Fix all errors and warnings on login, lock, and logout screens

There were three principal sources of errors and warnings:
1. Un-ported `onFooChanged` statements
2. `config.fontSize` being unconditionally referenced from components
   without access to it (it comes from the SDDM config)
3. Accessing units from the context property rather than the singleton

All are fixed now. Tested with:
1. `sddm-greeter --test-mode --theme ~/kde/usr/share/sddm/themes/breeze/`
2. `~/kde/usr/lib64/libexec/kscreenlocker_greet --testing --theme ~/kde/src/plasma-workspace/lookandfeel`
3. `/kde/usr/lib64/libexec/ksmserver-logout-greeter --fakearg`

No regressions found.

BUG: 425349
FIXED-IN: 5.20

components/workspace/BatteryIcon.qml

@@ -39,7 +39,7 @@ Item {
     PlasmaCore.SvgItem {
         id: batterySvg
         anchors.centerIn: parent
-        width: units.roundToIconSize(Math.min(parent.width, parent.height))
+        width: PlasmaCore.Units.roundToIconSize(Math.min(parent.width, parent.height))
         height: width
         svg: svg
         elementId: "Battery"

lookandfeel/contents/components/ActionButton.qml

@@ -30,7 +30,7 @@ Item {
     property alias labelRendering: label.renderType
     property alias circleOpacity: iconCircle.opacity
     property alias circleVisiblity: iconCircle.visible
-    property int fontSize: config.fontSize
+    property int fontSize: PlasmaCore.Theme.defaultFont.pointSize + 1
     readonly property bool softwareRendering: GraphicsInfo.api === GraphicsInfo.Software
     signal clicked
 
@@ -96,7 +96,7 @@ Item {
 
     PlasmaComponents3.Label {
         id: label
-        font.pointSize: Math.max(fontSize + 1,theme.defaultFont.pointSize + 1)
+        font.pointSize: root.fontSize
         anchors {
             top: icon.bottom
             topMargin: (softwareRendering ? 1.5 : 1) * units.smallSpacing

lookandfeel/contents/components/Battery.qml

@@ -24,7 +24,11 @@ import org.kde.plasma.components 3.0 as PlasmaComponents3
 import org.kde.plasma.workspace.components 2.0 as PW
 
 Row {
-    spacing: units.smallSpacing
+    id: row
+
+    property int fontSize: PlasmaCore.Theme.defaultFont.pointSize
+
+    spacing: PlasmaCore.Units.smallSpacing
     visible: pmSource.data["Battery"]["Has Cumulative"]
 
     PlasmaCore.DataSource {
@@ -45,7 +49,7 @@ Row {
 
     PlasmaComponents3.Label {
         id: batteryLabel
-        font.pointSize: config.fontSize
+        font.pointSize: row.fontSize
         text: i18nd("plasma_lookandfeel_org.kde.lookandfeel","%1%", battery.percent)
         Accessible.name: i18nd("plasma_lookandfeel_org.kde.lookandfeel","Battery at %1%", battery.percent)
     }

lookandfeel/contents/components/KeyboardLayoutButton.qml

@@ -25,14 +25,10 @@ import org.kde.plasma.components 3.0 as PlasmaComponents3
 import org.kde.plasma.workspace.keyboardlayout 1.0
 
 PlasmaComponents3.ToolButton {
-
-    property int fontSize: config.fontSize
-
     id: kbLayoutButton
 
     icon.name: "input-keyboard"
     text: layout.currentLayoutDisplayName
-    font.pointSize: Math.max(fontSize,theme.defaultFont.pointSize)
 
     Accessible.name: i18ndc("plasma_lookandfeel_org.kde.lookandfeel", "Button to change keyboard layout", "Switch layout")
 

lookandfeel/contents/components/SessionManagementScreen.qml

@@ -61,7 +61,7 @@ Item {
 
     property alias userList: userListView
 
-    property int fontSize: config.fontSize
+    property int fontSize: PlasmaCore.Theme.defaultFont.pointSize + 2
 
     default property alias _children: innerLayout.children
 
@@ -73,6 +73,7 @@ Item {
             left: parent.left
             right: parent.right
         }
+        fontSize: root.fontSize
     }
 
