feat: 4628 - refactoring as preparatory work

packages/smooth_app/lib/helpers/product_cards_helper.dart

@@ -47,19 +47,18 @@ Widget buildProductSmoothCard({
   EdgeInsets? margin = const EdgeInsets.symmetric(
     horizontal: SMALL_SPACE,
   ),
-}) {
-  return SmoothCard(
-    margin: margin,
-    padding: padding,
-    child: Column(
-      mainAxisSize: MainAxisSize.min,
-      children: <Widget>[
-        if (header != null) header,
-        body,
-      ],
-    ),
-  );
-}
+}) =>
+    SmoothCard(
+      margin: margin,
+      padding: padding,
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: <Widget>[
+          if (header != null) header,
+          body,
+        ],
+      ),
+    );
 
 // used to be in now defunct `AttributeListExpandable`
 List<Attribute> getPopulatedAttributes(

packages/smooth_app/lib/knowledge_panel/knowledge_panels/knowledge_panel_card.dart

@@ -5,7 +5,6 @@ import 'package:smooth_app/data_models/preferences/user_preferences.dart';
 import 'package:smooth_app/generic_lib/design_constants.dart';
 import 'package:smooth_app/knowledge_panel/knowledge_panels/knowledge_panel_expanded_card.dart';
 import 'package:smooth_app/knowledge_panel/knowledge_panels/knowledge_panel_page.dart';
-import 'package:smooth_app/knowledge_panel/knowledge_panels/knowledge_panel_summary_card.dart';
 import 'package:smooth_app/knowledge_panel/knowledge_panels_builder.dart';
 import 'package:smooth_app/widgets/smooth_scaffold.dart';
 
@@ -28,12 +27,11 @@ class KnowledgePanelCard extends StatelessWidget {
   Widget build(BuildContext context) {
     final UserPreferences userPreferences = context.watch<UserPreferences>();
     final KnowledgePanel? panel =
-        KnowledgePanelWidget.getKnowledgePanel(product, panelId);
+        KnowledgePanelsBuilder.getKnowledgePanel(product, panelId);
     if (panel == null) {
       return EMPTY_WIDGET;
     }
-    if (_isExpandedByUser(panel, userPreferences) ||
-        (panel.expanded ?? false)) {
+    if (_isExpandedByUser(panel, userPreferences) || (panel.expanded == true)) {
       return KnowledgePanelExpandedCard(
         panelId: panelId,
         product: product,
@@ -45,28 +43,23 @@ class KnowledgePanelCard extends StatelessWidget {
       padding: const EdgeInsets.symmetric(vertical: SMALL_SPACE),
       child: InkWell(
         borderRadius: ANGULAR_BORDER_RADIUS,
-        child: KnowledgePanelSummaryCard(
+        child: KnowledgePanelsBuilder.getPanelSummaryWidget(
           panel,
           isClickable: true,
           margin: EdgeInsets.zero,
         ),
-        onTap: () {
-          final Brightness? brightness =
-              SmoothBrightnessOverride.of(context)?.brightness;
-
-          Navigator.push<Widget>(
-            context,
-            MaterialPageRoute<Widget>(
-              builder: (BuildContext context) => SmoothBrightnessOverride(
-                brightness: brightness,
-                child: KnowledgePanelPage(
-                  panelId: panelId,
-                  product: product,
-                ),
+        onTap: () async => Navigator.push<Widget>(
+          context,
+          MaterialPageRoute<Widget>(
+            builder: (BuildContext context) => SmoothBrightnessOverride(
+              brightness: SmoothBrightnessOverride.of(context)?.brightness,
+              child: KnowledgePanelPage(
+                panelId: panelId,
+                product: product,
               ),
             ),
-          );
-        },
+          ),
+        ),
       ),
     );
   }
@@ -82,7 +75,7 @@ class KnowledgePanelCard extends StatelessWidget {
     for (final String panelId in expandedPanelIds) {
       if (panel.titleElement != null &&
           panel.titleElement!.title ==
-              KnowledgePanelWidget.getKnowledgePanel(product, panelId)
+              KnowledgePanelsBuilder.getKnowledgePanel(product, panelId)
                   ?.titleElement
                   ?.title) {
         if (userPreferences.getFlag(getExpandFlagTag(panelId)) ?? false) {

packages/smooth_app/lib/knowledge_panel/knowledge_panels/knowledge_panel_expanded_card.dart

