Add CodeMirror editor signals (selection, focus, viewport, geometry) and reveal_line#5984
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Jepson2k wants to merge 2 commits intozauberzeug:mainfrom
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Add CodeMirror editor signals (selection, focus, viewport, geometry) and reveal_line#5984Jepson2k wants to merge 2 commits intozauberzeug:mainfrom
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Three small editor-event primitives requested by host applications that embed CodeMirror as an in-app code editor: - `on_cursor_line` (typed `CodeMirrorCursorLineEventArguments`, 1-indexed line number, 30 ms debounce on the JS side) reports cursor-line changes. The debounce is short enough to feel immediate when arrow- keying through a file but long enough to coalesce bursts during multi-line selection drags. - `on_save` (typed `CodeMirrorSaveEventArguments`) fires on Ctrl/Cmd+S inside the editor and suppresses the browser's default save dialog. The Mod-s keymap binding is only installed when the host opts in via the `save-shortcut-enabled` prop, so editors without an `on_save` handler keep the browser's default behavior. - `reveal_line(line_number)` scrolls a 1-indexed line into view via CodeMirror's `EditorView.scrollIntoView` effect. Tests dispatch CM6 selection transactions directly rather than relying on Selenium keystroke focus timing. Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
Replaces the narrow `on_cursor_line` and `on_save` primitives added in
the prior commit with two generic mechanisms (one of which lands here,
the other deferred to a follow-up PR). Both removals are unreleased.
ViewUpdate signal dispatcher (this PR):
- Single JS `ViewPlugin` (`updateDispatcher`) reads four CM6 ViewUpdate
flags and emits one event per signal: `selection-change` (line +
column), `focus-change` (focused), `viewport-change` (visible line
range), `geometry-change` (width / height / content height). Each
signal has a dedicated `<signal>-tracking-enabled` prop so the
dispatcher bails early when the host has not subscribed; per-signal
`<signal>-debounce-ms` props (defaults 30 / 0 / 100 / 100) are read
fresh on each emit so runtime overrides apply on the next event
without a Vue watch. Per-signal dedupe of the last emitted payload
drops redundant traffic. Timers live on the plugin instance and
`destroy()` clears them, removing the leak-prone `_cursorTimer` on
the Vue component.
- Public Python API: four typed `on_*_change` handlers + corresponding
event-args dataclasses. Both the constructor kwargs and the methods
accept `Handler | CodeMirrorHandlerSpec`; per-registration overrides
go through a single `ui.codemirror.handler(callback, debounce_ms=...)`
factory (a static method exposing the spec dataclass) so constructor
and method surfaces stay shape-identical.
Generic keybindings API (separate follow-up PR): replaces `on_save` with
`keybindings={...}` and `editor.on_keybinding(key, handler)`. No
JS-plugin overlap with the dispatcher landed here (different CM6
primitives — `ViewPlugin` vs `keymap`); the only shared piece is
`CodeMirrorHandlerSpec`, which the keybindings PR extends with
`prevent_default`. Brief no-save-binding gap is invisible to users
since `on_save` is also unreleased.
`reveal_line` is unchanged. The new `viewport-change` signal closes
its previously missing feedback channel — a host can now confirm a
revealed line landed in the visible range.
Tests cover all four signals (with mid-line cursor positions to
exercise the column field, viewport range after `reveal_line`, focus
toggles via JS, geometry under container resize), plus
`test_no_handler_no_traffic` (verifies subscription gating prevents
emit when nothing is listening) and `test_debounce_override` (verifies
the spec factory's debounce_ms is honored end-to-end).
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
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Motivation
Hosts that embed
ui.codemirroras an in-app editor often need feedback about the editor's state — cursor line / column, focus, the visible line range, and editor geometry. None of this is exposed through the Python API today, and there's no programmatic way to scroll a specific line into view.Implementation
This PR adds:
reveal_line(line_number)— scrolls a 1-indexed line into view viaCM.EditorView.scrollIntoView.on_selection_change(line, column),on_focus_change(focused),on_viewport_change(from_line, to_line),on_geometry_change(width, height, content_height).ui.codemirror.handler(callback, debounce_ms=...)factory for per-registration debounce overrides. Both constructor kwargs and methods accept either a bare callable or a wrapped spec, so the two surfaces stay shape-identical.A single JS
ViewPluginreads the four CM6ViewUpdateflags and emits per-signal events. Each signal has its own enable prop (auto-flipped when a handler is registered) and debounce-ms prop (defaults 30 / 0 / 100 / 100); when nothing is subscribed the dispatcher bails before computing a payload, so unsubscribed signals cost nothing on the wire. Per-signal dedupe drops redundant emits; debounce timers live on the plugin instance anddestroy()clears them.Tests cover all four signals, the
reveal_line→ viewport feedback loop, subscription gating (no traffic when nothing's listening), and the debounce-override path end-to-end. Selection / focus events are driven viaeditor.dispatch({...})in JS rather than Selenium keystrokes to avoid focus-timing flakiness.Progress