feat(chart): support explicit nice x domains

AGENTS.md

@@ -1,57 +1,130 @@
 # Repository Guidelines
 
-## Project Structure & Module Organization
+## Project Overview
 
-This repository is a Vue 3 + TypeScript waveform component library with a Vite demo.
+This repository is a Vue 3, TypeScript, and D3 waveform component library with a Vite demo.
-Production exports are defined in `src/index.ts`; demo entry points are `src/main.ts` and
+The published package is `waveform-analysis`; its supported public surface is exported from
-`src/App.vue`. The main chart is `src/components/WaveformChart.vue`, with focused modules under
+`src/index.ts`. The demo is a consumer of that library code, not part of the public API.
-`src/components/{core,data,rendering,interaction,annotation}`. Shared types live in `src/types`,
-data normalization and chart logic in `src/core` and `src/utils`, styles in `src/styles.css`, and
-sample data in `src/data`. Tests are colocated with implementation files (`*.test.ts`), with shared
-setup in `src/test/setup.ts`. `dist/` and `dist-demo/` are generated; do not edit them.
 
-## Build, Test, and Development Commands
+Important behavioral contracts:
 
-Use pnpm (the lockfile is `pnpm-lock.yaml`) and Node.js 22 as CI does.
+- Treat waveform input as immutable. Replace the `data` reference to refresh normalization,
+  domains, caches, and the viewport; do not rely on in-place array mutation.
+- X coordinates are stored in seconds. `timeUnit` and X-axis formatters affect display only and
+  must not alter raw coordinates, zoom domains, or emitted event values.
+- Give every multi-series waveform a unique, stable `id`. Visibility, annotations, axes, and
+  state retention use normalized series IDs.
+- Annotations and hidden-series state are controlled by the consumer. Emit replacement arrays;
+  persistence belongs to the host application.
+- Rendering may downsample visible SVG geometry, but domains, nearest-point lookup, tooltips,
+  annotations, and error ranges must continue to use the full normalized data.
+
+## Repository Layout
+
+- `src/index.ts`: deliberate package exports for components, types, core helpers, and utilities.
+- `src/components/WaveformChart.vue`: top-level chart composition and public prop/event boundary.
+- `src/components/core/`: layout, domains, grids, presentation state, and chart controllers.
+- `src/components/data/`: component-facing data types and data-layer exports.
+- `src/components/rendering/`: SVG tracks, axes, series, legends, hover layers, and styles.
+- `src/components/interaction/`: viewport, zoom, hover, tooltip, and interaction hosts.
+- `src/components/annotation/`: annotation types, serialization, editing, layout, and interaction.
+- `src/core/`: package-level normalization and rendering/downsampling logic.
+- `src/types/`: shared public data and chart types.
+- `src/utils/`: domains, formatting, geometry, sampling, and waveform ID helpers.
+- `src/demo/`, `src/App.vue`: controls and the main interactive demo workspace.
+- `src/router.ts`, `src/DemoRouterApp.vue`, `src/views/`: hash-based demo routes and focused demos.
+- `src/data/`: simulated demo data; `src/test/`: shared Vitest setup and test helpers.
+- `scripts/`: repository checks and declaration-build cleanup scripts.
+- `docs/` and root Markdown notes: supporting or historical documentation; verify claims against
+  current source, tests, `README.md`, and `package.json` before relying on them.
+
+Tests are colocated as `*.test.ts`. The large chart suite is split under
+`src/components/waveformChartCases/`; add focused cases there instead of rebuilding a monolithic
+chart test file.
+
+## Toolchain and Commands
+
+Use Node.js 22 and pnpm 10.32.1, matching CI. Keep `pnpm-lock.yaml` synchronized with
+`package.json` and use the locked install in automation.
 
 ```bash
-pnpm install                 # Install locked dependencies
+pnpm install --frozen-lockfile # Reproduce the CI dependency graph
-pnpm dev                     # Start the Vite demo server
+pnpm dev                       # Start the Vite demo
-pnpm typecheck               # Run vue-tsc checks
+pnpm typecheck                 # Run vue-tsc project checks
+pnpm check:file-length         # Enforce the 400-line limit under src/
 pnpm lint                      # Run ESLint with zero warnings allowed
 pnpm test                      # Run Vitest once
 pnpm test:coverage             # Run tests and enforce coverage thresholds
-pnpm build                   # Type-check and build library plus demo bundles
+pnpm build                     # Type-check and build library, declarations, and demo
-pnpm preview                 # Preview the production demo build
+pnpm pack --dry-run            # Inspect the publishable package contents
+pnpm preview                   # Preview dist-demo/
+pnpm format                    # Apply the repository Prettier configuration
 ```
 
-Run `pnpm format` to apply the repository Prettier configuration.
+For a narrow change, run the closest test file while iterating, then run the full relevant gates
+before handoff. Do not describe a check as passing unless it actually ran.
 
