrag(color(), this)->start();
+        _k_createDrag(color(), this)->exec();
         setDown(false);
     }
 }
diff --git a/src/main.cc b/src/main.cc
index c364fd9..9440a28 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -21,29 +21,63 @@
 auto main(int argc, char** argv) -> int
 {
     CHtmlResType::add_basic_types();
-#if QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    // No need to enable High Dpi scaling because it's always on
+#elif QT_VERSION >= QT_VERSION_CHECK(5, 6, 0)
     QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
 #endif
-    CHtmlSysFrameQt* app = new CHtmlSysFrameQt(
-        argc, argv, "QTads", QTADS_VERSION, "Nikos Chantziaras", {});
+    CHtmlSysFrameQt* app =
+        new CHtmlSysFrameQt(argc, argv, "QTads", QTADS_VERSION, "Nikos Chantziaras", {});
+#if QT_VERSION <= QT_VERSION_CHECK(6, 0, 0)
     QApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
+#endif
 #if QT_VERSION >= QT_VERSION_CHECK(5, 7, 0)
     QApplication::setDesktopFileName("nikos.chantziaras.qtads");
 #endif
 
     // Filename of the game to run.
     QString gameFileName;
+    bool embed = false;
 
     const QStringList& args = app->arguments();
-    if (args.size() == 2) {
-        if (QFile::exists(args.at(1))) {
-            gameFileName = args.at(1);
-        } else if (QFile::exists(args.at(1) + ".gam")) {
-            gameFileName = args.at(1) + ".gam";
-        } else if (QFile::exists(args.at(1) + ".t3")) {
-            gameFileName = args.at(1) + ".t3";
-        } else {
-            qWarning() << "File" << args.at(1) << "not found.";
+    if (args.size() >= 1) {
+        bool prevNonFlagArgument = false;
+
+        for (int i = 1; i < args.size(); ++i) {
+            const auto& arg = args.at(i);
+
+            if (!arg.startsWith("-")) {
+                if (prevNonFlagArgument) {
+                    qWarning() << "It looks like you specified more than one non-flag command-line"
+                               << "argument at" << arg
+                               << "but QTADS can only accept one game file, so only the"
+                               << "first non flag argument will be used.";
+                } else if (gameFileName.isNull()) {
+                    if (QFile::exists(arg)) {
+                        gameFileName = arg;
+                    } else if (QFile::exists(arg + ".gam")) {
+                        gameFileName = arg + ".gam";
+                    } else if (QFile::exists(arg + ".t3")) {
+                        gameFileName = arg + ".t3";
+                    } else {
+                        qWarning() << "File" << arg << "not found.";
+                    }
+                }
+
+                prevNonFlagArgument = true;
+            } else if (arg == "--help" || arg == "-h") {
+                qInfo() << "qtads [OPTIONS] [FILE]\n"
+                        << "\t--help\t\tThis help message\n"
+                        << "\t--embed\t\tPrint out the window id on startup so that qtads can be "
+                           "embedded\n"
+                        << "\t-h\t\tSame as --help\n"
+                        << "\t-e\t\tSame as --embed";
+            } else if (arg == "--embed" || arg == "-e") {
+                embed = true;
+            } else {
+                qWarning() << "Unrecognized command line argument " << arg << ".";
+                return 1;
+            }
         }
     }
 
@@ -60,7 +94,8 @@ auto main(int argc, char** argv) -> int
     }
 #endif
 
-    QTimer::singleShot(0, app, [app, gameFileName] { app->entryPoint(gameFileName); });
+    QTimer::singleShot(
+        0, app, [app, embed, gameFileName] { app->entryPoint(gameFileName, embed); });
     int ret = CHtmlSysFrameQt::exec();
 
     delete app;
diff --git a/src/missing.cc b/src/missing.cc
index 947726f..9e24020 100644
--- a/src/missing.cc
+++ b/src/missing.cc
@@ -1,7 +1,9 @@
 // This is copyrighted software. More information is at the end of this file.
 #include <QDebug>
 #include <QString>
-#include <QTextCodec>
+#include <QStringConverter>
+#include <QStringDecoder>
+#include <QStringEncoder>
 #include <cctype>
 #include <cstdlib>
 #include <cstring>
diff --git a/src/osqt.cc b/src/osqt.cc
index 164715b..9484986 100644
--- a/src/osqt.cc
+++ b/src/osqt.cc
@@ -10,6 +10,7 @@
  */
 
