Fix lock button in locking state.

core/ui/src/main/java/org/signal/core/ui/compose/SignalIcons.kt

@@ -69,6 +69,7 @@ enum class SignalIcons(private val icon: SignalIcon) : SignalIcon by icon {
   Keyboard(icon(R.drawable.ic_keyboard_24)),
   Link(icon(R.drawable.symbol_link_24)),
   Lock(icon(R.drawable.symbol_lock_24)),
+  LockFill(icon(R.drawable.symbol_lock_fill_24)),
   Maximize(icon(R.drawable.symbol_maximize_24)),
   Mic(icon(R.drawable.symbol_mic_24)),
   MobileNextDisplay(icon(R.drawable.symbol_mobile_next_display_48)),

core/ui/src/main/res/drawable/symbol_lock_fill_24.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M12 0.63c-3.38 0-6.13 2.74-6.13 6.12V9.9c-0.64 0.34-1.16 0.86-1.49 1.51-0.2 0.4-0.3 0.85-0.34 1.38C4 13.3 4 13.96 4 14.78v2.94c0 0.82 0 1.47 0.04 2 0.05 0.52 0.14 0.97 0.34 1.37 0.34 0.66 0.87 1.2 1.53 1.53 0.4 0.2 0.85 0.3 1.38 0.34C7.8 23 8.46 23 9.28 23h5.44c0.82 0 1.47 0 2-0.04 0.52-0.05 0.97-0.14 1.37-0.34 0.66-0.34 1.2-0.87 1.53-1.53 0.2-0.4 0.3-0.85 0.34-1.38C20 19.2 20 18.54 20 17.72v-2.94c0-0.82 0-1.47-0.04-2-0.05-0.52-0.14-0.97-0.34-1.37-0.33-0.65-0.85-1.17-1.5-1.51V6.75c0-3.38-2.74-6.13-6.12-6.13Zm4.38 8.9c-0.46-0.03-1-0.03-1.66-0.03H9.28c-0.66 0-1.2 0-1.65 0.02V6.75c0-2.42 1.95-4.38 4.37-4.38s4.38 1.96 4.38 4.38v2.77Zm-6 5.6c0-0.9 0.72-1.63 1.62-1.63 0.9 0 1.63 0.73 1.63 1.63 0 0.57-0.3 1.08-0.76 1.36v1.76c0 0.48-0.39 0.88-0.87 0.88s-0.88-0.4-0.88-0.88v-1.76c-0.45-0.28-0.74-0.79-0.74-1.36Z"/>
+</vector>

feature/camera/src/main/java/org/signal/camera/hud/CaptureButton.kt

@@ -171,6 +171,9 @@ private val CaptureButtonState.innerShape: CaptureButtonInnerShape
  * @param onLongPressEnd Callback when long press ends (video recording stop)
  * @param onZoomChange Callback for zoom level changes during recording (0f to 1f)
  * @param onLock Callback when a drag has reached the lock, asking for the recording to run unheld
+ * @param onOverLockChanged Callback when a drag arrives over the lock or leaves it again, so the lock can show that
+ *   lifting there is what takes it. The circle this button carries there arrives underneath it, so the lock is what is
+ *   seen at the end of the drag.
  * @param lockOffset Where the lock sits relative to this button's center, in pixels of this button's own frame.
  *   [Offset.Zero] for a recording that has no lock to be dragged to.
  * @param modifier Modifier to be applied to the button
@@ -183,6 +186,7 @@ fun CaptureButton(
   onLongPressEnd: () -> Unit,
   onZoomChange: (Float) -> Unit,
   onLock: () -> Unit = {},
+  onOverLockChanged: (Boolean) -> Unit = {},
   lockOffset: Offset = Offset.Zero,
   modifier: Modifier = Modifier
 ) {
@@ -200,6 +204,7 @@ fun CaptureButton(
   val currentOnLongPressEnd by rememberUpdatedState(onLongPressEnd)
   val currentOnZoomChange by rememberUpdatedState(onZoomChange)
   val currentOnLock by rememberUpdatedState(onLock)
+  val currentOnOverLockChanged by rememberUpdatedState(onOverLockChanged)
   val currentLockOffset by rememberUpdatedState(lockOffset)
 
   // A drag toward the lock takes the shape part of the way to what it will be once it gets there, so the button shows
@@ -299,10 +304,14 @@ fun CaptureButton(
               val wasOverLock = overLock
               overLock = isOverLock(pointer.position, wasOverLock)
 