-## Coding Style & Naming Conventions
+## Coding and Architecture Conventions
 
-Use TypeScript and Vue 3 Composition API with two-space indentation, single quotes, no semicolons,
+Use Vue 3 Composition API and strict TypeScript. Follow the repository Prettier configuration:
-and a 100-column print width. Prettier and ESLint are authoritative.
+two-space indentation, single quotes, no semicolons, and a 100-column print width. Use PascalCase
-Use PascalCase for Vue components, component filenames, and types; use camelCase for functions,
+for Vue components and types, and camelCase for functions, composables, variables, and props in
-variables, and composables (for example, `useWaveformData`). Keep public exports deliberate and
+TypeScript. Vue template props and events use kebab-case.
-preserve stable series IDs for multi-channel data.
 
-## Testing Guidelines
+ESLint enforces a maximum of 400 physical lines for files under `src/`; the standalone length
+check applies the same limit to all text files below `src/`. Split code by existing ownership
+boundaries when a file approaches the limit. Keep rendering, layout, interaction, annotation, and
+data concerns in their existing modules rather than adding more orchestration to
+`WaveformChart.vue`.
 
-Vitest with `@vue/test-utils` and jsdom is used. Name tests `*.test.ts` beside the
+Use the `@/` alias for internal `src/` imports where it improves clarity. Keep public exports
-code they cover. Exercise normalization, rendering/layout helpers, formatting, and component
+explicit: adding a type or helper internally does not make it supported API. When changing a
-interactions, including empty, non-finite, and multi-series inputs. Coverage thresholds are 80%
+public prop, event, type, formatter, serialization format, or package export, update `src/index.ts`,
-for lines/statements/functions and 75% for branches; run `pnpm test:coverage` before submitting.
+tests, and `README.md` together. Preserve backwards compatibility unless the task explicitly calls
+for a breaking change.
 
-## Commit & Pull Request Guidelines
+Do not hand-edit generated output in `dist/`, `dist-demo/`, `coverage/`, or `.vite/`. Library peers
+are externalized by `vite.lib.config.ts`; validate packaging after dependency or export changes.
 
-The current history contains only `first commit`, so no established convention exists yet. Use short,
+## Testing Expectations
-imperative messages, preferably scoped (for example, `feat(chart): ...`, `fix(annotation): ...`, or
-`test: ...`). Pull requests should explain API or user-visible changes, list verification commands,
-link an issue or plan, and include screenshots or a short recording for visual changes. Keep generated
-files and unrelated refactors out of the change.
 
-## CI and Configuration
+Vitest runs in jsdom with `@vue/test-utils`; shared setup is in `src/test/setup.ts`. Coverage uses
+V8 and must remain at least 80% for lines, statements, and functions, and 75% for branches.
 
-GitHub Actions runs install, typecheck, lint, coverage, build, and `pnpm pack --dry-run` on pushes and
+Cover behavior at the narrowest useful layer:
-pull requests. Do not commit secrets or local environment files; review the staged file list before
+
-opening a pull request.
+- normalization: empty, invalid, non-finite, unsorted, duplicate-ID, and multi-series inputs;
+- layout and domains: display modes, overlays, fixed ranges, pagination, margins, and small sizes;
+- formatting: endpoint/tick consistency, time units, scientific notation, and custom formatters;
+- rendering: downsampling, styles, points, error bars, axes, grids, legends, and clean view;
+- interaction: wheel/box zoom, zoom-out, pan, reset, hover, visibility, and presentation mode;
+- annotations: CRUD, serialization validation, drag offsets, reprojection, and hidden series.
+
+Avoid brittle assertions against incidental SVG structure when a user-visible or emitted behavior
+can be asserted instead. Add regression coverage for every bug fix.
+
+## Build, CI, and Release
+
+`pnpm build` produces the ESM/CJS library and CSS in `dist/`, declarations in `dist/types/`, and the
+demo in `dist-demo/`. GitHub CI runs frozen install, typecheck, file-length checks, lint, coverage,
+build, and `pnpm pack --dry-run` on pushes and pull requests.
+
+Use short Conventional Commit-style messages consistent with current history, for example
+`feat(chart): support ...`, `fix(annotation): handle ...`, or `test: cover ...`. Keep generated
+files, local settings, and unrelated refactors out of commits. Review `git status` and the staged
+diff before committing. Pull requests should explain public or user-visible effects, list commands
+actually run, link the relevant issue or plan, and include screenshots or a short recording for
+visual changes.
+
+Releases are triggered by annotated tags matching `vX.Y.Z` or a semver prerelease such as
+`vX.Y.Z-rc.1`. The tag version must exactly match `package.json`. The Gitea workflow validates,
+tests, builds, packs, publishes to both configured npm registries, creates checksums and a release,
+and deploys the demo only for stable versions. Do not create or push a release tag until the version
+commit and full release checks are complete.
+
+## Change Discipline
+
+Keep edits scoped to the request and preserve unrelated worktree changes. Do not commit secrets,
+local environment files, IDE state, logs, or registry credentials. For visual behavior changes,
+verify both the reusable component and the relevant demo route at representative desktop and small
+container sizes; state clearly when browser verification was not performed.

