LockscreenShadeTransitionController: extract logic of keyguard and scrims

The file size was starting to grow for this class, so started extracting
some of it.

Also implemented dumpable for the new classes for better tracking of state
in bug reports.

Bug: 227604286
Test: LockscreenShadeTransitionControllerTest.kt
Test: adb shell dumpsys activity service SystemUIService
Test: Manually
Change-Id: Iebd36726ebffdb9b6a37e742f69d7e5a80f25e6e

6 files changed, 309 insertions, 108 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/AbstractLockscreenShadeTransitionController.kt b/packages/SystemUI/src/com/android/systemui/statusbar/AbstractLockscreenShadeTransitionController.kt
new file mode 100644
index 000000000000..189f38422dcb
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/AbstractLockscreenShadeTransitionController.kt
@@ -0,0 +1,61 @@
+package com.android.systemui.statusbar
+
+import android.content.Context
+import android.content.res.Configuration
+import android.util.IndentingPrintWriter
+import com.android.systemui.Dumpable
+import com.android.systemui.dump.DumpManager
+import com.android.systemui.statusbar.policy.ConfigurationController
+import com.android.systemui.util.LargeScreenUtils
+import java.io.FileDescriptor
+import java.io.PrintWriter
+
+/** An abstract implementation of a class that controls the lockscreen to shade transition. */
+abstract class AbstractLockscreenShadeTransitionController(
+    protected val context: Context,
+    configurationController: ConfigurationController,
+    dumpManager: DumpManager
+) : Dumpable {
+
+    protected var useSplitShade = false
+
+    /**
+     * The amount of pixels that the user has dragged down during the shade transition on
+     * lockscreen.
+     */
+    var dragDownAmount = 0f
+        set(value) {
+            if (value == field) {
+                return
+            }
+            field = value
+            onDragDownAmountChanged(value)
+        }
+
+    init {
+        updateResourcesInternal()
+        configurationController.addCallback(
+            object : ConfigurationController.ConfigurationListener {
+                override fun onConfigChanged(newConfig: Configuration?) {
+                    updateResourcesInternal()
+                }
+            })
+        @Suppress("LeakingThis")
+        dumpManager.registerDumpable(this)
+    }
+
+    private fun updateResourcesInternal() {
+        useSplitShade = LargeScreenUtils.shouldUseSplitNotificationShade(context.resources)
+        updateResources()
+    }
+
+    protected abstract fun updateResources()
+
+    protected abstract fun onDragDownAmountChanged(dragDownAmount: Float)
+
+    override fun dump(fd: FileDescriptor, pw: PrintWriter, args: Array<out String>) {
+        dump(IndentingPrintWriter(pw, /* singleIndent= */ "  "))
+    }
+
+    abstract fun dump(pw: IndentingPrintWriter)
+}
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeKeyguardTransitionController.kt b/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeKeyguardTransitionController.kt
new file mode 100644
index 000000000000..01eb4446ea8e
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeKeyguardTransitionController.kt
@@ -0,0 +1,120 @@
+package com.android.systemui.statusbar
+
+import android.content.Context
+import android.util.IndentingPrintWriter
+import android.util.MathUtils
+import com.android.systemui.R
+import com.android.systemui.dump.DumpManager
+import com.android.systemui.media.MediaHierarchyManager
+import com.android.systemui.statusbar.phone.NotificationPanelViewController
+import com.android.systemui.statusbar.policy.ConfigurationController
+import dagger.assisted.Assisted
+import dagger.assisted.AssistedFactory
+import dagger.assisted.AssistedInject
+
+/** Controls the lockscreen to shade transition for the keyguard elements. */
+class LockscreenShadeKeyguardTransitionController
+@AssistedInject
+constructor(
+    private val mediaHierarchyManager: MediaHierarchyManager,
+    @Assisted private val notificationPanelController: NotificationPanelViewController,
+    context: Context,
+    configurationController: ConfigurationController,
+    dumpManager: DumpManager
+) : AbstractLockscreenShadeTransitionController(context, configurationController, dumpManager) {
+
+    /**
+     * Distance that the full shade transition takes in order for the keyguard content on
+     * NotificationPanelViewController to fully fade (e.g. Clock & Smartspace).
+     */
+    private var alphaTransitionDistance = 0
+
+    /**
+     * Distance that the full shade transition takes in order for the keyguard elements to fully
+     * translate into their final position
+     */
+    private var keyguardTransitionDistance = 0
+
