Don't elide UserDelegate text when there's only one item

Summary:
In the lock screen the user delegate has to elide the text when there
are multiple items next to each other, otherwise it will overlap.

When there's only one item (which is quite common) we don't need to
and doing so looks weird.

Test Plan:
Modified SDDM dummydata/userModel to have one entry with a long name
and back to multiple entries.

Reviewers: #plasma, broulik

Reviewed By: #plasma, broulik

Subscribers: broulik, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D7472

lookandfeel/contents/components/UserDelegate.qml

@@ -32,6 +32,7 @@ Item {
     property string userName
     property string avatarPath
     property string iconSource
+    property bool constrainText: true
     signal clicked()
 
     property real faceSize: Math.min(width, height - usernameDelegate.height - units.largeSpacing)
@@ -132,10 +133,10 @@ Item {
         id: usernameDelegate
         anchors {
             bottom: parent.bottom
-            left: parent.left
+            horizontalCenter: parent.horizontalCenter
-            right: parent.right
         }
         height: implicitHeight // work around stupid bug in Plasma Components that sets the height
+        width: constrainText ? parent.width : implicitWidth
         text: wrapper.name
         elide: Text.ElideRight
         horizontalAlignment: Text.AlignHCenter

lookandfeel/contents/components/UserList.qml

@@ -76,6 +76,9 @@ ListView {
         width: userItemWidth
         height: userItemHeight
 
+        //if we only have one delegate, we don't need to clip the text as it won't be overlapping with anything
+        constrainText: ListView.view.count > 1
+
         isCurrent: ListView.isCurrentItem
 
         onClicked: {

lookandfeel/contents/logout/Logout.qml

@@ -132,6 +132,7 @@ PlasmaCore.ColorScope {
             horizontalCenter: parent.horizontalCenter
             bottom: parent.verticalCenter
         }
+        constrainText: false
         avatarPath: kuser.faceIconUrl
         iconSource: "user-identity"
         isCurrent: true