README.md

@@ -111,6 +111,7 @@ const data = ref<WaveformData>({
 | `minVisiblePoints`                | `number`                                    | `0`                                                     | 缩放后至少保留的不同 X 坐标数      |
 | `initialXDomain`                  | `[number, number]`                          | 未设置                                                  | 所有图框的初始 X 范围              |
 | `initialXDomains`                 | `Record<string, [number, number]>`          | 未设置                                                  | 按 track/series ID 配置初始范围    |
+| `xDomainStrategy`                 | `WaveformXDomainStrategy`                   | `{ type: 'data' }`                                      | 自动 X 轴视口范围策略              |
 | `yDomain`                         | `[number, number]`                          | 未设置                                                  | 所有波形的固定 Y 轴范围            |
 | `yDomains`                        | `Record<string, [number, number]>`          | 未设置                                                  | 按 track/series ID 配置固定范围    |
 | `grid`                            | `WaveformGridOptions`                       | `{ rowCount: 2, columnCount: 1, showPagination: true }` | 网格和分页                         |
@@ -129,7 +130,7 @@ const data = ref<WaveformData>({
 
 所有公开类型均可从包入口导入，例如 `WaveformData`、`WaveformSeries`、
 `WaveformAnnotation`、`WaveformLineStyle`、`WaveformRenderingOptions`、
-`WaveformAxesOptions`、`WaveformXAxisLabelFormatter`、`WaveformZeroLineOptions`、
+`WaveformAxesOptions`、`WaveformXAxisLabelFormatter`、`WaveformXDomainStrategy`、`WaveformZeroLineOptions`、
 `WaveformGridOptions` 和 `WaveformGridTrackLines`。
 
 ### 数据结构
@@ -252,8 +253,30 @@ X 轴且包含多个轨道时使用按稳定 track ID 索引的 `yRanges`。平
 重置组件内部缩放并触发 `zoom-reset`；调用方应在事件中取消区间请求并恢复首次完整数据。
 外部重置按钮也可以通过模板引用调用组件公开的 `resetViewport()` 方法，然后执行相同的数据恢复逻辑。
 
+没有显式配置初始范围时，可以通过 `xDomainStrategy` 将数据范围扩展为便于阅读的视口端点。
+默认的 `{ type: 'data' }` 保持数据最小值和最大值不变；`type: 'nice'` 使用固定刻度数量计算
+易读边界，且只扩展视口，不修改原始点位、tooltip、标注或缩放事件值：
+
+```vue
+<WaveformChart
+  :data="chartData"
+  :x-domain-strategy="{ type: 'nice', bounds: 'end', tickCount: 10, includeExplicit: true }"
+/>
+```
+
+例如秒坐标数据范围为 `[0, 4.999999]` 且 `timeUnit='ms'` 时，上述配置会使用
+`[0, 5]` 作为初始及重置视口，两端 label 显示 `0` 和 `5000`。`bounds: 'end'`
+只扩展右端；默认的 `bounds: 'both'`
+会同时扩展两端。`tickCount` 默认为 `10`，只参与边界计算，不随组件宽度变化。
+`initialXDomains`、`initialXDomain` 的显式配置默认保持原值；仅当 `includeExplicit: true` 时
+也应用 nice 扩展。独立模式在未配置显式范围时
+按图框分别计算，共享 X 轴模式则合并所有可见图框后计算。所有范围仍使用原始秒坐标，
+`timeUnit` 只影响显示。
+
 独立坐标模式下，回填响应应只替换 `seriesIds` 对应的系列，并调用
-`resetViewport(trackIndex)`；其他图框的数据和缩放状态应保持不变。
+`resetViewport(trackIndex)`；其他图框的数据和缩放状态应保持不变。独立模式下双击图框触发的
+`zoom-reset` payload 会包含该图框的 `trackIndex` 和 `seriesIds`；共享 X 范围模式的 payload
+不包含这两个字段，表示全局复位。忽略事件参数的既有监听器可以继续使用。
 
 多通道数据应为每个 `WaveformSeries` 提供稳定的 `id`。内部时间坐标始终使用秒，
 `timeUnit` 只控制坐标轴和 tooltip 的显示单位。
@@ -639,7 +662,7 @@ X 轴刻度和左右端点先按 `timeUnit` 转换为秒或毫秒，再显示为
 | `point-hover`                                                   | 当前最近点变化时触发，离开图表时传入 `null`                    |
 | `zoom-change`                                                   | 缩放过程中触发，参数为 `[start, end]`                          |
 | `zoom-end`                                                      | 滚轮或框选结束后触发；`gesture` 区分二者，独立模式附带轨道信息 |
-| `zoom-reset`                                                    | 双击重置视口时触发，调用方应恢复首次完整数据                   |
+| `zoom-reset`                                                    | 双击重置视口时触发；独立模式 payload 标识目标图框              |
 | `page-change`                                                   | 分页变化，参数为当前页和总页数                                 |
 | `series-visibility-change`                                      | 图例切换曲线显隐时触发                                         |
 | `annotation-create` / `annotation-update` / `annotation-delete` | 标注新增、更新或删除                                           |

package.json

@@ -1,6 +1,6 @@
 {
   "name": "waveform-analysis",
-  "version": "0.1.31",
+  "version": "0.1.33",
   "main": "./dist/index.cjs",
   "module": "./dist/index.js",
   "types": "./dist/types/index.d.ts",

