QML UI: more theme information

The fonts on my Nexus 6p are way too big (especially when compared
to the fonts of the same build on an iPhone 6plus that has very
similar screen size). Simply trying to get more data...

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

mobile-widgets/qml/ThemeTest.qml

@@ -107,6 +107,20 @@ Kirigami.Page {
 			text: font.pointSize
 		}
 
+		Kirigami.Label {
+			text: "Pixel density:"
+		}
+		Text {
+			text: Screen.pixelDensity
+		}
+
+		Kirigami.Label {
+			text: "Height of default font:"
+		}
+		Text {
+			text: font.pixelSize / Screen.pixelDensity + "mm"
+		}
+
 		Kirigami.Label {
 			Layout.columnSpan: 2
 			Layout.fillHeight: true