Components Growing

Looking past the irony that QML will be available for all platforms but WP8 in the short-term, and Nokias previous involvement in the development of QML, it is nice to see the platforms being created.

The last in the row is Ubuntu Phone, others are Jolla’s Sailfish, RIM’s BB10 Cascades, KDE’s Plasma and Nokia’s Components for Harmattan and Symbian. Qt seem to unlock the future UIs for devices.

What is striking is the interaction patterns being established. Nokia Swipe, Sailfish as well as Ubuntu Phone seems to rely heavily on swiping from the sides of the screen. This is, in my experience, the key to a truly one-handed device.

Using Android, you are constantly forced to hold the device in awkward angles or use two hands to reach the home button, be it physical or on-screen. Swiping with the thumb is always possible when using one hand (as long as you have an opposable thumbs), while the two-handed user can swipe using the index finger without feeling hindered by the interface.

From a development perspective, it is interesting to see how the different QML Components are shaped. Ubuntu seems to have some interesting ideas for theming going on, and the other platforms have their own strong points.

One interesting comparison is to look at the API for a single component. Comparing the CheckBox elements of Ubuntu Phone, BB10, Harmattan, Symbian and Plasma gives the following API (only looking at the properties and signals that I regard as relevant to the comparison in question).


  • text (BB10, Symbian, Harmattan, Plasma)
  • checked (BB10, Symbian, Harmattan, Ubuntu Phone, Plasma)
  • enabled (BB10, Harmattan)
  • pressed (Symbian, Harmattan, Ubuntu Phone, Plasma)
  • hovered (Ubuntu Phone)


  • onCheckedChanged (BB10, Symbian, Harmattan, Ubuntu Phone, Plasma)
  • onClicked (Symbian, Harmattan, Ubuntu Phone, Plasma)
  • onPressAndHold (Ubuntu Phone)

Where does this leave us? For all platforms, one can use the checked property and its onCheckedChanged signal to act. The rest is in up in the air. Ubuntu Phone seems to split the text from the checkbox while the others keep them together. The enabled property is missing from most platforms. Here, even Symbian and Harmattan, both from Nokia, seems to differ.

Still, as the concepts seems similar, the work to create a cross-platform set of components wrapping the components of each platform should not be an impossible task (looking at checkboxes only, that is). Hopefully the end result will not be a too fragmented API landscape and the involved parties will work towards a common setup of basic properties and signals.

Either way, I’m happy seeing that 2012 was a bad year, 2013 looks very exciting. Seeing all these innovative phone user interfaces being created with QtQuick, I’m happy to work at a company innovating in the automotive space using the same technology.

Disclamer! These findings are based on the API docs only. Feel free to correct me by commenting.

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