perf: Make CameraPositionState and MarkerState stable (#254)

googlemaps · Jan 19, 2023 · 52bd69e · 52bd69e
1 parent 12251ff
commit 52bd69e
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Showing 2 changed files with 11 additions and 8 deletions.
diff --git a/maps-compose/src/main/java/com/google/maps/android/compose/CameraPositionState.kt b/maps-compose/src/main/java/com/google/maps/android/compose/CameraPositionState.kt
@@ -110,16 +110,16 @@ public class CameraPositionState(
 
     // Used to perform side effects thread-safely.
     // Guards all mutable properties that are not `by mutableStateOf`.
-    private val lock = Any()
+    private val lock = Unit
 
     // The map currently associated with this CameraPositionState.
     // Guarded by `lock`.
-    private var map: GoogleMap? = null
+    private var map: GoogleMap? by mutableStateOf(null)
 
     // An action to run when the map becomes available or unavailable.
     // represents a mutually exclusive mutation to perform while holding `lock`.
     // Guarded by `lock`.
-    private var onMapChanged: OnMapChangedCallback? = null
+    private var onMapChanged: OnMapChangedCallback? by mutableStateOf(null)
 
     /**
      * Set [onMapChanged] to [callback], invoking the current callback's
@@ -133,7 +133,7 @@ public class CameraPositionState(
     // A token representing the current owner of any ongoing motion in progress.
     // Used to determine if map animation should stop when calls to animate end.
     // Guarded by `lock`.
-    private var movementOwner: Any? = null
+    private var movementOwner: Any? by mutableStateOf(null)
 
     /**
      * Used with [onMapChangedLocked] to execute one-time actions when a map becomes available

diff --git a/maps-compose/src/main/java/com/google/maps/android/compose/Marker.kt b/maps-compose/src/main/java/com/google/maps/android/compose/Marker.kt
@@ -18,6 +18,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.ComposeNode
 import androidx.compose.runtime.CompositionContext
 import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.MutableState
 import androidx.compose.runtime.currentComposer
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
@@ -81,13 +82,15 @@ public class MarkerState(
         internal set
 
     // The marker associated with this MarkerState.
-    internal var marker: Marker? = null
+    private val markerState: MutableState<Marker?> = mutableStateOf(null)
+    internal var marker: Marker?
+        get() = markerState.value
         set(value) {
-            if (field == null && value == null) return
-            if (field != null && value != null) {
+            if (markerState.value == null && value == null) return
+            if (markerState.value != null && value != null) {
                 error("MarkerState may only be associated with one Marker at a time.")
             }
-            field = value
+            markerState.value = value
         }
 
     /**