File applet.patch of Package applet-window-buttons

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5ecec88..d8eb476 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,14 +1,14 @@
 project(applet_windowbuttons)
-cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.16 FATAL_ERROR)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 20)
 set(VERSION 0.11.1)
 set(AUTHOR "Michail Vourlakos")
 set(EMAIL "mvourlakos@gmail.com")
 
 set(QT_MIN_VERSION "5.15.0")
 set(KF5_MIN_VERSION "5.81.0")
-set(KDECORATION2_MIN_VERSION "5.24.0")
+set(KDECORATION2_MIN_VERSION "5.27.0")
 
 set(KF5_LOCALE_PREFIX "")
 
diff --git a/libappletdecoration/CMakeLists.txt b/libappletdecoration/CMakeLists.txt
index 9a13741..759adf5 100644
--- a/libappletdecoration/CMakeLists.txt
+++ b/libappletdecoration/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.12 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.16 FATAL_ERROR)
 
 set(QT_MIN_VERSION "5.6.0")
 set(KF5_MIN_VERSION "5.26.0")
diff --git a/libappletdecoration/appletdecorationplugin.h b/libappletdecoration/appletdecorationplugin.h
index 63a898d..c25104f 100644
--- a/libappletdecoration/appletdecorationplugin.h
+++ b/libappletdecoration/appletdecorationplugin.h
@@ -17,8 +17,7 @@
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef APPLETDECORATIONPLUGIN_H
-#define APPLETDECORATIONPLUGIN_H
+#pragma once
 
 #include <QQmlExtensionPlugin>
 
@@ -35,6 +34,3 @@ public:
 
 }
 }
-
-#endif
-
diff --git a/libappletdecoration/auroraetheme.cpp b/libappletdecoration/auroraetheme.cpp
index 305587a..09f2f34 100644
--- a/libappletdecoration/auroraetheme.cpp
+++ b/libappletdecoration/auroraetheme.cpp
@@ -99,7 +99,7 @@ void AuroraeTheme::setTheme(QString theme)
     m_theme = theme;
     updateAurorae(theme);
 
-    emit themeChanged();
+    Q_EMIT themeChanged();
 }
 
 QString AuroraeTheme::themeName() const
@@ -209,7 +209,7 @@ void AuroraeTheme::loadSettings()
 
     parseThemeImages();
 
-    emit settingsChanged();
+    Q_EMIT settingsChanged();
 }
 
 void AuroraeTheme::parseThemeImages()
diff --git a/libappletdecoration/auroraetheme.h b/libappletdecoration/auroraetheme.h
index 869cce8..15373c3 100644
--- a/libappletdecoration/auroraetheme.h
+++ b/libappletdecoration/auroraetheme.h
@@ -17,8 +17,7 @@
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef AURORAETHEME_H
-#define AURORAETHEME_H
+#pragma once
 
 #include <QColor>
 #include <QObject>
@@ -75,11 +74,11 @@ public:
     bool hasMonochromeIcons() const;
     QString monochromePrefix() const;
 
-signals:
+Q_SIGNALS:
     void settingsChanged();
     void themeChanged();
 
-private slots:
+private Q_SLOTS:
     void parseThemeImages();
     void auroraeRCChanged(const QString &filename);
 
@@ -110,4 +109,3 @@ private:
 
 }
 }
-#endif
diff --git a/libappletdecoration/buttonsmodel.h b/libappletdecoration/buttonsmodel.h
index 1b536d5..1c0e7d1 100644
--- a/libappletdecoration/buttonsmodel.h
+++ b/libappletdecoration/buttonsmodel.h
@@ -21,8 +21,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef KDECOARTIONS_PREVIEW_BUTTONS_MODEL_H
-#define KDECOARTIONS_PREVIEW_BUTTONS_MODEL_H
+#pragma once
 
 #include <KDecoration2/DecorationButton>
 #include <QAbstractListModel>
@@ -61,6 +60,3 @@ private:
 
 }
 }
-
-#endif
-
diff --git a/libappletdecoration/config-decoration.h.cmake b/libappletdecoration/config-decoration.h.cmake
index 3d90693..ef06ca8 100644
--- a/libappletdecoration/config-decoration.h.cmake
+++ b/libappletdecoration/config-decoration.h.cmake
@@ -1,6 +1,3 @@
-#ifndef CONFIG_DECORATION_H
-#define CONFIG_DECORATION_H
+#pragma once
 
 #cmakedefine KDECORATION2_VERSION_MINOR @KDECORATION2_VERSION_MINOR@
-
-#endif // CONFIG_DECORATION_H
diff --git a/libappletdecoration/decorationpalette.cpp b/libappletdecoration/decorationpalette.cpp
index c96ebc7..06755c9 100644
--- a/libappletdecoration/decorationpalette.cpp
+++ b/libappletdecoration/decorationpalette.cpp
@@ -53,7 +53,7 @@ DecorationPalette::DecorationPalette(const QString &colorScheme)
     connect(&m_watcher, &QFileSystemWatcher::fileChanged, [this]() {
         m_watcher.addPath(m_colorScheme);
         update();
-        emit changed();
+        Q_EMIT changed();
     });
 
     update();
@@ -131,7 +131,7 @@ void DecorationPalette::update()
 
     m_palette = KColorScheme::createApplicationPalette(config);
 