 // Make sure we get vasprintf() from cstdio, which in mingw is a GNU extension.
+#include "qstringconverter_base.h"
 #if defined(__MINGW32__) and not defined(_GNU_SOURCE)
     #define _GNU_SOURCE
     #define GNU_SOURCE_DEFINED
@@ -35,9 +36,11 @@
 #include <QMessageBox>
 #include <QPushButton>
 #include <QStandardPaths>
+#include <QStringConverter>
+#include <QStringDecoder>
+#include <QStringEncoder>
 #include <QSysInfo>
 #include <QTemporaryFile>
-#include <QTextCodec>
 #include <QTimer>
 #include <algorithm>
 #include <chrono>
@@ -615,8 +618,18 @@ auto os_strlwr(char* const s) -> char*
     if (qFrame->tads3()) {
         lower = QString::fromUtf8(s).toLower().toUtf8();
     } else {
-        const auto* const codec = QTextCodec::codecForName(qFrame->settings().tads2Encoding);
-        lower = codec->fromUnicode(codec->toUnicode(s).toLower());
+        auto codec = QStringConverter::encodingForName(qFrame->settings().tads2Encoding);
+        if (codec.has_value()) {
+            QStringEncoder toUnicode{codec.value()};
+            const QByteArray encoded = toUnicode.encode(QString::fromLocal8Bit(s));
+            if (!toUnicode.hasError()) {
+                QStringDecoder fromUnicode{codec.value()};
+                auto decoded = fromUnicode.decode(encoded.toLower());
+                if (!fromUnicode.hasError()) {
+                    lower = decoded.data;
+                }
+            }
+        }
     }
     std::memcpy(s, lower.constData(), lower.size() + 1);
     return s;
@@ -678,7 +691,7 @@ void os_get_special_path(
 
     case OS_GSP_T3_APP_DATA:
     case OS_GSP_LOGFILE: {
-        const auto dirStr = QStandardPaths::writableLocation(QStandardPaths::DataLocation);
+        const auto dirStr = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
         QDir dir(dirStr);
         QByteArray result;
         // Create the directory if it doesn't exist.
@@ -1304,9 +1317,10 @@ auto os_askfile(
         filter += ";;" + QObject::tr("All Files") + " (*)";
     }
 
-    const auto promptStr = qFrame->tads3()
-        ? QString::fromUtf8(prompt)
-        : QTextCodec::codecForName(qFrame->settings().tads2Encoding)->toUnicode(prompt);
+    QStringEncoder toUnicode{
+        QStringConverter::encodingForName(qFrame->settings().tads2Encoding).value()};
+    const auto promptStr = qFrame->tads3() ? QString::fromUtf8(prompt)
+                                           : toUnicode(QString::fromLocal8Bit(prompt)).data;
     const auto filename = prompt_type == OS_AFP_OPEN
         ? QFileDialog::getOpenFileName(qFrame->gameWindow(), promptStr, QDir::currentPath(), filter)
         : QFileDialog::getSaveFileName(
@@ -1358,9 +1372,12 @@ auto os_input_dialog(
     QMessageBox dialog(qWinGroup);
 
     // We'll use that if we're running a T2 game.
-    const auto* const t2Codec = QTextCodec::codecForName(qFrame->settings().tads2Encoding);
+    QStringEncoder t2ToUnicode{
+        QStringConverter::encodingForName(qFrame->settings().tads2Encoding).value()};
 
-    dialog.setText(qFrame->tads3() ? QString::fromUtf8(prompt) : t2Codec->toUnicode(prompt));
+    dialog.setText(
+        qFrame->tads3() ? QString::fromUtf8(prompt)
+                        : t2ToUnicode(QString::fromLocal8Bit(prompt)).data);
 
     switch (icon_id) {
     case OS_INDLG_ICON_NONE:
@@ -1405,8 +1422,9 @@ auto os_input_dialog(
     } else {
         for (int i = 0; i < button_count; ++i) {
             Q_ASSERT(buttons[i] != nullptr);
-            const auto buttonText =
-                qFrame->tads3() ? QString::fromUtf8(buttons[i]) : t2Codec->toUnicode(buttons[i]);
+            const auto buttonText = qFrame->tads3()
+                ? QString::fromUtf8(buttons[i])
+                : t2ToUnicode(QString::fromLocal8Bit(buttons[i])).data;
             buttonList += dialog.addButton(buttonText, QMessageBox::AcceptRole);
         }
     }
diff --git a/src/sysframe.cc b/src/sysframe.cc
index 13f2512..7e646ad 100644
--- a/src/sysframe.cc
+++ b/src/sysframe.cc
@@ -8,10 +8,14 @@
 #include <QMessageBox>
 #include <QScreen>
 #include <QStatusBar>
-#include <QTextCodec>
+#include <QStringConverter>
+#include <QStringDecoder>
+#include <QStringEncoder>
+#include <Qt>
 #include <cstdlib>
 
