Themes: fix deprecated signal handler declarations

Fixes following warnings:
```
QML Connections: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
Parameter "event" is not declared. Injection of parameters into signal handlers is deprecated. Use JavaScript functions with formal parameters instead.
```

components/2.0/Button.qml

@@ -111,7 +111,7 @@ Rectangle {
         onReleased: { container.focus = true; container.released() }
     }
 
-    Keys.onPressed: {
+    Keys.onPressed: function (event) {
         if (event.key === Qt.Key_Space) {
             container.spaceDown = true;
             container.pressed()
@@ -122,7 +122,7 @@ Rectangle {
         }
     }
 
-    Keys.onReleased: {
+    Keys.onReleased: function (event) {
         if (event.key === Qt.Key_Space) {
             container.spaceDown = false;
             container.released()

components/2.0/ComboBox.qml

@@ -134,7 +134,7 @@ FocusScope {
         }
     }
 
-    Keys.onPressed: {
+    Keys.onPressed: function (event) {
         if (event.key === Qt.Key_Up) {
             listView.decrementCurrentIndex()
         } else if (event.key === Qt.Key_Down) {

components/2.0/ImageButton.qml

@@ -77,7 +77,7 @@ Image {
         onReleased: { container.focus = true; container.released() }
     }
 
-    Keys.onPressed: {
+    Keys.onPressed: function (event) {
         if (event.key === Qt.Key_Space) {
             container.spaceDown = true;
             container.pressed()
@@ -88,7 +88,7 @@ Image {
         }
     }
 
-    Keys.onReleased: {
+    Keys.onReleased: function (event) {
         if (event.key === Qt.Key_Space) {
             container.spaceDown = false;
             container.released()

components/2.0/LayoutBox.qml

@@ -30,12 +30,16 @@ ComboBox {
     model: keyboard.layouts
     index: keyboard.currentLayout
 
-    onValueChanged: keyboard.currentLayout = id
+    function onValueChanged(id) {
+        keyboard.currentLayout = id
+    }
 
     Connections {
         target: keyboard
 
-        onCurrentLayoutChanged: combo.index = keyboard.currentLayout
+        function onCurrentLayoutChanged() {
+            combo.index = keyboard.currentLayout
+        }
     }
 
     rowDelegate: Rectangle {

components/2.0/PictureBox.qml

@@ -105,7 +105,7 @@ FocusScope {
             focus: true
             visible: showPassword
 
-            Keys.onPressed: {
+            Keys.onPressed: function (event) {
                 if (event.key === Qt.Key_Return || event.key === Qt.Key_Enter) {
                     container.login();
                     event.accepted = true

data/themes/elarun/Main.qml

@@ -39,11 +39,11 @@ Rectangle {
 
     Connections {
         target: sddm
-        onLoginSucceeded: {
+        function onLoginSucceeded() {
         }
-        onInformationMessage: {
+        function onInformationMessage(message) {
         }
-        onLoginFailed: {
+        function onLoginFailed() {
             pw_entry.text = ""
         }
     }
@@ -135,7 +135,7 @@ Rectangle {
 
                             KeyNavigation.backtab: user_entry; KeyNavigation.tab: login_button
 
-                            Keys.onPressed: {
+                            Keys.onPressed: function (event) {
                                 if (event.key === Qt.Key_Return || event.key === Qt.Key_Enter) {
                                     sddm.login(user_entry.text, pw_entry.text, sessionIndex)
                                     event.accepted = true

data/themes/maldives/Main.qml

@@ -40,17 +40,16 @@ Rectangle {
     Connections {
         target: sddm
 
-        onLoginSucceeded: {
+        function onLoginSucceeded() {
             errorMessage.color = "steelblue"
             errorMessage.text = textConstants.loginSucceeded
         }
-
-        onLoginFailed: {
+        function onLoginFailed() {
             password.text = ""
             errorMessage.color = "red"
             errorMessage.text = textConstants.loginFailed
         }
-        onInformationMessage: {
+        function onInformationMessage(message) {
             errorMessage.color = "red"
             errorMessage.text = message
         }
@@ -126,7 +125,7 @@ Rectangle {
 
                         KeyNavigation.backtab: rebootButton; KeyNavigation.tab: password
 
-                        Keys.onPressed: {
+                        Keys.onPressed: function (event) {
                             if (event.key === Qt.Key_Return || event.key === Qt.Key_Enter) {
                                 sddm.login(name.text, password.text, sessionIndex)
                                 event.accepted = true
@@ -153,7 +152,7 @@ Rectangle {
 
                         KeyNavigation.backtab: name; KeyNavigation.tab: session
 
-                        Keys.onPressed: {
+                        Keys.onPressed: function (event) {
                             if (event.key === Qt.Key_Return || event.key === Qt.Key_Enter) {
                                 sddm.login(name.text, password.text, sessionIndex)
                                 event.accepted = true

data/themes/maya/Main.qml

@@ -75,7 +75,7 @@ Rectangle {
   Connections {
     target: sddm
 
-    onLoginSucceeded: {
+    function onLoginSucceeded() {
       prompt_bg.color = successText
       prompt_txt.text = textConstants.loginSucceeded
 
@@ -84,7 +84,7 @@ Rectangle {
 
       anim_success.start()
     }
-    onLoginFailed: {
+    function onLoginFailed() {
       prompt_bg.color = failureText
       prompt_txt.text = textConstants.loginFailed
 
@@ -93,7 +93,7 @@ Rectangle {
 
       anim_failure.start()
     }
-    onInformationMessage: {
+    function onInformationMessage(message) {
       prompt_bg.color = failureText
       prompt_txt.text = message
 
@@ -505,7 +505,7 @@ Rectangle {
         KeyNavigation.tab     : maya_login
         KeyNavigation.backtab : maya_username
 
-        Keys.onPressed: {
+        Keys.onPressed: function (event) {
           if ((event.key === Qt.Key_Return) || (event.key === Qt.Key_Enter)) {
             maya_root.tryLogin()
 
@@ -546,7 +546,7 @@ Rectangle {
 
         onClicked: maya_root.tryLogin()
 
-        Keys.onPressed: {
+        Keys.onPressed: function (event) {
           if ((event.key === Qt.Key_Return) || (event.key === Qt.Key_Enter)) {
             maya_root.tryLogin()
 

src/greeter/theme/Main.qml

@@ -40,15 +40,15 @@ Rectangle {
 
     Connections {
         target: sddm
-        onLoginSucceeded: {
+        function onLoginSucceeded() {
         }
 
-        onLoginFailed: {
+        function onLoginFailed() {
             txtMessage.text = textConstants.loginFailed
             listView.currentItem.password = ""
         }
 
-        onInformationMessage: {
+        function onInformationMessage(message) {
             txtMessage.text = message
         }
     }