Merge branch 'main' into fix/right-rail-css-hidden-panel-20261003

src/ui/layerKeyRequirement.test.mjs

@@ -141,3 +141,19 @@ test('the manager publishes the declared key id on the row', async () => {
   );
   assert.equal(layerKeyRequirementTooltip(ungated), '');
 });
+
+test('a key-gated layer with another source ready says how to use it', () => {
+  const text = layerKeyRequirementTooltip({
+    requiresKeyId: 'mapillary',
+    stats: {
+      keyRequired: true,
+      keyAlternatives: [
+        { id: 'google', label: 'STREET VIEW', requiresKeyId: 'google-maps' },
+      ],
+    },
+  });
+  assert.equal(
+    text,
+    'Needs MAPILLARY_CLIENT_TOKEN — add it in Provider Settings, or light STREET VIEW to use your Google Maps key',
+  );
+});

src/ui/layerPanel.js

@@ -3,7 +3,10 @@ import { syncRowList } from './rowList.js';
 import { layerFeedState } from '../data/feedState.js';
 export { layerFeedState } from '../data/feedState.js';
 import { GUIDANCE_STATUSES } from '../loadingFeedback.js';
-import { keySetupRequirement } from '../keySetupCore.mjs';
+import {
+  keySetupRequirement,
+  keySetupWithAlternatives,
+} from '../keySetupCore.mjs';
 import { createWeatherPanel } from './weatherPanel.js';
 const FEED_STATE_LABELS = Object.freeze({
   nominal: 'ON',
@@ -100,7 +103,11 @@ function panelLabel(layer) {
 export function layerKeyRequirementTooltip(layer = {}) {
   if (layer?.stats?.keyRequired !== true) return '';
   const requiresKeyId = String(layer.requiresKeyId || '').trim();
-  return requiresKeyId ? keySetupRequirement(requiresKeyId) : '';
+  // A layer with several sources also names the ones it could use instead.
+  return keySetupWithAlternatives(
+    requiresKeyId ? keySetupRequirement(requiresKeyId) : '',
+    layer.stats.keyAlternatives || [],
+  );
 }
 
 /** Layer row presentation over supplied state and actions; no layer imports. */

src/ui/streetLevelControls.js

@@ -66,10 +66,14 @@ export class StreetLevelControls {
       status: byId('sl-status'),
       controls: byId('sl-controls'),
       providerChips: byId('sl-provider-chips'),
+      nearestBtn: byId('sl-nearest-btn'),
       error: byId('sl-error'),
       errorText: byId('sl-error-text'),
+      panoRow: byId('sl-pano-row'),
+      sinceRow: byId('sl-since-row'),
       sinceRange: byId('sl-since'),
       sinceLabel: byId('sl-since-label'),
+      sinceNote: byId('sl-since-note'),
       legend: byId('sl-legend'),
       followBtn: byId('sl-follow-btn'),
       viewerWrap: byId('sl-viewer-wrap'),
@@ -103,9 +107,11 @@ export class StreetLevelControls {
     this.listen(el.providerChips, 'click', (event) => {
       const button = event.target?.closest?.('.data-toggle-chip');
       if (!button || button.disabled) return;
-      // Without a key the chips stay focusable for their tooltip; a click
-      // says the same thing rather than switching on a layer that cannot draw.
-      if (this._view?.controlsDisabled) {
+      // A keyless chip shows its tooltip instead of switching; others switch.
+      const chip = this._view?.providers.find(
+        (entry) => entry.id === button.dataset.chipId,
+      );
+      if (chip?.state === 'error') {
         if (button.title) this.actions.showToast?.(button.title);
         return;
       }
@@ -129,6 +135,15 @@ export class StreetLevelControls {
     this.listen(el.sinceRange, 'change', () =>
       this._setParams({ sinceDays: sinceDays() }),
     );
+    this.listen(el.nearestBtn, 'click', () => {
+      const nearest = this._view?.nearest;
+      if (!nearest?.visible || nearest.disabled) return;
+      this.layer.openNearest?.(undefined, {
+        providerIds: nearest.providerIds,
+        frame: false,
+        aim: 'screen-centre',
+      });
+    });
     this.listen(el.followBtn, 'click', () => {
       this.layer.setFollow?.(!(this._state?.street?.follow === true));
     });
@@ -238,24 +253,23 @@ export class StreetLevelControls {
   }
 
