Commit b4a9061

@@ -0,0 +1,125 @@
+
+import 'package:blood_pressure_app/components/dialoges/fullscreen_dialoge.dart';
+import 'package:blood_pressure_app/model/export_import/column.dart';
+import 'package:blood_pressure_app/model/export_import/csv_record_parsing_actor.dart';
+import 'package:blood_pressure_app/model/storage/export_columns_store.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+class ImportPreview extends StatefulWidget {
+
+  const ImportPreview({super.key,
+    required this.bottomAppBar,
+    required this.initialActor, 
+    required this.columnsManager,
+  });
+
+  /// Whether to move the app bar to the bottom of the screen.
+  final bool bottomAppBar;
+  
+  /// The columns available for selection.
+  final ExportColumnsManager columnsManager;
+
+  /// The actor to manage importing.
+  final CsvRecordParsingActor initialActor;
+
+  @override
+  State<ImportPreview> createState() => _ImportPreviewState();
+}
+
+class _ImportPreviewState extends State<ImportPreview> {
+  late CsvRecordParsingActor _actor;
+
+  @override
+  void initState() {
+    super.initState();
+    _actor = widget.initialActor;
+  }
+
+  @override
+  Widget build(BuildContext context) => FullscreenDialoge(
+    actionButtonText: AppLocalizations.of(context)!.import,
+    bottomAppBar: widget.bottomAppBar,
+    body: SingleChildScrollView(
+      child: SingleChildScrollView(
+        scrollDirection: Axis.horizontal,
+        child: Row(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            for (int colIdx = 0; colIdx < _actor.columnNames.length; colIdx++)
+              Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  DropdownButton(
+                    items: [
+                      DropdownMenuItem(
+                        child: Text(
+                          MaterialLocalizations.of(context).keyboardKeySelect,
+                          style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                            fontStyle: FontStyle.italic,
+                          ),
+                        ),
+                      ),
+                      for (final parser in widget.columnsManager.getAllColumns())
+                        DropdownMenuItem(
+                          value: parser,
+                          child: Padding(
+                            padding: EdgeInsets.only(top: 8),
+                            child: Column(
+                              crossAxisAlignment: CrossAxisAlignment.start,
+                              children: [
+                                Text(parser.csvTitle),
+                                if (parser.formatPattern != null)
+                                  Text(parser.formatPattern!, style: Theme.of(context).textTheme.labelSmall,),
+                              ],
+                            ),
+                          ), // TODO: consider more info
+                        ),
+                    ],
+                    value: _actor.columnParsers[_actor.columnNames[colIdx]],
+                    onChanged: (parser) {
+                      setState(() {
+                        _actor.changeColumnParser(_actor.columnNames[colIdx], parser);
+                      });
+                    },
+                  ),
+                  const Divider(),
+                  for (int rowIdx = 0; rowIdx < _actor.dataLines.length; rowIdx++) // TODO rework if needed (parsed?)
+                    _buildCell(
+                      rowIdx,
+                      _actor.dataLines[rowIdx][colIdx],
+                      _actor.columnParsers[_actor.columnNames[colIdx]],
+                    ),
+                ],
+              ),
+          ],
+        ),
+      ),
+    ),
+  );
+
+  Widget _buildCell(int lineNumber, String csvContent, ExportColumn? parser) {
+    final localizations = AppLocalizations.of(context)!;
+    final parsed = parser?.decode(csvContent);
+    if (parsed?.$2 == null) {
+      return Tooltip(
+        message: localizations.errParseFailedDecodingField(
+          lineNumber,
+          parsed?.$1.localize(localizations) ?? csvContent,
+        ),
+        child: Text(csvContent, style: TextStyle(
+          color: Theme.of(context).colorScheme.error,
+        ),),
+      );
+    }
+
+    // TODO: time formatting, more fitting localizations
+
+    var text = parsed!.$2.toString();
+    if (text.isEmpty) text = '-';
+    return Tooltip(
+      message: csvContent,
+      child: Text(text),
+    );
+  }
+}

@@ -37,8 +37,12 @@ class CsvRecordParsingActor {
   Map<String, ExportColumn> get columnParsers => _columnParsers;
 
   /// Override a columns with a custom one.
-  void changeColumnParser(String columnName, ExportColumn parser) {
+  void changeColumnParser(String columnName, ExportColumn? parser) {
     assert(_columnNames.contains(columnName));
+    if (parser == null) {
+      _columnParsers.remove(columnName);
+      return;
+    }
     _columnParsers[columnName] = parser;
   }