-              // Taking hold is felt as it happens, so the finger knows it has arrived without having to commit to find
-              // out. Only the crossing plays, not every event that follows it.
-              if (overLock && !wasOverLock) {
-                haptics.performHapticFeedback(LockSnapHaptic)
+              // Taking hold is felt as it happens, and the lock is told so it can show it, so the finger knows it has
+              // arrived without having to commit to find out. Only the crossing is reported, not every event after it.
+              if (overLock != wasOverLock) {
+                currentOnOverLockChanged(overLock)
+
+                if (overLock) {
+                  haptics.performHapticFeedback(LockSnapHaptic)
+                }
               }
 
               if (!pointer.pressed) {
@@ -347,6 +356,7 @@ fun CaptureButton(
           } finally {
             isPressed = false
             lockProgress = 0f
+            currentOnOverLockChanged(false)
           }
         }
       },

feature/camera/src/main/java/org/signal/camera/hud/CaptureButtonState.kt

@@ -55,11 +55,16 @@ enum class CaptureButtonState {
 enum class GallerySlotContent {
   GALLERY,
   LOCK,
+
+  /** The lock with a thumb over it, which says that lifting there is what takes it. */
+  LOCK_ENGAGED,
   PAUSE;
 
   companion object {
-    fun of(captureButtonState: CaptureButtonState): GallerySlotContent = when (captureButtonState) {
-      CaptureButtonState.RECORDING_HELD -> LOCK
+
+    /** @param isOverLock Whether a drag from the capture button has reached the lock, which only it has any use for. */
+    fun of(captureButtonState: CaptureButtonState, isOverLock: Boolean = false): GallerySlotContent = when (captureButtonState) {
+      CaptureButtonState.RECORDING_HELD -> if (isOverLock) LOCK_ENGAGED else LOCK
       CaptureButtonState.RECORDING_LOCKED -> PAUSE
       CaptureButtonState.PHOTO, CaptureButtonState.VIDEO -> GALLERY
     }

feature/camera/src/main/java/org/signal/camera/hud/RecordingActionButtons.kt

@@ -41,12 +41,22 @@ private val ActionIconSize = 24.dp
  * recording is held, which puts it within reach of the finger already on the capture button.
  *
  * There is nothing to tap: sliding onto it is what takes the offer up.
+ *
+ * @param isEngaged Whether a thumb has arrived over it, which it answers in the recording red so that letting go there
+ *   reads as taking the offer rather than as landing on an offer still being made. It is swapped for rather than
+ *   animated in place, so the two looks are told apart the same way every other control in this corner is.
  */
 @Composable
-fun RecordingLockButton(modifier: Modifier = Modifier) {
-  RecordingActionButton(modifier = modifier.testTag(TestTags.CAMERA_HUD_LOCK_BUTTON)) {
+fun RecordingLockButton(
+  isEngaged: Boolean = false,
+  modifier: Modifier = Modifier
+) {
+  RecordingActionButton(
+    backgroundColor = colorResource(if (isEngaged) R.color.CameraHud_control_red_background else R.color.CameraHud_control_background),
+    modifier = modifier.testTag(TestTags.CAMERA_HUD_LOCK_BUTTON)
+  ) {
     Icon(
-      imageVector = SignalIcons.Lock.imageVector,
+      imageVector = if (isEngaged) SignalIcons.LockFill.imageVector else SignalIcons.Lock.imageVector,
       contentDescription = null,
       tint = Color.White,
       modifier = Modifier.size(ActionIconSize)
@@ -107,6 +117,7 @@ fun RecordingPauseButton(
 @Composable
 private fun RecordingActionButton(
   modifier: Modifier = Modifier,
+  backgroundColor: Color = colorResource(R.color.CameraHud_control_background),
   onClick: (() -> Unit)? = null,
   content: @Composable () -> Unit
 ) {
@@ -115,7 +126,7 @@ private fun RecordingActionButton(
     modifier = modifier
       .size(RecordingActionButtonSize)
       .clip(CircleShape)
-      .background(colorResource(R.color.CameraHud_control_background), CircleShape)
+      .background(backgroundColor, CircleShape)
       .then(if (onClick != null) Modifier.clickable(onClick = onClick) else Modifier)
   ) {
     content()
@@ -130,6 +141,14 @@ private fun RecordingLockButtonPreview() {
   }
 }
 