-    m_activeFrameColor        = wmConfig.readEntry("frame", m_palette.color(QPalette::Active, QPalette::Background));
+    m_activeFrameColor        = wmConfig.readEntry("frame", m_palette.color(QPalette::Active, QPalette::Window));
     m_inactiveFrameColor      = wmConfig.readEntry("inactiveFrame", m_activeFrameColor);
     m_activeTitleBarColor     = wmConfig.readEntry("activeBackground", m_palette.color(QPalette::Active, QPalette::Highlight));
     m_inactiveTitleBarColor   = wmConfig.readEntry("inactiveBackground", m_inactiveFrameColor);
diff --git a/libappletdecoration/decorationpalette.h b/libappletdecoration/decorationpalette.h
index b4f8b4f..536f113 100644
--- a/libappletdecoration/decorationpalette.h
+++ b/libappletdecoration/decorationpalette.h
@@ -20,8 +20,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 
-#ifndef KWIN_DECORATION_PALETTE_H
-#define KWIN_DECORATION_PALETTE_H
+#pragma once
 
 #include <KDecoration2/DecorationSettings>
 #include <QFileSystemWatcher>
@@ -64,5 +63,3 @@ private:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/decorationsmodel.cpp b/libappletdecoration/decorationsmodel.cpp
index a19f65e..c7d1a4b 100644
--- a/libappletdecoration/decorationsmodel.cpp
+++ b/libappletdecoration/decorationsmodel.cpp
@@ -27,11 +27,9 @@
 #include <KDecoration2/DecorationSettings>
 #include <KDecoration2/DecorationThemeProvider>
 // KDE
+#include <KConfigGroup>
 #include <KDirWatch>
-#include <KPluginInfo>
-#include <KPluginLoader>
 #include <KPluginFactory>
-#include <KPluginTrader>
 #include <KSharedConfig>
 // Qt
 #include <QDebug>
@@ -82,7 +80,7 @@ void DecorationsModel::setCurrentPlugin(QString plugin)
     }
 
     m_currentPlugin = plugin;
-    emit currentPluginChanged();
+    Q_EMIT currentPluginChanged();
 }
 
 QString DecorationsModel::currentTheme() const
@@ -97,7 +95,7 @@ void DecorationsModel::setCurrentTheme(QString theme)
     }
 
     m_currentTheme = theme;
-    emit currentThemeChanged();
+    Q_EMIT currentThemeChanged();
 }
 
 int DecorationsModel::rowCount(const QModelIndex &parent) const
diff --git a/libappletdecoration/decorationsmodel.h b/libappletdecoration/decorationsmodel.h
index 10a8edd..47ce4ff 100644
--- a/libappletdecoration/decorationsmodel.h
+++ b/libappletdecoration/decorationsmodel.h
@@ -21,8 +21,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef DECORATIONSMODEL_H
-#define DECORATIONSMODEL_H
+#pragma once
 
 #include <QAbstractListModel>
 
@@ -59,12 +58,12 @@ public Q_SLOTS:
     Q_INVOKABLE bool decorationExists(const QString &plugin, const QString &theme);
     Q_INVOKABLE bool isAurorae(const QString &plugin, const QString &theme);
 
-signals:
+Q_SIGNALS:
     void countChanged();
     void currentThemeChanged();
     void currentPluginChanged();
 
-private slots:
+private Q_SLOTS:
     void init();
     void loadCurrents();
     void kwinChanged(const QString &filename);
@@ -94,5 +93,3 @@ private:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/environment.cpp b/libappletdecoration/environment.cpp
index 982705c..a686b46 100644
--- a/libappletdecoration/environment.cpp
+++ b/libappletdecoration/environment.cpp
@@ -24,7 +24,7 @@
 #include <QProcess>
 
 // Plasma
-#include <plasma/version.h>
+#include <KF5/Plasma/plasma_version.h>
 
 namespace Decoration {
 namespace Applet {
@@ -41,7 +41,7 @@ Environment::~Environment()
 
 uint Environment::frameworksVersion() const
 {
-    return Plasma::version();
+    return PLASMA_VERSION;
 }
 
 uint Environment::plasmaDesktopVersion()
diff --git a/libappletdecoration/environment.h b/libappletdecoration/environment.h
index b7cc15f..6a6eeb7 100644
--- a/libappletdecoration/environment.h
+++ b/libappletdecoration/environment.h
@@ -17,8 +17,7 @@
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef ENVIRONMENT_H
-#define ENVIRONMENT_H
+#pragma once
 
 // Qt
 #include <QObject>
@@ -52,10 +51,10 @@ public:
         return new Environment;
     }
 
-public slots:
+public Q_SLOTS:
     Q_INVOKABLE uint makeVersion(uint major, uint minor, uint release) const;
 
-signals:
+Q_SIGNALS:
     void frameworksVersionChanged();
     void plasmaDesktopVersionChanged();
 
@@ -72,5 +71,3 @@ private:
 
 }
 }
-
-#endif // ENVIRONMENT_H
diff --git a/libappletdecoration/padding.cpp b/libappletdecoration/padding.cpp
index 96eb314..efeaf26 100644
--- a/libappletdecoration/padding.cpp
+++ b/libappletdecoration/padding.cpp
@@ -46,7 +46,7 @@ void Padding::setTop(int top)
     }
 
     m_top = top;
-    emit topChanged();
+    Q_EMIT topChanged();
 }
 
 int Padding::left() const
@@ -61,7 +61,7 @@ void Padding::setLeft(int left)
     }
 
     m_left = left;
-    emit leftChanged();
+    Q_EMIT leftChanged();
 }
 
 int Padding::bottom()const
@@ -76,7 +76,7 @@ void Padding::setBottom(int bottom)
     }
 
     m_bottom = bottom;
-    emit bottomChanged();
+    Q_EMIT bottomChanged();
 }
 
 int Padding::right() const
@@ -91,7 +91,7 @@ void Padding::setRight(int right)
     }
 
     m_right = right;
-    emit rightChanged();
+    Q_EMIT rightChanged();
 }
 
 }
diff --git a/libappletdecoration/padding.h b/libappletdecoration/padding.h
index a574700..670c295 100644
--- a/libappletdecoration/padding.h
+++ b/libappletdecoration/padding.h
@@ -20,8 +20,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PADDING_H
-#define PADDING_H
+#pragma once
 
