Provide a handle for desktop portal via xdg-exporter

Change-Id: I6b2034c1833ae497ef05af7c377e4bfd3747b6fe
Reviewed-by: David Edmundson <davidedmundson@kde.org>

src/3rdparty/wayland/protocols/qt_attribution.json

@@ -301,5 +301,22 @@
         "License": "MIT License",
         "LicenseFile": "MIT_LICENSE.txt",
         "Copyright": "Copyright © 2013, 2014 Collabora, Ltd."
-     }
+     },
+
+    {
+        "Id": "xdg-foreign-unstable-v2",
+        "Name": "Wayland XDG Foreign Protocol",
+        "QDocModule": "qtwaylandcompositor",
+        "QtUsage": "Used in the Qt Wayland platform plugin",
+        "Files": "xdg-foreign-unstable-v2.xml",
+
+        "Description": "Allows referencing surfaces of different clients",
+        "Homepage": "https://wayland.freedesktop.org",
+        "Version": "1",
+        "DownloadLocation": "https://gitlab.freedesktop.org/wayland/wayland-protocols/-/raw/1.25/unstable/xdg-foreign/xdg-foreign-unstable-v2.xml",
+        "LicenseId": "MIT",
+        "License": "MIT License",
+        "LicenseFile": "MIT_LICENSE.txt",
+        "Copyright": "Copyright © 2015-2016 Red Hat Inc."
+     },
 ]

