linux: use screenshot portal for Wayland QR scanning

Author: waozixyz

CMakeLists.txt

@@ -131,6 +131,10 @@ set(QT5_LIBRARIES
   Qt5Xml
 )
 
+if(UNIX AND NOT APPLE AND NOT ANDROID)
+  list(APPEND QT5_LIBRARIES Qt5DBus)
+endif()
+
 if(WITH_SCANNER)
   list(APPEND QT5_LIBRARIES Qt5Multimedia)
 endif()
@@ -316,6 +320,11 @@ if(STATIC)
     pkg_check_modules(FONTCONFIG REQUIRED fontconfig)
     list(APPEND QT5_LIBRARIES ${FONTCONFIG_STATIC_LIBRARIES})
   endif()
+
+  if(UNIX AND NOT APPLE AND NOT ANDROID)
+    pkg_check_modules(DBUS1_PKG_CONFIG REQUIRED dbus-1)
+    list(APPEND QT5_LIBRARIES ${DBUS1_PKG_CONFIG_STATIC_LIBRARIES} ${DBUS1_PKG_CONFIG_STATIC_LDFLAGS_OTHER})
+  endif()
 endif()
 
 if(ANDROID)

Dockerfile.linux

@@ -9,10 +9,19 @@ ENV CXXFLAGS="-fPIC"
 ENV SOURCE_DATE_EPOCH=1397818193
 
 RUN apt update && \
-    apt install -y automake autopoint bison gettext git gperf libgl1-mesa-dev libglib2.0-dev \
+    apt install -y autoconf-archive automake autopoint bison gettext git gperf libexpat1-dev libgl1-mesa-dev libglib2.0-dev \
     libpng-dev libpthread-stubs0-dev libsodium-dev libtool-bin libudev-dev libusb-1.0-0-dev mesa-common-dev \
     pkg-config python wget xutils-dev
 
+RUN git clone -b dbus-1.12.2 --depth 1 https://gitlab.freedesktop.org/dbus/dbus.git && \
+    cd dbus && \
+    git reset --hard 0f0968336b9711349023e1d41f075b2bccf7c20b && \
+    ./autogen.sh && \
+    ./configure --disable-shared --enable-static --disable-systemd --disable-launchd --disable-selinux --disable-apparmor --disable-libaudit --disable-xml-docs --disable-doxygen-docs --disable-ducktype-docs --disable-modular-tests --disable-embedded-tests --disable-x11-autolaunch --without-x --with-systemdsystemunitdir=no --with-systemduserunitdir=no && \
+    make -j$THREADS && \
+    make -j$THREADS install && \
+    rm -rf $(pwd)
+
 RUN git clone -b xorgproto-2020.1 --depth 1 https://gitlab.freedesktop.org/xorg/proto/xorgproto && \
     cd xorgproto && \
     git reset --hard c62e8203402cafafa5ba0357b6d1c019156c9f36 && \
@@ -198,7 +207,7 @@ RUN rm /usr/lib/x86_64-linux-gnu/libX11.a && \
     sed -i s/\\/usr\\/X11R6\\/lib64/\\/usr\\/local\\/lib/ qtbase/mkspecs/linux-g++-64/qmake.conf && \
     ./configure --prefix=/usr -platform linux-g++-64 -opensource -confirm-license -release -static -no-avx \
     -opengl desktop -qpa xcb -xcb -xcb-xlib -feature-xlib -system-freetype -fontconfig -glib \
-    -no-dbus -no-feature-qml-worker-script -no-linuxfb -no-openssl -no-sql-sqlite -no-kms -no-use-gold-linker \
+    -no-feature-qml-worker-script -no-linuxfb -no-openssl -no-sql-sqlite -no-kms -no-use-gold-linker \
     -qt-harfbuzz -qt-libjpeg -qt-libpng -qt-pcre -qt-zlib \
     -skip qt3d -skip qtandroidextras -skip qtcanvas3d -skip qtcharts -skip qtconnectivity -skip qtdatavis3d \
     -skip qtdoc -skip qtgamepad -skip qtlocation -skip qtmacextras -skip qtnetworkauth -skip qtpurchasing \

src/main/oshelper.cpp

@@ -61,6 +61,14 @@
 #undef FocusOut
 // #undef those Xlib #defines that conflict with QEvent::Type enum
 #include "qt/utils.h"
+#include <QDBusConnection>
+#include <QDBusError>
+#include <QDBusInterface>
+#include <QDBusObjectPath>
+#include <QDBusPendingReply>
+#include <QDBusVariant>
+#include <QEventLoop>
+#include <QTimer>
 #endif
 