 #include <QObject>
 
@@ -53,7 +52,7 @@ public:
     int right() const;
     void setRight(int right);
 
-signals:
+Q_SIGNALS:
     void topChanged();
     void leftChanged();
     void bottomChanged();
@@ -68,5 +67,3 @@ private:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/previewbridge.cpp b/libappletdecoration/previewbridge.cpp
index 27a29ea..df19eeb 100644
--- a/libappletdecoration/previewbridge.cpp
+++ b/libappletdecoration/previewbridge.cpp
@@ -30,11 +30,9 @@
 #include <KDecoration2/DecoratedClient>
 #include <KDecoration2/Decoration>
 
-#include <KCModule>
 #include <KDirWatch>
-#include <KPluginLoader>
 #include <KPluginFactory>
-#include <KPluginTrader>
+#include <KPluginMetaData>
 
 #include <QDebug>
 #include <QDBusConnection>
@@ -74,14 +72,14 @@ std::unique_ptr<KDecoration2::DecoratedClientPrivate> PreviewBridge::createClien
 {
     auto ptr = std::unique_ptr<PreviewClient>(new PreviewClient(client, decoration));
     m_lastCreatedClient = ptr.get();
-    return std::move(ptr);
+    return ptr;
 }
 
 std::unique_ptr<KDecoration2::DecorationSettingsPrivate> PreviewBridge::settings(KDecoration2::DecorationSettings *parent)
 {
     auto ptr = std::unique_ptr<PreviewSettings>(new PreviewSettings(parent));
     m_lastCreatedSettings = ptr.get();
-    return std::move(ptr);
+    return ptr;
 }
 
 void PreviewBridge::registerButton(PreviewButtonItem *button)
@@ -102,7 +100,7 @@ void PreviewBridge::setPlugin(const QString &plugin)
 
     m_plugin = plugin;
     qDebug() << "Plugin changed to: " << m_plugin;
-    emit pluginChanged();
+    Q_EMIT pluginChanged();
 }
 
 QString PreviewBridge::theme() const
@@ -117,7 +115,7 @@ void PreviewBridge::setTheme(const QString &theme)
     }
 
     m_theme = theme;
-    emit themeChanged();
+    Q_EMIT themeChanged();
 }
 
 QString PreviewBridge::plugin() const
@@ -135,9 +133,11 @@ void PreviewBridge::createFactory()
         return;
     }
 
-    const auto offers = KPluginTrader::self()->query(s_pluginName,
-                        s_pluginName,
-                        QStringLiteral("[X-KDE-PluginInfo-Name] == '%1'").arg(m_plugin));
+    //const auto offers = KPluginMetaData::findPlugins(s_pluginName);
+    const auto offers = KPluginMetaData::findPlugins(s_pluginName,
+                        [this](const KPluginMetaData& md) {
+                            return md.pluginId() == m_plugin;
+                        });
 
     if (offers.isEmpty()) {
         setValid(false);
@@ -145,8 +145,9 @@ void PreviewBridge::createFactory()
         return;
     }
 
-    KPluginLoader loader(offers.first().libraryPath());
-    m_factory = loader.factory();
+    //m_factory = KPluginLoader(offers.first().fileName()).factory();
+    const KPluginMetaData& data = offers.first();
+    m_factory = KPluginFactory::loadFactory(data).plugin;
     qDebug() << "Factory: " << !m_factory.isNull();
     setValid(!m_factory.isNull());
     reconfigure();
@@ -164,7 +165,7 @@ void PreviewBridge::setValid(bool valid)
     }
 
     m_valid = valid;
-    emit validChanged();
+    Q_EMIT validChanged();
 }
 
 KDecoration2::Decoration *PreviewBridge::createDecoration(QObject *parent)
@@ -188,17 +189,7 @@ KDecoration2::DecorationButton *PreviewBridge::createButton(KDecoration2::Decora
         return nullptr;
     }
 
-    auto button = m_factory->create<KDecoration2::DecorationButton>(parent, QVariantList({QVariant::fromValue(type), QVariant::fromValue(decoration)}));
-
-    if (!button) {
-        //! support decorations that have not been updated yet to KWin 5.23 decoration plugin approach
-        button = m_factory->create<KDecoration2::DecorationButton>(QStringLiteral("button"), parent, QVariantList({QVariant::fromValue(type), QVariant::fromValue(decoration)}));
-        if (button) {
-            qWarning() << "Loading a KDecoration2::DecorationButton using the button keyword is deprecated in KWin 5.23, register the plugin without a keyword instead" << m_plugin;
-        }
-    }
-
-    return button;
+    return m_factory->create<KDecoration2::DecorationButton>(parent, QVariantList({QVariant::fromValue(type), QVariant::fromValue(decoration)}));
 }
 
 void PreviewBridge::settingsFileChanged(const QString &filename)
@@ -213,7 +204,7 @@ void PreviewBridge::settingsFileChanged(const QString &filename)
 void PreviewBridge::reconfigure()
 {
     if (m_lastCreatedSettings) {
-        emit m_lastCreatedSettings->decorationSettings()->reconfigured();
+        Q_EMIT m_lastCreatedSettings->decorationSettings()->reconfigured();
     }
 }
 
diff --git a/libappletdecoration/previewbridge.h b/libappletdecoration/previewbridge.h
index e6abda5..edc1a3e 100644
--- a/libappletdecoration/previewbridge.h
+++ b/libappletdecoration/previewbridge.h
@@ -21,8 +21,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef KDECORATIONS_PREVIEW_BRIDGE_H
-#define KDECORATIONS_PREVIEW_BRIDGE_H
+#pragma once
 
