Export screen: add a spinner during the save operation

app/src/main/java/org/fairscan/app/ui/screens/export/ExportScreen.kt

@@ -56,6 +56,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.graphics.Color
@@ -117,19 +118,25 @@ fun ExportScreenWrapper(
         uiState = uiState,
         navigation = navigation,
         onShare = {
+            if (!uiState.isSaving) {
                 ensureCorrectFileName()
                 pdfActions.share()
+            }
         },
         onSave = {
+            if (!uiState.isSaving) {
                 ensureCorrectFileName()
                 pdfActions.save()
+            }
         },
         onOpen = pdfActions.open,
         onCloseScan = {
+            if (!uiState.isSaving) {
                 if (uiState.hasSavedOrShared)
                     onCloseScan()
                 else
                     showConfirmationDialog.value = true
+            }
         },
     )
 
@@ -235,15 +242,32 @@ private fun TextFieldAndPdfInfos(
             )
         }
     }
-
-    if (uiState.savedBundle != null) {
-        SaveInfoBar(uiState.savedBundle, onOpen)
-    }
+    SaveStatusBar(uiState, onOpen)
     if (uiState.errorMessage != null) {
         ErrorBar(uiState.errorMessage)
     }
 }
 
+@Composable
+private fun SaveStatusBar(
+    uiState: ExportUiState,
+    onOpen: (SavedItem) -> Unit,
+) {
+    when {
+        uiState.isSaving -> {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                CircularProgressIndicator(
+                    modifier = Modifier.size(16.dp),
+                    strokeWidth = 2.dp
+                )
+            }
+        }
+        uiState.savedBundle != null -> {
+            SaveInfoBar(uiState.savedBundle, onOpen)
+        }
+    }
+}
+
 @Composable
 private fun FilenameTextField(
     filename: MutableState<String>,
@@ -299,7 +323,7 @@ private fun MainActions(
                 isPrimary = !uiState.hasSavedOrShared,
                 icon = Icons.Default.Download,
                 text = stringResource(R.string.save),
-                modifier = Modifier.weight(1f)
+                modifier = Modifier.weight(1f).alpha(if (uiState.isSaving) 0.6f else 1f)
             )
         }
         ExportButton(

app/src/main/java/org/fairscan/app/ui/screens/export/ExportUiState.kt

@@ -20,6 +20,7 @@ import org.fairscan.app.ui.screens.settings.ExportFormat
 data class ExportUiState(
     val format: ExportFormat = ExportFormat.PDF,
     val isGenerating: Boolean = false,
+    val isSaving: Boolean = false,
     val result: ExportResult? = null,
     val savedBundle: SavedBundle? = null,
     val hasShared: Boolean = false,

app/src/main/java/org/fairscan/app/ui/screens/export/ExportViewModel.kt

@@ -193,6 +193,7 @@ class ExportViewModel(container: AppContainer, val imageRepository: ImageReposit
 
     fun onRequestSave(context: Context) {
         viewModelScope.launch {
+            _uiState.update {it.copy(isSaving = true, errorMessage = null, savedBundle = null) }
             try {
                 // Must not run on the main thread: some SAF providers (e.g. Nextcloud)
                 // may perform network I/O
@@ -208,6 +209,8 @@ class ExportViewModel(container: AppContainer, val imageRepository: ImageReposit
             } catch (e: Exception) {
                 logger.e("FairScan", "Failed to save PDF", e)
                 _events.emit(ExportEvent.SaveError)
+            } finally {
+                _uiState.update { it.copy(isSaving = false) }
             }
         }
     }