+    /** The amount of vertical offset for the keyguard during the full shade transition. */
+    private var keyguardTransitionOffset = 0
+
+    /** The amount of alpha that was last set on the keyguard elements. */
+    private var alpha = 0f
+
+    /** The latest progress [0,1] of the alpha transition. */
+    private var alphaProgress = 0f
+
+    /** The amount of alpha that was last set on the keyguard status bar. */
+    private var statusBarAlpha = 0f
+
+    /** The amount of translationY that was last set on the keyguard elements. */
+    private var translationY = 0
+
+    /** The latest progress [0,1] of the translationY progress. */
+    private var translationYProgress = 0f
+
+    override fun updateResources() {
+        alphaTransitionDistance =
+            context.resources.getDimensionPixelSize(
+                R.dimen.lockscreen_shade_npvc_keyguard_content_alpha_transition_distance)
+        keyguardTransitionDistance =
+            context.resources.getDimensionPixelSize(
+                R.dimen.lockscreen_shade_keyguard_transition_distance)
+        keyguardTransitionOffset =
+            context.resources.getDimensionPixelSize(
+                R.dimen.lockscreen_shade_keyguard_transition_vertical_offset)
+    }
+
+    override fun onDragDownAmountChanged(dragDownAmount: Float) {
+        alphaProgress = MathUtils.saturate(dragDownAmount / alphaTransitionDistance)
+        alpha = 1f - alphaProgress
+        translationY = calculateKeyguardTranslationY(dragDownAmount)
+        notificationPanelController.setKeyguardTransitionProgress(alpha, translationY)
+
+        statusBarAlpha = if (useSplitShade) alpha else -1f
+        notificationPanelController.setKeyguardStatusBarAlpha(statusBarAlpha)
+    }
+
+    private fun calculateKeyguardTranslationY(dragDownAmount: Float): Int {
+        if (!useSplitShade) {
+            return 0
+        }
+        // On split-shade, the translationY of the keyguard should stay in sync with the
+        // translation of media.
+        if (mediaHierarchyManager.isCurrentlyInGuidedTransformation()) {
+            return mediaHierarchyManager.getGuidedTransformationTranslationY()
+        }
+        // When media is not showing, apply the default distance
+        translationYProgress = MathUtils.saturate(dragDownAmount / keyguardTransitionDistance)
+        val translationY = translationYProgress * keyguardTransitionOffset
+        return translationY.toInt()
+    }
+
+    override fun dump(indentingPrintWriter: IndentingPrintWriter) {
+        indentingPrintWriter.let {
+            it.println("LockscreenShadeKeyguardTransitionController:")
+            it.increaseIndent()
+            it.println("Resources:")
+            it.increaseIndent()
+            it.println("alphaTransitionDistance: $alphaTransitionDistance")
+            it.println("keyguardTransitionDistance: $keyguardTransitionDistance")
+            it.println("keyguardTransitionOffset: $keyguardTransitionOffset")
+            it.decreaseIndent()
+            it.println("State:")
+            it.increaseIndent()
+            it.println("dragDownAmount: $dragDownAmount")
+            it.println("alpha: $alpha")
+            it.println("alphaProgress: $alphaProgress")
+            it.println("statusBarAlpha: $statusBarAlpha")
+            it.println("translationProgress: $translationYProgress")
+            it.println("translationY: $translationY")
+        }
+    }
+
+    @AssistedFactory
+    fun interface Factory {
+        fun create(
+            notificationPanelController: NotificationPanelViewController
+        ): LockscreenShadeKeyguardTransitionController
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeScrimTransitionController.kt b/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeScrimTransitionController.kt
new file mode 100644
index 000000000000..00d3701a0cc7
--- /dev/null
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeScrimTransitionController.kt
@@ -0,0 +1,86 @@
+package com.android.systemui.statusbar
+
+import android.content.Context
+import android.util.IndentingPrintWriter
+import android.util.MathUtils
+import com.android.systemui.R
+import com.android.systemui.dump.DumpManager
+import com.android.systemui.statusbar.phone.ScrimController
+import com.android.systemui.statusbar.policy.ConfigurationController
+import javax.inject.Inject
+
+/** Controls the lockscreen to shade transition for scrims. */
+class LockscreenShadeScrimTransitionController
+@Inject
+constructor(
+    private val scrimController: ScrimController,
+    context: Context,
+    configurationController: ConfigurationController,
+    dumpManager: DumpManager
+) : AbstractLockscreenShadeTransitionController(context, configurationController, dumpManager) {
