Make map clusters expand into live viewports

assets/js/hooks.js

@@ -300,6 +300,7 @@ const createAidMap = element => {
     resizeObserver: null,
     markers: [],
     markerElements: new Map(),
+    clusterExpansionPending: false,
     initializedViewport: false,
     locationBounds: null,
     recenterControl: null,
@@ -625,10 +626,37 @@ const createAidMap = element => {
       element.title = element.getAttribute("aria-label")
       element.addEventListener("click", event => {
         event.stopPropagation()
+        state.clusterExpansionPending = true
+
+        const bounds = point.bounds
+        const hasBounds =
+          bounds &&
+          [bounds.west, bounds.south, bounds.east, bounds.north]
+            .every(value => Number.isFinite(Number(value)))
+        const hasArea =
+          hasBounds &&
+          (Math.abs(Number(bounds.east) - Number(bounds.west)) > 0.000001 ||
+            Math.abs(Number(bounds.north) - Number(bounds.south)) > 0.000001)
+
+        if (hasArea) {
+          state.map.fitBounds(
+            [
+              [Number(bounds.west), Number(bounds.south)],
+              [Number(bounds.east), Number(bounds.north)]
+            ],
+            {
+              padding: 72,
+              maxZoom: Math.min(state.map.getZoom() + 5, 18),
+              duration: 300
+            }
+          )
+        } else {
           state.map.easeTo({
             center: [point.longitude, point.latitude],
-          zoom: Math.min(state.map.getZoom() + 2, 20)
+            zoom: Math.min(state.map.getZoom() + 2, 20),
+            duration: 300
           })
+        }
       })
 
       const marker = new maplibregl.Marker({element})
@@ -726,7 +754,14 @@ const createAidMap = element => {
       if (!state.initializedViewport || state.element.dataset.discoveryMap !== "true") return
       state.renderMarkers()
       const viewport = mapViewport(state.map)
-      if (viewport) state.onViewportChange?.(viewport)
+      if (!viewport) return
+
+      if (state.clusterExpansionPending) {
+        state.clusterExpansionPending = false
+        state.onClusterExpand?.(viewport)
+      } else {
+        state.onViewportChange?.(viewport)
+      }
     }
 
     state.onRequestHighlight = event => state.highlightRequest(event.detail?.id)
@@ -1692,6 +1727,8 @@ export const Hooks = {
         this.pushEvent("initialize-map-area", viewport)
       this.aidMap.onViewportChange = viewport =>
         this.pushEvent("map-viewport-change", viewport)
+      this.aidMap.onClusterExpand = viewport =>
+        this.pushEvent("expand-map-cluster", viewport)
       this.aidMap.mount()
     },
     updated() {

assets/js/map_cluster_points.mjs

@@ -34,6 +34,45 @@ const coordinatesFromPixel = (map, pixel) => {
   }
 }
 
+const finiteCoordinate = value => {
+  const coordinate = Number(value)
+  return Number.isFinite(coordinate) ? coordinate : null
+}
+
+const pointBounds = point => {
+  const longitude = finiteCoordinate(point?.longitude)
+  const latitude = finiteCoordinate(point?.latitude)
+  const source = point?.bounds || {}
+  const west = finiteCoordinate(source.west) ?? longitude
+  const south = finiteCoordinate(source.south) ?? latitude
+  const east = finiteCoordinate(source.east) ?? longitude
+  const north = finiteCoordinate(source.north) ?? latitude
+
+  if ([west, south, east, north].some(value => value === null)) return null
+
+  return {
+    west: Math.min(west, east),
+    south: Math.min(south, north),
+    east: Math.max(west, east),
+    north: Math.max(south, north)
+  }
+}
+
+const groupBounds = points => {
+  const bounds = points.map(pointBounds).filter(Boolean)
+  if (bounds.length === 0) return null
+
+  return bounds.reduce(
+    (result, current) => ({
+      west: Math.min(result.west, current.west),
+      south: Math.min(result.south, current.south),
+      east: Math.max(result.east, current.east),
+      north: Math.max(result.north, current.north)
+    }),
+    bounds[0]
+  )
+}
+
 const nearbyMapPointGroups = (map, points, options = {}) => {
   const gap = Number.isFinite(options.gap) ? Math.max(options.gap, 0) : 8
 