   /**
-   * Lighting a chip turns the layer on; darkening the last lit one turns the
-   * layer off but keeps the provider on, so the layer comes back with it.
+   * Lighting a chip turns the layer on and darkens the others (one source at
+   * a time); darkening the lit one turns the layer off, keeping the provider.
    */
   async _toggleProvider(providerId) {
     const chip = this._view?.providers.find((entry) => entry.id === providerId);
     if (!chip) return;
     if (!chip.active) {
-      this._setParams({ [providerId]: true });
+      // Every registered provider in one update (those hidden on this map
+      // too), so the share link records the swap.
+      const ids =
+        this.layer.providerIds || this._view.providers.map((entry) => entry.id);
+      this._setParams(
+        Object.fromEntries(ids.map((id) => [id, id === providerId])),
+      );
       await this._ensureEnabled();
       return;
     }
-    const othersLit = this._view.providers.some(
-      (entry) => entry.id !== providerId && entry.active,
-    );
-    if (othersLit) {
-      this._setParams({ [providerId]: false });
-      return;
-    }
     try {
       await this.actions.setEnabled?.(false);
     } catch (error) {
@@ -466,6 +480,7 @@ export class StreetLevelControls {
     this._renderFilters(view);
     this._renderViewer(view);
     this._renderMeta(view);
+    this._renderNearest(view);
     this._reactToTransitions(view, state);
   }
 
@@ -510,6 +525,14 @@ export class StreetLevelControls {
 
   _renderFilters(view) {
     const el = this._elements;
+    const shows = view.filterControls || { pano: true, since: true };
+    setProp(el.panoRow, 'hidden', !shows.pano);
+    setProp(el.sinceRow, 'hidden', !shows.since);
+    // A lit source that dates by upload says so under the slider.
+    setProp(el.sinceNote, 'textContent', view.sinceNote || '');
+    setProp(el.sinceNote, 'hidden', !view.sinceNote);
+    setProp(el.controls, 'hidden', !shows.pano && !shows.since);
+    setProp(el.legend, 'hidden', view.legend.length === 0);
     this._renderRadios(
       el.panoButtons,
       (button) => button.dataset.slPano === view.filter.pano,
@@ -577,6 +600,9 @@ export class StreetLevelControls {
       el.renderButtons,
       (button) => button.dataset.slRender === viewer.renderMode,
     );
+    // Google's viewer always fills its frame: no FIT/FILL to offer.
+    const renderGroup = el.renderButtons[0]?.parentElement;
+    if (renderGroup) setProp(renderGroup, 'hidden', !viewer.renderModes);
     if (!viewer.open) return;
     setProp(el.imageBy, 'textContent', viewer.captionLeft);
     setProp(el.imageWhen, 'textContent', viewer.captionRight);
@@ -592,6 +618,17 @@ export class StreetLevelControls {
     setProp(this._elements.coverageMeta, 'textContent', view.meta);
   }
 
+  _renderNearest(view) {
+    const button = this._elements.nearestBtn;
+    if (!button) return;
+    const { nearest } = view;
+    setProp(button, 'hidden', !nearest.visible);
+    if (!nearest.visible) return;
+    setProp(button, 'textContent', nearest.label);
+    setProp(button, 'title', nearest.title);
+    setProp(button, 'disabled', nearest.disabled);
+  }
+
   /**
    * Open the panel on a switch-on or when an image opens. Never persisted:
    * the stored collapse state stays the user's own choice.