+
+    /**
+     * Distance that the full shade transition takes in order for scrim to fully transition to the
+     * shade (in alpha)
+     */
+    private var scrimTransitionDistance = 0
+
+    /** Distance it takes in order for the notifications scrim fade in to start. */
+    private var notificationsScrimTransitionDelay = 0
+
+    /** Distance it takes for the notifications scrim to fully fade if after it started. */
+    private var notificationsScrimTransitionDistance = 0
+
+    /** The latest progress [0,1] the scrims transition. */
+    var scrimProgress = 0f
+
+    /** The latest progress [0,1] specifically of the notifications scrim transition. */
+    var notificationsScrimProgress = 0f
+
+    /**
+     * The last drag amount specifically for the notifications scrim. It is different to the normal
+     * [dragDownAmount] as the notifications scrim transition starts relative to the other scrims'
+     * progress.
+     */
+    var notificationsScrimDragAmount = 0f
+
+    override fun updateResources() {
+        scrimTransitionDistance =
+            context.resources.getDimensionPixelSize(
+                R.dimen.lockscreen_shade_scrim_transition_distance)
+        notificationsScrimTransitionDelay =
+            context.resources.getDimensionPixelSize(
+                R.dimen.lockscreen_shade_notifications_scrim_transition_delay)
+        notificationsScrimTransitionDistance =
+            context.resources.getDimensionPixelSize(
+                R.dimen.lockscreen_shade_notifications_scrim_transition_distance)
+    }
+
+    override fun onDragDownAmountChanged(dragDownAmount: Float) {
+        scrimProgress = MathUtils.saturate(dragDownAmount / scrimTransitionDistance)
+        notificationsScrimDragAmount = dragDownAmount - notificationsScrimTransitionDelay
+        notificationsScrimProgress =
+            MathUtils.saturate(notificationsScrimDragAmount / notificationsScrimTransitionDistance)
+        scrimController.setTransitionToFullShadeProgress(scrimProgress, notificationsScrimProgress)
+    }
+
+    override fun dump(indentingPrintWriter: IndentingPrintWriter) {
+        indentingPrintWriter.let {
+            it.println("LockscreenShadeScrimTransitionController:")
+            it.increaseIndent()
+            it.println("Resources:")
+            it.increaseIndent()
+            it.println("scrimTransitionDistance: $scrimTransitionDistance")
+            it.println("notificationsScrimTransitionDelay: $notificationsScrimTransitionDelay")
+            it.println(
+                "notificationsScrimTransitionDistance: $notificationsScrimTransitionDistance")
+            it.decreaseIndent()
+            it.println("State")
+            it.increaseIndent()
+            it.println("dragDownAmount: $dragDownAmount")
+            it.println("scrimProgress: $scrimProgress")
+            it.println("notificationsScrimProgress: $notificationsScrimProgress")
+            it.println("notificationsScrimDragAmount: $notificationsScrimDragAmount")
+        }
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeTransitionController.kt b/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeTransitionController.kt
index 63ab3de14d24..b7d82c3e8f89 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeTransitionController.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/LockscreenShadeTransitionController.kt
@@ -38,7 +38,6 @@ import com.android.systemui.statusbar.phone.CentralSurfaces
 import com.android.systemui.statusbar.phone.KeyguardBypassController
 import com.android.systemui.statusbar.phone.LSShadeTransitionLogger
 import com.android.systemui.statusbar.phone.NotificationPanelViewController
-import com.android.systemui.statusbar.phone.ScrimController
 import com.android.systemui.statusbar.policy.ConfigurationController
 import com.android.systemui.util.LargeScreenUtils
 import java.io.FileDescriptor
@@ -61,7 +60,9 @@ class LockscreenShadeTransitionController @Inject constructor(
     private val falsingCollector: FalsingCollector,
     private val ambientState: AmbientState,
     private val mediaHierarchyManager: MediaHierarchyManager,
-    private val scrimController: ScrimController,
+    private val scrimTransitionController: LockscreenShadeScrimTransitionController,
+    private val keyguardTransitionControllerFactory:
+        LockscreenShadeKeyguardTransitionController.Factory,
     private val depthController: NotificationShadeDepthController,
     private val context: Context,
     private val splitShadeOverScrollerFactory: SplitShadeLockScreenOverScroller.Factory,
@@ -112,22 +113,6 @@ class LockscreenShadeTransitionController @Inject constructor(
     private var fullTransitionDistanceByTap = 0
 
