QtCS2018 QtQuick

Topics

• controls, quick and QML engine people working together better
  
  • more cooperation between Berlin (designer developers) and Oslo people to ensure optimization opportunities are found
    
  • refactorings in QtQuick break Controls sometimes
    
    • CI could help
      
    • testing private API is too much trouble though
• marketing/docs: focus on application development more than on building up controls from primitives
  
  • examples have to be in their own repo so they can use Controls
    
  • but QML is different than widget development: customers need to understand how custom controls are built too
    
  • get more QtCore example apps using Quick rather than Widgets
• QtQuick Core Declarative QML bug category is confusing
• keyboard focus, keyboard operating controls without mouse or touch (e.g. for drone UIs)
  
  • disabled buttons break tab navigation
    
  • too much work, JS etc.
    
  • important for lots of embedded UIs
• changing groups of properties more efficiently
  
  • avoid multiple binding evaluation overhead
    
  • avoid explosion of cascading changes and repeating re-evaluations
    
  • pull rather than push, lazy re-evaluation
    
  • dirty flag, maybe update on screen refresh
    
  • onXChanged JS handlers might cause trouble...
    
  • synchronized groups or blocks
• bad or lacking C++ APIs
  
  • text
    
  • QQmlListProperty
    
  • it's not just making more public headers
    
  • bindings
• working with NPM modules
  
  • maybe like NAPI (? or something like that) from Microsoft
• QML and Python
  
  • why have Python + JS when you could just have Python?
    
  • come up with a way to use Python to create bindings
    
    • capturing dependencies is hard
      
  • add C++ QtQuick APIs and expose them to Python

Current work in progress

• TableView
• Pointer Handlers
• Fix up the version number mess (QUIP 99 https://codereview.qt-project.org/#/c/215625/ )
  
  • main issue is name clashes: existing customer code vs. newly introduced stuff in new versions of QtQuick
• ES6
  
  • test suite is updated
    
  • most ES7 features are there
    
  • missing: atomics, weak map and set, reflect, promises, proxy
    
  • ES8 will add async stuff... that's later
• Tracing JIT
• Optimizing simple bindings

Upcoming work

• TreeView
• Dock widgets? ;-) (really?)
  
  • better start prototyping then, to see what goes wrong
    
  • inevitable performance bottlenecks
• Native menus
• Strict mode
  
  • improve portability
    
  • type safety, strong typing
    
  • resolution of types at compile time
    
  • need to specify types of arguments, variables etc. (use TypeScript syntax)
    
  • sane scoping
    
  • no implicit type conversions (i.e. equality testing will not be the same)

Issues

• Complex UIs are slow, can't afford too many objects
  
  • Layer.enabled: true can help
• Item Views don't have true delegates like widget item views do
• Looking up property bindings by name is slow