# iris: known problems and things still to build

Only open Iris framework work lives here. Delete an item when it lands.

## Build (for the port)

Framework capabilities needed by `RUST.md`'s port plan:

- [ ] **Overflow ellipsis with an explicit retained end.** `TextAttrs` can
  only wrap or clip, so a tool summary is cut with no mark. Parley has no
  ellipsis primitive; use its line breaker to find the cut, but keep source
  and displayed strings distinct with one byte mapping shared by spans,
  links, selection and editing. Replace `wrap: bool` with an enum that can
  say wrap, clip, head ellipsis and tail ellipsis—the caller must choose
  because a command is identified by its head and a path by its tail.
- [ ] **Expose the distance from a `LazySpan` viewport to its unloaded
  edge.** (**P1**.) `viewport_len` and the visible extents are already
  measured internally, but a paging caller cannot ask whether it is within
  the product's six-viewport `HISTORY_SCREENS` cushion. The API should
  answer in pixels or viewport multiples, never rows: a row ranges from one
  line to a screen, so a fixed row count is not a distance.
- [ ] **Let an image fit a bounded box while preserving its aspect ratio.**
  (**P1**.) `Image` currently always reports and draws the decoded texture's
  natural pixel size. Decoding and fetching a server-produced attachment
  belong in `app`; iris only owes the generic fit/scale widget used to
  draw its thumbnail.
- [ ] **Per-range backgrounds for rich text.** (**P1**.) Inline code is
  already monospace and coloured, but the inline-code chip also needs
  the glyph run's boxes so a surface can be drawn behind exactly that byte
  range. The shared `TextSelection` engine already computes the same geometry
  for selection highlights; expose one shared primitive rather than giving
  the app a second text-layout path.
- [ ] **A horizontal gauge/bar widget.** (**P1**.) For
  `SessionUsageBar`'s equivalent — a bounded fill reflecting a fraction,
  nothing fancier.
- [ ] **A toggle switch.** (**P3**.) For the delete dialog's
  `deleteForeign` control; iris has no switch/checkbox widget yet as far
  as this pass found.

## Later

- [ ] **Intern independently constructed solid paint definitions.** Inline
  `rect(Srgba8::...)` values currently receive a new `PaintId` each time.
  Cache them by canonical linear RGBA bits, but keep `Paints::add` explicitly
  unique so two semantic theme roles that start with the same value can later
  change independently. Cache entries must be weak and disappear when the
  last real handle releases the slot; gradients and texture paints need their
  own identity rules rather than inheriting solid-value interning blindly.

- [ ] **Property/content animations.** Cosmetic, so after correctness and
  parity. Keep them modular, like input; scrolling already animates through
  `Widget::tick` and `UiData::animate`. A widget that does not opt in must
  pay nothing and import nothing for them.

- [ ] **Remove `WidgetView` unless a real composite adopts it.** Every
  composite in `app/src/ui` uses ordinary child handles plus a root;
  `WidgetView` and its derive are used only by `iris/examples/view.rs`.
  It currently demonstrates itself rather than shortening production code.

- [ ] **A `Stack` that chooses its mask the way it chooses its size
  should replace `masked_by`.** For a square-cornered surface,
  `.background(rect(BAR_FILL)).masked()` was measured
  against `.masked_by(rect(BAR_FILL))` on the composer at the phone's own
  size and density and the two are identical to the pixel. What the pair
  cannot express is a clip that is not a box: `Painter::set_mask` writes
  a `RectPrimitive::color` using `PaintId::NONE` at the widget's own region,
  with no radius, so `.background(rect(fill).radius(r)).masked()` draws a
  rounded panel and then cuts its content square. Both other call sites
  (`row.rs`'s fence, `tool.rs`'s raw output) are rounded, which is why
  the method stands for now.
  Let `Stack` name the mask child the way `StackSize::Child(n)` names the
  sizing child. Then `.background(x)` remains the one way to add a surface
  and clipping to it is a stack property; the named mask child must have
  drawn before any child that uses it. Once that exists, delete
  `masked_by` and `Masked::shape` rather than retaining two APIs.