Integrate the GuiPlatformPlugin interface

This is an internal interface for plugins that can be provided by
the platform to give platform-specific features by platforms built on
top of Qt.

We can easlily integrate Qt on Windows, Mac, Gnome, ... without any
plugin because we can link to their respective library (dynamically
if we don't want to depend on it).  On Gnome, we can dynamically
resolve Gtk+ symbols.
This is however not possible for KDE or other platform built on top
of Qt: we can't link against their library because they depend on us
and we can't dynamically resolve the symbols because they are
mangled (C++)

So this plugin provides hooks inside Qt to be able to do things
like native File or Color dialog, native icons, accurate reading of
the config file, and so on.

This is currently private API.

Task-number: QT-406
Reviewed-by: Jens Bache-Wiig
Reviewed-by: Oswald Buddenhagen

1 files changed, 231 insertions, 0 deletions

diff --git a/src/gui/kernel/qguiplatformplugin.cpp b/src/gui/kernel/qguiplatformplugin.cpp
new file mode 100644
index 0000000..cf15aa2
--- /dev/null
+++ b/src/gui/kernel/qguiplatformplugin.cpp
@@ -0,0 +1,231 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** 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, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qguiplatformplugin_p.h"
+#include <qdebug.h>
+#include "private/qfactoryloader_p.h"
+#include "qstylefactory.h"
+#include "qapplication.h"
+#include "qplatformdefs.h"
+
+#ifdef Q_WS_WINCE
+#include "qguifunctions_wince.h"
+extern bool qt_wince_is_smartphone(); //qguifunctions_wince.cpp
+extern bool qt_wince_is_mobile();     //qguifunctions_wince.cpp
+extern bool qt_wince_is_pocket_pc();  //qguifunctions_wince.cpp
+#endif
+
+
+#if defined(Q_WS_X11)
+#include "qkde_p.h"
+#include "qt_x11_p.h"
+#endif
+
+
+QT_BEGIN_NAMESPACE
+
+
+/*! \internal
+    Return (an construct if necesseray) the Gui Platform plugin.
+
+    The plugin key to be loaded is inside the QT_PLATFORM_PLUGIN environment variable.
+    If it is not set, it will be the DESKTOP_SESSION on X11.
+
+    If no plugin can be loaded, the default one is returned.
+ */
+QGuiPlatformPlugin *qt_guiPlatformPlugin()
+{
+    static QGuiPlatformPlugin *plugin;
+    if (!plugin)
+    {
+#if !defined(QT_NO_LIBRARY) && !defined(QT_NO_SETTINGS)
+
+        QString key = QString::fromLocal8Bit(qgetenv("QT_PLATFORM_PLUGIN"));
+#ifdef Q_WS_X11
+        if (key.isEmpty()) {
+            switch(X11->desktopEnvironment) {
+            case DE_KDE:
+                key = QString::fromLatin1("kde");
+                break;
+            default:
+                key = QString::fromLocal8Bit(qgetenv("DESKTOP_SESSION"));
+                break;
+            }
+        }
+#endif
+
+        if (!key.isEmpty() && QApplication::desktopSettingsAware()) {
+            QFactoryLoader loader(QGuiPlatformPluginInterface_iid, QLatin1String("/gui_platform"));
+            plugin = qobject_cast<QGuiPlatformPlugin *>(loader.instance(key));
+        }
+#endif // QT_NO_LIBRARY
+
+        if(!plugin) {
+            static QGuiPlatformPlugin def;
+            plugin = &def;
+        }
+    }
+    return plugin;
+}
+
+
+/* \class QPlatformPlugin
+    QGuiPlatformPlugin can be used to integrate Qt applications in a platform built on top of Qt.
+    The application developer should not know or use the plugin, it is only used by Qt internaly.
+
+    But full platform that are built on top of Qt may provide a plugin so 3rd party Qt application
+    running in the platform are integrated.
+ */
+
+/*
+    The constructor can be used to install hooks in Qt
+ */
+QGuiPlatformPlugin::QGuiPlatformPlugin(QObject *parent) : QObject(parent) {}