src/ui/streetLevelControls.test.mjs

@@ -1,4 +1,5 @@
 import assert from 'node:assert/strict';
+import fs from 'node:fs';
 import test from 'node:test';
 import { StreetLevelControls } from './streetLevelControls.js';
 import { createStreetLevelLayer } from '../layers/streetLevel/index.js';
@@ -307,12 +308,17 @@ function panelDom() {
     add(settings, 'div', { id });
   // A missing key gates the filters only; the chips stay outside the gate.
   const controls = add(settings, 'fieldset', { id: 'sl-controls' });
+  const panoRow = add(controls, 'div', { id: 'sl-pano-row' });
   for (const pano of ['all', 'pano', 'flat'])
-    add(controls, 'button', { dataset: { slPano: pano } });
-  add(controls, 'input', { id: 'sl-since' });
-  add(controls, 'output', { id: 'sl-since-label' });
+    add(panoRow, 'button', { dataset: { slPano: pano } });
+  const sinceRow = add(controls, 'div', { id: 'sl-since-row' });
+  add(sinceRow, 'input', { id: 'sl-since' });
+  add(sinceRow, 'output', { id: 'sl-since-label' });
+  add(sinceRow, 'small', { id: 'sl-since-note' });
   add(settings, 'ul', { id: 'sl-legend' });
-  add(settings, 'div', { id: 'sl-coverage-meta' });
+  const metaRow = add(settings, 'div', { classes: ['sl-meta-row'] });
+  add(metaRow, 'div', { id: 'sl-coverage-meta' });
+  add(metaRow, 'button', { id: 'sl-nearest-btn' });
   // The globe's canvas is focusable too (tabindex=0).
   const globe = add(
     add(document.body, 'div', { id: 'cesiumContainer' }),
@@ -1136,3 +1142,142 @@ test('a <body> child added while the viewer is expanded goes inert with the rest
       assert.equal(observer.watching(), false);
     }),
   ));
+
+test('OPEN STREET VIEW opens the nearest panorama at the view centre without moving the camera', () =>
+  withDom(async (dom) => {
+    const state = uiState();
+    state.providers.push({
+      ...state.providers[0],
+      id: 'google',
+      name: 'Google Street View',
+      label: 'STREET VIEW',
+      groundClick: true,
+      count: 0,
+    });
+    state.groundClickReady = true;
+    const { layer } = stubPanel(dom, state);
+    const asked = [];
+    layer.openNearest = (point, options) => asked.push([point, options]);
+    const button = dom.root.querySelector('#sl-nearest-btn');
+    assert.equal(button.hidden, false);
+    assert.equal(button.textContent, 'OPEN STREET VIEW');
+    button.click();
+    assert.deepEqual(asked, [
+      [
+        undefined,
+        { providerIds: ['google'], frame: false, aim: 'screen-centre' },
+      ],
+    ]);
+    // Too high to mean a street: disabled, and a click does nothing.
+    layer.publish({ ...state, groundClickReady: false });
+    assert.equal(button.disabled, true);
+    button.click();
+    assert.equal(asked.length, 1);
+    // Off Google 3D the provider is not listed: no button.
+    layer.publish({ ...state, providers: [state.providers[0]] });
+    assert.equal(button.hidden, true);
+  }));
+
+test('a refused Street View key cannot lock Mapillary out; its chip only explains itself', () =>
+  withDom(async (dom) => {
+    const state = uiState({ on: false, keyRequired: true });
+    state.providers.push({
+      ...state.providers[0],
+      id: 'google',
+      name: 'Google Street View',
+      label: 'STREET VIEW',
+      on: true,
+      keyRequired: true,
+      keyRejected: true,