 #include "gameinfodialog.h"
+#include "qstringconverter_base.h"
 #include "qtadshostifc.h"
 #include "qtadssound.h"
 #include "syswinaboutbox.h"
@@ -335,7 +339,7 @@ bool CHtmlSysFrameQt::event(QEvent* e)
 }
 #endif
 
-void CHtmlSysFrameQt::entryPoint(QString gameFileName)
+void CHtmlSysFrameQt::entryPoint(QString gameFileName, bool embed)
 {
     // Restore the application's size and position.
     if (not fSettings.appGeometry.isEmpty()) {
@@ -344,6 +348,8 @@ void CHtmlSysFrameQt::entryPoint(QString gameFileName)
         auto h = QApplication::primaryScreen()->availableSize().height() / 1.1;
         fMainWin->resize(h, h);
     }
+    if (embed)
+        qInfo() << "WinId: " << fMainWin->winId();
     fMainWin->show();
 
     // Do an online update check.
@@ -392,8 +398,10 @@ static auto find_font_match(const std::vector<QString>& font_names) -> QString
                 return system_font;
             }
             // Also try the font name without the "[foundry]" part.
-            auto clean_font_name = font_name.leftRef(font_name.lastIndexOf('[')).trimmed();
-            auto clean_system_font = system_font.leftRef(system_font.lastIndexOf('[')).trimmed();
+            QStringView font_view{font_name};
+            auto clean_font_name = font_view.left(font_name.lastIndexOf('[')).trimmed();
+            QStringView system_font_view{system_font};
+            auto clean_system_font = system_font_view.left(system_font.lastIndexOf('[')).trimmed();
             if (clean_font_name.compare(clean_system_font, Qt::CaseInsensitive) == 0) {
                 return system_font;
             }
@@ -457,7 +465,7 @@ auto CHtmlSysFrameQt::createFont(const CHtmlFontDesc* font_desc) -> CHtmlSysFont
         // The face name field can contain multiple face names separated by
         // commas.  We split them into a list and try each one individualy.
         const auto strList =
-            QString(QString::fromLatin1(newFontDesc.face)).split(',', QString::SkipEmptyParts);
+            QString(QString::fromLatin1(newFontDesc.face)).split(',', Qt::SkipEmptyParts);
         for (int i = 0; i < strList.size(); ++i) {
             auto s = strList.at(i).simplified().toLower();
             if (s == QString::fromLatin1(HTMLFONT_TADS_SERIF).toLower()) {
@@ -591,8 +599,7 @@ auto CHtmlSysFrameQt::createFont(const CHtmlFontDesc* font_desc) -> CHtmlSysFont
     // Workaround for QTBUG-76908 (wrong font variant is used and is out of sync with font metrics.)
     new_font.setStyleName({});
 
-    new_font.setStyleStrategy(QFont::StyleStrategy(
-        QFont::PreferOutline | QFont::PreferQuality | QFont::ForceIntegerMetrics));
+    new_font.setStyleStrategy(QFont::StyleStrategy(QFont::PreferOutline | QFont::PreferQuality));
     new_font.setUnderline(newFontDesc.underline);
     new_font.setStrikeOut(newFontDesc.strikeout);
     if (use_bold and weight < QFont::Bold) {
@@ -807,8 +814,9 @@ void CHtmlSysFrameQt::display_output(const textchar_t* buf, size_t len)
         fBuffer.append(buf, len);
     } else {
         // TADS 2 does not use UTF-8; use the encoding from our settings.
-        QTextCodec* codec = QTextCodec::codecForName(fSettings.tads2Encoding);
-        fBuffer.append(codec->toUnicode(buf, len).toUtf8().constData());
+        QStringEncoder toUnicode{
+            QStringConverter::encodingForName(fSettings.tads2Encoding).value()};
+        fBuffer.append(toUnicode(QString::fromLocal8Bit(buf, len)).data.toLocal8Bit());
     }
 }
 
