Improve UX feedback during export preparation

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

@@ -28,6 +28,7 @@ import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.OpenInNew
@@ -37,6 +38,7 @@ import androidx.compose.material.icons.filled.Download
 import androidx.compose.material.icons.filled.Share
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
@@ -208,7 +210,19 @@ private fun TextFieldAndPdfInfos(
     ) {
 
         if (uiState.isGenerating) {
-            Text(stringResource(R.string.creating_export), fontStyle = FontStyle.Italic)
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                horizontalArrangement = Arrangement.spacedBy(8.dp)
+            ) {
+                CircularProgressIndicator(
+                    modifier = Modifier.size(16.dp),
+                    strokeWidth = 2.dp
+                )
+                Text(
+                    text = stringResource(R.string.creating_export),
+                    fontStyle = FontStyle.Italic
+                )
+            }
         } else if (result != null) {
             val context = LocalContext.current
             val formattedFileSize = formatFileSize(result.sizeInBytes, context)

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

@@ -96,7 +96,7 @@ class ExportViewModel(container: AppContainer, val imageRepository: ImageReposit
         preparationJob = viewModelScope.launch {
             val exportQuality = settingsRepository.exportQuality.first()
             exportFormat = settingsRepository.exportFormat.first()
-            _uiState.update { it.copy(format = exportFormat) }
+            _uiState.update { it.copy(format = exportFormat, isGenerating = true) }
             try {
                 val t1 = System.currentTimeMillis()
                 val result = if (exportFormat == ExportFormat.JPEG) {
@@ -108,7 +108,8 @@ class ExportViewModel(container: AppContainer, val imageRepository: ImageReposit
                     it.copy(isGenerating = false, result = result)
                 }
                 val t2 = System.currentTimeMillis()
-                Log.i("Export", "Generation time: ${t2-t1} ms")
+                val pageCount = result.pageCount
+                Log.i("Export", "Generation: $pageCount pages, $exportQuality, ${t2-t1} ms")
             } catch (e: Exception) {
                 val message = "Failed to prepare $exportFormat export"
                 logger.e("FairScan", message, e)