 #include "QR-Code-scanner/Decoder.h"
@@ -70,7 +78,7 @@
 namespace
 {
 
-QPixmap screenshot()
+std::unordered_set<QWindow *> hideVisibleWindows()
 {
     std::unordered_set<QWindow *> hidden;
     const QWindowList windows = QGuiApplication::allWindows();
@@ -82,16 +90,43 @@ QPixmap screenshot()
             window->hide();
         }
     }
-    const auto unhide = sg::make_scope_guard([&hidden]() {
-        for (QWindow *window : hidden)
-        {
-            window->show();
-        }
-    });
+    return hidden;
+}
 
-    return QGuiApplication::primaryScreen()->grabWindow(0);
+void showWindows(const std::unordered_set<QWindow *> &windows)
+{
+    for (QWindow *window : windows)
+    {
+        window->show();
+    }
 }
 
+#if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
+bool isWayland()
+{
+    if (QGuiApplication::platformName().contains("wayland", Qt::CaseInsensitive))
+    {
+        return true;
+    }
+
+    if (!qEnvironmentVariableIsEmpty("WAYLAND_DISPLAY"))
+    {
+        return true;
+    }
+
+    return QString::fromLocal8Bit(qgetenv("XDG_SESSION_TYPE")).compare(QStringLiteral("wayland"), Qt::CaseInsensitive) == 0;
+}
+
+QVariant unwrapDbusVariant(const QVariant &value)
+{
+    if (value.canConvert<QDBusVariant>())
+    {
+        return value.value<QDBusVariant>().variant();
+    }
+    return value;
+}
+#endif
+
 } // namespace
 
 #if defined(Q_OS_WIN)
@@ -126,6 +161,129 @@ OSHelper::OSHelper(QObject *parent) : QObject(parent)
 
 }
 
+#if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
+void OSHelper::resetScreenshotPortalResponse()
+{
+    m_screenshotPortalResponseReceived = false;
+    m_screenshotPortalResponse = 1;
+    m_screenshotPortalResults.clear();
+}
+
+void OSHelper::handleScreenshotPortalResponse(uint responseCode, const QVariantMap &responseResults)
+{
+    m_screenshotPortalResponseReceived = true;
+    m_screenshotPortalResponse = responseCode;
+    m_screenshotPortalResults = responseResults;
+    emit screenshotPortalResponseReceived();
+}
+
+QImage OSHelper::screenshotPortal()
+{
+    QDBusInterface portal(
+        QStringLiteral("org.freedesktop.portal.Desktop"),
+        QStringLiteral("/org/freedesktop/portal/desktop"),
+        QStringLiteral("org.freedesktop.portal.Screenshot"),
+        QDBusConnection::sessionBus());
+    if (!portal.isValid())
+    {
+        qWarning() << "XDG screenshot portal is unavailable:" << QDBusConnection::sessionBus().lastError().message();
+        return QImage();
+    }
+
+    QVariantMap options;
+    options.insert(QStringLiteral("interactive"), true);
+    options.insert(QStringLiteral("modal"), true);
+
+    QDBusPendingReply<QDBusObjectPath> reply = portal.asyncCallWithArgumentList(
+        QStringLiteral("Screenshot"),
+        QVariantList{QString(), options});
+    reply.waitForFinished();
+    if (reply.isError())
+    {
+        qWarning() << "XDG screenshot portal request failed:" << reply.error().message();
+        return QImage();
+    }
+
+    resetScreenshotPortalResponse();
+
+    const QDBusObjectPath requestPath = reply.value();
+    if (!QDBusConnection::sessionBus().connect(
+            QStringLiteral("org.freedesktop.portal.Desktop"),
+            requestPath.path(),
+            QStringLiteral("org.freedesktop.portal.Request"),
+            QStringLiteral("Response"),
+            this,
+            SLOT(handleScreenshotPortalResponse(uint,QVariantMap))))
+    {
+        qWarning() << "Failed to connect to XDG screenshot portal response";
+        return QImage();
+    }
+
+    QEventLoop loop;
+    QTimer timer;
+    timer.setSingleShot(true);
+    QObject::connect(this, SIGNAL(screenshotPortalResponseReceived()), &loop, SLOT(quit()));
+    QObject::connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit()));
+    timer.start(60000);
+
+    if (!m_screenshotPortalResponseReceived)
+    {
+        loop.exec();
+    }
+
+    QDBusConnection::sessionBus().disconnect(
+        QStringLiteral("org.freedesktop.portal.Desktop"),
+        requestPath.path(),
+        QStringLiteral("org.freedesktop.portal.Request"),
+        QStringLiteral("Response"),
+        this,
+        SLOT(handleScreenshotPortalResponse(uint,QVariantMap)));
+
+    if (!m_screenshotPortalResponseReceived)
+    {
+        qWarning() << "Timed out waiting for XDG screenshot portal response";
+        return QImage();
+    }
+    if (m_screenshotPortalResponse != 0)
+    {
+        qWarning() << "XDG screenshot portal request was not approved:" << m_screenshotPortalResponse;
+        return QImage();
+    }
+
+    const QVariant uriValue = unwrapDbusVariant(m_screenshotPortalResults.value(QStringLiteral("uri")));
+    const QUrl uri(uriValue.toString());
+    if (!uri.isLocalFile())
+    {
+        qWarning() << "XDG screenshot portal returned an unsupported URI:" << uri;
+        return QImage();
+    }
+
+    QImage image(uri.toLocalFile());
+    if (image.isNull())
+    {
+        qWarning() << "Failed to load XDG screenshot portal image:" << uri;
+    }
+    return image;
+}
+#endif
+
+QImage OSHelper::screenshot()
+{
+    const std::unordered_set<QWindow *> hidden = hideVisibleWindows();
+    const auto unhide = sg::make_scope_guard([&hidden]() {
+        showWindows(hidden);
+    });
+
+#if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
+    if (isWayland())
+    {
+        return screenshotPortal();
+    }
+#endif
+
+    return QGuiApplication::primaryScreen()->grabWindow(0).toImage();
+}
+
 void OSHelper::createDesktopEntry() const
 {
 #if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
@@ -138,13 +296,18 @@ QString OSHelper::downloadLocation() const
     return QStandardPaths::writableLocation(QStandardPaths::DownloadLocation);
 }
 