+      error: 'Google refused GOOGLE_MAPS_API_KEY for Street View',
+    });
+    state.providers[0].keyRequired = false;
+    const { calls, layer } = stubPanel(dom, state);
+    const chips = () => dom.root.querySelector('#sl-provider-chips').children;
+    chips()[0].click(); // Mapillary: configured, dark
+    await settle();
+    // One source at a time: lighting Mapillary darkens Street View too.
+    assert.deepEqual(calls.setParams, [
+      [{ mapillary: true, google: false }, { origin: 'user' }],
+    ]);
+    // Now dark, the refused chip says why instead of lighting.
+    state.providers[0].on = true;
+    state.providers[1].on = false;
+    state.keyRequired = false;
+    layer.publish({ ...state });
+    chips()[1].click();
+    await settle();
+    assert.equal(calls.setParams.length, 1);
+    assert.deepEqual(calls.toasts, [
+      dom.root.querySelector('#sl-provider-chips').children[1].title,
+    ]);
+  }));
+
+test('a swap names every registered provider, also those hidden on this map', () =>
+  withDom(async (dom) => {
+    const state = uiState({ on: false });
+    const { calls, layer, chip } = stubPanel(dom, state);
+    // Off Google 3D the Street View chip is not listed, but stays registered.
+    layer.providerIds = ['mapillary', 'google'];
+    chip().click();
+    await settle();
+    assert.deepEqual(calls.setParams, [
+      [{ mapillary: true, google: false }, { origin: 'user' }],
+    ]);
+  }));
+
+test('a note under SINCE says what date it compares, only while one is given', () =>
+  withDom(async (dom) => {
+    const state = uiState();
+    const { layer } = stubPanel(dom, state);
+    const note = () => dom.root.querySelector('#sl-since-note');
+    assert.equal(note().hidden, true, 'none for Mapillary');
+    layer.publish({ ...state, sinceNote: 'KartaView: by upload date' });
+    assert.equal(note().hidden, false);
+    assert.equal(note().textContent, 'KartaView: by upload date');
+    layer.publish(state);
+    assert.equal(note().hidden, true);
+    // The panel's own markup has it, read out with the slider.
+    const template = fs.readFileSync(
+      new URL('./templates/layer-panels.html', import.meta.url),
+      'utf8',
+    );
+    assert.match(template, /<small id="sl-since-note"[^>]* hidden>/);
+    assert.match(template, /aria-describedby="sl-since-label sl-since-note"/);
+  }));
+
+test('Street View lit hides the imagery filters and the legend; Mapillary lit shows them', () =>
+  withDom(async (dom) => {
+    const state = uiState();
+    const { layer } = stubPanel(dom, state);
+    const shown = () => ({
+      pano: !dom.root.querySelector('#sl-pano-row').hidden,
+      since: !dom.root.querySelector('#sl-since-row').hidden,
+      controls: !dom.root.querySelector('#sl-controls').hidden,
+      legend: !dom.root.querySelector('#sl-legend').hidden,
+    });
+    assert.deepEqual(shown(), {
+      pano: true,
+      since: true,
+      controls: true,
+      legend: true,
+    });
+    layer.publish({
+      ...state,
+      filterControls: { pano: false, since: false },
+      legend: [],
+    });
+    assert.deepEqual(shown(), {
+      pano: false,
+      since: false,
+      controls: false,
+      legend: false,
+    });
+    layer.publish(state);
+    assert.deepEqual(shown(), {
+      pano: true,
+      since: true,
+      controls: true,
+      legend: true,
+    });
+  }));

