wayland:enable previews for Plasma 5.20

BUG:426913

plasmoid/package/contents/ui/main.qml

@@ -61,8 +61,9 @@ Item {
     LayoutMirroring.enabled: Qt.application.layoutDirection === Qt.RightToLeft && !root.vertical
     LayoutMirroring.childrenInherit: true
 
-    property bool plasma515: latteView ? latteView.plasma515 : LatteCore.Environment.plasmaDesktopVersion >= LatteCore.Environment.makeVersion(5,15,0)
-    property bool plasma518: latteView ? latteView.plasma518 : LatteCore.Environment.plasmaDesktopVersion >= LatteCore.Environment.makeVersion(5,18,0)
+    property bool plasma515: LatteCore.Environment.plasmaDesktopVersion >= LatteCore.Environment.makeVersion(5,15,0)
+    property bool plasma518: LatteCore.Environment.plasmaDesktopVersion >= LatteCore.Environment.makeVersion(5,18,0)
+    property bool plasma520: LatteCore.Environment.plasmaDesktopVersion >= LatteCore.Environment.makeVersion(5,20,0)
 
     property bool editMode: latteView ? latteView.editMode : plasmoid.userConfiguring
     property bool inConfigureAppletsMode: latteView ? latteView.inConfigureAppletsMode : true

plasmoid/package/contents/ui/previews/PipeWireThumbnail.qml

@@ -0,0 +1,33 @@
+/*
+ *   Copyright 2020 Aleix Pol Gonzalez <aleixpol@kde.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Library General Public License as
+ *   published by the Free Software Foundation; either version 2, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU Library General Public License for more details
+ *
+ *   You should have received a copy of the GNU Library General Public
+ *   License along with this program; if not, write to the
+ *   Free Software Foundation, Inc.,
+ *   51 Franklin Street, Fifth Floor, Boston, MA  2.010-1301, USA.
+ */
+
+import QtQuick.Window 2.6
+import org.kde.taskmanager 0.1 as TaskManager
+
+TaskManager.PipeWireSourceItem {
+    visible: waylandItem.nodeId > 0
+    nodeId: waylandItem.nodeId
+
+    anchors.fill: parent
+
+    TaskManager.ScreencastingRequest {
+        id: waylandItem
+        uuid: !windowsPreviewDlg.visible ? "" : thumbnailSourceItem.winId
+    }
+}

plasmoid/package/contents/ui/previews/PlasmaCoreThumbnail.qml

@@ -0,0 +1,33 @@
+/*
+*  Copyright 2020  Michail Vourlakos <mvourlakos@gmail.com>
+*
+*
+*  This file is part of Latte-Dock
+*
+*  Latte-Dock is free software; you can redistribute it and/or
+*  modify it under the terms of the GNU General Public License as
+*  published by the Free Software Foundation; either version 2 of
+*  the License, or (at your option) any later version.
+*
+*  Latte-Dock is distributed in the hope that it will be useful,
+*  but WITHOUT ANY WARRANTY; without even the implied warranty of
+*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*  GNU General Public License for more details.
+*
+*  You should have received a copy of the GNU General Public License
+*  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import QtQuick 2.6
+import org.kde.plasma.core 2.0 as PlasmaCore
+
+PlasmaCore.WindowThumbnail {
+    winId: thumbnailSourceItem.winId
+
+    onWinIdChanged: {
+        //! WORKAROUND, in order for toolTipDelegate to re-instantiate the previews model when
+        //! previews are changing from single instance preview to another single instance
+        visible = false;
+        visible = true;
+    }
+}

plasmoid/package/contents/ui/previews/ToolTipInstance.qml

@@ -187,7 +187,7 @@ Column {
 
             readonly property bool isMinimized: isGroup ? instance.isMinimized : mainToolTip.isMinimizedParent
             // TODO: this causes XCB error message when being visible the first time
-            property int winId: isWin && windows[flatIndex] !== undefined ? windows[flatIndex] : 0
+            readonly property var winId: isWin && windows[flatIndex] !== undefined ? windows[flatIndex] : 0
 
             // There's no PlasmaComponents3 version
             PlasmaComponents.Highlight {
@@ -197,22 +197,12 @@ Column {
             }
 
             Loader{
-                id:previewThumbX11Loader
+                id:previewThumbLoader
                 anchors.fill: parent
                 anchors.margins: 2
-                active: !LatteCore.WindowSystem.isPlatformWayland
+                active: LatteCore.WindowSystem.isPlatformX11 || (root.plasma520 && LatteCore.WindowSystem.isPlatformWayland)
                 visible: !albumArtImage.visible && !thumbnailSourceItem.isMinimized
-
-                sourceComponent: PlasmaCore.WindowThumbnail {
-                    winId: thumbnailSourceItem.winId
-
-                    onWinIdChanged: {
-                        //! WORKAROUND, in order for toolTipDelegate to re-instantiate the previews model when
-                        //! previews are changing from single instance preview to another single instance
-                        visible = false;
-                        visible = true;
-                    }
-                }
+                source: root.plasma520 && LatteCore.WindowSystem.isPlatformWayland ? "PipeWireThumbnail.qml" : "PlasmaCoreThumbnail.qml"
             }
 
             ToolTipWindowMouseArea {
@@ -262,7 +252,7 @@ Column {
                 animated: false
                 usesPlasmaTheme: false
                 visible: (thumbnailSourceItem.isMinimized && !albumArtImage.visible) //X11 case
-                         || (!previewThumbX11Loader.active && !albumArtImage.visible) //Wayland case
+                         || (!previewThumbLoader.active && !albumArtImage.visible) //Wayland case
             }
         }