From b646c7b76c7787cff57bca0fde04d9f58abdfbb8 Mon Sep 17 00:00:00 2001 From: Harald Sitter Date: Mon, 11 Jul 2022 14:45:40 +0200 Subject: add color picking support on wayland using the XDG desktop portal On wayland applications are not trusted to perform screen grabs by default, it is however possible to let the user specifically pick the color of a pixel using the XDG desktop portal (otherwise used for sandboxing etc.). Try to use this portal on unix systems by default. To support this use case some extra abstraction is necessary as this constitutes a platformservice rather than a platform feature. To that end the QPlatformService has gained a capability system and a pure virtual helper class to facilitate asynchronous color picking. When supported the color picking capability takes precedence over the custom picking code in QColorDialog. Fixes: QTBUG-81538 Change-Id: I4acb3af11d459e9d5ebefe5abbb41e50e3ccf7f0 Reviewed-by: Thiago Macieira --- src/gui/platform/unix/qgenericunixservices.cpp | 143 +++++++++++++++++++++++++ 1 file changed, 143 insertions(+) (limited to 'src/gui/platform/unix/qgenericunixservices.cpp') diff --git a/src/gui/platform/unix/qgenericunixservices.cpp b/src/gui/platform/unix/qgenericunixservices.cpp index 54a0406cab3..eb66e5b1a4d 100644 --- a/src/gui/platform/unix/qgenericunixservices.cpp +++ b/src/gui/platform/unix/qgenericunixservices.cpp @@ -257,8 +257,132 @@ static inline QDBusMessage xdgDesktopPortalSendEmail(const QUrl &url, const QStr return QDBusConnection::sessionBus().call(message); } + +namespace { +struct XDGDesktopColor +{ + double r = 0; + double g = 0; + double b = 0; + + QColor toQColor() const + { + constexpr auto rgbMax = 255; + return { static_cast(r * rgbMax), static_cast(g * rgbMax), + static_cast(b * rgbMax) }; + } +}; + +const QDBusArgument &operator>>(const QDBusArgument &argument, XDGDesktopColor &myStruct) +{ + argument.beginStructure(); + argument >> myStruct.r >> myStruct.g >> myStruct.b; + argument.endStructure(); + return argument; +} + +class XdgDesktopPortalColorPicker : public QPlatformServiceColorPicker +{ + Q_OBJECT +public: + XdgDesktopPortalColorPicker(const QString &parentWindowId, QWindow *parent) + : QPlatformServiceColorPicker(parent), m_parentWindowId(parentWindowId) + { + } + + void pickColor() override + { + // DBus signature: + // PickColor (IN s parent_window, + // IN a{sv} options + // OUT o handle) + // Options: + // handle_token (s) - A string that will be used as the last element of the @handle. + + QDBusMessage message = QDBusMessage::createMethodCall( + "org.freedesktop.portal.Desktop"_L1, "/org/freedesktop/portal/desktop"_L1, + "org.freedesktop.portal.Screenshot"_L1, "PickColor"_L1); + message << m_parentWindowId << QVariantMap(); + + QDBusPendingCall pendingCall = QDBusConnection::sessionBus().asyncCall(message); + auto watcher = new QDBusPendingCallWatcher(pendingCall, this); + connect(watcher, &QDBusPendingCallWatcher::finished, this, + [this](QDBusPendingCallWatcher *watcher) { + watcher->deleteLater(); + QDBusPendingReply reply = *watcher; + if (reply.isError()) { + qWarning("DBus call to pick color failed: %s", + qPrintable(reply.error().message())); + Q_EMIT colorPicked({}); + } else { + QDBusConnection::sessionBus().connect( + "org.freedesktop.portal.Desktop"_L1, reply.value().path(), + "org.freedesktop.portal.Request"_L1, "Response"_L1, this, + // clang-format off + SLOT(gotColorResponse(uint,QVariantMap)) + // clang-format on + ); + } + }); + } + +private Q_SLOTS: + void gotColorResponse(uint result, const QVariantMap &map) + { + if (result != 0) + return; + XDGDesktopColor color{}; + map.value(u"color"_s).value() >> color; + Q_EMIT colorPicked(color.toQColor()); + deleteLater(); + } + +private: + const QString m_parentWindowId; +}; +} // namespace + #endif // QT_CONFIG(dbus) +QGenericUnixServices::QGenericUnixServices() +{ +#if QT_CONFIG(dbus) + QDBusMessage message = QDBusMessage::createMethodCall( + "org.freedesktop.portal.Desktop"_L1, "/org/freedesktop/portal/desktop"_L1, + "org.freedesktop.DBus.Properties"_L1, "Get"_L1); + message << "org.freedesktop.portal.Screenshot"_L1 + << "version"_L1; + + QDBusPendingCall pendingCall = QDBusConnection::sessionBus().asyncCall(message); + auto watcher = new QDBusPendingCallWatcher(pendingCall); + QObject::connect(watcher, &QDBusPendingCallWatcher::finished, watcher, + [this](QDBusPendingCallWatcher *watcher) { + watcher->deleteLater(); + QDBusPendingReply reply = *watcher; + if (!reply.isError() && reply.value().toUInt() >= 2) + m_hasScreenshotPortalWithColorPicking = true; + }); + +#endif +} + +QPlatformServiceColorPicker *QGenericUnixServices::colorPicker(QWindow *parent) +{ +#if QT_CONFIG(dbus) + // Make double sure that we are in a wayland environment. In particular check + // WAYLAND_DISPLAY so also XWayland apps benefit from portal-based color picking. + // Outside wayland we'll rather rely on other means than the XDG desktop portal. + if (!qEnvironmentVariableIsEmpty("WAYLAND_DISPLAY") + || QGuiApplication::platformName().startsWith("wayland"_L1)) { + return new XdgDesktopPortalColorPicker(portalWindowIdentifier(parent), parent); + } + return nullptr; +#else + Q_UNUSED(parent); + return nullptr; +#endif +} + QByteArray QGenericUnixServices::desktopEnvironment() const { static const QByteArray result = detectDesktopEnvironment(); @@ -322,6 +446,8 @@ bool QGenericUnixServices::openDocument(const QUrl &url) } #else +QGenericUnixServices::QGenericUnixServices() = default; + QByteArray QGenericUnixServices::desktopEnvironment() const { return QByteArrayLiteral("UNKNOWN"); @@ -341,6 +467,12 @@ bool QGenericUnixServices::openDocument(const QUrl &url) return false; } +QPlatformServiceColorPicker *QGenericUnixServices::colorPicker(QWindow *parent) +{ + Q_UNUSED(parent); + return nullptr; +} + #endif // QT_NO_MULTIPROCESS QString QGenericUnixServices::portalWindowIdentifier(QWindow *window) @@ -351,4 +483,15 @@ QString QGenericUnixServices::portalWindowIdentifier(QWindow *window) return QString(); } +bool QGenericUnixServices::hasCapability(Capability capability) const +{ + switch (capability) { + case Capability::ColorPicking: + return m_hasScreenshotPortalWithColorPicking; + } + return false; +} + QT_END_NAMESPACE + +#include "qgenericunixservices.moc" -- cgit v1.2.3