src/ui/streetLevelPresentation.js

@@ -1,4 +1,7 @@
-import { keySetupRequirement } from '../keySetupCore.mjs';
+import {
+  keySetupRequirement,
+  keySetupWithAlternatives,
+} from '../keySetupCore.mjs';
 
 // Street Level UI state to panel strings and flags. Pure, so it is testable.
 
@@ -44,22 +47,43 @@ function presentSince(days, now) {
   };
 }
 
-function formatDate(ms) {
+/** YYYY-MM-DD, or YYYY-MM for a provider that dates images by month. */
+function formatDate(ms, precision = 'day') {
   if (!Number.isFinite(ms)) return '';
   try {
-    return new Date(ms).toISOString().slice(0, 10);
+    return new Date(ms).toISOString().slice(0, precision === 'month' ? 7 : 10);
   } catch {
     return '';
   }
 }
 
+/**
+ * What the key-gated layer needs: each switched-on provider's key, and the
+ * switched-off ones that would draw with a key already set.
+ */
+function keyGuidance(state) {
+  const needs = (state.providers || [])
+    .filter((p) => p.on && p.keyRequired && p.requiresKeyId)
+    .map((p) => keySetupRequirement(p.requiresKeyId))
+    .filter(Boolean);
+  return keySetupWithAlternatives(
+    [...new Set(needs)].join('; '),
+    state.keyAlternatives || [],
+  );
+}
+
 function presentStatus(state) {
   const pressed = state.enabled === true;
   const title = pressed ? 'Turn Street Level off' : 'Turn Street Level on';
   if (state.keyRejected)
     return { text: 'KEY REJECTED', tone: 'warn', pressed, title };
   if (state.keyRequired)
-    return { text: 'KEY REQUIRED', tone: 'warn', pressed, title };
+    return {
+      text: 'KEY REQUIRED',
+      tone: 'warn',
+      pressed,
+      title: keyGuidance(state) || title,
+    };
   if (state.coverage.loading)
     return { text: 'LOADING', tone: 'busy', pressed, title };
   return pressed
@@ -104,12 +128,17 @@ function presentViewer(state) {
   if (street.isPano) right.push('360°');
   if (Number.isFinite(street.bearing))
     right.push(`${Math.round(street.bearing)}°`);
-  if (street.capturedAt) right.push(formatDate(street.capturedAt));
+  if (street.capturedAt)
+    right.push(formatDate(street.capturedAt, street.capturedAtPrecision));
+  const left = [];
+  if (street.title) left.push(street.title);
+  if (street.creator) left.push(`Image by ${street.creator}`);
   return {
     open: street.open === true,
     loading: street.loading === true && !street.imageId,
     renderMode: street.renderMode === 'fill' ? 'fill' : 'letterbox',
-    captionLeft: street.creator ? `Image by ${street.creator}` : '',
+    renderModes: street.renderModes !== false,
+    captionLeft: left.join(' · '),
     captionRight: right.join(' · '),
     link: street.externalUrl || null,
     linkLabel: street.providerLabel ? `${street.providerLabel} ↗` : '',
@@ -124,16 +153,52 @@ function presentViewer(state) {
   };
 }
 
+/** OPEN STREET VIEW: the keyboard path to providers with no coverage to click. */
+function presentNearest(state) {
+  const targets = (state.providers || []).filter(
+    (provider) =>
+      provider.on && provider.groundClick && provider.keyRequired !== true,
+  );
+  if (state.enabled !== true || !targets.length)
+    return {
+      visible: false,
+      label: '',
+      title: '',
+      disabled: true,
+      providerIds: [],
+    };
+  const names = targets.map((provider) => provider.name).join(' or ');
+  const ready = state.groundClickReady === true;
+  return {
+    visible: true,
+    label: `OPEN ${targets.map((provider) => provider.label).join(' / ')}`,
+    title: ready
+      ? `Open ${names} at the centre of the view`
+      : `Zoom in to a street to open ${names} here`,
+    disabled: !ready || state.street.loading === true,
+    providerIds: targets.map((provider) => provider.id),
+  };
+}
+
 function presentMeta(state) {
   if (state.providers.length === 0) return state.coverage.hint || '';
   if (!state.enabled) return 'Switch a provider on to draw its coverage.';
+  // Key-gated with another source ready: say how to use it.
+  if (state.keyRequired && state.keyAlternatives?.length)
+    return keyGuidance(state);
   if (state.sequence.selectedId)
     return state.sequence.loading
       ? 'Loading this sequence…'
       : `${state.sequence.images.toLocaleString()} images in this sequence · Esc clears`;
+  const hint = state.coverage.hint || '';
   if (state.coverage.count > 0)
-    return `${state.coverage.count.toLocaleString()} sequences in view · click a line for its photos`;
-  return state.coverage.hint || '';
+    return [
+      `${state.coverage.count.toLocaleString()} ${state.coverage.label?.noun || 'sequences'} in view · ${state.coverage.label?.action || 'click a line for its photos'}`,
+      hint,
+    ]
+      .filter(Boolean)
+      .join(' · ');
+  return hint;
 }
 
 /** @param {{now?: number}} [options] Clock for the SINCE readout. */
@@ -154,10 +219,16 @@ export function presentStreetLevelPanel(state, { now = Date.now() } = {}) {
       ? null
       : state.street.error || state.coverage.error || null,
     filter: { pano: filter.pano, sinceDays: Number(filter.sinceDays) || 0 },
+    filterControls: {
+      pano: state.filterControls?.pano !== false,
+      since: state.filterControls?.since !== false,
+    },
     since: presentSince(filter.sinceDays, now),
+    sinceNote: state.sinceNote || null,
     legend: state.legend || [],
     viewer: presentViewer(state),
     meta: presentMeta(state),
+    nearest: presentNearest(state),
     wantsOpen: state.street.open === true,
   };
 }