@@ -895,9 +903,10 @@ auto CHtmlSysFrameQt::get_input_event(unsigned long timeout, int use_timeout, os
                 info->href, fGameWin->pendingHrefEvent().toUtf8().constData(),
                 sizeof(info->href) - 1);
         } else {
-            QTextCodec* codec = QTextCodec::codecForName(fSettings.tads2Encoding);
+            QStringDecoder fromUnicode{
+                QStringConverter::encodingForName(fSettings.tads2Encoding).value()};
             strncpy(
-                info->href, codec->fromUnicode(fGameWin->pendingHrefEvent()).constData(),
+                info->href, fromUnicode(fGameWin->pendingHrefEvent().toUtf8()).data,
                 sizeof(info->href) - 1);
         }
         info->href[sizeof(info->href) - 1] = '\0';
@@ -1076,7 +1085,7 @@ void CHtmlSysFrameQt::remove_banner_window(CHtmlSysWin* win)
 
 auto CHtmlSysFrameQt::get_exe_resource(
     const textchar_t* /*resname*/, size_t /*resnamelen*/, textchar_t* /*fname_buf*/,
-    size_t /*fname_buf_len*/, unsigned long* /*seek_pos*/, unsigned long * /*siz*/) -> int
+    size_t /*fname_buf_len*/, unsigned long* /*seek_pos*/, unsigned long* /*siz*/) -> int
 {
     // qDebug() << Q_FUNC_INFO;
     // qDebug() << "resname:" << resname << "fname_buf:" << fname_buf << "seek_pos:" << seek_pos;
diff --git a/src/sysframe.h b/src/sysframe.h
index 21ecf9d..26f92d8 100644
--- a/src/sysframe.h
+++ b/src/sysframe.h
@@ -75,6 +75,10 @@ class CHtmlSysFrameQt: public QApplication, public CHtmlSysFrame
 
     int fPendingWaitForKeystrokeCmd = 0;
 
+    // Are we running in embed mode (i.e. do we need to print out our window ID
+    // so another application can capture it?)
+    bool fEmbedMode;
+
     // Run the game file contained in fNextGame.
     void fRunGame();
 
@@ -108,7 +112,7 @@ class CHtmlSysFrameQt: public QApplication, public CHtmlSysFrame
 public slots:
     // Replacement for main().  We need this so that we can start the Tads VM
     // after the QApplication main event loop has started.
-    void entryPoint(QString gameFileName);
+    void entryPoint(QString gameFileName, bool embed = false);
 
 public:
     CHtmlSysFrameQt(
@@ -183,6 +187,11 @@ public slots:
         return fNonStopMode;
     }
 
+    void setEmbedMode(bool fmode)
+    {
+        fEmbedMode = fmode;
+    }
+
     // Recalculate and adjust the sizes of all HTML banners.
     void adjustBannerSizes();
 
diff --git a/src/syswin.cc b/src/syswin.cc
index cfc7a8f..581f8c6 100644
--- a/src/syswin.cc
+++ b/src/syswin.cc
@@ -539,7 +539,7 @@ auto CHtmlSysWinQt::measure_text(CHtmlSysFont* font, const textchar_t* str, size
     // subsequent text should be drawn.  This is really what our caller needs
     // to know, otherwise letters will start jumping left and right when
     // selecting text or moving the text cursor.
-    return {tmpMetr.width(QString::fromUtf8(str, len)), tmpMetr.height()};
+    return {tmpMetr.horizontalAdvance(QString::fromUtf8(str, len)), tmpMetr.height()};
 }
 
 auto CHtmlSysWinQt::get_max_chars_in_width(
@@ -614,7 +614,7 @@ void CHtmlSysWinQt::draw_text_space(int hilite, long x, long y, CHtmlSysFont* fo
     // Construct a string of spaces that's at least 'width' pixels wide.
     QString str(' ');
     const QFontMetrics& metr = painter.fontMetrics();
-    while (metr.width(str) < wid) {
+    while (metr.horizontalAdvance(str) < wid) {
         str.append(' ');
     }
 
diff --git a/src/syswin.h b/src/syswin.h
index 583ff0e..10bc5fb 100644
--- a/src/syswin.h
+++ b/src/syswin.h
@@ -1,8 +1,8 @@
 // This is copyrighted software. More information is at the end of this file.
 #pragma once
 #include <QApplication>
-#include <QDesktopWidget>
 #include <QScrollArea>
+#include <QScreen>
 
