Decompose CamConfig into data, domain and UI layers

AGENTS.md

@@ -141,12 +141,14 @@ extension bind `UnsupportedOperationException`s, gallery NPEs.
 
 ### Legacy
 
-The pre-migration code has no DI, no ViewModels, no coroutines in the camera path (raw
-`thread {}`, `Executors`, `Handler`).
-`CamConfig` holds `private val mActivity: MainActivity` and some of its properties read the View
-tree directly (e.g. `requireLocation`'s getter returns
-`mActivity.settingsDialog.locToggle.isChecked`). This coupling is the thing the migration exists to
-undo — do not add to it.
+The pre-migration code has no ViewModels and no coroutines in the camera path (raw `thread {}`,
+`Executors`, `Handler`). `MainActivity` still owns the viewfinder's View tree, and the classes
+around it — `SettingsDialog`, `ImageCapturer`, `VideoCapturer`, `QRAnalyzer`, the custom Views —
+hold a `MainActivity` and reach into it. Reading state back out of that tree is the coupling the
+migration exists to undo (`CamConfig` used to answer `requireLocation` with
+`settingsDialog.locToggle.isChecked`); `ViewfinderController` now holds the state and pushes it out
+through `ViewfinderChrome`/`ViewfinderEffects`. Do not add a new read of the View tree from below
+the UI.
 
 ### Target
 
@@ -252,11 +254,11 @@ not otherwise changing — whitespace churn buries the diff and makes the migrat
 - **No expression-body functions.** Always a block body with an explicit return type:
   ```kotlin
   // WRONG
-  fun currentMode() = camConfig.currentMode
+  fun currentMode() = viewfinder.currentMode
 
   // CORRECT
   fun currentMode(): CameraMode {
-      return camConfig.currentMode
+      return viewfinder.currentMode
   }
   ```
   Return type is omitted for functions returning `Unit`; write `fun bind() {`, not
@@ -446,5 +448,6 @@ migrating the UI is exactly when they stop being reachable, and left behind they
 - **Never add a commit co-author unless the user explicitly asks.**
 - Commit messages: imperative mood, describing the behavior change rather than the mechanism —
   match the existing log ("Don't initialize the camera while its permission is not granted").
-- Test-facing seams in `CamConfig` (`mPlayer`, `photoQuality`, `camera`, `switchMode`) are written
-  to by the instrumented suite. They stay writable until the screen that owns them is migrated.
+- Test-facing seams in `ViewfinderController` (`mPlayer`, `photoQuality`, `switchMode`) and
+  `CameraSession` (`camera`) are written to by the instrumented suite. They stay writable until the
+  screen that owns them is migrated.

app/build.gradle.kts

@@ -182,9 +182,11 @@ dependencies {
     testImplementation(libs.junit4)
     testImplementation(libs.robolectric)
     testImplementation(libs.androidx.test.core.ktx)
+    testImplementation(libs.kotlinx.coroutines.test)
 
     androidTestImplementation(libs.androidx.test.core.ktx)
     androidTestImplementation(libs.androidx.test.ext.junit.ktx)
     androidTestImplementation(libs.androidx.test.rules)
     androidTestImplementation(libs.androidx.test.runner)
+    androidTestImplementation(libs.kotlinx.coroutines.test)
 }

app/src/androidTest/java/app/grapheneos/camera/BottomTabLayoutRegressionTest.kt

@@ -47,7 +47,7 @@ class BottomTabLayoutRegressionTest {
 
             var travel = 0
             scenario.onActivity { activity ->
-                activity.camConfig.switchMode(activity.tabLayout.getTabAt(0)!!.tag as CameraMode)
+                activity.viewfinder.switchMode(activity.tabLayout.getTabAt(0)!!.tag as CameraMode)
             }
             waitUntil(scenario, "the strip is centred on the first tab") {
                 it.tabLayout.scrollX == centreOf(it.tabLayout, 0)
@@ -127,7 +127,7 @@ class BottomTabLayoutRegressionTest {
             dragStrip(scenario, scrollPx = travel)
 
             waitUntil(scenario, "the camera switched to $targetMode") {
-                it.camConfig.currentMode == targetMode
+                it.viewfinder.currentMode == targetMode
             }
             waitUntil(scenario, "the strip settled on tab $target") {
                 it.tabLayout.scrollX == centreOf(it.tabLayout, target)
@@ -176,7 +176,7 @@ class BottomTabLayoutRegressionTest {
 
