Draft Agenda for the GTK+ 2017 Hackfest

1. High level topics

1.1. GDK

• Windows
  • How to get rid of child windows

  • SubsurfaceWindow: delete or all backends

  • x/y coordinate removal

  • Do we need WindowImpl?

  • class hierarchy
  • drawing context semantics
    • cairo context?
    • Vulkan/GL Context for same window
    • sharing resources (ie glyph cache) across windows/displays/processes
• Events
  • Use only for input?
  • Settings
  • DND/Clipboard
• review API design for Wayland

1.2. GSK

• OpenGL drivers/backend

  • OpenGL core profile (>4.0?)

  • OpenGL legacy support
  • OpenGL ES (2.0, 3.x) for embedded platforms
• Shader API for GTK/applications

• GskTexture

  • solidify use cases

  • replacement for GdkPixbuf

  • gsk_texture_new_from_gl (context, texture_id)
• Improving performance
  • Memory allocation
  • Threading
  • Improving data structures
  • Caching
• Make it fast

1.3. Canvas/scene graph

• Should we add a mid-level scene graph for applications that want to replace Clutter?
  • Not all apps want to use widgets
  • No styling, no direct input handling
  • e.g. games, full screen UIs
• Input transformations on GTK widgets

1.4. Animation framework

• More apps are taking the Builder animation API

  • Heavily modelled on ClutterAnimation

  • Cost of value/property marshalling
  • Potential hot path for performance

1.5. Layout

• Responsive layout - can we make this easier ? Does Emeus help for this ?
• What about Emeus - is there a future where it becomes part of GTK+, or do we keep this separate ?

1.6. Widgets

• GtkWidget

  • Composite UI files for direct GtkWidget subclasses (No GtkContainer, so no gtk_container_add)

  • What's necessary to get rid of Gadgets entirely?

• GtkImage

  • What's the preferred (most efficient) API to keep images in memory? GskTexture? Do application developers (have to) care whether it's in VRAM or not?

• GtkListBox/FlowBox

  • model-only
  • performance with large lists

  • replacing GtkTreeView?

  • GtkBuilder to construct children

• GtkWindow

  • embedding
  • popovers
  • menus vs popups vs tooltips vs toplevels

  • Rework current GtkWindow class hierarchy

• GtkDrawingArea => GL/Cairo/Vulkan

• GtkTextView / GtkSourceView

  • spell checking
  • undo
  • CSS
  • multiple views per buffer abstraction
  • performance

1.7. Other

• Flatpak
  • secure app identification
  • portals
• Pango
  • CSS
  • GL
• Meson support for GTK4
• DX questionnaire