 #include <KDecoration2/Private/DecorationBridge>
 #include <KDecoration2/DecorationButton>
@@ -79,7 +78,7 @@ Q_SIGNALS:
     void themeChanged();
     void validChanged();
 
-private slots:
+private Q_SLOTS:
     void settingsFileChanged(const QString &filename);
 
 private:
@@ -140,5 +139,3 @@ private:
 }
 
 Q_DECLARE_METATYPE(Decoration::Applet::PreviewBridge *)
-
-#endif
diff --git a/libappletdecoration/previewbutton.cpp b/libappletdecoration/previewbutton.cpp
index 0b785ae..b48edeb 100644
--- a/libappletdecoration/previewbutton.cpp
+++ b/libappletdecoration/previewbutton.cpp
@@ -97,7 +97,7 @@ void PreviewButtonItem::setIsActive(bool active)
         m_client->setActive(m_isActive);
     }
 
-    emit isActiveChanged();
+    Q_EMIT isActiveChanged();
 }
 
 bool PreviewButtonItem::isMaximized() const
@@ -124,7 +124,7 @@ void PreviewButtonItem::setIsMaximized(bool maximized)
         }
     }
 
-    emit isMaximizedChanged();
+    Q_EMIT isMaximizedChanged();
 }
 
 bool PreviewButtonItem::isOnAllDesktops() const
@@ -148,7 +148,7 @@ void PreviewButtonItem::setIsOnAllDesktops(bool onalldesktops)
         }
     }
 
-    emit isOnAllDesktopsChanged();
+    Q_EMIT isOnAllDesktopsChanged();
 }
 
 bool PreviewButtonItem::isKeepAbove() const
@@ -172,7 +172,7 @@ void PreviewButtonItem::setIsKeepAbove(bool keepabove)
         }
     }
 
-    emit isKeepAboveChanged();
+    Q_EMIT isKeepAboveChanged();
 }
 
 KDecoration2::DecorationButtonType PreviewButtonItem::type() const
@@ -197,7 +197,7 @@ void PreviewButtonItem::setType(KDecoration2::DecorationButtonType type)
     }
 
     m_type = type;
-    emit typeChanged();
+    Q_EMIT typeChanged();
 }
 
 QString PreviewButtonItem::scheme() const
@@ -218,7 +218,7 @@ void PreviewButtonItem::setScheme(QString scheme)
         qDebug() << "buttons scheme update to:" << m_scheme;
     }
 
-    emit schemeChanged();
+    Q_EMIT schemeChanged();
 }
 
 PreviewBridge *PreviewButtonItem::bridge() const
@@ -242,7 +242,7 @@ void PreviewButtonItem::setBridge(PreviewBridge *bridge)
         m_bridge->registerButton(this);
     }
 
-    emit bridgeChanged();
+    Q_EMIT bridgeChanged();
 }
 
 int PreviewButtonItem::typeAsInt() const
@@ -263,7 +263,7 @@ void PreviewButtonItem::setLocalX(int x)
 
     m_localX = x;
 
-    emit localXChanged();
+    Q_EMIT localXChanged();
 }
 
 int PreviewButtonItem::localY() const
@@ -279,7 +279,7 @@ void PreviewButtonItem::setLocalY(int y)
 
     m_localY = y;
 
-    emit localYChanged();
+    Q_EMIT localYChanged();
 }
 
 KDecoration2::Decoration *PreviewButtonItem::decoration() const
@@ -306,7 +306,7 @@ void PreviewButtonItem::setSharedDecoration(SharedDecoration *sharedDecoration)
 
     connect(m_sharedDecoration, &Decoration::Applet::SharedDecoration::decorationChanged, this, &Decoration::Applet::PreviewButtonItem::createButton);
 
-    emit sharedDecorationChanged();
+    Q_EMIT sharedDecorationChanged();
 }
 
 void PreviewButtonItem::componentComplete()
@@ -395,7 +395,7 @@ void PreviewButtonItem::syncInternalGeometry()
 void PreviewButtonItem::onButtonDamaged()
 {
     if (m_sharedDecoration && m_sharedDecoration->decoration()) {
-        emit m_sharedDecoration->decoration()->damaged(m_visualGeometry);
+        Q_EMIT m_sharedDecoration->decoration()->damaged(m_visualGeometry);
     } else {
         update();
     }
@@ -464,7 +464,7 @@ void PreviewButtonItem::mouseReleaseEvent(QMouseEvent *event)
     QCoreApplication::instance()->sendEvent(m_button, event);
 
     if (inItem) {
-        emit clicked();
+        Q_EMIT clicked();
     }
 }
 
diff --git a/libappletdecoration/previewbutton.h b/libappletdecoration/previewbutton.h
index 05b202e..d6f798b 100644
--- a/libappletdecoration/previewbutton.h
+++ b/libappletdecoration/previewbutton.h
@@ -21,8 +21,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef KDECORATIONS_PREVIEW_BUTTON_ITEM_H
-#define KDECORATIONS_PREVIEW_BUTTON_ITEM_H
+#pragma once
 