+QGuiPlatformPlugin::~QGuiPlatformPlugin() {}
+
+
+/* return the string key to be used by default the application */
+QString QGuiPlatformPlugin::styleName()
+{
+#if defined(Q_WS_WIN) && defined(Q_WS_WINCE)
+    if (qt_wince_is_smartphone() || qt_wince_is_pocket_pc())
+        return QLatin1String("WindowsMobile");
+    else
+        return QLatin1String("WindowsCE");
+#elif defined(Q_WS_WIN)
+    if ((QSysInfo::WindowsVersion >= QSysInfo::WV_VISTA
+        && QSysInfo::WindowsVersion < QSysInfo::WV_NT_based))
+        return QLatin1String("WindowsVista");
+    else if ((QSysInfo::WindowsVersion >= QSysInfo::WV_XP
+        && QSysInfo::WindowsVersion < QSysInfo::WV_NT_based))
+        return QLatin1String("WindowsXP");
+    else
+        return QLatin1String("Windows");                // default styles for Windows
+#elif defined(Q_WS_X11) && defined(Q_OS_SOLARIS)
+    return QLatin1String("CDE");                        // default style for X11 on Solaris
+#elif defined(Q_WS_S60)
+    return QLatin1String("S60");                        // default style for Symbian with S60
+#elif defined(Q_OS_SYMBIAN)
+    return QLatin1String("Windows");                    // default style for Symbian without S60
+#elif defined(Q_WS_X11) && defined(Q_OS_IRIX)
+    return QLatin1String("SGI");                        // default style for X11 on IRIX
+#elif defined(Q_WS_QWS)
+    return QLatin1String("Plastique");                  // default style for X11 and small devices
+#elif defined(Q_WS_MAC)
+    return QLatin1String("Macintosh");              // default style for all Mac's
+#elif defined(Q_WS_X11)
+    QString stylename;
+    switch(X11->desktopEnvironment) {
+    case DE_KDE:
+        stylename = QKde::kdeStyle();
+        break;
+    case DE_GNOME: {
+        QStringList availableStyles = QStyleFactory::keys();
+        // Set QGtkStyle for GNOME if available
+        QString gtkStyleKey = QString::fromLatin1("GTK+");
+        if (availableStyles.contains(gtkStyleKey)) {
+            stylename = gtkStyleKey;
+            break;
+        }
+        if (X11->use_xrender)
+            stylename = QLatin1String("cleanlooks");
+        else
+            stylename = QLatin1String("windows");
+        break;
+    }
+    case DE_CDE:
+        stylename = QLatin1String("cde");
+        break;
+    default:
+        // Don't do anything
+        break;
+    }
+    return stylename;
+#endif
+}
+
+/* return an aditional default palette  (only work on X11) */
+QPalette QGuiPlatformPlugin::palette()
+{
+#ifdef Q_WS_X11
+    if (QApplication::desktopSettingsAware() && X11->desktopEnvironment == DE_KDE)
+        return QKde::kdePalette();
+#endif
+
+    return QPalette();
+}
+
+/* backend for QIcon::fromTheme. A null icon means it uses the default backend */
+QIcon QGuiPlatformPlugin::loadIcon(const QString &name)
+{
+    return QIcon();
+}
+
+/* Like QStyle::styleHint */
+int QGuiPlatformPlugin::platformHint(PlatformHint hint)
+{
+    int ret = 0;
+    switch(hint)
+    {
+        case PH_ToolButtonStyle:
+            ret = Qt::ToolButtonIconOnly;
+#ifdef Q_WS_X11
+            if (X11->desktopEnvironment == DE_KDE && X11->desktopVersion >= 4
+                && QApplication::desktopSettingsAware()) {
+                ret = QKde::kdeToolButtonStyle();
+            }
+#endif
+            break;
+        case PH_ToolBarIconSize:
+#ifdef Q_WS_X11
+            if (X11->desktopEnvironment == DE_KDE && X11->desktopVersion >= 4
+                && QApplication::desktopSettingsAware()) {
+                ret = QKde::kdeToolBarIconSize();
+            }
+#endif
+            //by default keep ret = 0 so QCommonStyle will use the style default
+            break;
+    }
+    return ret;
+}
+
+
+QT_END_NAMESPACE