             assertNotEquals(selectedAtStart, target)
             waitUntil(scenario, "the camera switched to the tab the drag ended on") {
-                it.camConfig.currentMode == it.tabLayout.getTabAt(target)!!.tag
+                it.viewfinder.currentMode == it.tabLayout.getTabAt(target)!!.tag
             }
         }
     }
@@ -199,7 +199,7 @@ class BottomTabLayoutRegressionTest {
             var travel = 0
             scenario.onActivity { activity ->
                 val tabs = activity.tabLayout
-                startMode = activity.camConfig.currentMode
+                startMode = activity.viewfinder.currentMode
                 target = nextTo(tabs.selectedTabPosition, tabs.tabCount)
                 // Two thirds of the way over: enough to commit the mode, and far enough short of
                 // the centre that the strip has a settle worth measuring left to run.
@@ -215,12 +215,12 @@ class BottomTabLayoutRegressionTest {
                 assertEquals(
                     "the camera rebound while the strip was still moving",
                     startMode,
-                    activity.camConfig.currentMode,
+                    activity.viewfinder.currentMode,
                 )
             }
 
             waitUntil(scenario, "the camera switched once the strip had settled") {
-                it.camConfig.currentMode == it.tabLayout.getTabAt(target)!!.tag
+                it.viewfinder.currentMode == it.tabLayout.getTabAt(target)!!.tag
             }
         }
     }
@@ -254,7 +254,7 @@ class BottomTabLayoutRegressionTest {
                 assertEquals(
                     "the mode the strip was settling into never reached the camera",
                     tabs.getTabAt(target)!!.tag,
-                    activity.camConfig.currentMode,
+                    activity.viewfinder.currentMode,
                 )
             }
         }
@@ -278,7 +278,7 @@ class BottomTabLayoutRegressionTest {
             var travel = 0
             scenario.onActivity { activity ->
                 val tabs = activity.tabLayout
-                startMode = activity.camConfig.currentMode
+                startMode = activity.viewfinder.currentMode
                 target = nextTo(tabs.selectedTabPosition, tabs.tabCount)
                 travel = (centreOf(tabs, target) - tabs.scrollX) * 2 / 3
             }
@@ -288,14 +288,14 @@ class BottomTabLayoutRegressionTest {
                 assertEquals(
                     "the camera switched before there was anything to check",
                     startMode,
-                    activity.camConfig.currentMode,
+                    activity.viewfinder.currentMode,
                 )
                 prefetched = activity.lastFrame
                 assertNotNull("the drag started no copy of the preview", prefetched)
             }
 
             waitUntil(scenario, "the camera switched to tab $target") {
-                it.camConfig.currentMode == it.tabLayout.getTabAt(target)!!.tag
+                it.viewfinder.currentMode == it.tabLayout.getTabAt(target)!!.tag
             }
             scenario.onActivity {
                 assertSame(
@@ -325,7 +325,7 @@ class BottomTabLayoutRegressionTest {
             var travel = 0
             scenario.onActivity { activity ->
                 val tabs = activity.tabLayout
-                startMode = activity.camConfig.currentMode
+                startMode = activity.viewfinder.currentMode
                 target = nextTo(tabs.selectedTabPosition, tabs.tabCount)
                 travel = (centreOf(tabs, target) - tabs.scrollX) * 2 / 3
             }
@@ -334,7 +334,7 @@ class BottomTabLayoutRegressionTest {
                 assertEquals(
                     "the camera rebound before there was anything to check",
                     startMode,
-                    activity.camConfig.currentMode,
+                    activity.viewfinder.currentMode,
                 )
                 assertEquals(
                     "the preview was left live over the freeze the switch is about to cost",
@@ -360,7 +360,7 @@ class BottomTabLayoutRegressionTest {
                 val tabs = activity.tabLayout
                 // Started against a surface the rebind has just emptied, so the copy comes back
                 // with nothing and schedules the retry this is about.
-                activity.camConfig.switchMode(
+                activity.viewfinder.switchMode(
                     tabs.getTabAt(nextTo(tabs.selectedTabPosition, tabs.tabCount))!!.tag
                         as CameraMode
                 )
@@ -371,7 +371,7 @@ class BottomTabLayoutRegressionTest {
             Thread.sleep(RETRY_WINDOW_MS)
 
             scenario.moveToState(Lifecycle.State.RESUMED)
-            waitUntil(scenario, "the camera came back") { it.camConfig.camera != null }
+            waitUntil(scenario, "the camera came back") { it.session.camera != null }
         }
     }
 