src/3rdparty/wayland/protocols/xdg-foreign-unstable-v2.xml

@@ -0,0 +1,200 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="xdg_foreign_unstable_v2">
+
+  <copyright>
+    Copyright © 2015-2016 Red Hat Inc.
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice (including the next
+    paragraph) shall be included in all copies or substantial portions of the
+    Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+  </copyright>
+
+  <description summary="Protocol for exporting xdg surface handles">
+    This protocol specifies a way for making it possible to reference a surface
+    of a different client. With such a reference, a client can, by using the
+    interfaces provided by this protocol, manipulate the relationship between
+    its own surfaces and the surface of some other client. For example, stack
+    some of its own surface above the other clients surface.
+
+    In order for a client A to get a reference of a surface of client B, client
+    B must first export its surface using xdg_exporter.export_toplevel. Upon
+    doing this, client B will receive a handle (a unique string) that it may
+    share with client A in some way (for example D-Bus). After client A has
+    received the handle from client B, it may use xdg_importer.import_toplevel
+    to create a reference to the surface client B just exported. See the
+    corresponding requests for details.
+
+    A possible use case for this is out-of-process dialogs. For example when a
+    sandboxed client without file system access needs the user to select a file
+    on the file system, given sandbox environment support, it can export its
+    surface, passing the exported surface handle to an unsandboxed process that
+    can show a file browser dialog and stack it above the sandboxed client's
+    surface.
+
+    Warning! The protocol described in this file is experimental and backward
+    incompatible changes may be made. Backward compatible changes may be added
+    together with the corresponding interface version bump. Backward
+    incompatible changes are done by bumping the version number in the protocol
+    and interface names and resetting the interface version. Once the protocol
+    is to be declared stable, the 'z' prefix and the version number in the
+    protocol and interface names are removed and the interface version number is
+    reset.
+  </description>
+
+  <interface name="zxdg_exporter_v2" version="1">
+    <description summary="interface for exporting surfaces">
+      A global interface used for exporting surfaces that can later be imported
+      using xdg_importer.
+    </description>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the xdg_exporter object">
+	Notify the compositor that the xdg_exporter object will no longer be
+	used.
+      </description>
+    </request>
+
+    <enum name="error">
+      <description summary="error values">
+        These errors can be emitted in response to invalid xdg_exporter
+        requests.
+      </description>
+      <entry name="invalid_surface" value="0" summary="surface is not an xdg_toplevel"/>
+    </enum>
+
+    <request name="export_toplevel">
+      <description summary="export a toplevel surface">
+	The export_toplevel request exports the passed surface so that it can later be
+	imported via xdg_importer. When called, a new xdg_exported object will
+	be created and xdg_exported.handle will be sent immediately. See the
+	corresponding interface and event for details.
+
+	A surface may be exported multiple times, and each exported handle may
+	be used to create an xdg_imported multiple times. Only xdg_toplevel
+        equivalent surfaces may be exported, otherwise an invalid_surface
+        protocol error is sent.
+      </description>
+      <arg name="id" type="new_id" interface="zxdg_exported_v2"
+	   summary="the new xdg_exported object"/>
+      <arg name="surface" type="object" interface="wl_surface"
+	   summary="the surface to export"/>
+    </request>
+  </interface>
+
+  <interface name="zxdg_importer_v2" version="1">
+    <description summary="interface for importing surfaces">
+      A global interface used for importing surfaces exported by xdg_exporter.
+      With this interface, a client can create a reference to a surface of
+      another client.
+    </description>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the xdg_importer object">
+	Notify the compositor that the xdg_importer object will no longer be
+	used.
+      </description>
+    </request>
+
+    <request name="import_toplevel">
+      <description summary="import a toplevel surface">
+	The import_toplevel request imports a surface from any client given a handle
+	retrieved by exporting said surface using xdg_exporter.export_toplevel.
+	When called, a new xdg_imported object will be created. This new object
+	represents the imported surface, and the importing client can
+	manipulate its relationship using it. See xdg_imported for details.
+      </description>
+      <arg name="id" type="new_id" interface="zxdg_imported_v2"
+	   summary="the new xdg_imported object"/>
+      <arg name="handle" type="string"
+	   summary="the exported surface handle"/>
+    </request>
+  </interface>
+
+  <interface name="zxdg_exported_v2" version="1">
+    <description summary="an exported surface handle">
+      An xdg_exported object represents an exported reference to a surface. The
+      exported surface may be referenced as long as the xdg_exported object not
+      destroyed. Destroying the xdg_exported invalidates any relationship the
+      importer may have established using xdg_imported.
+    </description>
+
+    <request name="destroy" type="destructor">
+      <description summary="unexport the exported surface">
+	Revoke the previously exported surface. This invalidates any
+	relationship the importer may have set up using the xdg_imported created
+	given the handle sent via xdg_exported.handle.
+      </description>
+    </request>
+
+    <event name="handle">
+      <description summary="the exported surface handle">
+	The handle event contains the unique handle of this exported surface
+	reference. It may be shared with any client, which then can use it to
+	import the surface by calling xdg_importer.import_toplevel. A handle
+	may be used to import the surface multiple times.
+      </description>
+      <arg name="handle" type="string" summary="the exported surface handle"/>
+    </event>
+  </interface>
+
+  <interface name="zxdg_imported_v2" version="1">
+    <description summary="an imported surface handle">
+      An xdg_imported object represents an imported reference to surface exported
+      by some client. A client can use this interface to manipulate
+      relationships between its own surfaces and the imported surface.
+    </description>
+
+    <enum name="error">
+      <description summary="error values">
+        These errors can be emitted in response to invalid xdg_imported
+        requests.
+      </description>
+      <entry name="invalid_surface" value="0" summary="surface is not an xdg_toplevel"/>
+    </enum>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the xdg_imported object">
+	Notify the compositor that it will no longer use the xdg_imported
+	object. Any relationship that may have been set up will at this point
+	be invalidated.
+      </description>
+    </request>
+
+    <request name="set_parent_of">
+      <description summary="set as the parent of some surface">
+        Set the imported surface as the parent of some surface of the client.
+        The passed surface must be an xdg_toplevel equivalent, otherwise an
+        invalid_surface protocol error is sent. Calling this function sets up
+        a surface to surface relation with the same stacking and positioning
+        semantics as xdg_toplevel.set_parent.
+      </description>
+      <arg name="surface" type="object" interface="wl_surface"
+	   summary="the child surface"/>
+    </request>
+
+    <event name="destroyed">
+      <description summary="the imported surface handle has been destroyed">
+	The imported surface handle has been destroyed and any relationship set
+	up has been invalidated. This may happen for various reasons, for
+	example if the exported surface or the exported surface handle has been
+	destroyed, if the handle used for importing was invalid.
+      </description>
+    </event>
+  </interface>
+
+</protocol>

src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/CMakeLists.txt

@@ -16,6 +16,7 @@ qt_internal_add_plugin(QWaylandXdgShellIntegrationPlugin
         qwaylandxdgactivationv1.cpp qwaylandxdgactivationv1_p.h
         qwaylandxdgshell.cpp qwaylandxdgshell_p.h
         qwaylandxdgshellintegration.cpp qwaylandxdgshellintegration_p.h
+        qwaylandxdgexporterv2.cpp qwaylandxdgexporterv2_p.h
     LIBRARIES
         Qt::Core
         Qt::Gui
@@ -29,6 +30,7 @@ qt6_generate_wayland_protocol_client_sources(QWaylandXdgShellIntegrationPlugin
         ${CMAKE_CURRENT_SOURCE_DIR}/../../../3rdparty/protocol/xdg-decoration-unstable-v1.xml
         ${CMAKE_CURRENT_SOURCE_DIR}/../../../3rdparty/protocol/xdg-shell.xml
         ${CMAKE_CURRENT_SOURCE_DIR}/../../../3rdparty/protocol/xdg-activation-v1.xml
+        ${CMAKE_CURRENT_SOURCE_DIR}/../../../3rdparty/protocol/xdg-foreign-unstable-v2.xml
 )
 