src/ui/streetLevelPresentation.test.mjs

@@ -405,3 +405,137 @@ test('FOLLOW is disabled off Google 3D and says where to switch', () => {
   );
   assert.equal(closed.viewer.follow.disabled, true, 'nothing to follow');
 });
+
+test('a Street View caption names the place, dates it by month, and offers no FIT/FILL', () => {
+  const view = presentStreetLevelPanel(
+    snapshot({
+      enabled: true,
+      street: {
+        open: true,
+        providerId: 'google',
+        providerName: 'Google Street View',
+        providerLabel: 'STREET VIEW',
+        imageId: 'pano-1',
+        title: '1014 10th St',
+        creator: 'Google',
+        capturedAt: Date.UTC(2023, 0, 1),
+        capturedAtPrecision: 'month',
+        bearing: 0,
+        isPano: true,
+        renderModes: false,
+        externalUrl:
+          'https://www.google.com/maps/@?api=1&map_action=pano&pano=pano-1',
+      },
+    }),
+  );
+  assert.equal(view.viewer.captionLeft, '1014 10th St · Image by Google');
+  assert.equal(view.viewer.captionRight, '360° · 0° · 2023-01');
+  assert.equal(view.viewer.linkLabel, 'STREET VIEW ↗');
+  assert.equal(view.viewer.renderModes, false);
+});
+
+test('the meta line keeps the sequence count and adds the other providers’ hints', () => {
+  const view = presentStreetLevelPanel(
+    snapshot({
+      enabled: true,
+      coverage: {
+        loading: false,
+        count: 2514,
+        hint: 'click a street to open Street View',
+        error: null,
+      },
+    }),
+  );
+  assert.equal(
+    view.meta,
+    `${(2514).toLocaleString()} sequences in view · click a line for its photos · click a street to open Street View`,
+  );
+});
+
+test('OPEN STREET VIEW shows while Street View is on, and waits for street zoom', () => {
+  const streetView = provider({
+    id: 'google',
+    name: 'Google Street View',
+    label: 'STREET VIEW',
+    groundClick: true,
+    requiresKeyId: 'google-maps',
+  });
+  const view = (overrides) =>
+    presentStreetLevelPanel(
+      snapshot({
+        enabled: true,
+        providers: [provider(), streetView],
+        ...overrides,
+      }),
+    ).nearest;
+  const ready = view({ groundClickReady: true });
+  assert.deepEqual(ready, {
+    visible: true,
+    label: 'OPEN STREET VIEW',
+    title: 'Open Google Street View at the centre of the view',
+    disabled: false,
+    providerIds: ['google'],
+  });
+  const high = view({ groundClickReady: false });
+  assert.equal(high.disabled, true);
+  assert.equal(
+    high.title,
+    'Zoom in to a street to open Google Street View here',
+  );
+  // Hidden with Street View off, without its key, or with the layer off
+  // (off Google 3D the provider is not listed at all).
+  assert.equal(
+    view({ providers: [provider(), { ...streetView, on: false }] }).visible,
+    false,
+  );
+  assert.equal(
+    view({ providers: [provider(), { ...streetView, keyRequired: true }] })
+      .visible,
+    false,
+  );
+  assert.equal(view({ providers: [provider()] }).visible, false);
+  assert.equal(
+    presentStreetLevelPanel(snapshot({ providers: [provider(), streetView] }))
+      .nearest.visible,
+    false,
+  );
+});
+
+test('KEY REQUIRED points at Street View when it would draw with the Google key', () => {
+  const view = presentStreetLevelPanel(
+    snapshot({
+      enabled: true,
+      keyRequired: true,
+      providers: [
+        provider({ keyRequired: true, configured: false }),
+        provider({
+          id: 'google',
+          name: 'Google Street View',
+          label: 'STREET VIEW',
+          on: false,
+          configured: true,
+          requiresKeyId: 'google-maps',
+        }),
+      ],
+      keyAlternatives: [
+        { id: 'google', label: 'STREET VIEW', requiresKeyId: 'google-maps' },
+      ],
+    }),
+  );
+  const guidance =
+    'Needs MAPILLARY_CLIENT_TOKEN — add it in Provider Settings, or light STREET VIEW to use your Google Maps key';
+  assert.equal(view.status.text, 'KEY REQUIRED');
+  assert.equal(view.status.title, guidance);
+  assert.equal(view.meta, guidance);
+  // Off Google 3D Street View is not listed: plain KEY REQUIRED.
+  const plain = presentStreetLevelPanel(
+    snapshot({
+      enabled: true,
+      keyRequired: true,
+      providers: [provider({ keyRequired: true, configured: false })],
+      keyAlternatives: [],
+    }),
+  );
+  assert.equal(plain.status.text, 'KEY REQUIRED');
+  assert.notEqual(plain.meta, guidance);
+});