 #include <QMargins>
 #include <QQuickPaintedItem>
@@ -81,7 +80,7 @@ public:
 
     bool isOnAllDesktops() const;
     void setIsOnAllDesktops(bool onalldesktops);
-    
+
     bool isKeepAbove() const;
     void setIsKeepAbove(bool keepabove);
 
@@ -165,5 +164,3 @@ private:
 
 } // namespace Applet
 } // namespace Decoration
-
-#endif
diff --git a/libappletdecoration/previewclient.cpp b/libappletdecoration/previewclient.cpp
index 2cf184b..e34f8b6 100644
--- a/libappletdecoration/previewclient.cpp
+++ b/libappletdecoration/previewclient.cpp
@@ -86,27 +86,27 @@ PreviewClient::PreviewClient(KDecoration2::DecoratedClient *c, KDecoration2::Dec
     //         connect(this, &PreviewClient::, c, &DecoratedClient::);
     connect(this, &PreviewClient::maximizedVerticallyChanged, this,
             [this]() {
-        emit maximizedChanged(isMaximized());
+        Q_EMIT maximizedChanged(isMaximized());
     }
     );
     connect(this, &PreviewClient::maximizedHorizontallyChanged, this,
             [this]() {
-        emit maximizedChanged(isMaximized());
+        Q_EMIT maximizedChanged(isMaximized());
     }
     );
     connect(this, &PreviewClient::iconNameChanged, this,
             [this]() {
         m_icon = QIcon::fromTheme(m_iconName);
-        emit iconChanged(m_icon);
+        Q_EMIT iconChanged(m_icon);
     }
     );
     connect(this, &PreviewClient::desktopChanged, this,
             [this](int) {
-        emit onAllDesktopsChanged(isOnAllDesktops());
+        Q_EMIT onAllDesktopsChanged(isOnAllDesktops());
     }
     );
     /* connect(m_palette, &KWin::Decoration::DecorationPalette::changed, [this]() {
-         emit paletteChanged(m_palette->palette());
+         Q_EMIT paletteChanged(m_palette->palette());
      });*/
     auto emitEdgesChanged = [this, c]() {
         c->adjacentScreenEdgesChanged(adjacentScreenEdges());
@@ -126,7 +126,7 @@ PreviewClient::~PreviewClient() = default;
 void PreviewClient::setIcon(const QIcon &pixmap)
 {
     m_icon = pixmap;
-    emit iconChanged(m_icon);
+    Q_EMIT iconChanged(m_icon);
 }
 
 int PreviewClient::width() const
@@ -165,7 +165,7 @@ void PreviewClient::setDesktop(int desktop)
     }
 
     m_desktop = desktop;
-    emit desktopChanged(m_desktop);
+    Q_EMIT desktopChanged(m_desktop);
 }
 
 QIcon PreviewClient::icon() const
@@ -263,6 +263,11 @@ WId PreviewClient::windowId() const
     return 0;
 }
 
+QString PreviewClient::windowClass() const
+{
+    return QString("kwin_preview");
+}
+
 QPalette PreviewClient::palette() const
 {
     return m_palette->palette();
@@ -287,7 +292,7 @@ void PreviewClient::setColorScheme(QString scheme)
 
     m_palette = new Decoration::Applet::DecorationPalette(scheme);
 
-    emit paletteChanged(m_palette->palette());
+    Q_EMIT paletteChanged(m_palette->palette());
 }
 
 Qt::Edges PreviewClient::adjacentScreenEdges() const
@@ -350,7 +355,7 @@ void PreviewClient::setBordersBottomEdge(bool enabled)
     }
 
     m_bordersBottomEdge = enabled;
-    emit bordersBottomEdgeChanged(enabled);
+    Q_EMIT bordersBottomEdgeChanged(enabled);
 }
 
 void PreviewClient::setBordersLeftEdge(bool enabled)
@@ -360,7 +365,7 @@ void PreviewClient::setBordersLeftEdge(bool enabled)
     }
 
     m_bordersLeftEdge = enabled;
-    emit bordersLeftEdgeChanged(enabled);
+    Q_EMIT bordersLeftEdgeChanged(enabled);
 }
 
 void PreviewClient::setBordersRightEdge(bool enabled)
@@ -370,7 +375,7 @@ void PreviewClient::setBordersRightEdge(bool enabled)
     }
 
     m_bordersRightEdge = enabled;
-    emit bordersRightEdgeChanged(enabled);
+    Q_EMIT bordersRightEdgeChanged(enabled);
 }
 
 void PreviewClient::setBordersTopEdge(bool enabled)
@@ -380,7 +385,7 @@ void PreviewClient::setBordersTopEdge(bool enabled)
     }
 
     m_bordersTopEdge = enabled;
-    emit bordersTopEdgeChanged(enabled);
+    Q_EMIT bordersTopEdgeChanged(enabled);
 }
 
