Fix destination of animation for the first element

Author: pynicolas

app/src/main/java/org/mydomain/myscan/view/CameraScreen.kt

@@ -131,7 +131,7 @@ fun CameraScreen(
                 onPageClick = { index -> viewModel.navigateTo(Screen.FinalizeDocument(index)) },
                 listState = listState,
                 onLastItemPosition =
-                    { coords -> thumbnailCoords.value = coords.localToWindow(Offset.Zero) }
+                    { offset -> thumbnailCoords.value = offset }
             )
         },
         cameraUiState = CameraUiState(pageIds.size, liveAnalysisState, captureState),
@@ -223,7 +223,7 @@ private fun CapturedImage(cameraUiState: CameraUiState, thumbnailCoords: Mutable
                 val centerX = bounds.left + bounds.width / 2
                 val centerY = bounds.top + bounds.height / 2
                 with(density) {
-                    targetOffsetX = thumbnailCoords.value.x - centerX + PAGE_LIST_ELEMENT_SIZE_DP.dp.toPx()
+                    targetOffsetX = thumbnailCoords.value.x - centerX
                     targetOffsetY = thumbnailCoords.value.y - centerY + justABitToTheTop.toPx()
                 }
             }

app/src/main/java/org/mydomain/myscan/view/PageList.kt

@@ -34,10 +34,11 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.asImageBitmap
-import androidx.compose.ui.layout.LayoutCoordinates
 import androidx.compose.ui.layout.onGloballyPositioned
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.dp
 
 const val PAGE_LIST_ELEMENT_SIZE_DP = 120
@@ -49,7 +50,7 @@ fun CommonPageList(
     onPageClick: (Int) -> Unit,
     listState: LazyListState = rememberLazyListState(),
     currentPageIndex: Int? = null,
-    onLastItemPosition: ((LayoutCoordinates) -> Unit)? = null,
+    onLastItemPosition: ((Offset) -> Unit)? = null,
 ) {
     LazyRow (
         state = listState,
@@ -77,7 +78,14 @@ fun CommonPageList(
                         Modifier.width(maxImageSize)
                 val isLastItem = index == pageIds.lastIndex
                 if (isLastItem && onLastItemPosition != null) {
-                    modifier = modifier.onGloballyPositioned(onLastItemPosition)
+                    val density = LocalDensity.current
+                    modifier = modifier.onGloballyPositioned()
+                        { coordinates ->
+                            with(density) {
+                                onLastItemPosition(coordinates.localToWindow(
+                                    Offset(x = PAGE_LIST_ELEMENT_SIZE_DP.dp.toPx(), y = 0f)))
+                            }
+                        }
                 }
                 Image(
                     bitmap = bitmap,
@@ -91,6 +99,11 @@ fun CommonPageList(
         }
     }
     if (pageIds.isEmpty()) {
-        Box(modifier = Modifier.height(120.dp)) {}
+        var modifier = Modifier.height(120.dp)
+        if (onLastItemPosition != null) {
+            modifier = modifier.onGloballyPositioned()
+                { coordinates -> onLastItemPosition(coordinates.localToWindow(Offset.Zero)) }
+        }
+        Box(modifier = modifier) {}
     }
 }