Normalize bar icon size and alignment

shell/plugins/panels/dropbox/DropboxIcon.qml

@@ -7,11 +7,13 @@ Item {
   id: root
 
   property real iconSize: Style.font.icon
+  readonly property real aspectRatio: 1.18
+  property real artworkScale: 0.95
   property color color: Commons.Color.foreground
 
-  width: iconSize * 1.18
+  width: iconSize * aspectRatio
   height: iconSize
-  implicitWidth: iconSize * 1.18
+  implicitWidth: iconSize * aspectRatio
   implicitHeight: iconSize
 
   Shape {
@@ -19,7 +21,7 @@ Item {
     antialiasing: true
     layer.enabled: true
     layer.samples: 4
-    scale: 0.95
+    scale: root.artworkScale
 
     Tile { cx: root.width * 0.25; cy: root.height * 0.188 }
     Tile { cx: root.width * 0.75; cy: root.height * 0.188 }

shell/plugins/panels/dropbox/Panel.qml

@@ -175,8 +175,10 @@ Panel {
     iconComponent: Component {
       Item {
         DropboxIcon {
-          anchors.centerIn: parent
-          iconSize: Style.space(12)
+          x: (parent.width - width) / 2
+          y: (parent.height - height) / 2
+          iconSize: button.iconSize / aspectRatio
+          artworkScale: 1
           color: root.barIconColor
           opacity: dropbox.active ? 1.0 : 0.6
         }

shell/plugins/panels/power/Panel.qml

@@ -278,9 +278,8 @@ Panel {
     id: button
     anchors.fill: parent
     bar: root.bar
-    text: root.showPercentage && !vertical
-      ? Math.round(root.batteryFraction * 100) + "% " + root.batteryIcon()
-      : root.batteryIcon()
+    text: root.batteryIcon()
+    labelText: root.showPercentage && !vertical ? Math.round(root.batteryFraction * 100) + "%" : ""
     slotSize: Style.bar.iconSlot * (root.showPercentage && !vertical ? 2 : 1)
     tooltipText: ""
     onPressed: function(b) {

shell/plugins/panels/tailscale/Panel.qml

@@ -385,8 +385,9 @@ Panel {
     iconComponent: Component {
       Item {
         TailscaleIcon {
-          anchors.centerIn: parent
-          iconSize: Style.space(11)
+          x: (parent.width - width) / 2
+          y: (parent.height - height) / 2
+          iconSize: button.iconSize
           color: root.barIconColor
           badgeColor: root.urgent
           crossed: !tailscale.active && !tailscale.needsLogin