 
@@ -408,19 +413,19 @@ QSize PreviewClient::size() const
 #if KDECORATION2_VERSION_MINOR <= 20
 void PreviewClient::requestShowWindowMenu()
 {
-    emit showWindowMenuRequested();
+    Q_EMIT showWindowMenuRequested();
 }
 #else
-void PreviewClient::requestShowWindowMenu(const QRect &rect)
+void PreviewClient::requestShowWindowMenu(const QRect &/*rect*/)
 {
-    emit showWindowMenuRequested();
+    Q_EMIT showWindowMenuRequested();
 }
 #endif
 
 
 void PreviewClient::requestClose()
 {
-    emit closeRequested();
+    Q_EMIT closeRequested();
 }
 
 void PreviewClient::requestContextHelp()
@@ -443,7 +448,7 @@ void PreviewClient::requestToggleMaximization(Qt::MouseButtons buttons)
 
 void PreviewClient::requestMinimize()
 {
-    emit minimizeRequested();
+    Q_EMIT minimizeRequested();
 }
 
 void PreviewClient::requestToggleKeepAbove()
@@ -484,7 +489,7 @@ void PreviewClient::requestToggleShade()
     return; \
 } \
     m_##variable = variable; \
-    emit variable##Changed(m_##variable); \
+    Q_EMIT variable##Changed(m_##variable); \
 }
 
 #define SETTER2(name, variable) SETTER(bool, name, variable)
diff --git a/libappletdecoration/previewclient.h b/libappletdecoration/previewclient.h
index c479acc..a0071f4 100644
--- a/libappletdecoration/previewclient.h
+++ b/libappletdecoration/previewclient.h
@@ -21,8 +21,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef KDECORATIONS_PREVIEW_CLIENT_H
-#define KDECORATIONS_PREVIEW_CLIENT_H
+#pragma once
 
 #include "decorationpalette.h"
 
@@ -74,6 +73,7 @@ public:
     QString caption() const override;
     WId decorationId() const override;
     WId windowId() const override;
+    QString windowClass() const override;
     int desktop() const override;
     QIcon icon() const override;
     bool isActive() const override;
@@ -229,5 +229,3 @@ private:
 
 } // namespace Applet
 } // namespace Decoration
-
-#endif
diff --git a/libappletdecoration/previewsettings.cpp b/libappletdecoration/previewsettings.cpp
index c0d31a7..1b4f05f 100644
--- a/libappletdecoration/previewsettings.cpp
+++ b/libappletdecoration/previewsettings.cpp
@@ -155,7 +155,7 @@ void PreviewSettings::setAlphaChannelSupported(bool supported)
     }
 
     m_alphaChannelSupported = supported;
-    emit alphaChannelSupportedChanged(m_alphaChannelSupported);
+    Q_EMIT alphaChannelSupportedChanged(m_alphaChannelSupported);
 }
 
 void PreviewSettings::setOnAllDesktopsAvailable(bool available)
@@ -165,7 +165,7 @@ void PreviewSettings::setOnAllDesktopsAvailable(bool available)
     }
 
     m_onAllDesktopsAvailable = available;
-    emit onAllDesktopsAvailableChanged(m_onAllDesktopsAvailable);
+    Q_EMIT onAllDesktopsAvailableChanged(m_onAllDesktopsAvailable);
 }
 
 void PreviewSettings::setCloseOnDoubleClickOnMenu(bool enabled)
@@ -175,7 +175,7 @@ void PreviewSettings::setCloseOnDoubleClickOnMenu(bool enabled)
     }
 
     m_closeOnDoubleClick = enabled;
-    emit closeOnDoubleClickOnMenuChanged(enabled);
+    Q_EMIT closeOnDoubleClickOnMenuChanged(enabled);
 }
 
 QVector< KDecoration2::DecorationButtonType > PreviewSettings::decorationButtonsLeft() const
@@ -217,8 +217,8 @@ void PreviewSettings::setBorderSizesIndex(int index)
     }
 
     m_borderSize = index;
-    emit borderSizesIndexChanged(index);
-    emit decorationSettings()->borderSizeChanged(borderSize());
+    Q_EMIT borderSizesIndexChanged(index);
+    Q_EMIT decorationSettings()->borderSizeChanged(borderSize());
 }
 
 KDecoration2::BorderSize PreviewSettings::borderSize() const
@@ -233,7 +233,7 @@ void PreviewSettings::setFont(const QFont &font)
     }
 
     m_font = font;
-    emit fontChanged(m_font);
+    Q_EMIT fontChanged(m_font);
 }
 
 Settings::Settings(QObject *parent)
@@ -251,7 +251,7 @@ void Settings::setBridge(PreviewBridge *bridge)
     }
 
     m_bridge = bridge;
-    emit bridgeChanged();
+    Q_EMIT bridgeChanged();
 }
 
 PreviewBridge *Settings::bridge() const
@@ -270,7 +270,7 @@ void Settings::createSettings()
         connect(this, &Settings::borderSizesIndexChanged, m_previewSettings, &PreviewSettings::setBorderSizesIndex);
     }
 
-    emit settingsChanged();
+    Q_EMIT settingsChanged();
 }
 
 QSharedPointer<KDecoration2::DecorationSettings> Settings::settings() const
@@ -290,7 +290,7 @@ void Settings::setBorderSizesIndex(int index)
     }
 
     m_borderSize = index;
-    emit borderSizesIndexChanged(m_borderSize);
+    Q_EMIT borderSizesIndexChanged(m_borderSize);
 }
 
 }
diff --git a/libappletdecoration/previewsettings.h b/libappletdecoration/previewsettings.h
index 87a86c0..0413bb9 100644
--- a/libappletdecoration/previewsettings.h
+++ b/libappletdecoration/previewsettings.h
@@ -21,8 +21,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef KDECOARTIONS_PREVIEW_SETTINGS_H
-#define KDECOARTIONS_PREVIEW_SETTINGS_H
+#pragma once
 