@@ -1,8 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:openfoodfacts/openfoodfacts.dart';
 import 'package:smooth_app/generic_lib/design_constants.dart';
-import 'package:smooth_app/knowledge_panel/knowledge_panels/knowledge_panel_element_card.dart';
-import 'package:smooth_app/knowledge_panel/knowledge_panels/knowledge_panel_summary_card.dart';
 import 'package:smooth_app/knowledge_panel/knowledge_panels_builder.dart';
 
 class KnowledgePanelExpandedCard extends StatelessWidget {
@@ -19,21 +17,31 @@ class KnowledgePanelExpandedCard extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final KnowledgePanel panel =
-        KnowledgePanelWidget.getKnowledgePanel(product, panelId)!;
+        KnowledgePanelsBuilder.getKnowledgePanel(product, panelId)!;
     final List<Widget> elementWidgets = <Widget>[];
-    elementWidgets.add(KnowledgePanelSummaryCard(panel, isClickable: false));
-    for (final KnowledgePanelElement element
-        in panel.elements ?? <KnowledgePanelElement>[]) {
-      elementWidgets.add(
-        Padding(
-          padding: const EdgeInsetsDirectional.only(top: VERY_SMALL_SPACE),
-          child: KnowledgePanelElementCard(
-            knowledgePanelElement: element,
-            product: product,
-            isInitiallyExpanded: isInitiallyExpanded,
-          ),
-        ),
-      );
+    final Widget? summary = KnowledgePanelsBuilder.getPanelSummaryWidget(
+      panel,
+      isClickable: false,
+    );
+    if (summary != null) {
+      elementWidgets.add(summary);
+    }
+    if (panel.elements != null) {
+      for (final KnowledgePanelElement element in panel.elements!) {
+        final Widget? elementWidget = KnowledgePanelsBuilder.getElementWidget(
+          knowledgePanelElement: element,
+          product: product,
+          isInitiallyExpanded: isInitiallyExpanded,
+        );
+        if (elementWidget != null) {
+          elementWidgets.add(
+            Padding(
+              padding: const EdgeInsetsDirectional.only(top: VERY_SMALL_SPACE),
+              child: elementWidget,
+            ),
+          );
+        }
+      }
     }
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,

packages/smooth_app/lib/knowledge_panel/knowledge_panels/knowledge_panel_image_card.dart

@@ -0,0 +1,18 @@
+import 'package:flutter/material.dart';
+import 'package:openfoodfacts/openfoodfacts.dart';
+
+/// Card that displays a Knowledge Panel _Image_ element.
+class KnowledgePanelImageCard extends StatelessWidget {
+  const KnowledgePanelImageCard({
+    required this.imageElement,
+  });
+
+  final KnowledgePanelImageElement imageElement;
+
+  @override
+  Widget build(BuildContext context) => Image.network(
+        imageElement.url,
+        width: imageElement.width?.toDouble(),
+        height: imageElement.height?.toDouble(),
+      );
+}

packages/smooth_app/lib/knowledge_panel/knowledge_panels/knowledge_panel_page.dart

@@ -13,6 +13,7 @@ import 'package:smooth_app/pages/product/common/product_refresher.dart';
 import 'package:smooth_app/widgets/smooth_app_bar.dart';
 import 'package:smooth_app/widgets/smooth_scaffold.dart';
 
+/// Detail page of knowledge panels (if you click on the forward/more button).
 class KnowledgePanelPage extends StatefulWidget {
   const KnowledgePanelPage({
     required this.panelId,
@@ -116,7 +117,7 @@ class _KnowledgePanelPageState extends State<KnowledgePanelPage>
         groupElement?.title!.isNotEmpty == true) {
       return groupElement!.title!;
     }
-    final KnowledgePanel? panel = KnowledgePanelWidget.getKnowledgePanel(
+    final KnowledgePanel? panel = KnowledgePanelsBuilder.getKnowledgePanel(
       upToDateProduct,
       widget.panelId,
     );