improve input

docs/PLAN.md

@@ -207,7 +207,7 @@ Each row is one review unit: build it, show it in the gallery, review, then move
 | 7 | core | Slider | Click-to-set + in-track drag; controlled value. |
 | 8 | core | Progress | Determinate + indeterminate. |
 | 9 | core | Avatar | Initials; image slot later. |
-| 10 | core | Input (single-line) then multiline, NumberInput | String buffer + `unicode-segmentation` word movement; the field owns its own selection. May seed `crates/editor`. |
+| 10 | core | Input (single-line) then multiline, NumberInput | String buffer + `unicode-segmentation` word movement; the field owns its own selection. May seed `crates/editor`. Single-line finishing pass: §6.2. |
 | 11+ | core | Popover, Tooltip, Menu, Dialog, AlertDialog, Sheet, Toast | One unit each, same gate. |
 | then | data (new) | List, Table, Tree, Tabs, Sidebar | Created on demand, same gate. |
 | then | pickers or data | Calendar/DatePicker, TimeField, ColorPicker | Decide at unit time. |
@@ -219,7 +219,26 @@ Deferred until a real need: Markdown/TextView, Dock, VirtualList, window-wide te
 
 **Landed** (2026-10-29): the `Size` enum (`XSmall` / `Small` / `Medium` default / `Large` / `Custom(Pixels)`), the `Sizable` trait (`with_size(impl Into<Size>)` + `xsmall()` / `small()` / `large()`), and the `SizeTable` of per-class control metrics (height, padding-x, text size, icon/indicator size, avatar size) now live where they belong — `Size`/`SizeTable`/`ControlMetrics` in the theme (they are native-metric values, §5.5), the trait in core's ungated `common`.
 
-Our divergence from gpui-kit held: the per-size metrics resolve from the **theme's size table at paint time**, not from constants in the component layer. All ten controls implement `Sizable`; `Size::Custom(side)` derives the other metrics from the side length. Still open, when a real need arrives: TOML overrides for the size table in `ThemeDefinition`, and per-platform size tables from the Phase F native-metrics work.
+Our divergence from gpui-kit held: the per-size metrics resolve from **the theme's size table at paint time**, not from constants in the component layer. All ten controls implement `Sizable`; `Size::Custom(side)` derives the other metrics from the side length. Still open, when a real need arrives: TOML overrides for the size table in `ThemeDefinition`, and per-platform size tables from the Phase F native-metrics work.
+
+### 6.2 Input completion (unit 10 finishing pass) — next
+
+Gap analysis against gpuikit's input (2026-10-29; source read as an API reference, §9 — no porting). gpuikit splits input three ways: core state whose edits are actions, infrastructure (`bindings` / `blink` / `bidi`), and a chrome-less element with chrome in wrapper elements. We keep one component with chrome included; only the ideas below are adopted.
+
+Already at parity: buffer + selection + caret, grapheme/word movement, home/end, clipboard, select-all, IME (`EntityInputHandler`, marked range, UTF-16 conversions), double-click word / shift-click / drag selection, placeholder, disabled, focus ring, a11y `TextInput` role, `TextChanged`/`Focused`/`Blurred`/`Submitted` events, `set_value` + silent variant.
+
+Remaining, in order:
+
+| Step | Scope | Notes |
+| --- | --- | --- |
+| 1 | macOS modifier split | `cmd-left/right` → home/end, `cmd-up/down` → start/end of field, `cmd-backspace` → delete to start, `alt` modifiers → word ops. The handler currently treats cmd and alt alike — wrong on macOS (D8); ctrl stays the word-modifier fallback off-mac |
+| 2 | Undo/redo | Patch-based history (range, replaced text, new length, prior selection), 300 ms grouping (`set_group_interval`), `cmd-z` / `cmd-shift-z`; `set_value` clears the stacks |
+| 3 | Read-only, Escape-blur, triple-click | Read-only: focus, movement, selection, copy still work; edits and paste refused — distinct from disabled. Escape → `window.blur()`. Triple-click selects the line (all of it, single-line) |
+| 4 | Actions + key context | Replace the monolithic `on_key_down` match with `actions!(input, [...])` + an `"Input"` key context; `bind_input_keys(cx, overrides)` over a per-platform-default `InputBindings` table of `Option<KeyBinding>` fields (override or unbind each). Step 1's bindings become data |
+| 5 | Caret blink | 500 ms tick on the GPUI executor, paused (caret visible) while typing or moving, suppressed in read-only |
+| 6 | Paint polish | IME marked-text underline; I-beam cursor on hover; two-sided horizontal scroll (clamped offset in state, follows caret) plus horizontal wheel scroll |
+
+Deferred until a real need: bidi/RTL; prefix/suffix adornments and a form field wrapper (label/description/error — separate units); `SubmitOn` enter/cmd-enter modes (multiline concern); `Undo`/`Redo` events; selection/cursor color overrides (theme tokens are deliberate); password masking, max length, clear button (gpuikit has none of these either — decide on first need).
 
 ## 7. Milestones