@@ -89,7 +128,8 @@ const visualCluster = (map, group) => {
     count: group.count,
     urgent_count: group.urgent_count,
     longitude: coordinates.longitude,
-      latitude: coordinates.latitude
+    latitude: coordinates.latitude,
+    bounds: groupBounds(group.points)
   }
 }
 

assets/js/map_cluster_points.test.mjs

@@ -15,8 +15,24 @@ const flatMap = scale => ({
 
 test("merges visually overlapping clusters and preserves their total", () => {
   const points = [
-    {id: "a", type: "cluster", count: 100, urgent_count: 2, longitude: 0, latitude: 0},
+    {
-    {id: "b", type: "cluster", count: 50, urgent_count: 1, longitude: 30, latitude: 0},
+      id: "a",
+      type: "cluster",
+      count: 100,
+      urgent_count: 2,
+      longitude: 0,
+      latitude: 0,
+      bounds: {west: -5, south: -2, east: 5, north: 2}
+    },
+    {
+      id: "b",
+      type: "cluster",
+      count: 50,
+      urgent_count: 1,
+      longitude: 30,
+      latitude: 0,
+      bounds: {west: 25, south: -3, east: 35, north: 4}
+    },
     {id: "c", type: "cluster", count: 7, urgent_count: 0, longitude: 140, latitude: 0}
   ]
 
@@ -29,6 +45,7 @@ test("merges visually overlapping clusters and preserves their total", () => {
   assert.equal(merged.urgent_count, 3)
   assert.equal(merged.longitude, 10)
   assert.equal(merged.latitude, 0)
+  assert.deepEqual(merged.bounds, {west: -5, south: -3, east: 35, north: 4})
 })
 
 test("splits the same clusters again at a closer zoom", () => {
@@ -52,6 +69,7 @@ test("merges a singleton into an overlapping cluster at a distant zoom", () => {
   assert.equal(result.length, 1)
   assert.equal(result[0].type, "cluster")
   assert.equal(result[0].count, 352)
+  assert.deepEqual(result[0].bounds, {west: 0, south: 0, east: 28, north: 0})
 })
 
 test("keeps separated singleton points interactive at a closer zoom", () => {

lib/mix/tasks/wnh.scale_fixtures.ex

@@ -11,9 +11,9 @@ defmodule Mix.Tasks.Wnh.ScaleFixtures do
   @default_rows 1_000_000
   @synthetic_users 1_000
   @viewer_email "scale-viewer@example.invalid"
-  @fixture_version 6
+  @fixture_version 7
-  @request_open_modulus 100
+  @request_open_modulus 1
-  @activity_open_modulus 50
+  @activity_open_modulus 1
   @places [
     {"Kyiv", 30.5234, 50.4501},
     {"Lviv", 24.0316, 49.8429},
@@ -586,10 +586,7 @@ defmodule Mix.Tasks.Wnh.ScaleFixtures do
           ST_MakePoint(coordinates.longitude, coordinates.latitude),
           4326
         ),
-        CASE WHEN variation.visibility_key % 10 = 0
+        'approximate_public',
-          THEN 'hidden'
-          ELSE 'approximate_public'
-        END,
         CASE WHEN variation.status_key % #{@activity_open_modulus} = 0 THEN 'open'
              WHEN variation.status_key % #{@activity_open_modulus} < 41 THEN 'completed'
              ELSE 'cancelled' END,
@@ -854,7 +851,7 @@ defmodule Mix.Tasks.Wnh.ScaleFixtures do
       assert_distribution_keys!(
         "request statuses",
         profile.help_requests.statuses,
-        ~w(cancelled completed open)
+        ~w(open)
       )
 
       assert_distribution_keys!(
@@ -872,13 +869,13 @@ defmodule Mix.Tasks.Wnh.ScaleFixtures do
       assert_distribution_keys!(
         "activity statuses",
         profile.activities.statuses,
-        ~w(cancelled completed open)
+        ~w(open)
       )
 
       assert_distribution_keys!(
         "activity visibility modes",
         profile.activities.visibility,
-        ~w(approximate_public hidden)
+        ~w(approximate_public)
       )
 
       assert_geographic_profile!("help requests", profile.help_requests, request_count)

lib/who_need_help/activities.ex

@@ -112,6 +112,10 @@ defmodule WhoNeedHelp.Activities do
           point.public_location,
           point.public_location
         ),
+      west: fragment("min(ST_X(?))", point.public_location),
+      south: fragment("min(ST_Y(?))", point.public_location),
+      east: fragment("max(ST_X(?))", point.public_location),
+      north: fragment("max(ST_Y(?))", point.public_location),
       cell_x:
         fragment(
           "ST_X(ST_SnapToGrid(ST_Transform(?, 3857), ?))",
@@ -987,7 +991,13 @@ defmodule WhoNeedHelp.Activities do
       id: "activity-cluster-#{digest}",
       count: row.count,
       latitude: row.latitude,
-      longitude: row.longitude
+      longitude: row.longitude,
+      bounds: %{
+        west: row.west,
+        south: row.south,
+        east: row.east,
+        north: row.north
+      }
     }
   end
 

lib/who_need_help/help.ex

@@ -137,6 +137,10 @@ defmodule WhoNeedHelp.Help do
           point.public_location,
           point.public_location
         ),
+      west: fragment("min(ST_X(?))", point.public_location),
+      south: fragment("min(ST_Y(?))", point.public_location),
+      east: fragment("max(ST_X(?))", point.public_location),
+      north: fragment("max(ST_Y(?))", point.public_location),
       cell_x:
         fragment(
           "ST_X(ST_SnapToGrid(ST_Transform(?, 3857), ?))",
@@ -1295,7 +1299,13 @@ defmodule WhoNeedHelp.Help do
       count: row.count,
       urgent_count: row.urgent_count,
       latitude: row.latitude,
-      longitude: row.longitude
+      longitude: row.longitude,
+      bounds: %{
+        west: row.west,
+        south: row.south,
+        east: row.east,
+        north: row.north
+      }
     }
   end
 

lib/who_need_help_web/live/activity_live/index.ex

@@ -181,6 +181,16 @@ defmodule WhoNeedHelpWeb.ActivityLive.Index do
     end
   end
 