@@ -392,7 +392,7 @@ class BottomTabLayoutRegressionTest {
                 // The rebind that applies the new ratio runs whole inside one message, so a poll
                 // that sees the mode has landed sees a layout the resize has already asked for.
                 waitUntil(scenario, "the preview took $mode's aspect ratio") {
-                    it.camConfig.currentMode == mode && !it.previewView.isLayoutRequested
+                    it.viewfinder.currentMode == mode && !it.previewView.isLayoutRequested
                 }
 
                 scenario.onActivity { activity ->
@@ -431,14 +431,14 @@ class BottomTabLayoutRegressionTest {
             var startMode: CameraMode? = null
             scenario.onActivity { activity ->
                 val tabs = activity.tabLayout
-                startMode = activity.camConfig.currentMode
+                startMode = activity.viewfinder.currentMode
 
                 activity.finalizeMode(tabs.getTabAt(nextTo(tabs.selectedTabPosition, tabs.tabCount)))
 
                 assertEquals(
                     "the switch reached the camera before it could be taken back",
                     startMode,
-                    activity.camConfig.currentMode,
+                    activity.viewfinder.currentMode,
                 )
                 assertEquals(
                     "the switch put up no transition to strand",
@@ -458,7 +458,7 @@ class BottomTabLayoutRegressionTest {
                 assertEquals(
                     "the camera left the mode the strip came back to",
                     startMode,
-                    it.camConfig.currentMode,
+                    it.viewfinder.currentMode,
                 )
             }
         }

app/src/androidTest/java/app/grapheneos/camera/CameraModeTabsRegressionTest.kt

@@ -42,10 +42,10 @@ class CameraModeTabsRegressionTest {
             awaitModeTabs(scenario)
 
             scenario.onActivity { activity ->
-                activity.camConfig.switchMode(CameraMode.VIDEO)
+                activity.viewfinder.switchMode(CameraMode.VIDEO)
                 assertEquals(CameraMode.VIDEO, activity.tabLayout.selectedTab?.tag)
 
-                activity.camConfig.switchMode(CameraMode.CAMERA)
+                activity.viewfinder.switchMode(CameraMode.CAMERA)
                 assertEquals(CameraMode.CAMERA, activity.tabLayout.selectedTab?.tag)
             }
         }
@@ -60,7 +60,7 @@ class CameraModeTabsRegressionTest {
         ActivityScenario.launch(MainActivity::class.java).use { scenario ->
             awaitModeTabs(scenario)
 
-            scenario.onActivity { it.camConfig.switchMode(CameraMode.VIDEO) }
+            scenario.onActivity { it.viewfinder.switchMode(CameraMode.VIDEO) }
 
             // Counting passes rather than reading isLayoutRequested: a request issued from inside a
             // layout pass is parked for the next traversal and the flag is cleared on the way, so it
@@ -116,7 +116,7 @@ class CameraModeTabsRegressionTest {
             scenario.onActivity { activity ->
                 val tabs = activity.tabLayout
                 val next = tabs.getTabAt(tabs.selectedTabPosition + 1)
-                assertNotNull("no mode to the left of ${activity.camConfig.currentMode}", next)
+                assertNotNull("no mode to the left of ${activity.viewfinder.currentMode}", next)
                 nextMode = next!!.tag as CameraMode
 
                 flingLeft(activity)
@@ -125,26 +125,26 @@ class CameraModeTabsRegressionTest {
             // The strip slides to the new mode before the camera rebinds, so the switch lands a
             // few frames after the fling rather than inside it.
             waitUntil(scenario, "the fling switched the mode to $nextMode") {
-                it.camConfig.currentMode == nextMode
+                it.viewfinder.currentMode == nextMode
             }
         }
 
         launchCaptureSession(CaptureActivity::class.java, MediaStore.ACTION_IMAGE_CAPTURE)
             .use { scenario ->
-                waitUntil(scenario, "camera is bound") { it.camConfig.camera != null }
+                waitUntil(scenario, "camera is bound") { it.session.camera != null }
 
                 // Flinging before the tabs were built would pass whether or not any get built
                 Thread.sleep(TAB_BUILD_DWELL_MS)
 
                 scenario.onActivity { activity ->
                     flingLeft(activity)
-                    assertEquals(CameraMode.CAMERA, activity.camConfig.currentMode)
+                    assertEquals(CameraMode.CAMERA, activity.viewfinder.currentMode)
                 }
             }
     }
 
     private fun <A : MainActivity> assertNoModeTabs(scenario: ActivityScenario<A>) {
-        waitUntil(scenario, "camera is bound") { it.camConfig.camera != null }
+        waitUntil(scenario, "camera is bound") { it.session.camera != null }
 
         // Asserting straight after the bind would also hold while a build was merely still
         // pending, so outlast the extension probe round that used to precede one.