Merge pull request #35 from grundid/type_selectors

added description for the new field

Author: deandreamatias

README.md

@@ -35,6 +35,50 @@ Since this package makes use of [file_picker package](https://pub.dev/packages/f
   ),
 ```
 
+On mobile platforms the file picker will open a default document picker if used with FileType.any. 
+If you want to be able to pick documents and images in the same form field you will need to define
+different file types and thus different selectors. To achieve this use the typeSelectors parameter:
+This way the user will see two buttons to open a file picker for documents and a file picker for the photos
+gallery.
+
+For example:
+
+```dart
+FormBuilderFilePicker(
+  name: "attachments",
+  previewImages: false,
+  allowMultiple: true,
+  withData: true,
+  typeSelectors: [
+    TypeSelector(
+      type: FileType.any,
+      selector: Row(
+        children: <Widget>[
+          Icon(Icons.add_circle),
+          Padding(
+            padding: const EdgeInsets.only(left: 8.0),
+            child: Text("Add documents"),
+          ),
+        ],
+      ),
+    ),
+    if (!kIsWeb)
+      TypeSelector(
+        type: FileType.image,
+        selector: Row(
+          children: <Widget>[
+            Icon(Icons.add_photo_alternate),
+            Padding(
+              padding: const EdgeInsets.only(left: 8.0),
+              child: Text("Add images"),
+            ),
+          ],
+        ),
+      ),
+    ],
+  )
+```
+
 ## Credits
 
 <a href="https://github.com/flutter-form-builder-ecosystem/form_builder_file_picker/graphs/contributors">

lib/src/form_builder_file_picker.dart

@@ -24,7 +24,7 @@ class TypeSelector {
   final FileType type;
   final Widget selector;
 
-  TypeSelector({required this.type, required this.selector});
+  const TypeSelector({required this.type, required this.selector});
 }
 
 /// Field for image(s) from user device storage
@@ -91,8 +91,13 @@ class FormBuilderFilePicker extends FormBuilderField<List<PlatformFile>> {
     this.withReadStream = false,
     this.allowMultiple = false,
     this.previewImages = true,
-    this.selector = const Icon(Icons.add_circle),
-    this.type = FileType.any,
+    @Deprecated("please use typeSelectors for better picker and file type control")
+        this.selector = const Icon(Icons.add_circle),
+    @Deprecated("please use typeSelectors for better picker and file type control")
+        this.type = FileType.any,
+    // TODO: once the above fields are removed typeSelectors should be made not null and initialized as
+    // const [TypeSelector(type: FileType.any, selector: Icon(Icons.add_circle))]
+    // the typeSelectorList variable can be then removed and we can use typeSelectors directly
     this.typeSelectors,
     this.allowedExtensions,
     this.onFileLoading,