     /**
-     * Distance that the full shade transition takes in order for scrim to fully transition to the
-     * shade (in alpha)
-     */
-    private var scrimTransitionDistance = 0
-
-    /**
-     * Distance that it takes in order for the notifications scrim fade in to start.
-     */
-    private var notificationsScrimTransitionDelay = 0
-
-    /**
-     * Distance that it takes for the notifications scrim to fully fade if after it started.
-     */
-    private var notificationsScrimTransitionDistance = 0
-
-    /**
      * Distance that the full shade transition takes in order for the notification shelf to fully
      * expand.
      */
@@ -140,12 +125,6 @@ class LockscreenShadeTransitionController @Inject constructor(
     private var qsTransitionDistance = 0
 
     /**
-     * Distance that the full shade transition takes in order for the keyguard content on
-     * NotificationPanelViewController to fully fade (e.g. Clock & Smartspace).
-     */
-    private var npvcKeyguardContentAlphaTransitionDistance = 0
-
-    /**
      * Distance that the full shade transition takes in order for depth of the wallpaper to fully
      * change.
      */
@@ -164,17 +143,6 @@ class LockscreenShadeTransitionController @Inject constructor(
     private var statusBarTransitionDistance = 0
 
     /**
-     * Distance that the full shade transition takes in order for the keyguard elements to fully
-     * translate into their final position
-     */
-    private var keyguardTransitionDistance = 0
-
-    /**
-     * The amount of vertical offset for the keyguard during the full shade transition.
-     */
-    private var keyguardTransitionOffset = 0
-
-    /**
      * Flag to make sure that the dragDownAmount is applied to the listeners even when in the
      * locked down shade.
      */
@@ -215,6 +183,10 @@ class LockscreenShadeTransitionController @Inject constructor(
         singleShadeOverScrollerFactory.create(nsslController)
     }
 
+    private val keyguardTransitionController by lazy {
+        keyguardTransitionControllerFactory.create(notificationPanelController)
+    }
+
     /**
      * [LockScreenShadeOverScroller] property that delegates to either
      * [SingleShadeLockScreenOverScroller] or [SplitShadeLockScreenOverScroller].
@@ -267,18 +239,10 @@ class LockscreenShadeTransitionController @Inject constructor(
                 R.dimen.lockscreen_shade_full_transition_distance)
         fullTransitionDistanceByTap = context.resources.getDimensionPixelSize(
             R.dimen.lockscreen_shade_transition_by_tap_distance)
-        scrimTransitionDistance = context.resources.getDimensionPixelSize(
-                R.dimen.lockscreen_shade_scrim_transition_distance)
-        notificationsScrimTransitionDelay = context.resources.getDimensionPixelSize(
-                R.dimen.lockscreen_shade_notifications_scrim_transition_delay)
-        notificationsScrimTransitionDistance = context.resources.getDimensionPixelSize(
-                R.dimen.lockscreen_shade_notifications_scrim_transition_distance)
         notificationShelfTransitionDistance = context.resources.getDimensionPixelSize(
                 R.dimen.lockscreen_shade_notif_shelf_transition_distance)
         qsTransitionDistance = context.resources.getDimensionPixelSize(
                 R.dimen.lockscreen_shade_qs_transition_distance)
-        npvcKeyguardContentAlphaTransitionDistance = context.resources.getDimensionPixelSize(
-                R.dimen.lockscreen_shade_npvc_keyguard_content_alpha_transition_distance)
         depthControllerTransitionDistance = context.resources.getDimensionPixelSize(
                 R.dimen.lockscreen_shade_depth_controller_transition_distance)
         udfpsTransitionDistance = context.resources.getDimensionPixelSize(
@@ -286,10 +250,6 @@ class LockscreenShadeTransitionController @Inject constructor(
         statusBarTransitionDistance = context.resources.getDimensionPixelSize(
                 R.dimen.lockscreen_shade_status_bar_transition_distance)
         useSplitShade = LargeScreenUtils.shouldUseSplitNotificationShade(context.resources)
-        keyguardTransitionDistance = context.resources.getDimensionPixelSize(
-            R.dimen.lockscreen_shade_keyguard_transition_distance)
-        keyguardTransitionOffset = context.resources.getDimensionPixelSize(
-            R.dimen.lockscreen_shade_keyguard_transition_vertical_offset)
     }
 