src/components/WaveformChart.vue

@@ -16,6 +16,7 @@ const props = withDefaults(defineProps<WaveformChartProps>(), {
   zoomable: true,
   pannable: false,
   minVisiblePoints: 0,
+  xDomainStrategy: () => ({ type: 'data' }),
   timeUnit: 'ms',
   frameNumber: undefined,
   annotations: () => [],

src/components/core/trackLayoutBuilder.ts

@@ -16,6 +16,7 @@ import type {
   WaveformDisplayMode,
   WaveformOverlayMode,
   WaveformPoint,
+  WaveformXDomainStrategy,
   WaveformXAxisLabelFormatter,
 } from '../../types'
 import { buildMinorTicks, formatXAxisLabel } from '../../utils'
@@ -26,6 +27,7 @@ import {
 } from './grid'
 import { axisTextMetrics, resolveYAxisSeriesGroups } from './layout'
 import type { DisplaySeries, DisplayTrack, TrackLayout, WaveformYAxisLayout } from './types'
+import { applyXDomainStrategy } from './xDomain'
 import {
   Y_AXIS_LABEL_BAND_WIDTH,
   Y_AXIS_LABEL_GAP,
@@ -46,6 +48,7 @@ export interface BuildTrackLayoutsOptions {
   sharedZoomDomain: [number, number]
   initialXDomain?: [number, number]
   initialXDomains?: Record<string, [number, number]>
+  xDomainStrategy?: WaveformXDomainStrategy
   fixedYDomain?: [number, number]
   fixedYDomains?: Record<string, [number, number]>
   yDomains?: Record<string, [number, number]>
@@ -57,6 +60,21 @@ export interface BuildTrackLayoutsOptions {
   showCompactEmptyTracks: boolean
 }
 
+function resolveIndependentXDomain(
+  track: DisplayTrack,
+  seriesId: string,
+  options: BuildTrackLayoutsOptions,
+): [number, number] {
+  const strategy = options.xDomainStrategy ?? { type: 'data' }
+  const explicitDomain =
+    options.initialXDomains?.[track.id] ??
+    options.initialXDomains?.[seriesId] ??
+    options.initialXDomain
+  return explicitDomain
+    ? applyXDomainStrategy(explicitDomain, strategy, true)
+    : applyXDomainStrategy(track.xDomain, strategy)
+}
+
 export function buildTrackLayouts(options: BuildTrackLayoutsOptions): TrackLayout[] {
   const visibleCells = options.cells.map((cell) => ({ ...cell, hasSeries: Boolean(cell.series) }))
   const bottomCells = getBottomRowCellIndexes(visibleCells, options.grid.columnCount)
@@ -88,13 +106,7 @@ export function buildTrackLayouts(options: BuildTrackLayoutsOptions): TrackLayou
     const series = displayTrack.visibleSeries[0] ?? displayTrack.series[0] ?? emptySeries
     const baseXScale =
       options.displayMode === 'independent'
-        ? scaleLinear(
+        ? scaleLinear(resolveIndependentXDomain(displayTrack, series.id, options), [0, cell.width])
-            options.initialXDomains?.[displayTrack.id] ??
-              options.initialXDomains?.[series.id] ??
-              options.initialXDomain ??
-              displayTrack.xDomain,
-            [0, cell.width],
-          )
         : scaleLinear(options.sharedZoomDomain, [0, cell.width])
     const transform =
       options.displayMode === 'independent'

src/components/core/useWaveformChartLifecycle.ts

@@ -204,6 +204,7 @@ export function useWaveformChartLifecycle(context: LifecycleContext) {
       () => props.minVisiblePoints,
       () => props.initialXDomain,
       () => props.initialXDomains,
+      () => props.xDomainStrategy,
       () => props.displayMode,
       () => chartTracks.value.length,
       currentPage,

src/components/core/useWaveformLayout.ts

@@ -34,6 +34,7 @@ import {
 import type { DisplaySeries, DisplayTrack, TrackLayout } from './types'
 import type { PreparedWaveformSeries } from './useWaveformData'
 import type { ResolvedWaveformChartProps } from './waveformChartTypes'
+import { applyXDomainStrategy } from './xDomain'
 import type { useWaveformAnnotationInteraction } from '../annotation'
 
 interface LayoutContext {
@@ -224,9 +225,13 @@ export function useWaveformLayout(context: LayoutContext) {
       Number.isFinite(domain[1]) &&
       domain[0] !== domain[1]
     ) {
-      return domain[0] < domain[1] ? domain : [domain[1], domain[0]]
+      return applyXDomainStrategy(
+        domain[0] < domain[1] ? domain : [domain[1], domain[0]],
+        props.xDomainStrategy,
+        true,
+      )
     }
-    return sharedXDomain.value
+    return applyXDomainStrategy(sharedXDomain.value, props.xDomainStrategy)
   })
   const resolveInitialTrackDomain = (track: TrackLayout): [number, number] => {
     const configuredDomain =
@@ -239,11 +244,18 @@ export function useWaveformLayout(context: LayoutContext) {
       Number.isFinite(configuredDomain[1]) &&
       configuredDomain[0] !== configuredDomain[1]
     ) {
-      return configuredDomain[0] < configuredDomain[1]
+      return applyXDomainStrategy(
+        configuredDomain[0] < configuredDomain[1]
           ? configuredDomain
-        : [configuredDomain[1], configuredDomain[0]]
+          : [configuredDomain[1], configuredDomain[0]],
+        props.xDomainStrategy,
+        true,
+      )
     }
-    return paddedDomain(track.seriesList.flatMap((series) => series.xDomain))
+    return applyXDomainStrategy(
+      paddedDomain(track.seriesList.flatMap((series) => series.xDomain)),
+      props.xDomainStrategy,
+    )
   }
   const sharedZoomDomain = computed(
     () =>
@@ -272,6 +284,7 @@ export function useWaveformLayout(context: LayoutContext) {
       sharedZoomDomain: sharedZoomDomain.value,
       initialXDomain: props.initialXDomain ? initialXDomain.value : undefined,
       initialXDomains: props.initialXDomains,
+      xDomainStrategy: props.xDomainStrategy,
       fixedYDomain: props.yDomain,
       fixedYDomains: props.yDomains,
       yDomains:

