Add a way to have out of source shell integrations

Some platforms (especially non-desktop ones) may use a custom
Wayland shell extension, more tailored to the form factor than
the generic and desktoppy wl_shell or xdg_shell. Instead of stuffing
N protocol implementations in the QPA plugin use a plugin architecture
to allow them to live out of tree.
When creating a shell surface the QT_WAYLAND_SHELL_INTEGRATION env
variable will be checked, and if it points to a valid plugin that
will be used to create the shell surface, falling back to wl_shell
or xdg_shell if no plugin is specified.

Change-Id: I05019174bb915199dd726f5fdcc0385ef846e8de
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
Reviewed-by: Philippe Coval <rzr@gna.org>
Reviewed-by: Jan Arne Petersen <jan.petersen@kdab.com>
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

6 files changed, 358 insertions, 0 deletions

diff --git a/src/client/shellintegration/qwaylandshellintegration_p.h b/src/client/shellintegration/qwaylandshellintegration_p.h
new file mode 100644
index 000000000..45a78199c
--- /dev/null
+++ b/src/client/shellintegration/qwaylandshellintegration_p.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Jolla Ltd
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QWAYLANDSHELLINTEGRATION_H
+#define QWAYLANDSHELLINTEGRATION_H
+
+#include <QtCore/qglobal.h>
+#include <QtWaylandClient/private/qwaylandclientexport_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QWaylandWindow;
+class QWaylandDisplay;
+class QWaylandShellSurface;
+
+class Q_WAYLAND_CLIENT_EXPORT QWaylandShellIntegration
+{
+public:
+    QWaylandShellIntegration() {}
+    virtual ~QWaylandShellIntegration() {}
+
+    virtual bool initialize(QWaylandDisplay *display) = 0;
+    virtual QWaylandShellSurface *createShellSurface(QWaylandWindow *window) = 0;
+};
+
+QT_END_NAMESPACE
+
+#endif // QWAYLANDSHELLINTEGRATION_H
diff --git a/src/client/shellintegration/qwaylandshellintegrationfactory.cpp b/src/client/shellintegration/qwaylandshellintegrationfactory.cpp
new file mode 100644
index 000000000..f780409e1
--- /dev/null
+++ b/src/client/shellintegration/qwaylandshellintegrationfactory.cpp
@@ -0,0 +1,96 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Jolla Ltd
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qwaylandshellintegrationfactory_p.h"
+#include "qwaylandshellintegrationplugin_p.h"
+#include "qwaylandshellintegration_p.h"
+#include <QtCore/private/qfactoryloader_p.h>
+#include <QtCore/QCoreApplication>
+#include <QtCore/QDir>
+
+QT_BEGIN_NAMESPACE
+
+#ifndef QT_NO_LIBRARY
+Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader,
+    (QWaylandShellIntegrationFactoryInterface_iid, QLatin1String("/wayland-shell-integration"), Qt::CaseInsensitive))
+Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, directLoader,
+                          (QWaylandShellIntegrationFactoryInterface_iid, QLatin1String(""), Qt::CaseInsensitive))
+#endif
+
+QStringList QWaylandShellIntegrationFactory::keys(const QString &pluginPath)
+{
+#ifndef QT_NO_LIBRARY
+    QStringList list;
+    if (!pluginPath.isEmpty()) {
+        QCoreApplication::addLibraryPath(pluginPath);
+        list = directLoader()->keyMap().values();
+        if (!list.isEmpty()) {
+            const QString postFix = QStringLiteral(" (from ")
+                                    + QDir::toNativeSeparators(pluginPath)
+                                    + QLatin1Char(')');
+            const QStringList::iterator end = list.end();
+            for (QStringList::iterator it = list.begin(); it != end; ++it)
+                (*it).append(postFix);
+        }
+    }
+    list.append(loader()->keyMap().values());
+    return list;
+#else
+    return QStringList();
+#endif
+}
+
+QWaylandShellIntegration *QWaylandShellIntegrationFactory::create(const QString &name, const QStringList &args, const QString &pluginPath)
+{
+#ifndef QT_NO_LIBRARY
+    // Try loading the plugin from platformPluginPath first:
