The scene view and the animation preview share one camera, the three form dialogs one base, and keys are found through one set of helpers (#85)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/core/commands/animationCommands.ts

@@ -2,7 +2,10 @@ import { newId } from '../ids';
 import {
   ANIMATION_ROOT_TYPES,
   blends,
+  findTrack,
+  hasKey,
   isKeyInterpolation,
+  type KeyRef,
   normalizeKeys,
   targetAssetOf,
   targetDefs,
@@ -16,12 +19,6 @@ import { coerceValue } from '../properties/PropertySchema';
 import { type Command, CommandError } from './Command';
 import { requireAsset } from './require';
 
-/** A key on one row, as the timeline selects it. */
-export interface KeyRef {
-  trackId: string;
-  frame: number;
-}
-
 function requireAnimation(project: Project, assetId: string): AnimationAsset {
   const asset = requireAsset(project, assetId);
   if (asset.type !== 'animation') throw new CommandError(`${asset.name} is not an animation`);
@@ -29,11 +26,27 @@ function requireAnimation(project: Project, assetId: string): AnimationAsset {
 }
 
 function requireTrack(asset: AnimationAsset, trackId: string): AnimationTrack {
-  const track = asset.tracks.find((t) => t.id === trackId);
+  const track = findTrack(asset, trackId);
   if (!track) throw new CommandError(`${asset.name} has no such row`);
   return track;
 }
 
+function requireKey(asset: AnimationAsset, ref: KeyRef): { track: AnimationTrack; key: AnimationKey } {
+  const track = requireTrack(asset, ref.trackId);
+  const key = track.keys.find((k) => k.frame === ref.frame);
+  if (!key) throw new CommandError(`No key on frame ${ref.frame}`);
+  return { track, key };
+}
+
+function requireFrame(frame: number, message: string): void {
+  if (!Number.isInteger(frame) || frame < 0) throw new CommandError(message);
+}
+
+/** `Remove key`, `Remove 3 keys` – how a key command names itself. */
+function keysLabel(verb: string, count: number): string {
+  return count === 1 ? `${verb} key` : `${verb} ${count} keys`;
+}
+
 /** The kind of `property` on the object `target` names, refusing what cannot be animated there. */
 function requireAnimatable(
   project: Project,
@@ -217,8 +230,7 @@ export class SetAnimationKeyCommand extends TimelineCommand {
 
   protected apply(project: Project, asset: AnimationAsset): void {
     const track = requireTrack(asset, this.trackId);
-    if (!Number.isInteger(this.frame) || this.frame < 0)
-      throw new CommandError('A key sits on a whole frame from 0');
+    requireFrame(this.frame, 'A key sits on a whole frame from 0');
     const def = trackDef(project, asset, track);
     if (!def) throw new CommandError('The row aims at something that is gone');
     const current = trackValueAt(track.keys, def.kind, this.frame);
@@ -250,9 +262,7 @@ export class SetKeyInterpolationCommand extends TimelineCommand {
     if (!isKeyInterpolation(this.interpolation)) throw new CommandError('No such easing');
     let changed = 0;
     for (const ref of this.keys) {
-      const track = requireTrack(asset, ref.trackId);
-      const key = track.keys.find((k) => k.frame === ref.frame);
-      if (!key) throw new CommandError(`No key on frame ${ref.frame}`);
+      const { track, key } = requireKey(asset, ref);
       const kind = trackDef(project, asset, track)?.kind;
       if (kind !== undefined && !blends(kind)) continue;
       if (this.interpolation === 'linear') delete key.interpolation;
@@ -271,16 +281,14 @@ export class RemoveAnimationKeysCommand extends TimelineCommand {
     private readonly keys: readonly KeyRef[],
   ) {
     super(assetId);
-    this.label = keys.length === 1 ? 'Remove key' : `Remove ${keys.length} keys`;
+    this.label = keysLabel('Remove', keys.length);
   }
 