+@NightPreview
+@Composable
+private fun RecordingLockButtonEngagedPreview() {
+  Previews.Preview {
+    RecordingLockButton(isEngaged = true)
+  }
+}
+
 @NightPreview
 @Composable
 private fun RecordingPauseButtonPreview() {

feature/camera/src/main/java/org/signal/camera/hud/StandardCameraHud.kt

@@ -416,17 +416,19 @@ private enum class RequestedRecording {
 /**
  * What stands in the gallery's corner. Everything it can hold is the same circle, so each fades into the next in place.
  *
+ * @param isOverLock Whether a drag from the capture button has reached the lock, which the lock answers for itself.
  * @param onLockCenterChanged Where the lock sits in the root's frame, which is one end of the drag that takes it.
  */
 @Composable
 private fun GallerySlot(
   captureButtonState: CaptureButtonState,
   isRecordingPaused: Boolean,
+  isOverLock: Boolean,
   emitter: (StandardCameraHudEvents) -> Unit,
   onLockCenterChanged: (Offset) -> Unit
 ) {
   AnimatedContent(
-    targetState = GallerySlotContent.of(captureButtonState),
+    targetState = GallerySlotContent.of(captureButtonState, isOverLock),
     transitionSpec = { CameraHudMotion.swap },
     label = "GallerySlotContent",
     modifier = Modifier.onGloballyPositioned { onLockCenterChanged(it.boundsInRoot().center) }
@@ -438,6 +440,7 @@ private fun GallerySlot(
       )
 
       GallerySlotContent.LOCK -> RecordingLockButton()
+      GallerySlotContent.LOCK_ENGAGED -> RecordingLockButton(isEngaged = true)
       GallerySlotContent.PAUSE -> RecordingPauseButton(
         isPaused = isRecordingPaused,
         onClick = { emitter(StandardCameraHudEvents.RecordingPauseToggled) }
@@ -483,11 +486,16 @@ private fun CameraControls(
   var captureButtonCenter by remember { mutableStateOf(Offset.Zero) }
   var lockCenter by remember { mutableStateOf(Offset.Zero) }
 
+  // Whether the thumb dragging from the capture button has reached the lock. The lock is the one that shows it: the
+  // circle the drag carries there arrives underneath it, since this corner is drawn after the capture button.
+  var isOverLock by remember { mutableStateOf(false) }
+
   val gallery: @Composable (CaptureButtonState) -> Unit = remember {
     movableContentOf { captureButtonState ->
       GallerySlot(
         captureButtonState = captureButtonState,
         isRecordingPaused = currentIsRecordingPaused,
+        isOverLock = isOverLock,
         emitter = currentEmitter,
         onLockCenterChanged = { lockCenter = it }
       )
@@ -539,6 +547,7 @@ private fun CameraControls(
           requestedRecording = RequestedRecording.UNHELD
           currentEmitter(StandardCameraHudEvents.VideoCaptureLocked)
         },
+        onOverLockChanged = { isOverLock = it },
         onTap = { captureButtonState.tapRequest?.let { request(it) } },
         onLongPressStart = {
           if (!captureButtonState.isRecording) {

feature/camera/src/test/java/org/signal/camera/hud/CaptureButtonStateTest.kt

@@ -103,11 +103,24 @@ class CaptureButtonStateTest {
     assertThat(GallerySlotContent.of(CaptureButtonState.RECORDING_HELD)).isEqualTo(GallerySlotContent.LOCK)
   }
 
+  /** The thumb covers the lock on the way to it, so the lock answering for itself is all there is to go by. */
+  @Test
+  fun `Given a thumb over the lock, when the gallery's corner is filled, then the engaged lock is what fills it`() {
+    assertThat(GallerySlotContent.of(CaptureButtonState.RECORDING_HELD, isOverLock = true)).isEqualTo(GallerySlotContent.LOCK_ENGAGED)
+  }
+
   @Test
   fun `Given a recording that is locked, when the gallery's corner is filled, then the pause is what fills it`() {
     assertThat(GallerySlotContent.of(CaptureButtonState.RECORDING_LOCKED)).isEqualTo(GallerySlotContent.PAUSE)
   }
 
+  /** Only a held recording has a lock on offer, so nothing else has any use for a thumb being over one. */
+  @Test
+  fun `Given no lock on offer, when a thumb is reported over one, then the corner is filled as it would have been`() {
+    assertThat(GallerySlotContent.of(CaptureButtonState.PHOTO, isOverLock = true)).isEqualTo(GallerySlotContent.GALLERY)
+    assertThat(GallerySlotContent.of(CaptureButtonState.RECORDING_LOCKED, isOverLock = true)).isEqualTo(GallerySlotContent.PAUSE)
+  }
+
   private fun stateOf(
     captureButtonMode: CaptureButtonMode,
     isRecording: Boolean,