From 7321453337e6f9809e7e0cc04279f5d81b10871c Mon Sep 17 00:00:00 2001
From: Hank <hank@jointsecurityarea.org>
Date: Mon, 6 Jul 2026 11:22:47 -0700
Subject: [PATCH] Map: pin current view before 'Search this area' to defeat
 camera stop-revert

The native MapLibre camera re-applies its last setCamera() stop on the search
re-render (confirmed via trace: revert to prior target with userInteraction=false).
Track the live viewport and, before searching the current area, setCamera() to the
current center (0ms) so the re-applied stop is a no-op instead of a jump-back.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 app/src/screens/MapScreen.tsx | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/app/src/screens/MapScreen.tsx b/app/src/screens/MapScreen.tsx
index 2857600..f8ca745 100644
--- a/app/src/screens/MapScreen.tsx
+++ b/app/src/screens/MapScreen.tsx
@@ -59,6 +59,11 @@ export function MapScreen() {
   // We position the camera exactly once, then never auto-recenter — otherwise
   // re-renders (from searching) would snap the map back and fight the user's pan.
   const positioned = useRef(false);
+  // The live viewport, tracked from region changes. MapLibre's native camera
+  // re-applies its last setCamera() stop on any re-render, so before a search we
+  // overwrite that stop with the current view (zero-duration) — otherwise the
+  // results re-render snaps the map back to the previous programmatic target.
+  const viewRef = useRef<{ center: [number, number]; zoom: number } | null>(null);
   // The native UserLocation dot has its own GPS feed — capture it so "My
   // location" works even when expo-location can't get a fix (e.g. indoors).
   const nativeFix = useRef<Coords | null>(null);
@@ -109,15 +114,16 @@ export function MapScreen() {
   const searchThisArea = async () => {
     try {
       const center = await mapRef.current?.getCenter?.(); // [lng, lat]
-      console.log('[CAM] searchThisArea getCenter=', JSON.stringify(center));
       if (center && center.length === 2) {
+        // Commit the current view as the camera's stop so the results re-render
+        // doesn't revert to the last programmatic (e.g. "My location") target.
+        cameraRef.current?.setCamera?.({ centerCoordinate: center, animationDuration: 0 });
         await searchAt({ latitude: center[1], longitude: center[0] }, 'this area');
         return;
       }
-    } catch (err) {
-      console.log('[CAM] getCenter threw', String(err));
+    } catch {
+      /* fall through */
     }
-    console.log('[CAM] searchThisArea FALLBACK coords=', JSON.stringify(coords));
     if (coords) await searchAt(coords, 'this area');
   };
 
@@ -212,14 +218,19 @@ export function MapScreen() {
           console.log('[CAM] onDidFinishLoadingMap (mapReady already', mapReady, ')');
           setMapReady(true);
         }}
-        onRegionDidChange={(f: any) =>
+        onRegionDidChange={(f: any) => {
+          const c = f?.geometry?.coordinates;
+          const z = f?.properties?.zoomLevel;
+          if (Array.isArray(c) && c.length === 2) {
+            viewRef.current = { center: [c[0], c[1]], zoom: typeof z === 'number' ? z : 14 };
+          }
           console.log(
             '[CAM] regionDidChange center=',
-            JSON.stringify(f?.geometry?.coordinates),
-            'userInteraction=',
+            JSON.stringify(c),
+            'ui=',
             f?.properties?.isUserInteraction,
-          )
-        }
+          );
+        }}
       >
         {cameraEl}
         {userLocationEl}