   protected apply(_project: Project, asset: AnimationAsset): void {
     if (this.keys.length === 0) throw new CommandError('No keys to remove');
     for (const ref of this.keys) {
-      const track = requireTrack(asset, ref.trackId);
-      const at = track.keys.findIndex((k) => k.frame === ref.frame);
-      if (at < 0) throw new CommandError(`No key on frame ${ref.frame}`);
-      track.keys.splice(at, 1);
+      const { track, key } = requireKey(asset, ref);
+      track.keys.splice(track.keys.indexOf(key), 1);
     }
   }
 }
@@ -299,8 +307,7 @@ export class MoveAnimationKeysCommand extends TimelineCommand {
     private readonly copy = false,
   ) {
     super(assetId);
-    const noun = keys.length === 1 ? 'key' : `${keys.length} keys`;
-    this.label = `${copy ? 'Duplicate' : 'Move'} ${noun}`;
+    this.label = keysLabel(copy ? 'Duplicate' : 'Move', keys.length);
   }
 
   protected apply(_project: Project, asset: AnimationAsset): void {
@@ -308,9 +315,7 @@ export class MoveAnimationKeysCommand extends TimelineCommand {
     if (this.copy && this.delta === 0) throw new CommandError('A duplicate has to land somewhere else');
     const byTrack = new Map<string, Set<number>>();
     for (const ref of this.keys) {
-      const track = requireTrack(asset, ref.trackId);
-      if (!track.keys.some((k) => k.frame === ref.frame))
-        throw new CommandError(`No key on frame ${ref.frame}`);
+      requireKey(asset, ref);
       if (ref.frame + this.delta < 0) throw new CommandError('A key cannot move before frame 0');
       byTrack.set(ref.trackId, (byTrack.get(ref.trackId) ?? new Set()).add(ref.frame));
     }
@@ -342,6 +347,10 @@ export interface KeyClipboard {
   rows: ClipboardRow[];
 }
 
+export function clipboardKeyCount(clipboard: KeyClipboard): number {
+  return clipboard.rows.reduce((n, r) => n + r.keys.length, 0);
+}
+
 /** The picked keys as a clipboard, or null when none of them exists. */
 export function copyAnimationKeys(
   project: Project,
@@ -351,7 +360,7 @@ export function copyAnimationKeys(
   const picked = asset.tracks
     .map((track) => ({
       track,
-      keys: track.keys.filter((k) => refs.some((r) => r.trackId === track.id && r.frame === k.frame)),
+      keys: track.keys.filter((k) => hasKey(refs, { trackId: track.id, frame: k.frame })),
     }))
     .filter((p) => p.keys.length > 0);
   if (picked.length === 0) return null;
@@ -391,13 +400,11 @@ export class PasteAnimationKeysCommand extends TimelineCommand {
     private readonly intoTrackId = '',
   ) {
     super(assetId);
-    const count = clipboard.rows.reduce((n, r) => n + r.keys.length, 0);
-    this.label = count === 1 ? 'Paste key' : `Paste ${count} keys`;
+    this.label = keysLabel('Paste', clipboardKeyCount(clipboard));
   }
 
   protected apply(project: Project, asset: AnimationAsset): void {
-    if (!Number.isInteger(this.frame) || this.frame < 0)
-      throw new CommandError('Keys paste onto a whole frame from 0');
+    requireFrame(this.frame, 'Keys paste onto a whole frame from 0');
     this.pasted = [];
     this.skipped = 0;
     const single = this.clipboard.rows.length === 1 && this.intoTrackId !== '';
@@ -434,7 +441,7 @@ export class PasteAnimationKeysCommand extends TimelineCommand {
 
   private matchingTrack(asset: AnimationAsset, row: ClipboardRow): AnimationTrack | undefined {
     return asset.id === this.clipboard.assetId
-      ? asset.tracks.find((t) => t.id === row.trackId)
+      ? findTrack(asset, row.trackId)
       : asset.tracks.find((t) => t.target === row.target && t.property === row.property);
   }
 }
@@ -467,8 +474,7 @@ export class ShiftAnimationFramesCommand extends TimelineCommand {
   }
 
   protected apply(_project: Project, asset: AnimationAsset): void {
-    if (!Number.isInteger(this.at) || this.at < 0)
-      throw new CommandError('Frames are inserted at a whole frame from 0');
+    requireFrame(this.at, 'Frames are inserted at a whole frame from 0');
     if (!Number.isInteger(this.count) || this.count === 0)
       throw new CommandError('Give a whole number of frames');
     let touched = 0;