     //goal is to show the prompts, in ~16 grid units high, then the action buttons
@@ -87,7 +88,7 @@ Item {
         anchors.bottom: parent.bottom
         PlasmaComponents3.Label {
             id: notificationsLabel
-            font.pointSize: Math.max(fontSize + 1,theme.defaultFont.pointSize + 1)
+            font.pointSize: root.fontSize
             Layout.maximumWidth: units.gridUnit * 16
             Layout.alignment: Qt.AlignHCenter
             Layout.fillWidth: true

lookandfeel/contents/components/UserDelegate.qml

@@ -31,14 +31,13 @@ Item {
 
     property bool isCurrent: true
 
-    readonly property var m: model
     property string name
     property string userName
     property string avatarPath
     property string iconSource
     property bool constrainText: true
     property alias nameFontSize: usernameDelegate.font.pointSize
-    property int fontSize: config.fontSize
+    property int fontSize: PlasmaCore.Theme.defaultFont.pointSize + 2
     signal clicked()
 
     property real faceSize: units.gridUnit * 7
@@ -161,7 +160,7 @@ Item {
 
     PlasmaComponents3.Label {
         id: usernameDelegate
-        font.pointSize: Math.max(fontSize + 2,theme.defaultFont.pointSize + 2)
+        font.pointSize: wrapper.fontSize
         anchors {
             bottom: parent.bottom
             horizontalCenter: parent.horizontalCenter

lookandfeel/contents/components/UserList.qml

@@ -18,12 +18,14 @@
  */
 
 import QtQuick 2.2
+import org.kde.plasma.core 2.0 as PlasmaCore
 
 ListView {
     id: view
     readonly property string selectedUser: currentItem ? currentItem.userName : ""
     readonly property int userItemWidth: units.gridUnit * 8
     readonly property int userItemHeight: units.gridUnit * 8
+    property int fontSize: PlasmaCore.Theme.defaultFont.pointSize + 2
 
     implicitHeight: userItemHeight
 
@@ -47,6 +49,7 @@ ListView {
     delegate: UserDelegate {
         avatarPath: model.icon || ""
         iconSource: model.iconName || "user-identity"
+        fontSize: view.fontSize
 
         name: {
             var displayName = model.realName || model.name

lookandfeel/contents/lockscreen/LockScreen.qml

@@ -52,7 +52,7 @@ Item {
     Connections {
         id:loaderConnection
         target: org_kde_plasma_screenlocker_greeter_view
-        onFrameSwapped: {
+        function onFrameSwapped() {
             mainLoader.source = "LockScreenUi.qml";
             loaderConnection.target = null;
         }

lookandfeel/contents/lockscreen/LockScreenUi.qml

@@ -40,19 +40,19 @@ PlasmaCore.ColorScope {
 
     Connections {
         target: authenticator
-        onFailed: {
+        function onFailed() {
             root.notification = i18nd("plasma_lookandfeel_org.kde.lookandfeel","Unlocking failed");
         }
-        onGraceLockedChanged: {
+        function onGraceLockedChanged() {
             if (!authenticator.graceLocked) {
                 root.notification = "";
                 root.clearPassword();
             }
         }
-        onMessage: {
+        function onMessage() {
             root.notification = msg;
         }
-        onError: {
+        function onError() {
             root.notification = err;
         }
     }
@@ -63,7 +63,7 @@ PlasmaCore.ColorScope {
 
     Connections {
         target: sessionManagement
-        onAboutToSuspend: {
+        function onAboutToSuspend() {
             root.clearPassword();
         }
     }

lookandfeel/contents/lockscreen/MainBlock.qml

@@ -87,7 +87,7 @@ SessionManagementScreen {
 
             Connections {
                 target: root
-                onClearPassword: {
+                function onClearPassword() {
                     passwordBox.forceActiveFocus()
                     passwordBox.text = "";
                 }

lookandfeel/contents/logout/Logout.qml

@@ -119,7 +119,6 @@ PlasmaCore.ColorScope {
     UserDelegate {
         width: units.gridUnit * 7
         height: width
-        nameFontSize: theme.defaultFont.pointSize + 2
         anchors {
             horizontalCenter: parent.horizontalCenter
             bottom: parent.verticalCenter

sddm-theme/KeyboardButton.qml

@@ -12,7 +12,6 @@ PlasmaComponents.ToolButton {
 
     text: i18nd("plasma_lookandfeel_org.kde.lookandfeel", "Keyboard Layout: %1", instantiator.objectAt(currentIndex).shortName)
     implicitWidth: minimumWidth
-    font.pointSize: config.fontSize
 
     visible: menu.items.length > 1
 

sddm-theme/Login.qml

@@ -19,7 +19,7 @@ SessionManagementScreen {
     property int visibleBoundary: mapFromItem(loginButton, 0, 0).y
     onHeightChanged: visibleBoundary = mapFromItem(loginButton, 0, 0).y + loginButton.height + units.smallSpacing
 
-    property int fontSize: config.fontSize
+    property int fontSize: parseInt(config.fontSize)
 
     signal loginRequest(string username, string password)
 

sddm-theme/Main.qml

@@ -29,6 +29,11 @@ import org.kde.plasma.extras 2.0 as PlasmaExtras
 
 import "components"
 
+// TODO: Once SDDM 0.19 is released and we are setting the font size using the
+// SDDM KCM's syncing feature, remove the `config.fontSize` overrides here and
+// the fontSize properties in various components, because the theme's default
+// font size will be correctly propagated to the login screen
+
 PlasmaCore.ColorScope {
     id: root
 