     fun setStackScroller(nsslController: NotificationStackScrollLayoutController) {
@@ -457,9 +417,9 @@ class LockscreenShadeTransitionController @Inject constructor(
                             false /* animate */, 0 /* delay */)
 
                     mediaHierarchyManager.setTransitionToFullShadeAmount(field)
-                    transitionToShadeAmountScrim(field)
+                    scrimTransitionController.dragDownAmount = value
                     transitionToShadeAmountCommon(field)
-                    transitionToShadeAmountKeyguard(field)
+                    keyguardTransitionController.dragDownAmount = value
                     shadeOverScroller.expansionDragDownAmount = dragDownAmount
                 }
             }
@@ -471,14 +431,6 @@ class LockscreenShadeTransitionController @Inject constructor(
     var qSDragProgress = 0f
         private set
 
-    private fun transitionToShadeAmountScrim(dragDownAmount: Float) {
-        val scrimProgress = MathUtils.saturate(dragDownAmount / scrimTransitionDistance)
-        val notificationsScrimDragAmount = dragDownAmount - notificationsScrimTransitionDelay
-        val notificationsScrimProgress = MathUtils.saturate(
-                notificationsScrimDragAmount / notificationsScrimTransitionDistance)
-        scrimController.setTransitionToFullShadeProgress(scrimProgress, notificationsScrimProgress)
-    }
-
     private fun transitionToShadeAmountCommon(dragDownAmount: Float) {
         if (depthControllerTransitionDistance == 0) { // split shade
             depthController.transitionToFullShadeProgress = 0f
@@ -495,34 +447,6 @@ class LockscreenShadeTransitionController @Inject constructor(
         centralSurfaces.setTransitionToFullShadeProgress(statusBarProgress)
     }
 