src/components/core/waveformChartTypes.ts

@@ -11,8 +11,10 @@ import type {
   WaveformPoint,
   WaveformRenderingOptions,
   WaveformTitleOptions,
+  WaveformXDomainStrategy,
   WaveformZeroLineOptions,
   WaveformZoomEndPayload,
+  WaveformZoomResetPayload,
 } from '../data/types'
 import type { WaveformGridOptions } from './grid'
 
@@ -32,6 +34,7 @@ export interface WaveformChartProps {
   minVisiblePoints?: number
   initialXDomain?: [number, number]
   initialXDomains?: Record<string, [number, number]>
+  xDomainStrategy?: WaveformXDomainStrategy
   yDomain?: [number, number]
   yDomains?: Record<string, [number, number]>
   timeUnit?: 's' | 'ms'
@@ -62,6 +65,7 @@ type DefaultedProp =
   | 'zoomable'
   | 'pannable'
   | 'minVisiblePoints'
+  | 'xDomainStrategy'
   | 'timeUnit'
   | 'annotations'
   | 'annotationsVisible'
@@ -82,7 +86,7 @@ export interface WaveformChartEmit {
   (event: 'point-hover', point: WaveformPoint | null): void
   (event: 'zoom-change', domain: [number, number]): void
   (event: 'zoom-end', payload: WaveformZoomEndPayload): void
-  (event: 'zoom-reset'): void
+  (event: 'zoom-reset', payload: WaveformZoomResetPayload): void
   (event: 'update:annotations', annotations: WaveformAnnotation[]): void
   (event: 'update:hidden-series-ids', ids: string[]): void
   (

src/components/core/xDomain.test.ts

@@ -0,0 +1,28 @@
+import { describe, expect, it } from 'vitest'
+
+import { applyXDomainStrategy } from './xDomain'
+
+describe('applyXDomainStrategy', () => {
+  it('keeps the exact data domain by default', () => {
+    expect(applyXDomainStrategy([0, 4999.999], { type: 'data' })).toEqual([0, 4999.999])
+  })
+
+  it('expands both bounds to stable nice values', () => {
+    expect(applyXDomainStrategy([123, 456], { type: 'nice' })).toEqual([100, 500])
+  })
+
+  it('can expand only the end bound', () => {
+    expect(applyXDomainStrategy([123, 456], { type: 'nice', bounds: 'end' })).toEqual([123, 500])
+  })
+
+  it('keeps explicit domains exact unless they are included', () => {
+    expect(applyXDomainStrategy([123, 456], { type: 'nice' }, true)).toEqual([123, 456])
+    expect(applyXDomainStrategy([123, 456], { type: 'nice', includeExplicit: true }, true)).toEqual(
+      [100, 500],
+    )
+  })
+
+  it('falls back to the default tick count for invalid values', () => {
+    expect(applyXDomainStrategy([0, 4999.999], { type: 'nice', tickCount: 0 })).toEqual([0, 5000])
+  })
+})

src/components/core/xDomain.ts

@@ -0,0 +1,25 @@
+import { scaleLinear } from 'd3'
+
+import type { WaveformXDomainStrategy } from '../../types'
+
+const DEFAULT_NICE_TICK_COUNT = 10
+
+function resolveTickCount(value: number | undefined): number {
+  if (!Number.isFinite(value) || (value ?? 0) < 1) return DEFAULT_NICE_TICK_COUNT
+  return Math.max(1, Math.trunc(value as number))
+}
+
+/** Derives a viewport domain without changing any source coordinates. */
+export function applyXDomainStrategy(
+  domain: [number, number],
+  strategy: WaveformXDomainStrategy,
+  explicit = false,
+): [number, number] {
+  if (strategy.type !== 'nice' || (explicit && !strategy.includeExplicit)) return [...domain]
+
+  const niceDomain = scaleLinear()
+    .domain(domain)
+    .nice(resolveTickCount(strategy.tickCount))
+    .domain() as [number, number]
+  return strategy.bounds === 'end' ? [domain[0], niceDomain[1]] : niceDomain
+}

src/components/data/types.ts

@@ -9,7 +9,9 @@ export type {
   WaveformDisplayMode,
   WaveformOverlayMode,
   WaveformInteractionMode,
+  WaveformXDomainStrategy,
   WaveformZoomEndPayload,
+  WaveformZoomResetPayload,
   WaveformAnnotationStyle,
   WaveformAnnotation,
   WaveformRenderingOptions,