 #### Keys ignored in scope 1:.:.:xdg-shell.pro:<TRUE>:

src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgexporterv2.cpp

@@ -0,0 +1,47 @@
+// Copyright (C) 2022 David Reondo <kde@david-redondo.de>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qwaylandxdgexporterv2_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QtWaylandClient {
+
+QWaylandXdgExportedV2::QWaylandXdgExportedV2(::zxdg_exported_v2 *object)
+    : QtWayland::zxdg_exported_v2(object)
+{
+}
+
+QWaylandXdgExportedV2::~QWaylandXdgExportedV2()
+{
+    destroy();
+}
+
+void QWaylandXdgExportedV2::zxdg_exported_v2_handle(const QString &handle)
+{
+    mHandle = handle;
+}
+
+QString QWaylandXdgExportedV2::handle() const
+{
+    return mHandle;
+}
+
+QWaylandXdgExporterV2::QWaylandXdgExporterV2(wl_registry *registry, uint32_t id, int version)
+    : QtWayland::zxdg_exporter_v2(registry, id, qMin(version, 1))
+{
+}
+
+QWaylandXdgExporterV2::~QWaylandXdgExporterV2()
+{
+    destroy();
+}
+
+QtWaylandClient::QWaylandXdgExportedV2 *QWaylandXdgExporterV2::exportToplevel(wl_surface *surface)
+{
+    return new QWaylandXdgExportedV2(export_toplevel(surface));
+}
+
+}
+
+QT_END_NAMESPACE

src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgexporterv2_p.h

@@ -0,0 +1,50 @@
+// Copyright (C) 2022 David Reondo <kde@david-redondo.de>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QWAYLANDXDGEXPORTERV2_H
+#define QWAYLANDXDGEXPORTERV2_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <qwayland-xdg-foreign-unstable-v2.h>
+
+#include <QtWaylandClient/qtwaylandclientglobal.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QtWaylandClient {
+
+class QWaylandXdgExportedV2 : public QtWayland::zxdg_exported_v2
+{
+public:
+    explicit QWaylandXdgExportedV2(::zxdg_exported_v2 *object);
+    ~QWaylandXdgExportedV2() override;
+    QString handle() const;
+
+private:
+    void zxdg_exported_v2_handle(const QString &handle) override;
+    QString mHandle;
+};
+
+class QWaylandXdgExporterV2 : public QtWayland::zxdg_exporter_v2
+{
+public:
+    QWaylandXdgExporterV2(wl_registry *registry, uint32_t id, int version);
+    ~QWaylandXdgExporterV2() override;
+    QWaylandXdgExportedV2 *exportToplevel(wl_surface *surface);
+};
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QWAYLANDXDGEXPORTERV2_H

src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell.cpp

@@ -4,6 +4,8 @@
 
 #include "qwaylandxdgshell_p.h"
 
+#include "qwaylandxdgexporterv2_p.h"
+
 #include <QtWaylandClient/private/qwaylanddisplay_p.h>
 #include <QtWaylandClient/private/qwaylandwindow_p.h>
 #include <QtWaylandClient/private/qwaylandinputdevice_p.h>
@@ -537,6 +539,19 @@ void QWaylandXdgSurface::setXdgActivationToken(const QString &token)
     }
 }
 
+QString QWaylandXdgSurface::externWindowHandle()
+{
+    if (!m_toplevel || !m_shell->exporter()) {
+        return QString();
+    }
+    if (!m_toplevel->m_exported) {
+        m_toplevel->m_exported.reset(m_shell->exporter()->exportToplevel(m_window->wlSurface()));
+        // handle events is sent immediately
+        m_shell->display()->forceRoundTrip();
+    }
+    return m_toplevel->m_exported->handle();
+}
+
 QWaylandXdgShell::QWaylandXdgShell(QWaylandDisplay *display, uint32_t id, uint32_t availableVersion)
     : QtWayland::xdg_wm_base(display->wl_registry(), id, qMin(availableVersion, 2u))
     , m_display(display)
@@ -570,6 +585,10 @@ void QWaylandXdgShell::handleRegistryGlobal(void *data, wl_registry *registry, u
     if (interface == QLatin1String(QWaylandXdgActivationV1::interface()->name)) {
         xdgShell->m_xdgActivation.reset(new QWaylandXdgActivationV1(registry, id, version));
     }
+
+    if (interface == QLatin1String(QWaylandXdgExporterV2::interface()->name)) {
+        xdgShell->m_xdgExporter.reset(new QWaylandXdgExporterV2(registry, id, version));
+    }
 }
 
