UI Definition of Done

From SailfishOS Documentation

Definition of done

When you've developed a new feature, fixed a bug or generally have a contribution to the SailfishOS UI then this checklist can help you get it accepted:


  • Code has been reviewed and approved by the area maintainer, preferably with UI development background
  • Any user facing changes have been reviewed and approved by Jolla design.
  • Code matches the design in pixel perfection.
    • Pixel accuracy is easy in QML, no reason to be lazy.
    • Icons, backgrounds, margins, colors, fonts match platform style.
    • Implementation matches the design and overall platform style.
  • Implemented UI performs smoothly on the device.
    • There are no abrupt jumps, stutters or other noticeable drops in the frame rate during interaction.
    • Introduced changes do not compromise the application or page loading times.
    • All UI state transitions are fluid and smoothly animated.
    • Use the available [performance tools] to measure and analyze the perfomance.
    • Application memory consumption stays reasonable (e.g. measure with smem).
    • UI scales gracefully to a lot of data points.
  • Feature is feature complete.
    • No states that look unfinished or stand out in a bad way.
    • No empty views, dummy or other-wise temporary development data.
    • User is offered actions to recover from possible errors like no network or data corruption.
  • Text contain working translation hooks.
  • Fonts, colors, margins and other layout parameters come from the Silica to guarantee scalability and consistent platform look&feel.
  • Feature has unit tests that test the internal states and imperative functions.
  • Existing component tests pass.
  • Changes don't cause regression elsewhere, are tested by contributor and verified by the reviewer.
  • Code is committed to the source control and successfully built in OBS.

Further recommendations

  • Develop and test features on a real device.
  • Expect multiple rounds of design review until the experience is polished enough.
  • When unsure how a feature should behave it is a good idea to check how similar use cases have been implemented in existing Sailfish applications.
  • When QML fails to perform, be prepared to write the problematic parts in lower level C/C++ and GLSL OpenGL shading language.
  • Unless you have done already read all the Qt Quick documentation you find in the Qt documentation pages.
  • Read official Qt performance documentation. Tomorrow read it again. Also KDAB Qt Partner has also written few excellent posts about QML engine internals.
  • Measure, don't assume, run QML profiler and gather console API traces to see nothing stupid is happening behind the scenes, for example unnecessary QML component constructions or compilations, redundant binding evaluations, long nested JavaScript function calls or blocking C++ function calls. Basically any operation that stalls the main thread for tens to hundreds of milliseconds should be optimized or executed instead on a separate thread.