-QList<QString> OSHelper::grabQrCodesFromScreen() const
+QList<QString> OSHelper::grabQrCodesFromScreen()
 {
     QList<QString> codes;
 
     try
     {
-        const QImage image = screenshot().toImage();
+        const QImage image = screenshot();
+        if (image.isNull())
+        {
+            return codes;
+        }
+
         const std::vector<std::string> decoded = QrDecoder().decode(image);
         std::for_each(decoded.begin(), decoded.end(), [&codes](const std::string &code) {
             codes.push_back(QString::fromStdString(code));

src/main/oshelper.h

@@ -30,8 +30,12 @@
 #define OSHELPER_H
 
 #include <QList>
+#include <QImage>
 #include <QObject>
 #include <QString>
+#if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
+#include <QVariantMap>
+#endif
 /**
  * @brief The OSHelper class - exports to QML some OS-related functions
  */
@@ -45,7 +49,7 @@ class OSHelper : public QObject
 
     Q_INVOKABLE void createDesktopEntry() const;
     Q_INVOKABLE QString downloadLocation() const;
-    Q_INVOKABLE QList<QString> grabQrCodesFromScreen() const;
+    Q_INVOKABLE QList<QString> grabQrCodesFromScreen();
     Q_INVOKABLE bool openFile(const QString &filePath) const;
     Q_INVOKABLE bool openContainingFolder(const QString &filePath) const;
     Q_INVOKABLE QString openSaveFileDialog(const QString &title, const QString &folder, const QString &filename) const;
@@ -61,10 +65,25 @@ class OSHelper : public QObject
 
     static std::pair<quint8, QString> getNetworkTypeAndAddressFromFile(const QString &wallet);
 private:
+    QImage screenshot();
+#if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
+    QImage screenshotPortal();
+    void resetScreenshotPortalResponse();
+
+    bool m_screenshotPortalResponseReceived = false;
+    uint m_screenshotPortalResponse = 1;
+    QVariantMap m_screenshotPortalResults;
+#endif
 
 signals:
+#if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
+    void screenshotPortalResponseReceived();
+#endif
 
-public slots:
+private slots:
+#if defined(Q_OS_LINUX) && !defined(Q_OS_ANDROID)
+    void handleScreenshotPortalResponse(uint responseCode, const QVariantMap &responseResults);
+#endif
 };
 
 #endif // OSHELPER_H