@@ -203,6 +208,7 @@ PlasmaCore.ColorScope {
                     ActionButton {
                         iconSource: "system-suspend"
                         text: i18ndc("plasma_lookandfeel_org.kde.lookandfeel","Suspend to RAM","Sleep")
+                        fontSize: parseInt(config.fontSize) + 1
                         onClicked: sddm.suspend()
                         enabled: sddm.canSuspend
                         visible: !inputPanel.keyboardActive
@@ -210,6 +216,7 @@ PlasmaCore.ColorScope {
                     ActionButton {
                         iconSource: "system-reboot"
                         text: i18nd("plasma_lookandfeel_org.kde.lookandfeel","Restart")
+                        fontSize: parseInt(config.fontSize) + 1
                         onClicked: sddm.reboot()
                         enabled: sddm.canReboot
                         visible: !inputPanel.keyboardActive
@@ -217,6 +224,7 @@ PlasmaCore.ColorScope {
                     ActionButton {
                         iconSource: "system-shutdown"
                         text: i18nd("plasma_lookandfeel_org.kde.lookandfeel","Shut Down")
+                        fontSize: parseInt(config.fontSize) + 1
                         onClicked: sddm.powerOff()
                         enabled: sddm.canPowerOff
                         visible: !inputPanel.keyboardActive
@@ -224,6 +232,7 @@ PlasmaCore.ColorScope {
                     ActionButton {
                         iconSource: "system-user-prompt"
                         text: i18ndc("plasma_lookandfeel_org.kde.lookandfeel", "For switching to a username and password prompt", "Other...")
+                        fontSize: parseInt(config.fontSize) + 1
                         onClicked: mainStack.push(userPromptComponent)
                         enabled: true
                         visible: !userListComponent.showUsernamePrompt && !inputPanel.keyboardActive
@@ -361,6 +370,7 @@ PlasmaCore.ColorScope {
                 showUsernamePrompt: true
                 notificationMessage: root.notificationMessage
                 loginScreenUiVisible: loginScreenRoot.uiVisible
+                fontSize: parseInt(config.fontSize) + 2
 
                 // using a model rather than a QObject list to avoid QTBUG-75900
                 userListModel: ListModel {
@@ -383,6 +393,7 @@ PlasmaCore.ColorScope {
                     ActionButton {
                         iconSource: "system-suspend"
                         text: i18ndc("plasma_lookandfeel_org.kde.lookandfeel","Suspend to RAM","Sleep")
+                        fontSize: parseInt(config.fontSize) + 1
                         onClicked: sddm.suspend()
                         enabled: sddm.canSuspend
                         visible: !inputPanel.keyboardActive
@@ -390,6 +401,7 @@ PlasmaCore.ColorScope {
                     ActionButton {
                         iconSource: "system-reboot"
                         text: i18nd("plasma_lookandfeel_org.kde.lookandfeel","Restart")
+                        fontSize: parseInt(config.fontSize) + 1
                         onClicked: sddm.reboot()
                         enabled: sddm.canReboot
                         visible: !inputPanel.keyboardActive
@@ -397,6 +409,7 @@ PlasmaCore.ColorScope {
                     ActionButton {
                         iconSource: "system-shutdown"
                         text: i18nd("plasma_lookandfeel_org.kde.lookandfeel","Shut Down")
+                        fontSize: parseInt(config.fontSize) + 1
                         onClicked: sddm.powerOff()
                         enabled: sddm.canPowerOff
                         visible: !inputPanel.keyboardActive
@@ -404,6 +417,7 @@ PlasmaCore.ColorScope {
                     ActionButton {
                         iconSource: "system-user-list"
                         text: i18nd("plasma_lookandfeel_org.kde.lookandfeel","List Users")
+                        fontSize: parseInt(config.fontSize) + 1
                         onClicked: mainStack.pop()
                         visible: !inputPanel.keyboardActive
                     }
@@ -460,7 +474,7 @@ PlasmaCore.ColorScope {
                 bottom: parent.bottom
                 left: parent.left
                 right: parent.right
-                margins: units.smallSpacing
+                margins: PlasmaCore.Units.smallSpacing
             }
 
             Behavior on opacity {
@@ -478,17 +492,21 @@ PlasmaCore.ColorScope {
             }
 
             KeyboardButton {
+                font.pointSize: config.fontSize
             }
 
             SessionButton {
                 id: sessionButton
+                font.pointSize: config.fontSize
             }
 
             Item {
                 Layout.fillWidth: true
             }
 
-            Battery { }
+            Battery {
+                fontSize: config.fontSize
+            }
         }
     }
 

sddm-theme/SessionButton.qml

@@ -34,8 +34,6 @@ PlasmaComponents.ToolButton {
 
     text: i18nd("plasma_lookandfeel_org.kde.lookandfeel", "Desktop Session: %1", instantiator.objectAt(currentIndex).text || "")
 
-    font.pointSize: config.fontSize
-
     Component.onCompleted: {
         currentIndex = sessionModel.lastIndex
     }