DRIVE3D-1931: improve camera behaviour in HD Lite

GitOrigin-RevId: eeb3448bbdf0899e8668667dacd6aad42b97b188

Author: dzinad

ui-maps/src/main/java/com/mapbox/navigation/ui/maps/internal/camera/FollowingFramingModeHolder.kt

@@ -11,12 +11,26 @@ enum class FollowingFramingMode {
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP_PREFIX)
 class FollowingFramingModeHolder {
 
+    private val observers = mutableListOf<(FollowingFramingMode?) -> Unit>()
+
     var prevMode: FollowingFramingMode = FollowingFramingMode.LOCATION_INDICATOR
         private set
 
     var mode: FollowingFramingMode = FollowingFramingMode.LOCATION_INDICATOR
         set(value) {
             prevMode = field
             field = value
+            if (prevMode != value) {
+                observers.forEach { it(value) }
+            }
         }
+
+    fun addObserver(observer: (FollowingFramingMode?) -> Unit) {
+        observers.add(observer)
+        observer(mode)
+    }
+
+    fun removeObserver(observer: (FollowingFramingMode?) -> Unit) {
+        observers.remove(observer)
+    }
 }

ui-maps/src/test/java/com/mapbox/navigation/ui/maps/internal/camera/FollowingFramingModeHolderTest.kt

@@ -1,5 +1,9 @@
 package com.mapbox.navigation.ui.maps.internal.camera
 
+import io.mockk.clearMocks
+import io.mockk.mockk
+import io.mockk.verify
+import io.mockk.verifyOrder
 import org.junit.Assert.assertEquals
 import org.junit.Before
 import org.junit.Test
@@ -55,4 +59,69 @@ class FollowingFramingModeHolderTest {
         assertEquals(FollowingFramingMode.LOCATION_INDICATOR, holder.mode)
         assertEquals(FollowingFramingMode.MULTIPLE_POINTS, holder.prevMode)
     }
+
+    @Test
+    fun `addObserver with custom initial mode invokes observer with that mode`() {
+        holder.mode = FollowingFramingMode.MULTIPLE_POINTS
+        val observer: (FollowingFramingMode?) -> Unit = mockk(relaxed = true)
+
+        holder.addObserver(observer)
+
+        verify(exactly = 1) { observer(FollowingFramingMode.MULTIPLE_POINTS) }
+    }
+
+    @Test
+    fun `observer is notified when mode changes to different value`() {
+        val observer: (FollowingFramingMode?) -> Unit = mockk(relaxed = true)
+        holder.addObserver(observer)
+
+        holder.mode = FollowingFramingMode.MULTIPLE_POINTS
+
+        verifyOrder {
+            observer(FollowingFramingMode.LOCATION_INDICATOR) // initial call
+            observer(FollowingFramingMode.MULTIPLE_POINTS) // mode change
+        }
+    }
+
+    @Test
+    fun `observer is not notified when mode is set to same value`() {
+        val observer: (FollowingFramingMode?) -> Unit = mockk(relaxed = true)
+        holder.addObserver(observer)
+
+        clearMocks(observer, answers = false)
+
+        holder.mode = FollowingFramingMode.LOCATION_INDICATOR
+
+        verify(exactly = 0) { observer(any()) }
+    }
+
+    @Test
+    fun `multiple observers are all notified on mode change`() {
+        val observer1: (FollowingFramingMode?) -> Unit = mockk(relaxed = true)
+        val observer2: (FollowingFramingMode?) -> Unit = mockk(relaxed = true)
+        val observer3: (FollowingFramingMode?) -> Unit = mockk(relaxed = true)
+
+        holder.addObserver(observer1)
+        holder.addObserver(observer2)
+        holder.addObserver(observer3)
+
+        holder.mode = FollowingFramingMode.MULTIPLE_POINTS
+
+        verify(exactly = 1) { observer1(FollowingFramingMode.MULTIPLE_POINTS) }
+        verify(exactly = 1) { observer2(FollowingFramingMode.MULTIPLE_POINTS) }
+        verify(exactly = 1) { observer3(FollowingFramingMode.MULTIPLE_POINTS) }
+    }
+
+    @Test
+    fun `removeObserver stops notifications to that observer`() {
+        val observer: (FollowingFramingMode?) -> Unit = mockk(relaxed = true)
+        holder.addObserver(observer)
+
+        holder.removeObserver(observer)
+        holder.mode = FollowingFramingMode.MULTIPLE_POINTS
+
+        // Only the initial call from addObserver, no call after removal
+        verify(exactly = 1) { observer(FollowingFramingMode.LOCATION_INDICATOR) }
+        verify(exactly = 0) { observer(FollowingFramingMode.MULTIPLE_POINTS) }
+    }
 }