feat(stammbaum): land a fresh visit at readable z=3, keep fit-to-screen at z=1 (#692)

A fresh visit (no URL state) now opens at INITIAL_VIEW (z=3) so node tiles and
generation labels are legible on arrival; the fit-to-screen control still zooms
out to the whole tree (DEFAULT_VIEW, z=1). Shared links with ?z still win.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Marcel
2026-05-29 18:00:17 +02:00
parent 578bebbd8b
commit bb2a89da58
3 changed files with 24 additions and 13 deletions

View File

@@ -28,9 +28,17 @@ export const ZOOM_STEP_KB = 0.1;
*/ */
export type PanZoomState = { x: number; y: number; z: number }; export type PanZoomState = { x: number; y: number; z: number };
/** Fit-to-screen / initial view (US-PAN-004). */ /** Fit-to-screen target — frames the whole tree at z=1 (US-PAN-004). */
export const DEFAULT_VIEW: PanZoomState = { x: 0, y: 0, z: DEFAULT_ZOOM }; export const DEFAULT_VIEW: PanZoomState = { x: 0, y: 0, z: DEFAULT_ZOOM };
/**
* Landing zoom for a fresh visit (no URL state). Higher than fit so node tiles
* and generation labels are legible on arrival; the fit-to-screen control
* (DEFAULT_VIEW, z=1) zooms back out to the whole tree.
*/
export const INITIAL_ZOOM = 3;
export const INITIAL_VIEW: PanZoomState = { x: 0, y: 0, z: INITIAL_ZOOM };
/** Clamp a zoom factor into the supported range. */ /** Clamp a zoom factor into the supported range. */
export function clampZoom(z: number): number { export function clampZoom(z: number): number {
return Math.min(MAX_ZOOM, Math.max(MIN_ZOOM, z)); return Math.min(MAX_ZOOM, Math.max(MIN_ZOOM, z));

View File

@@ -1,7 +1,7 @@
import { error, redirect } from '@sveltejs/kit'; import { error, redirect } from '@sveltejs/kit';
import { createApiClient, extractErrorCode } from '$lib/shared/api.server'; import { createApiClient, extractErrorCode } from '$lib/shared/api.server';
import { getErrorMessage } from '$lib/shared/errors'; import { getErrorMessage } from '$lib/shared/errors';
import { parsePanZoomParams } from '$lib/person/genealogy/panZoom'; import { parsePanZoomParams, INITIAL_VIEW } from '$lib/person/genealogy/panZoom';
export async function load({ fetch, url }) { export async function load({ fetch, url }) {
const api = createApiClient(fetch); const api = createApiClient(fetch);
@@ -13,14 +13,17 @@ export async function load({ fetch, url }) {
throw error(result.response.status, getErrorMessage(extractErrorCode(result.error))); throw error(result.response.status, getErrorMessage(extractErrorCode(result.error)));
} }
// Sanitise the shareable pan/zoom params server-side so a crafted link // A fresh visit (no shared pan/zoom state) lands at the readable INITIAL_VIEW
// (?z=Infinity, ?cx=NaN) degrades to a safe view before reaching layout // (z=3). When a link carries a zoom param we honour it, sanitising server-side
// geometry (Nora #692). // so a crafted link (?z=Infinity, ?cx=NaN) degrades to a safe view before
const initialView = parsePanZoomParams({ // reaching layout geometry (Nora #692).
cx: url.searchParams.get('cx'), const initialView = url.searchParams.has('z')
cy: url.searchParams.get('cy'), ? parsePanZoomParams({
z: url.searchParams.get('z') cx: url.searchParams.get('cx'),
}); cy: url.searchParams.get('cy'),
z: url.searchParams.get('z')
})
: INITIAL_VIEW;
const network = result.data!; const network = result.data!;
return { nodes: network.nodes ?? [], edges: network.edges ?? [], initialView }; return { nodes: network.nodes ?? [], edges: network.edges ?? [], initialView };

View File

@@ -6,7 +6,7 @@ vi.mock('$lib/shared/api.server', () => ({
})); }));
import { createApiClient } from '$lib/shared/api.server'; import { createApiClient } from '$lib/shared/api.server';
import { DEFAULT_VIEW, MAX_ZOOM } from '$lib/person/genealogy/panZoom'; import { DEFAULT_VIEW, INITIAL_VIEW, MAX_ZOOM } from '$lib/person/genealogy/panZoom';
beforeEach(() => vi.clearAllMocks()); beforeEach(() => vi.clearAllMocks());
@@ -26,11 +26,11 @@ function loadEvent(query = '') {
} }
describe('/stammbaum +page.server load — initialView', () => { describe('/stammbaum +page.server load — initialView', () => {
it('returns DEFAULT_VIEW when no pan/zoom params are present', async () => { it('returns the readable INITIAL_VIEW (z=3) for a fresh visit with no params', async () => {
mockNetwork(); mockNetwork();
const { load } = await import('./+page.server'); const { load } = await import('./+page.server');
const result = await load(loadEvent() as never); const result = await load(loadEvent() as never);
expect(result.initialView).toEqual(DEFAULT_VIEW); expect(result.initialView).toEqual(INITIAL_VIEW);
}); });
it('parses and returns valid ?cx&cy&z params', async () => { it('parses and returns valid ?cx&cy&z params', async () => {