040-041_EETE-VF

EETE MAY 2013

Ultra-Miniature - High Reliability Quartz Crystals, Oscillators and Sensors • Highest shock capability in the industry • Military temperature range and beyond • Ultra-low power consumption • High stability and precision EXTREME INNOVATION High Reliability Crystals and Oscillators • Expert technical support • Designed and manufactured in the USA CX16A Medical Military and Industrial Applications CXOX_A CX16 CXOX/HG/HT CXOMK • Excellent long term aging 24 MHz to 50 MHz Crystal 2.0 x 1.2 x 0.4 mm 16 MHz to 250 MHz Crystal 3.2 x 1.5 x 0.5 mm 32.768 kHz to 160 MHz Oscillator 3.2 x 2.5 mm 32.768 kHz to 200 MHz Oscillator CX11A CX11L/HG CXOMK/HG/HT 6.5 x 5.0 mm High-Shock • High-Temperature • High-Precision Military and Avionics | Industrial | Medical MEETING THE EXTREME DEMANDS OF RAPIDLY EVOLVING TECHNOLOGY AS9100C ISO 9001:2008 STATEK CORPORATION 512 N. Main St., Orange, CA 92868 Tel. 714-639-7810 Fax 714-997-1256 www.statek.com One by one, these can be replaced with the correct shapes and texts. More complex features such as graphics can be added at a later stage. This gives design teams the flexibility to begin working with actual prototype products at an early stage and gain a clear Fig. 3: A 3D element is implemented in the third iteration. understanding of how the UI will work even before the user-interface designers have finalised any graphics. The UI can be quickly deployed to multiple devices, taking advantage of the crossplatform capability of the Qt framework, so that usability tests can be carried out for all of the target products and markets. Feedback from end-user workshops can be used to make quick alterations on the host desktop to produce a new version. The QML files can be immediately replaced dynamically without having to recompile and deploy the actual software. To summarise, the following practical example illustrates a typical user-interface development flow using QML. The first UI mock-up is made with QML Rectangles and layout managers acting as placeholders for the actual elements – see figure 1. In the second iteration, a custom Slider element has been implemented. This is done quickly, once again using only rectangles and not graphics – see figure 2. However, it is now made functional and can be used to test the UI. Some of the graphics have also been brought in. As the purpose of the application is to rotate the 3D element (a globe), at this stage the sliders would only rotate the blue rectangle. The 3D element is implemented in the third iteration shown in figure 3. By this stage usability tests had showed that two dimensions were adequate to rotate the globe, and the third slider was removed. The sliders were also moved to the appropriate edges of the globe to provide a more intuitive action. The menu was also implemented. Before the application was finalised, testing showed that the sliders could be eliminated completely in favour of dragging the globe. The drag functionality was quickly implemented, and the sliders removed completely to create the finished, simplified user interface with natural interaction – see figure 4. Without using an incremental approach or having technologically separated UI designers and developers, the latter might have just implemented the first—and last—design given to them, resulting in something like iteration number 2. Fig. 4: Implementing drag functionality and sliders to create the finished, simplified user interface with natural interaction. www.electronics-eetimes.com Electronic Engineering Times Europe May 2013 39


EETE MAY 2013
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