src/components/interaction/useWaveformViewport.ts

@@ -346,9 +346,23 @@ export function useWaveformViewport(context: ViewportContext) {
   }
   const requestViewportReset = (event: MouseEvent) => {
     if (isPresentationMode.value || !props.zoomable || !isZoomMode.value) return
+    if (props.displayMode === 'independent') {
+      const target = event.target instanceof Element ? event.target : null
+      const overlay = target?.closest('[data-independent-overlay-index]')
+      const trackIndex = Number(overlay?.getAttribute('data-independent-overlay-index'))
+      const track = trackLayouts.value.find((item) => item.index === trackIndex)
+      if (!track) return
+      event.preventDefault()
+      resetViewport(trackIndex)
+      emit('zoom-reset', {
+        trackIndex,
+        seriesIds: track.legendSeries.map((series) => series.id),
+      })
+      return
+    }
     event.preventDefault()
     resetViewport()
-    emit('zoom-reset')
+    emit('zoom-reset', {})
   }
   return {
     selectionBox,

src/components/waveform.ts

@@ -9,6 +9,7 @@ export type {
   WaveformDisplayMode,
   WaveformOverlayMode,
   WaveformInteractionMode,
+  WaveformXDomainStrategy,
   WaveformAnnotationStyle,
   WaveformAnnotation,
   WaveformRenderingOptions,

src/components/waveformChartCases/viewportConstraintsAndReset.test.ts

@@ -308,69 +308,4 @@ describe('WaveformChart', () => {
     expect(wrapper.emitted('zoom-change')?.length ?? 0).toBe(eventCount + 1)
     expect(zoomedOutDomain).toEqual([0, 2])
   })
-
-  it('resets a shared viewport on double-click and emits zoom-reset', async () => {
-    const wrapper = await mountSizedChart({
-      kind: 'points',
-      points: [
-        { x: 0, y: 0 },
-        { x: 2, y: 1 },
-      ],
-    })
-    const overlay = wrapper.get('.waveform-chart__overlay')
-    const width = Number(overlay.attributes('width'))
-    Object.defineProperty(overlay.element, 'getBoundingClientRect', {
-      value: () => ({ left: 0, top: 0, width, height: 290 }),
-    })
-    overlay.element.dispatchEvent(
-      new WheelEvent('wheel', {
-        deltaY: -4000,
-        clientX: width / 2,
-        clientY: 145,
-        bubbles: true,
-        cancelable: true,
-      }),
-    )
-    flushAnimationFrames()
-    await flushPromises()
-    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).not.toBe('0')
-
-    overlay.element.dispatchEvent(new MouseEvent('dblclick', { bubbles: true, cancelable: true }))
-    await flushPromises()
-
-    expect(wrapper.emitted('zoom-reset')).toHaveLength(1)
-    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
-    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2000')
-  })
-
-  it('exposes resetViewport for independent tracks', async () => {
-    const wrapper = await mountSizedChart(gridSeries(2), {
-      displayMode: 'independent',
-      grid: { rowCount: 1, columnCount: 2 },
-    })
-    const overlay = wrapper.findAll('.waveform-chart__overlay--independent')[0]
-    const width = Number(overlay.attributes('width'))
-    Object.defineProperty(overlay.element, 'getBoundingClientRect', {
-      value: () => ({ left: 0, top: 0, width, height: 260 }),
-    })
-    overlay.element.dispatchEvent(
-      new WheelEvent('wheel', {
-        deltaY: -4000,
-        clientX: width / 2,
-        clientY: 130,
-        bubbles: true,
-        cancelable: true,
-      }),
-    )
-    flushAnimationFrames()
-    await flushPromises()
-    expect(wrapper.findAll('.waveform-chart__axis-endpoint--start')[0].text()).not.toBe('0')
-
-    const chart = wrapper.vm as unknown as { resetViewport: () => void }
-    chart.resetViewport()
-    await flushPromises()
-
-    expect(wrapper.findAll('.waveform-chart__axis-endpoint--start')[0].text()).toBe('0')
-    expect(wrapper.findAll('.waveform-chart__axis-endpoint--end')[0].text()).toBe('1000')
-  })
 })

