Port SDDM theme to PlasmaComponents 3.0

sddm-theme/BreezeMenuStyle.qml

-import QtQuick 2.15
-// Don't bump them any further, these are the latest.
-import QtQuick.Controls 1.6 as QQC
-import QtQuick.Controls.Styles 1.4 as QQCS
-
-import org.kde.plasma.core 2.0 as PlasmaCore
-
-QQCS.MenuStyle {
-    frame: Rectangle {
-        color: PlasmaCore.ColorScope.backgroundColor
-        border.color: Qt.tint(PlasmaCore.ColorScope.textColor, Qt.rgba(color.r, color.g, color.b, 0.7))
-        border.width: 1
-    }
-    itemDelegate.label: QQC.Label {
-        height: contentHeight * 1.2
-        verticalAlignment: Text.AlignVCenter
-        color: styleData.selected ? PlasmaCore.ColorScope.highlightedTextColor : PlasmaCore.ColorScope.textColor
-        font.pointSize: config.fontSize
-        text: styleData.text
-    }
-    itemDelegate.background: Rectangle {
-        visible: styleData.selected
-        color: PlasmaCore.ColorScope.highlightColor
-    }
-}

sddm-theme/KeyboardButton.qml

+/*
+    SPDX-FileCopyrightText: 2016 David Edmundson <davidedmundson@kde.org>
+    SPDX-FileCopyrightText: 2022 Aleix Pol Gonzalez <aleixpol@kde.org>
+
+    SPDX-License-Identifier: LGPL-2.0-or-later
+*/
+
 import QtQuick 2.15
-import QtQuick.Controls 1.6 as QQC // Don't bump it any further, this is the latest.
 
 import org.kde.plasma.core 2.0 as PlasmaCore
-import org.kde.plasma.components 2.0 as PlasmaComponents // Because PC3 ToolButton can't take a menu
+import org.kde.plasma.components 3.0 as PlasmaComponents
 
 PlasmaComponents.ToolButton {
-    id: keyboardButton
+    id: root
 
-    property int currentIndex: -1
+    property int currentIndex: keyboard.currentLayout
+    onCurrentIndexChanged: keyboard.currentLayout = currentIndex
 
     text: i18nd("plasma_lookandfeel_org.kde.lookandfeel", "Keyboard Layout: %1", instantiator.objectAt(currentIndex).shortName)
-    implicitWidth: minimumWidth
-
-    visible: menu.items.length > 1
+    visible: menu.count > 1
 
     Component.onCompleted: {
         currentIndex = Qt.binding(() => keyboard.currentLayout);
     }
+    checkable: true
+    checked: menu.opened
+    onToggled: {
+        if (checked) {
+            menu.popup(root, 0, 0)
+        } else {
+            menu.dismiss()
+        }
+    }
+
+    PlasmaComponents.Menu {
+        id: menu
+        PlasmaCore.ColorScope.colorGroup: PlasmaCore.Theme.NormalColorGroup
+        PlasmaCore.ColorScope.inherit: false
 
-    menu: QQC.Menu {
-        id: keyboardMenu
-        style: BreezeMenuStyle {}
         Instantiator {
             id: instantiator
             model: keyboard.layouts
-            onObjectAdded: keyboardMenu.insertItem(index, object)
-            onObjectRemoved: keyboardMenu.removeItem(object)
-            delegate: QQC.MenuItem {
+            onObjectAdded: menu.insertItem(index, object)
+            onObjectRemoved: menu.removeItem(object)
+            delegate: PlasmaComponents.MenuItem {
                 text: modelData.longName
                 property string shortName: modelData.shortName
                 onTriggered: {

sddm-theme/Main.qml

@@ -6,7 +6,6 @@
 
 import QtQuick 2.15
 import QtQuick.Layouts 1.15
-import QtQuick.Controls 1.6 // Don't bump it any further, this is the latest.
 import QtQuick.Controls 2.15 as QQC2
 import QtGraphicalEffects 1.15
 

sddm-theme/SessionButton.qml

 /*
     SPDX-FileCopyrightText: 2016 David Edmundson <davidedmundson@kde.org>
+    SPDX-FileCopyrightText: 2022 Aleix Pol Gonzalez <aleixpol@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 import QtQuick 2.15
-import QtQuick.Controls 1.6 as QQC // Don't bump it any further, this is the latest.
 
 import org.kde.plasma.core 2.0 as PlasmaCore
-import org.kde.plasma.components 2.0 as PlasmaComponents // Because PC3 ToolButton can't take a menu
+import org.kde.plasma.components 3.0 as PlasmaComponents
 
 PlasmaComponents.ToolButton {
     id: root
     property int currentIndex: -1
-
-    implicitWidth: minimumWidth
-
-    visible: menu.items.length > 1
-
+    visible: menu.count > 1
     text: i18nd("plasma_lookandfeel_org.kde.lookandfeel", "Desktop Session: %1", instantiator.objectAt(currentIndex).text || "")
 
     Component.onCompleted: {
         currentIndex = sessionModel.lastIndex
     }
+    checkable: true
+    checked: menu.opened
+    onToggled: {
+        if (checked) {
+            menu.popup(root, 0, 0)
+        } else {
+            menu.dismiss()
+        }
+    }
+
+    PlasmaComponents.Menu {
+        PlasmaCore.ColorScope.colorGroup: PlasmaCore.Theme.NormalColorGroup
+        PlasmaCore.ColorScope.inherit: false
 
-    menu: QQC.Menu {
         id: menu
-        style: BreezeMenuStyle {}
         Instantiator {
             id: instantiator
             model: sessionModel
             onObjectAdded: menu.insertItem(index, object)
             onObjectRemoved: menu.removeItem( object )
-            delegate: QQC.MenuItem {
+            delegate: PlasmaComponents.MenuItem {
                 text: model.name
                 onTriggered: {
                     root.currentIndex = model.index