 }

src/plugins/platforms/wayland/plugins/shellintegration/xdg-shell/qwaylandxdgshell_p.h

@@ -37,6 +37,8 @@ namespace QtWaylandClient {
 class QWaylandDisplay;
 class QWaylandInputDevice;
 class QWaylandXdgShell;
+class QWaylandXdgExportedV2;
+class QWaylandXdgExporterV2;
 
 class Q_WAYLANDCLIENT_EXPORT QWaylandXdgSurface : public QWaylandShellSurface, public QtWayland::xdg_surface
 {
@@ -62,6 +64,7 @@ public:
     bool requestActivate() override;
     void setXdgActivationToken(const QString &token) override;
     void requestXdgActivationToken(quint32 serial) override;
+    QString externWindowHandle() override;
 
     void setSizeHints();
 
@@ -98,6 +101,7 @@ private:
 
         QWaylandXdgSurface *m_xdgSurface = nullptr;
         QWaylandXdgToplevelDecorationV1 *m_decoration = nullptr;
+        QScopedPointer<QWaylandXdgExportedV2> m_exported;
     };
 
     class Popup : public QtWayland::xdg_popup {
@@ -138,8 +142,11 @@ public:
     QWaylandXdgShell(QWaylandDisplay *display, uint32_t id, uint32_t availableVersion);
     ~QWaylandXdgShell() override;
 
+    QWaylandDisplay *display() const { return m_display; }
+
     QWaylandXdgDecorationManagerV1 *decorationManager() { return m_xdgDecorationManager.data(); }
     QWaylandXdgActivationV1 *activation() const { return m_xdgActivation.data(); }
+    QWaylandXdgExporterV2 *exporter() const { return m_xdgExporter.data(); }
     QWaylandXdgSurface *getXdgSurface(QWaylandWindow *window);
 
 protected:
@@ -152,6 +159,7 @@ private:
     QWaylandDisplay *m_display = nullptr;
     QScopedPointer<QWaylandXdgDecorationManagerV1> m_xdgDecorationManager;
     QScopedPointer<QWaylandXdgActivationV1> m_xdgActivation;
+    QScopedPointer<QWaylandXdgExporterV2> m_xdgExporter;
     QWaylandXdgSurface::Popup *m_topmostGrabbingPopup = nullptr;
 
     friend class QWaylandXdgSurface;

src/plugins/platforms/wayland/qwaylandshellsurface_p.h

@@ -71,6 +71,8 @@ public:
     virtual void setXdgActivationToken(const QString &token);
     virtual void requestXdgActivationToken(quint32 serial);
 
+    virtual QString externWindowHandle() { return QString(); }
+
     inline QWaylandWindow *window() { return m_window; }
     QPlatformWindow *platformWindow();
     struct wl_surface *wlSurface();

src/plugins/platforms/wayland/qwaylandwindowmanagerintegration.cpp

@@ -5,6 +5,7 @@
 #include "qwaylandscreen_p.h"
 #include "qwaylandwindow_p.h"
 #include "qwaylanddisplay_p.h"
+#include "qwaylandshellsurface_p.h"
 
 #include <stdint.h>
 #include <QtCore/QEvent>
@@ -106,6 +107,17 @@ bool QWaylandWindowManagerIntegration::openDocument(const QUrl &url)
     return QGenericUnixServices::openDocument(url);
 }
 
+QString QWaylandWindowManagerIntegration::portalWindowIdentifier(QWindow *window)
+{
+    if (window && window->handle()) {
+        auto shellSurface = static_cast<QWaylandWindow *>(window->handle())->shellSurface();
+        if (shellSurface) {
+            const QString handle = shellSurface->externWindowHandle();
+            return QLatin1String("wayland:") + handle;
+        }
+    }
+    return QString();
+}
 }
 
 QT_END_NAMESPACE

src/plugins/platforms/wayland/qwaylandwindowmanagerintegration_p.h

@@ -42,6 +42,7 @@ public:
 
     bool openUrl(const QUrl &url) override;
     bool openDocument(const QUrl &url) override;
+    QString portalWindowIdentifier(QWindow *window) override;
 
     bool showIsFullScreen() const;