 #include <KDecoration2/Private/DecorationSettingsPrivate>
 #include <KDecoration2/DecorationSettings>
@@ -165,5 +164,3 @@ private:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/previewshareddecoration.cpp b/libappletdecoration/previewshareddecoration.cpp
index 25a3bc2..9f60562 100644
--- a/libappletdecoration/previewshareddecoration.cpp
+++ b/libappletdecoration/previewshareddecoration.cpp
@@ -61,7 +61,7 @@ void SharedDecoration::setBridge(PreviewBridge *bridge)
 
     connect(m_bridge, &Decoration::Applet::PreviewBridge::validChanged, this, &Decoration::Applet::SharedDecoration::createDecoration);
 
-    emit bridgeChanged();
+    Q_EMIT bridgeChanged();
 }
 
 KDecoration2::Decoration *SharedDecoration::decoration() const
@@ -84,7 +84,7 @@ void SharedDecoration::setSettings(Settings *settings)
 
     createDecoration();
 
-    emit settingsChanged();
+    Q_EMIT settingsChanged();
 }
 
 void SharedDecoration::applySettings()
@@ -122,7 +122,7 @@ void SharedDecoration::createDecoration()
     m_lastPlugin = m_bridge->plugin();
     m_lastTheme = m_bridge->theme();
 
-    emit decorationChanged();
+    Q_EMIT decorationChanged();
 }
 
 void SharedDecoration::initDecoration()
diff --git a/libappletdecoration/previewshareddecoration.h b/libappletdecoration/previewshareddecoration.h
index be5c9bd..a11fda0 100644
--- a/libappletdecoration/previewshareddecoration.h
+++ b/libappletdecoration/previewshareddecoration.h
@@ -20,8 +20,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PREVIEWSHAREDDECORATION_H
-#define PREVIEWSHAREDDECORATION_H
+#pragma once
 
 #include <QObject>
 
@@ -81,5 +80,3 @@ private:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/schemecolors.cpp b/libappletdecoration/schemecolors.cpp
index f0f263e..4314767 100644
--- a/libappletdecoration/schemecolors.cpp
+++ b/libappletdecoration/schemecolors.cpp
@@ -145,7 +145,7 @@ void SchemeColors::setSchemeFile(QString file)
     }
 
     m_schemeFile = file;
-    emit schemeFileChanged();
+    Q_EMIT schemeFileChanged();
 }
 
 QString SchemeColors::possibleSchemeFile(QString scheme)
@@ -237,7 +237,7 @@ void SchemeColors::updateScheme()
     m_buttonHoverColor = buttonGroup.readEntry("DecorationHover", QColor());
     m_buttonFocusColor = buttonGroup.readEntry("DecorationFocus", QColor());
 
-    emit colorsChanged();
+    Q_EMIT colorsChanged();
 }
 
 }
diff --git a/libappletdecoration/schemecolors.h b/libappletdecoration/schemecolors.h
index b01e573..b46f742 100644
--- a/libappletdecoration/schemecolors.h
+++ b/libappletdecoration/schemecolors.h
@@ -18,8 +18,7 @@
  *
  */
 
-#ifndef SCHEMECOLORS_H
-#define SCHEMECOLORS_H
+#pragma once
 
 #include <QObject>
 #include <QColor>
@@ -75,11 +74,11 @@ public:
     static QString possibleSchemeFile(QString scheme);
     static QString schemeName(QString originalFile);
 
-signals:
+Q_SIGNALS:
     void colorsChanged();
     void schemeFileChanged();
 
-public slots:
+public Q_SLOTS:
     void updateScheme();
 
 private:
@@ -108,5 +107,3 @@ private:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/schemesmodel.h b/libappletdecoration/schemesmodel.h
index 3050cd1..fbe23b5 100644
--- a/libappletdecoration/schemesmodel.h
+++ b/libappletdecoration/schemesmodel.h
@@ -18,8 +18,7 @@
  *
  */
 
-#ifndef SCHEMESMODEL_H
-#define SCHEMESMODEL_H
+#pragma once
 
 #include <QAbstractListModel>
 
@@ -44,7 +43,7 @@ public:
     Q_INVOKABLE QColor backgroundOf(const int &index) const;
 
     Q_INVOKABLE QString defaultSchemeFile() const;
-private slots:
+private Q_SLOTS:
     void initSchemes();
 
 private:
@@ -57,5 +56,3 @@ private:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/themeextended.cpp b/libappletdecoration/themeextended.cpp
index b2b1587..fd5efc8 100644
--- a/libappletdecoration/themeextended.cpp
+++ b/libappletdecoration/themeextended.cpp
@@ -74,7 +74,7 @@ void ExtendedTheme::setOriginalSchemeFile(const QString &file)
 
     updateDefaultScheme();
 
-    emit themeChanged();
+    Q_EMIT themeChanged();
 }
 
 //! WM records need to be updated based on the colors that
@@ -96,14 +96,14 @@ void ExtendedTheme::updateDefaultScheme()
     if (m_colorsScheme) {
         disconnect(m_colorsScheme, &SchemeColors::colorsChanged, this, &ExtendedTheme::themeChanged);
         m_colorsScheme->deleteLater();
-    }    
+    }
 
     m_colorsScheme = new SchemeColors(this, m_colorsSchemePath, true);
     connect(m_colorsScheme, &SchemeColors::colorsChanged, this, &ExtendedTheme::themeChanged);
 
     qDebug() << "Window Buttons : plasma theme default colors ::: " << m_colorsSchemePath;
 
