大图页面的展示和基础框架

lib/photo.dart

 library photo;
 
-import 'package:flutter/material.dart';
 import 'dart:async';
 
+import 'package:flutter/material.dart';
 import 'package:photo/src/entity/options.dart';
 import 'package:photo/src/provider/i18n_provider.dart';
 import 'package:photo/src/ui/dialog/not_permission_dialog.dart';
-import 'package:photo/src/ui/page/photo_main_page.dart';
+import 'package:photo/src/ui/photo_app.dart';
 import 'package:photo_manager/photo_manager.dart';
 
 /// A Calculator.
       rowCount: rowCount,
       dividerColor: dividerColor,
       maxSelected: maxSelected,
-      itemRadio:itemRadio,
+      itemRadio: itemRadio,
       padding: padding,
       disableColor: disableColor,
       textColor: textColor,
       BuildContext context, Options options, I18nProvider provider) {
     return Navigator.of(context).push(
       MaterialPageRoute(
-        builder: (ctx) => PhotoMainPage(
+        builder: (ctx) => PhotoApp(
               options: options,
               provider: provider,
             ),

lib/src/provider/config_provider.dart

+import 'package:flutter/material.dart';
+import 'package:photo/src/entity/options.dart';
+import 'package:photo/src/provider/i18n_provider.dart';
+
+class ConfigProvider extends InheritedWidget {
+  final Options options;
+  final I18nProvider provider;
+
+  ConfigProvider({
+    @required this.options,
+    @required this.provider,
+    @required Widget child,
+    Key key,
+  }) : super(key: key, child: child);
+
+  @override
+  bool updateShouldNotify(InheritedWidget oldWidget) {
+    return true;
+  }
+
+  static ConfigProvider of(BuildContext context) =>
+      context.inheritFromWidgetOfExactType(ConfigProvider);
+}

lib/src/ui/page/photo_main_page.dart

 import 'package:flutter/material.dart';
 import 'package:photo/src/engine/lru_cache.dart';
 import 'package:photo/src/entity/options.dart';
+import 'package:photo/src/provider/config_provider.dart';
 import 'package:photo/src/provider/gallery_list_provider.dart';
 import 'package:photo/src/provider/i18n_provider.dart';
 import 'package:photo/src/provider/selected_provider.dart';
 import 'package:photo/src/ui/dialog/change_gallery_dialog.dart';
+import 'package:photo/src/ui/page/photo_preview_page.dart';
 import 'package:photo_manager/photo_manager.dart';
 
 class PhotoMainPage extends StatefulWidget {
-  final Options options;
-  final I18nProvider provider;
+  final ValueChanged<List<ImageEntity>> onClose;
 
-  const PhotoMainPage({Key key, this.options, this.provider}) : super(key: key);
+  const PhotoMainPage({
+    Key key,
+    this.onClose,
+  }) : super(key: key);
 
   @override
   _PhotoMainPageState createState() => _PhotoMainPageState();
 
 class _PhotoMainPageState extends State<PhotoMainPage>
     with SelectedProvider, GalleryListProvider {
-  Options get options => widget.options;
+  Options get options => ConfigProvider.of(context).options;
 
-  I18nProvider get i18nProvider => widget.provider;
+  I18nProvider get i18nProvider => ConfigProvider.of(context).provider;
 
   List<ImageEntity> list = [];
 
       color: options.textColor,
       fontSize: 14.0,
     );
-    return WillPopScope(
+    return Theme(
+      data: Theme.of(context).copyWith(primaryColor: options.themeColor),
       child: DefaultTextStyle(
         style: textStyle,
         child: Scaffold(
           appBar: AppBar(
-            backgroundColor: options.themeColor,
+            leading: IconButton(
+              icon: Icon(Icons.close),
+              onPressed: _cancel,
+            ),
             title: Text(
               i18nProvider.getTitleText(options),
             ),
             options: options,
             galleryName: currentPath.name,
             onGalleryChange: _onGalleryChange,
+            onTapPreview: _onTapPreview,
             selectedProvider: this,
             galleryListProvider: this,
           ),
         ),
       ),
-      onWillPop: () async {
-        selectedList.clear();
-        Navigator.of(context).pop(selectedList);
-        return false;
-      },
     );
   }
 