src/ui/styles/street-level.css

@@ -4,6 +4,9 @@
 #street-level-panel,
 .sl-viewer-wrap {
   --sl-green: #05cb63;
+  /* KartaView's purple for lines; a lighter one where it is text (WCAG AA). */
+  --sl-kartaview: #635bff;
+  --sl-kartaview-text: #8f8aff;
   --sl-text: 0.62rem;
   --sl-text-small: 0.6rem;
 }
@@ -174,6 +177,11 @@ button.sl-status:focus-visible {
   );
 }
 
+/* #635bff text on its own tint is 3.7:1 at this size; the lighter one is ~6:1. */
+.sl-chips .data-toggle-chip.active[data-chip-id='kartaview'] {
+  color: var(--sl-kartaview-text);
+}
+
 .sl-chips .data-toggle-chip.active::before {
   opacity: 1;
 }
@@ -183,6 +191,28 @@ button.sl-status:focus-visible {
   border-color: rgba(255, 179, 0, 0.55);
 }
 
+/* The coverage hint and OPEN STREET VIEW share a line; the hint wraps. */
+.sl-meta-row {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.sl-meta-row .sl-meta {
+  flex: 1 1 auto;
+  min-width: 0;
+}
+
+/* Scoped to outrank .scene-btn's flex: 1, which squeezed the button to its
+   min-width beside a long coverage line and clipped its one-line label. */
+.sl-meta-row .sl-nearest-btn {
+  flex: 0 0 auto;
+}
+
+.sl-nearest-btn[hidden] {
+  display: none;
+}
+
 /* ── Errors ──────────────────────────────────────────────────────────────── */
 .sl-error {
   font-family: var(--font-sans);
@@ -207,6 +237,14 @@ button.sl-status:focus-visible {
   border-radius: 999px;
 }
 
+.sl-seg[hidden],
+.sl-controls[hidden],
+.sl-filters[hidden],
+.sl-since[hidden],
+.sl-legend[hidden] {
+  display: none;
+}
+
 .sl-seg-btn {
   font-family: var(--font-mono);
   font-size: var(--sl-text-small);
@@ -261,6 +299,17 @@ button.sl-status:focus-visible {
   outline-offset: 3px;
 }
 
+.sl-since-note {
+  grid-column: 2;
+  font-family: var(--font-mono);
+  font-size: var(--sl-text-small);
+  color: var(--text-secondary);
+}
+
+.sl-since-note[hidden] {
+  display: none;
+}
+
 .sl-since-label {
   grid-column: 2;
   font-family: var(--font-mono);
@@ -480,7 +529,9 @@ button.sl-status:focus-visible {
 /* A dragged window keeps its natural height, so bound it to the viewport:
    the rail's max-height: 100% does not bind an auto-height parent.
    Id-qualified to outrank that rule. */
-#right-context-rail > #street-level-panel.panel-floating > .street-level-panel-inner {
+#right-context-rail
+  > #street-level-panel.panel-floating
+  > .street-level-panel-inner {
   max-height: calc(100vh - 12px);
   overflow-y: auto;
 }
@@ -581,6 +632,97 @@ button.sl-status:focus-visible {
   font-size: 1.3rem;
 }
 