-    emit colorsChanged();
+    Q_EMIT colorsChanged();
 }
 
 void ExtendedTheme::updateDefaultSchemeValues()
diff --git a/libappletdecoration/themeextended.h b/libappletdecoration/themeextended.h
index 280fde7..23ae8f6 100644
--- a/libappletdecoration/themeextended.h
+++ b/libappletdecoration/themeextended.h
@@ -18,8 +18,7 @@
  *
  */
 
-#ifndef PLASMAEXTENDEDTHEME_H
-#define PLASMAEXTENDEDTHEME_H
+#pragma once
 
 // C++
 #include <array>
@@ -58,7 +57,7 @@ public:
 
     void load();
 
-signals:
+Q_SIGNALS:
     void colorsChanged();
     void themeChanged();
 
@@ -86,5 +85,3 @@ private:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/types.h b/libappletdecoration/types.h
index 254f3dc..7d2d58f 100644
--- a/libappletdecoration/types.h
+++ b/libappletdecoration/types.h
@@ -17,8 +17,7 @@
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef TYPES_H
-#define TYPES_H
+#pragma once
 
 #include <QObject>
 #include <QMetaEnum>
@@ -101,5 +100,3 @@ public:
 
 }
 }
-
-#endif
diff --git a/libappletdecoration/windowsystem.cpp b/libappletdecoration/windowsystem.cpp
index 05ecb28..19299d1 100644
--- a/libappletdecoration/windowsystem.cpp
+++ b/libappletdecoration/windowsystem.cpp
@@ -37,7 +37,9 @@ WindowSystem::~WindowSystem() = default;
 bool WindowSystem::kwin_disabledMaximizedBorders() const
 {
     QProcess process;
-    process.start("kreadconfig5 --file kwinrc --group Windows --key BorderlessMaximizedWindows");
+    QStringList arguments;
+    arguments << "--file" << "kwinrc" << "--group" << "Windows" << "--key" << "BorderlessMaximizedWindows";
+    process.start("kreadconfig5", arguments);
     process.waitForFinished();
     QString output(process.readAllStandardOutput());
 
@@ -55,8 +57,9 @@ void WindowSystem::setDisabledMaximizedBorders(bool disable)
     QString disableText = disable ? "true" : "false";
 
     QProcess process;
-    QString commandStr = "kwriteconfig5 --file kwinrc --group Windows --key BorderlessMaximizedWindows --type bool " + disableText;
-    process.start(commandStr);
+    QStringList arguments;
+    arguments << "--file" << "kwinrc" << "--group" << "Windows" << "--key" << "BorderlessMaximizedWindows" << "--type" << "bool" << disableText;
+    process.start("kwriteconfig5", arguments);
     process.waitForFinished();
 
     QDBusInterface iface("org.kde.KWin", "/KWin", "", QDBusConnection::sessionBus());
diff --git a/libappletdecoration/windowsystem.h b/libappletdecoration/windowsystem.h
index 881b6ea..ca7ad71 100644
--- a/libappletdecoration/windowsystem.h
+++ b/libappletdecoration/windowsystem.h
@@ -18,8 +18,7 @@
  *
  */
 
-#ifndef WINDOWSYSTEM_H
-#define WINDOWSYSTEM_H
+#pragma once
 
 #include <QObject>
 
@@ -42,6 +41,3 @@ private:
 
 }
 }
-
-#endif
-
diff --git a/package/metadata.desktop b/package/metadata.desktop
deleted file mode 100644
index ceea2c3..0000000
--- a/package/metadata.desktop
+++ /dev/null
@@ -1,21 +0,0 @@
-[Desktop Entry]
-Name=Window Buttons
-Comment=Window buttons for your panels
-
-Encoding=UTF-8
-Icon=focus-windows
-Keywords=window buttons
-Type=Service
-
-X-Plasma-API=declarativeappletscript
-X-Plasma-MainScript=ui/main.qml
-
-X-KDE-PluginInfo-Author=Michail Vourlakos
-X-KDE-PluginInfo-Category=Windows and Tasks
-X-KDE-PluginInfo-Email=mvourlakos@gmail.com
-X-KDE-PluginInfo-License=GPLv2
-X-KDE-PluginInfo-Name=org.kde.windowbuttons
-X-KDE-PluginInfo-Version=0.11.1
-X-KDE-PluginInfo-Website=https://github.com/psifidotos/applet-window-buttons
-X-KDE-ServiceTypes=Plasma/Applet
-
diff --git a/package/metadata.json b/package/metadata.json
new file mode 100644
index 0000000..a5da32a
--- /dev/null
+++ b/package/metadata.json
@@ -0,0 +1,24 @@
+{
+    "KPlugin": {
+        "Authors": [
+            {
+                "Email": "mvourlakos@gmail.com",
+                "Name": "Michail Vourlakos"
+            }
+        ],
+        "Category": "Windows and Tasks",
+        "Description": "Window buttons for your panels",
+        "Icon": "focus-windows",
+        "Id": "org.kde.windowbuttons",
+        "License": "GPLv2",
+        "Name": "Window Buttons",
+        "ServiceTypes": [
+            "Plasma/Applet"
+        ],
+        "Version": "0.11.1",
+        "Website": "https://github.com/psifidotos/applet-window-buttons"
+    },
+    "Keywords": "window buttons",
+    "X-Plasma-API": "declarativeappletscript",
+    "X-Plasma-MainScript": "ui/main.qml"
+}