+    if (!pluginPath.isEmpty()) {
+        QCoreApplication::addLibraryPath(pluginPath);
+        if (QWaylandShellIntegration *ret = qLoadPlugin1<QWaylandShellIntegration, QWaylandShellIntegrationPlugin>(directLoader(), name, args))
+            return ret;
+    }
+    if (QWaylandShellIntegration *ret = qLoadPlugin1<QWaylandShellIntegration, QWaylandShellIntegrationPlugin>(loader(), name, args))
+        return ret;
+#endif
+    return Q_NULLPTR;
+}
+
+QT_END_NAMESPACE
diff --git a/src/client/shellintegration/qwaylandshellintegrationfactory_p.h b/src/client/shellintegration/qwaylandshellintegrationfactory_p.h
new file mode 100644
index 000000000..415067ef8
--- /dev/null
+++ b/src/client/shellintegration/qwaylandshellintegrationfactory_p.h
@@ -0,0 +1,61 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Jolla Ltd
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QWAYLANDSHELLINTEGRATIONFACTORY_H
+#define QWAYLANDSHELLINTEGRATIONFACTORY_H
+
+#include <QtWaylandClient/private/qwaylandclientexport_p.h>
+#include <QtCore/QStringList>
+
+QT_BEGIN_NAMESPACE
+
+class QWaylandShellIntegration;
+
+class Q_WAYLAND_CLIENT_EXPORT QWaylandShellIntegrationFactory
+{
+public:
+    static QStringList keys(const QString &pluginPath = QString());
+    static QWaylandShellIntegration *create(const QString &name, const QStringList &args, const QString &pluginPath = QString());
+};
+
+QT_END_NAMESPACE
+
+#endif // QWAYLANDSHELLINTEGRATIONFACTORY_H
diff --git a/src/client/shellintegration/qwaylandshellintegrationplugin.cpp b/src/client/shellintegration/qwaylandshellintegrationplugin.cpp
new file mode 100644
index 000000000..05b5e91ad
--- /dev/null
+++ b/src/client/shellintegration/qwaylandshellintegrationplugin.cpp
@@ -0,0 +1,55 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Jolla Ltd
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qwaylandshellintegrationplugin_p.h"
+
+QT_BEGIN_NAMESPACE
+
+QWaylandShellIntegrationPlugin::QWaylandShellIntegrationPlugin(QObject *parent)
+                              : QObject(parent)
+{
+}
+
+QWaylandShellIntegrationPlugin::~QWaylandShellIntegrationPlugin()
+{
+}
+
+QT_END_NAMESPACE
diff --git a/src/client/shellintegration/qwaylandshellintegrationplugin_p.h b/src/client/shellintegration/qwaylandshellintegrationplugin_p.h
new file mode 100644
index 000000000..7d01fb4e5
--- /dev/null
+++ b/src/client/shellintegration/qwaylandshellintegrationplugin_p.h
@@ -0,0 +1,69 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Jolla Ltd
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QWAYLANDSHELLINTEGRATIONPLUGIN_H
+#define QWAYLANDSHELLINTEGRATIONPLUGIN_H
+
+#include <QtWaylandClient/private/qwaylandclientexport_p.h>
+
+#include <QtCore/qplugin.h>
+#include <QtCore/qfactoryinterface.h>
+#include <QtCore/QObject>
+
+QT_BEGIN_NAMESPACE
+
+class QWaylandShellIntegration;
+
+#define QWaylandShellIntegrationFactoryInterface_iid "org.qt-project.Qt.WaylandClient.QWaylandShellIntegrationFactoryInterface.5.3"
+
+class Q_WAYLAND_CLIENT_EXPORT QWaylandShellIntegrationPlugin : public QObject
+{
+    Q_OBJECT
+public:
+    explicit QWaylandShellIntegrationPlugin(QObject *parent = 0);
+    ~QWaylandShellIntegrationPlugin();
+
+    virtual QWaylandShellIntegration *create(const QString &key, const QStringList &paramList) = 0;
+};
+
+QT_END_NAMESPACE
+
+#endif // QWAYLANDSHELLINTEGRATIONPLUGIN_H
diff --git a/src/client/shellintegration/shellintegration.pri b/src/client/shellintegration/shellintegration.pri
new file mode 100644
index 000000000..de889a47a
--- /dev/null
+++ b/src/client/shellintegration/shellintegration.pri
@@ -0,0 +1,11 @@
+INCLUDEPATH += $$PWD
+
+SOURCES += \
+           $$PWD/qwaylandshellintegrationplugin.cpp \
+           $$PWD/qwaylandshellintegrationfactory.cpp
+
+HEADERS += \
+           $$PWD/qwaylandshellintegration_p.h \
+           $$PWD/qwaylandshellintegrationplugin_p.h \
+           $$PWD/qwaylandshellintegrationfactory_p.h
+