-    private fun transitionToShadeAmountKeyguard(dragDownAmount: Float) {
-        // Fade out all content only visible on the lockscreen
-        val keyguardAlphaProgress =
-            MathUtils.saturate(dragDownAmount / npvcKeyguardContentAlphaTransitionDistance)
-        val keyguardAlpha = 1f - keyguardAlphaProgress
-        val keyguardTranslationY = calculateKeyguardTranslationY(dragDownAmount)
-        notificationPanelController
-            .setKeyguardTransitionProgress(keyguardAlpha, keyguardTranslationY)
-
-        val statusBarAlpha = if (useSplitShade) keyguardAlpha else -1f
-        notificationPanelController.setKeyguardStatusBarAlpha(statusBarAlpha)
-    }
-
-    private fun calculateKeyguardTranslationY(dragDownAmount: Float): Int {
-        if (!useSplitShade) {
-            return 0
-        }
-        // On split-shade, the translationY of the keyguard should stay in sync with the
-        // translation of media.
-        if (mediaHierarchyManager.isCurrentlyInGuidedTransformation()) {
-            return mediaHierarchyManager.getGuidedTransformationTranslationY()
-        }
-        // When media is not showing, apply the default distance
-        val translationProgress = MathUtils.saturate(dragDownAmount / keyguardTransitionDistance)
-        val translationY = translationProgress * keyguardTransitionOffset
-        return translationY.toInt()
-    }
-
     private fun setDragDownAmountAnimated(
         target: Float,
         delay: Long = 0,
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/LockscreenShadeTransitionControllerTest.kt b/packages/SystemUI/tests/src/com/android/systemui/statusbar/LockscreenShadeTransitionControllerTest.kt
index e2d6ae07fe70..562c97017862 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/LockscreenShadeTransitionControllerTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/LockscreenShadeTransitionControllerTest.kt
@@ -93,24 +93,34 @@ class LockscreenShadeTransitionControllerTest : SysuiTestCase() {
                 .addOverride(R.bool.config_use_split_notification_shade, false)
         context.getOrCreateTestableResources()
             .addOverride(R.dimen.lockscreen_shade_depth_controller_transition_distance, 100)
-        transitionController = LockscreenShadeTransitionController(
-            statusBarStateController = statusbarStateController,
-            logger = logger,
-            keyguardBypassController = keyguardBypassController,
-            lockScreenUserManager = lockScreenUserManager,
-            falsingCollector = falsingCollector,
-            ambientState = ambientState,
-            mediaHierarchyManager = mediaHierarchyManager,
-            scrimController = scrimController,
-            depthController = depthController,
-            wakefulnessLifecycle = wakefulnessLifecycle,
-            context = context,
-            configurationController = configurationController,
-            falsingManager = falsingManager,
-            dumpManager = dumpManager,
-            splitShadeOverScrollerFactory = { _, _ -> splitShadeOverScroller },
-            singleShadeOverScrollerFactory = { singleShadeOverScroller }
-        )
+        transitionController =
+            LockscreenShadeTransitionController(
+                statusBarStateController = statusbarStateController,
+                logger = logger,
+                keyguardBypassController = keyguardBypassController,
+                lockScreenUserManager = lockScreenUserManager,
+                falsingCollector = falsingCollector,
+                ambientState = ambientState,
+                mediaHierarchyManager = mediaHierarchyManager,
+                depthController = depthController,
+                wakefulnessLifecycle = wakefulnessLifecycle,
+                context = context,
+                configurationController = configurationController,
+                falsingManager = falsingManager,
+                dumpManager = dumpManager,
+                splitShadeOverScrollerFactory = { _, _ -> splitShadeOverScroller },
+                singleShadeOverScrollerFactory = { singleShadeOverScroller },
+                scrimTransitionController =
+                LockscreenShadeScrimTransitionController(
+                    scrimController, context, configurationController, dumpManager),
+                keyguardTransitionControllerFactory = { notificationPanelController ->
+                    LockscreenShadeKeyguardTransitionController(
+                        mediaHierarchyManager,
+                        notificationPanelController,
+                        context,
+                        configurationController,
+                        dumpManager)
+                })
         whenever(nsslController.view).thenReturn(stackscroller)
         whenever(nsslController.expandHelperCallback).thenReturn(expandHelperCallback)
         transitionController.notificationPanelController = notificationPanelController
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/FakeConfigurationController.kt b/packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/FakeConfigurationController.kt
index 3a5d9ee16b0a..146b56e49e65 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/FakeConfigurationController.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/policy/FakeConfigurationController.kt
@@ -5,22 +5,22 @@ import android.content.res.Configuration
 /** Fake implementation of [ConfigurationController] for tests. */
 class FakeConfigurationController : ConfigurationController {
 
-    private var listener: ConfigurationController.ConfigurationListener? = null
+    private var listeners = mutableListOf<ConfigurationController.ConfigurationListener>()
 
     override fun addCallback(listener: ConfigurationController.ConfigurationListener) {
-        this.listener = listener
+        listeners += listener
     }
 
     override fun removeCallback(listener: ConfigurationController.ConfigurationListener) {
-        this.listener = null
+        listeners -= listener
     }
 
     override fun onConfigurationChanged(newConfiguration: Configuration?) {
-        listener?.onConfigChanged(newConfiguration)
+        listeners.forEach { it.onConfigChanged(newConfiguration) }
     }
 
     override fun notifyThemeChanged() {
-        listener?.onThemeChanged()
+        listeners.forEach { it.onThemeChanged() }
     }
 
     fun notifyConfigurationChanged() {