+/* ── KartaView photo viewer ──────────────────────────────────────────────── */
+.sl-kv-viewer {
+  position: absolute;
+  inset: 0;
+  background: #000;
+  outline: none;
+  overflow: hidden;
+}
+
+.sl-kv-viewer:focus-visible {
+  outline: none;
+}
+
+/* The photo and canvas fill the viewer and would cover a ring drawn on it:
+   draw the ring on a layer above them (clicks pass through). */
+.sl-kv-viewer:focus-visible::after {
+  content: '';
+  position: absolute;
+  inset: 0;
+  z-index: 3;
+  border: 2px solid var(--sl-kartaview-text);
+  pointer-events: none;
+}
+
+.sl-kv-photo,
+.sl-kv-pano {
+  position: absolute;
+  inset: 0;
+  width: 100%;
+  height: 100%;
+  user-select: none;
+}
+
+.sl-kv-photo {
+  object-fit: contain;
+}
+
+.sl-kv-pano {
+  cursor: grab;
+  touch-action: none;
+}
+
+.sl-kv-pano.sl-kv-dragging {
+  cursor: grabbing;
+}
+
+.sl-kv-photo[hidden],
+.sl-kv-pano[hidden] {
+  display: none;
+}
+
+.sl-kv-step {
+  position: absolute;
+  top: 50%;
+  z-index: 2;
+  width: 34px;
+  height: 44px;
+  margin-top: -22px;
+  border: 1px solid rgba(255, 255, 255, 0.18);
+  border-radius: 8px;
+  background: rgba(10, 10, 15, 0.62);
+  color: #fff;
+  font-size: 1.5rem;
+  line-height: 1;
+  cursor: pointer;
+}
+
+.sl-kv-step-prev {
+  left: 6px;
+}
+
+.sl-kv-step-next {
+  right: 6px;
+}
+
+.sl-kv-step:hover:not(:disabled),
+.sl-kv-step:focus-visible {
+  background: color-mix(in srgb, var(--sl-kartaview) 85%, transparent);
+  outline: none;
+}
+
+.sl-kv-step:disabled {
+  opacity: 0.3;
+  cursor: default;
+}
+
+/* Nothing to step through until a photo shows. */
+.sl-kv-viewer:not([data-kind='flat']):not([data-kind='pano']) .sl-kv-step {
+  display: none;
+}
+
 /* ── Short viewports ─────────────────────────────────────────────────────── */
 @media (max-height: 640px) {
   .street-level-panel-inner {

src/ui/templates/layer-panels.html

@@ -118,7 +118,7 @@
             <!-- A missing key gates the filters only: the chips above stay
                  focusable so their tooltip can say how to add the key. -->
             <fieldset id="sl-controls" class="sl-controls">
-              <div class="sl-filters" role="group" aria-label="Imagery filters">
+              <div id="sl-pano-row" class="sl-filters" role="group" aria-label="Imagery filters">
                 <span class="cctv-summary-label">IMAGERY</span>
                 <div class="sl-seg" role="radiogroup" aria-label="Panorama filter">
                   <button type="button" class="sl-seg-btn is-active" data-sl-pano="all" role="radio" aria-checked="true">ALL</button>
@@ -126,14 +126,19 @@
                   <button type="button" class="sl-seg-btn" data-sl-pano="flat" role="radio" aria-checked="false" tabindex="-1">FLAT</button>
                 </div>
               </div>
-              <div class="sl-since">
+              <div id="sl-since-row" class="sl-since">
                 <label class="cctv-summary-label" for="sl-since">SINCE</label>
-                <input id="sl-since" class="sl-range" type="range" min="0" max="8" step="1" value="0" aria-valuetext="ANY DATE" aria-describedby="sl-since-label" />
+                <input id="sl-since" class="sl-range" type="range" min="0" max="8" step="1" value="0" aria-valuetext="ANY DATE" aria-describedby="sl-since-label sl-since-note" />
                 <output id="sl-since-label" class="sl-since-label" for="sl-since">ANY DATE</output>
+                <small id="sl-since-note" class="sl-since-note" hidden></small>
               </div>
             </fieldset>
             <ul id="sl-legend" class="sl-legend" aria-label="Coverage colours"></ul>
-            <div id="sl-coverage-meta" class="sl-meta"></div>
+            <!-- The hint says how to open imagery; the button does it without a pointer. -->
+            <div class="sl-meta-row">
+              <div id="sl-coverage-meta" class="sl-meta"></div>
+              <button id="sl-nearest-btn" class="scene-btn sl-nearest-btn" type="button" hidden>OPEN STREET VIEW</button>
+            </div>
           </div>
         </div>
       </div>