src/components/waveformChartCases/viewportReset.test.ts

@@ -0,0 +1,149 @@
+import { flushPromises } from '@vue/test-utils'
+import { describe, expect, it } from 'vitest'
+
+import { flushAnimationFrames } from '../../test/setup'
+import { gridSeries, mountSizedChart } from '../../test/waveformChart'
+
+describe('WaveformChart viewport reset', () => {
+  const niceExplicitStrategy = {
+    type: 'nice' as const,
+    bounds: 'end' as const,
+    tickCount: 10,
+    includeExplicit: true,
+  }
+
+  it('resets a shared viewport on double-click and emits a global payload', async () => {
+    const wrapper = await mountSizedChart(
+      {
+        kind: 'points',
+        points: [
+          { x: 0, y: 0 },
+          { x: 2, y: 1 },
+        ],
+      },
+      { displayMode: 'separated' },
+    )
+    const overlay = wrapper.get('.waveform-chart__overlay')
+    const width = Number(overlay.attributes('width'))
+    Object.defineProperty(overlay.element, 'getBoundingClientRect', {
+      value: () => ({ left: 0, top: 0, width, height: 290 }),
+    })
+    overlay.element.dispatchEvent(
+      new WheelEvent('wheel', {
+        deltaY: -4000,
+        clientX: width / 2,
+        clientY: 145,
+        bubbles: true,
+        cancelable: true,
+      }),
+    )
+    flushAnimationFrames()
+    await flushPromises()
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).not.toBe('0')
+
+    overlay.element.dispatchEvent(new MouseEvent('dblclick', { bubbles: true, cancelable: true }))
+    await flushPromises()
+
+    expect(wrapper.emitted('zoom-reset')).toEqual([[{}]])
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('2000')
+  })
+
+  it('resets only the double-clicked independent track and identifies it', async () => {
+    const wrapper = await mountSizedChart(gridSeries(2), {
+      displayMode: 'independent',
+      grid: { rowCount: 1, columnCount: 2 },
+    })
+    const overlays = wrapper.findAll('.waveform-chart__overlay--independent')
+    for (const overlay of overlays) {
+      const width = Number(overlay.attributes('width'))
+      Object.defineProperty(overlay.element, 'getBoundingClientRect', {
+        value: () => ({ left: 0, top: 0, width, height: 260 }),
+      })
+      overlay.element.dispatchEvent(
+        new WheelEvent('wheel', {
+          deltaY: -4000,
+          clientX: width / 2,
+          clientY: 130,
+          bubbles: true,
+          cancelable: true,
+        }),
+      )
+      flushAnimationFrames()
+      await flushPromises()
+    }
+    const startsBeforeReset = wrapper.findAll('.waveform-chart__axis-endpoint--start')
+    expect(startsBeforeReset[0].text()).not.toBe('0')
+    expect(startsBeforeReset[1].text()).not.toBe('0')
+    const secondTrackStart = startsBeforeReset[1].text()
+
+    overlays[0].element.dispatchEvent(
+      new MouseEvent('dblclick', { bubbles: true, cancelable: true }),
+    )
+    await flushPromises()
+
+    const startsAfterReset = wrapper.findAll('.waveform-chart__axis-endpoint--start')
+    expect(startsAfterReset[0].text()).toBe('0')
+    expect(startsAfterReset[1].text()).toBe(secondTrackStart)
+    expect(wrapper.emitted('zoom-reset')).toEqual([[{ trackIndex: 0, seriesIds: ['channel-0'] }]])
+  })
+
+  it('keeps the exposed no-argument resetViewport global', async () => {
+    const wrapper = await mountSizedChart(gridSeries(2), {
+      displayMode: 'independent',
+      grid: { rowCount: 1, columnCount: 2 },
+    })
+    const overlay = wrapper.findAll('.waveform-chart__overlay--independent')[0]
+    const width = Number(overlay.attributes('width'))
+    Object.defineProperty(overlay.element, 'getBoundingClientRect', {
+      value: () => ({ left: 0, top: 0, width, height: 260 }),
+    })
+    overlay.element.dispatchEvent(
+      new WheelEvent('wheel', {
+        deltaY: -4000,
+        clientX: width / 2,
+        clientY: 130,
+        bubbles: true,
+        cancelable: true,
+      }),
+    )
+    flushAnimationFrames()
+    await flushPromises()
+    expect(wrapper.findAll('.waveform-chart__axis-endpoint--start')[0].text()).not.toBe('0')
+
+    const chart = wrapper.vm as unknown as { resetViewport: () => void }
+    chart.resetViewport()
+    await flushPromises()
+
+    expect(wrapper.findAll('.waveform-chart__axis-endpoint--start')[0].text()).toBe('0')
+    expect(wrapper.findAll('.waveform-chart__axis-endpoint--end')[0].text()).toBe('1000')
+  })
+
+  it('resets shared and independent explicit domains to their included nice bounds', async () => {
+    const shared = await mountSizedChart(
+      {
+        kind: 'points',
+        points: [
+          { x: 0, y: 0 },
+          { x: 4.999999, y: 1 },
+        ],
+      },
+      { initialXDomain: [0, 4.999999], xDomainStrategy: niceExplicitStrategy },
+    )
+    const independent = await mountSizedChart(gridSeries(2), {
+      displayMode: 'independent',
+      initialXDomains: { 'channel-0': [0, 4.999999] },
+      xDomainStrategy: niceExplicitStrategy,
+    })
+
+    ;(shared.vm as unknown as { resetViewport: () => void }).resetViewport()
+    ;(independent.vm as unknown as { resetViewport: () => void }).resetViewport()
+    await flushPromises()
+
+    expect(shared.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(shared.get('.waveform-chart__axis-endpoint--end').text()).toBe('5000')
+    const firstTrack = independent.findAll('.waveform-chart__track')[0]
+    expect(firstTrack.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(firstTrack.get('.waveform-chart__axis-endpoint--end').text()).toBe('5000')
+  })
+})