+  def handle_event("expand-map-cluster", params, socket) do
+    case DiscoveryViewport.cast(params) do
+      {:ok, viewport} ->
+        {:noreply, push_patch(socket, to: activity_path(socket, viewport: viewport))}
+
+      :error ->
+        {:noreply, socket}
+    end
+  end
+
   def handle_event("load-more-activities", _params, socket) do
     page =
       Activities.paginate_open_activities(

lib/who_need_help_web/live/request_live/index.ex

@@ -132,6 +132,16 @@ defmodule WhoNeedHelpWeb.RequestLive.Index do
     end
   end
 
+  def handle_event("expand-map-cluster", params, socket) do
+    case DiscoveryViewport.cast(params) do
+      {:ok, viewport} ->
+        {:noreply, push_patch(socket, to: request_path(socket, viewport: viewport))}
+
+      :error ->
+        {:noreply, socket}
+    end
+  end
+
   def handle_event("load-more-requests", _params, socket) do
     page =
       Help.paginate_open_requests(

test/who_need_help/activities_test.exs

@@ -450,6 +450,10 @@ defmodule WhoNeedHelp.ActivitiesTest do
     assert cluster
     assert_in_delta cluster.latitude, 50.45, 0.000_001
     assert_in_delta cluster.longitude, 30.52, 0.000_001
+    assert_in_delta cluster.bounds.west, 30.52, 0.000_001
+    assert_in_delta cluster.bounds.east, 30.52, 0.000_001
+    assert_in_delta cluster.bounds.south, 50.45, 0.000_001
+    assert_in_delta cluster.bounds.north, 50.45, 0.000_001
 
     assert Enum.any?(items, fn
              %{type: "activity", id: id} -> id == sparse.id

test/who_need_help/mutual_aid_flow_test.exs

@@ -566,6 +566,10 @@ defmodule WhoNeedHelp.MutualAidFlowTest do
     assert cluster
     assert_in_delta cluster.latitude, 50.4501, 0.000_001
     assert_in_delta cluster.longitude, 30.52345, 0.000_001
+    assert_in_delta cluster.bounds.west, 30.5234, 0.000_001
+    assert_in_delta cluster.bounds.east, 30.5235, 0.000_001
+    assert_in_delta cluster.bounds.south, 50.4501, 0.000_001
+    assert_in_delta cluster.bounds.north, 50.4501, 0.000_001
 
     assert Enum.any?(items, fn
              %{type: "request", id: id, exact: true} -> id == sparse_request.id

test/who_need_help_web/live/mutual_aid_live_test.exs

@@ -358,6 +358,48 @@ defmodule WhoNeedHelpWeb.MutualAidLiveTest do
     assert has_element?(view, "#activity-map[data-items='[]']")
   end
 
+  test "request cluster expansion immediately searches the expanded viewport", %{conn: conn} do
+    {:ok, view, _html} = live(conn, requests_in_kyiv_path())
+
+    expanded = %{
+      "west" => "30.40",
+      "south" => "50.35",
+      "east" => "30.60",
+      "north" => "50.55",
+      "zoom" => "12",
+      "width" => "900",
+      "height" => "700"
+    }
+
+    render_hook(view, "expand-map-cluster", expanded)
+
+    assert_patch(
+      view,
+      ~p"/requests?#{Map.merge(expanded, %{"east" => "30.6", "view" => "split", "west" => "30.4"})}"
+    )
+  end
+
+  test "activity cluster expansion immediately searches the expanded viewport", %{conn: conn} do
+    {:ok, view, _html} = live(conn, activities_in_kyiv_path())
+
+    expanded = %{
+      "west" => "30.40",
+      "south" => "50.35",
+      "east" => "30.60",
+      "north" => "50.55",
+      "zoom" => "12",
+      "width" => "900",
+      "height" => "700"
+    }
+
+    render_hook(view, "expand-map-cluster", expanded)
+
+    assert_patch(
+      view,
+      ~p"/activities?#{Map.merge(expanded, %{"east" => "30.6", "view" => "split", "west" => "30.4"})}"
+    )
+  end
+
   test "profile social-link creation uses the shared action limiter", %{conn: conn} do
     previous = Application.get_env(:who_need_help, :rate_limit_policies)