 #include "config.h"
 #include "globals.h"
@@ -154,7 +154,7 @@ class CHtmlSysWinQt: public QScrollArea, public CHtmlSysWin
 
     auto get_pix_per_inch() -> long override
     {
-        return QApplication::desktop()->logicalDpiX();
+        return QApplication::primaryScreen()->logicalDotsPerInchX();
     }
 
     auto measure_text(class CHtmlSysFont* font, const textchar_t* str, size_t len, int* ascent)
diff --git a/src/syswininput.cc b/src/syswininput.cc
index 7fba0a7..784ab5e 100644
--- a/src/syswininput.cc
+++ b/src/syswininput.cc
@@ -5,7 +5,9 @@
 #include <QLabel>
 #include <QScrollBar>
 #include <QStatusBar>
-#include <QTextCodec>
+#include <QStringConverter>
+#include <QStringDecoder>
+#include <QStringEncoder>
 #include <QTime>
 #include <QTimer>
 #include <QUrl>
@@ -215,7 +217,8 @@ void CHtmlSysWinInputQt::keyPressEvent(QKeyEvent* e)
         fTadsBuffer.start_of_line(false);
         fCastDispWidget->clearSelection();
     } else if (
-        e->matches(QKeySequence::MoveToEndOfLine) or e->matches(QKeySequence::MoveToEndOfBlock)) {
+        e->matches(QKeySequence::MoveToEndOfLine) or e->matches(QKeySequence::MoveToEndOfBlock))
+    {
         fTadsBuffer.end_of_line(false);
         fCastDispWidget->clearSelection();
     } else if (e->matches(QKeySequence::InsertParagraphSeparator)) {
@@ -285,7 +288,8 @@ void CHtmlSysWinInputQt::keyPressEvent(QKeyEvent* e)
         }
         fTadsBuffer.start_of_line(true);
     } else if (
-        e->matches(QKeySequence::SelectEndOfLine) or e->matches(QKeySequence::SelectEndOfBlock)) {
+        e->matches(QKeySequence::SelectEndOfLine) or e->matches(QKeySequence::SelectEndOfBlock))
+    {
         if (not fTadsBuffer.has_sel_range()) {
             fCastDispWidget->clearSelection();
         }
@@ -326,7 +330,7 @@ void CHtmlSysWinInputQt::inputMethodEvent(QInputMethodEvent* e)
 
     if (fInputMode == SingleKeyInput) {
         fLastKeyEvent = static_cast<Qt::Key>(0);
-        fLastKeyText = 0;
+        fLastKeyText = '\0';
         // If the keypress doesn't correspond to exactly one character, ignore
         // it.
         if (e->commitString().size() != 1) {
@@ -349,7 +353,7 @@ void CHtmlSysWinInputQt::singleKeyPressEvent(QKeyEvent* event)
     Q_ASSERT(fInputMode == SingleKeyInput);
 
     fLastKeyEvent = static_cast<Qt::Key>(0);
-    fLastKeyText = 0;
+    fLastKeyText = '\0';
 
     switch (event->key()) {
     case 0:
@@ -484,11 +488,11 @@ void CHtmlSysWinInputQt::getInput(
     if (qFrame->tads3()) {
         strncpy(buf, fTadsBuffer.getbuf(), len);
     } else {
-        QTextCodec* codec = QTextCodec::codecForName(qFrame->settings().tads2Encoding);
+        QStringDecoder fromUnicode{
+            QStringConverter::encodingForName(qFrame->settings().tads2Encoding).value()};
         strncpy(
             buf,
-            codec->fromUnicode(QString::fromUtf8(fTadsBuffer.getbuf(), fTadsBuffer.getlen()))
-                .constData(),
+            fromUnicode(QByteArray::fromRawData(fTadsBuffer.getbuf(), fTadsBuffer.getlen())).data,
             len);
     }
     buf[len] = '\0';
@@ -681,7 +685,7 @@ auto CHtmlSysWinInputQt::getKeypress(unsigned long timeout, bool useTimeout, boo
         default:
             // If we got here, something went wrong.  Just report a
             // space.
-            qWarning() << Q_FUNC_INFO << "unrecognized key event in switch:" << hex
+            qWarning() << Q_FUNC_INFO << "unrecognized key event in switch:" << Qt::hex
                        << fLastKeyEvent;
             return ' ';
         }