src/components/waveformChartCases/xDomainStrategy.test.ts

@@ -0,0 +1,96 @@
+import { describe, expect, it } from 'vitest'
+
+import { gridSeries, mountSizedChart } from '../../test/waveformChart'
+
+describe('WaveformChart x domain strategy', () => {
+  it('expands automatic x domains without changing source seconds', async () => {
+    const data = {
+      kind: 'points' as const,
+      points: [
+        { x: 0, y: 0 },
+        { x: 4.999999, y: 1 },
+      ],
+    }
+    const wrapper = await mountSizedChart(data, {
+      timeUnit: 'ms',
+      xDomainStrategy: { type: 'nice', bounds: 'end' },
+    })
+
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('5000')
+    expect(data.points[1]?.x).toBe(4.999999)
+  })
+
+  it('keeps explicit initial x domains exact by default', async () => {
+    const wrapper = await mountSizedChart(
+      {
+        kind: 'points',
+        points: [
+          { x: 123, y: 0 },
+          { x: 456, y: 1 },
+        ],
+      },
+      {
+        timeUnit: 's',
+        initialXDomain: [120, 460],
+        xDomainStrategy: { type: 'nice' },
+      },
+    )
+
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('120')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('460')
+  })
+
+  it('keeps explicit per-track initial x domains exact by default', async () => {
+    const wrapper = await mountSizedChart(gridSeries(1), {
+      displayMode: 'independent',
+      initialXDomains: { 'channel-0': [0, 4.999999] },
+      xDomainStrategy: { type: 'nice', bounds: 'end' },
+    })
+
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('4999.999')
+  })
+
+  it('includes an explicit shared initial x domain when requested', async () => {
+    const wrapper = await mountSizedChart(
+      {
+        kind: 'points',
+        points: [
+          { x: 0, y: 0 },
+          { x: 4.999999, y: 1 },
+        ],
+      },
+      {
+        initialXDomain: [0, 4.999999],
+        xDomainStrategy: {
+          type: 'nice',
+          bounds: 'end',
+          tickCount: 10,
+          includeExplicit: true,
+        },
+      },
+    )
+
+    expect(wrapper.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(wrapper.get('.waveform-chart__axis-endpoint--end').text()).toBe('5000')
+  })
+
+  it('includes explicit per-track initial x domains in independent mode', async () => {
+    const wrapper = await mountSizedChart(gridSeries(2), {
+      displayMode: 'independent',
+      grid: { rowCount: 1, columnCount: 2 },
+      initialXDomains: {
+        'channel-0': [0, 4.999999],
+        'channel-1': [10, 14.999999],
+      },
+      xDomainStrategy: { type: 'nice', bounds: 'end', tickCount: 10, includeExplicit: true },
+    })
+
+    const tracks = wrapper.findAll('.waveform-chart__track')
+    expect(tracks[0]?.get('.waveform-chart__axis-endpoint--start').text()).toBe('0')
+    expect(tracks[0]?.get('.waveform-chart__axis-endpoint--end').text()).toBe('5000')
+    expect(tracks[1]?.get('.waveform-chart__axis-endpoint--start').text()).toBe('10000')
+    expect(tracks[1]?.get('.waveform-chart__axis-endpoint--end').text()).toBe('15000')
+  })
+})

src/index.ts

@@ -13,7 +13,9 @@ export type {
   WaveformDisplayMode,
   WaveformOverlayMode,
   WaveformInteractionMode,
+  WaveformXDomainStrategy,
   WaveformZoomEndPayload,
+  WaveformZoomResetPayload,
   WaveformAnnotationStyle,
   WaveformAnnotation,
   WaveformRenderingOptions,

src/types/chart.ts

@@ -26,6 +26,17 @@ export type WaveformOverlayMode = 'single-axis' | 'multi-axis'
 /** 标注工具模式 */
 export type WaveformInteractionMode = 'zoom' | 'annotation'
 
+/** Controls how the initial X viewport is derived when no explicit domain is configured. */
+export interface WaveformXDomainStrategy {
+  type: 'data' | 'nice'
+  /** Selects which bounds are expanded when type is `nice`. Defaults to `both`. */
+  bounds?: 'both' | 'end'
+  /** Stable tick count used to calculate nice bounds. Defaults to 10. */
+  tickCount?: number
+  /** Applies the strategy to explicit initial domains. Defaults to false. */
+  includeExplicit?: boolean
+}
+
 /** Describes the X-axis viewport after a zoom gesture completes. */
 export interface WaveformZoomEndPayload {
   start: number
@@ -38,6 +49,12 @@ export interface WaveformZoomEndPayload {
   gesture?: 'wheel' | 'box'
 }
 
+/** Identifies the viewport reset by a double-click gesture. */
+export interface WaveformZoomResetPayload {
+  trackIndex?: number
+  seriesIds?: string[]
+}
+
 /** 标注颜色样式 */
 export interface WaveformAnnotationStyle {
   borderColor?: string

src/types/index.ts

@@ -8,7 +8,9 @@ export type {
   WaveformDisplayMode,
   WaveformOverlayMode,
   WaveformInteractionMode,
+  WaveformXDomainStrategy,
   WaveformZoomEndPayload,
+  WaveformZoomResetPayload,
   WaveformAnnotationStyle,
   WaveformAnnotation,
   WaveformRenderingOptions,