+  void _cancel() {
+    selectedList.clear();
+    widget.onClose(selectedList);
+  }
+
   @override
   bool isUpperLimit() {
     var result = selectedCount == options.maxSelected;
   }
 
   void sure() {
-    Navigator.pop(context, selectedList);
+    widget.onClose?.call(selectedList);
   }
 
   void _showTip(String msg) {
     var imageList = await currentPath.imageList;
     this.list.clear();
     this.list.addAll(imageList);
-    print(list);
     setState(() {});
   }
 
       setState(() {});
     });
   }
+
+  void _onTapPreview() {
+    Navigator.of(context).push(
+      MaterialPageRoute(
+        builder: (ctx) => ConfigProvider(
+              provider: ConfigProvider.of(context).provider,
+              options: options,
+              child: PhotoPreviewPage(
+                selectedProvider: this,
+                list: List.of(selectedList),
+              ),
+            ),
+      ),
+    );
+  }
 }
 
 class _BottomWidget extends StatefulWidget {
   final String galleryName;
 
   final GalleryListProvider galleryListProvider;
+  final VoidCallback onTapPreview;
 
   const _BottomWidget({
     Key key,
     this.selectedProvider,
     this.galleryName = "",
     this.galleryListProvider,
+    this.onTapPreview,
   }) : super(key: key);
 
   @override
   @override
   Widget build(BuildContext context) {
     var textStyle = TextStyle(fontSize: 14.0, color: options.textColor);
-    print(MediaQuery.of(context).padding.bottom);
     const textPadding = const EdgeInsets.symmetric(horizontal: 16.0);
     return Container(
       color: options.themeColor,
       child: SafeArea(
         bottom: true,
+        top: false,
         child: Container(
           height: 44.0,
           child: Row(
               Expanded(
                 child: Container(),
               ),
-              Container(
-                height: 44.0,
-                alignment: Alignment.center,
-                child: Text(
-                  i18nProvider.getPreviewText(options, widget.selectedProvider),
-                  style: textStyle,
+              GestureDetector(
+                behavior: HitTestBehavior.translucent,
+                onTap: widget.onTapPreview,
+                child: Container(
+                  height: 44.0,
+                  alignment: Alignment.center,
+                  child: Text(
+                    i18nProvider.getPreviewText(
+                        options, widget.selectedProvider),
+                    style: textStyle,
+                  ),
+                  padding: textPadding,
                 ),
-                padding: textPadding,
               ),
             ],
           ),

lib/src/ui/page/photo_preview_page.dart

+import 'dart:async';
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:photo/src/entity/options.dart';
+import 'package:photo/src/provider/config_provider.dart';
+import 'package:photo/src/provider/selected_provider.dart';
+import 'package:photo_manager/photo_manager.dart';
+
+class PhotoPreviewPage extends StatefulWidget {
+  final SelectedProvider selectedProvider;
+
+  final List<ImageEntity> list;
+
+  const PhotoPreviewPage({Key key, this.selectedProvider, this.list})
+      : super(key: key);
+
+  @override
+  _PhotoPreviewPageState createState() => _PhotoPreviewPageState();
+}
+
+class _PhotoPreviewPageState extends State<PhotoPreviewPage> {
+  ConfigProvider get config => ConfigProvider.of(context);
+
+  Options get options => config.options;
+
+  Color get themeColor => options.themeColor;
+
+  Color get textColor => options.textColor;
+
+  List<ImageEntity> get list => widget.list;
+
+  StreamController<int> pageChangeController = StreamController.broadcast();
+
+  @override
+  void initState() {
+    super.initState();
+    pageChangeController.add(0);
+  }
+
+  @override
+  void dispose() {
+    pageChangeController.close();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Theme(
+      data: Theme.of(context).copyWith(primaryColor: options.themeColor),
+      child: Scaffold(
+        appBar: AppBar(
+          backgroundColor: config.options.themeColor,
+          title: StreamBuilder(
+            stream: pageChangeController.stream,
+            initialData: 0,
+            builder: (ctx, snap) => Text(
+                  "${snap.data + 1}/${widget.list.length}",
+                ),
+          ),
+        ),
+        body: PageView.builder(
+          itemBuilder: _buildItem,
+          itemCount: list.length,
+          onPageChanged: _onPageChanged,
+        ),
+        bottomNavigationBar: _buildBottom(),
+      ),
+    );
+  }
+
+  Widget _buildBottom() {
+    return Container(
+      height: 44.0,
+      color: themeColor,
+    );
+  }
+
+  Widget _buildItem(BuildContext context, int index) {
+    var data = list[index];
+    return BigPhotoImage(
+      imageEntity: data,
+    );
+  }
+
+  void _onPageChanged(int value) {
+    pageChangeController.add(value);
+  }
+}
+
+class BigPhotoImage extends StatefulWidget {
+  final ImageEntity imageEntity;
+
+  const BigPhotoImage({Key key, this.imageEntity}) : super(key: key);
+
+  @override
+  _BigPhotoImageState createState() => _BigPhotoImageState();
+}
+
+class _BigPhotoImageState extends State<BigPhotoImage>
+    with AutomaticKeepAliveClientMixin {
+  @override
+  Widget build(BuildContext context) {
+    return FutureBuilder(
+      future: widget.imageEntity.file,
+      builder: (BuildContext context, AsyncSnapshot<File> snapshot) {
+        var file = snapshot.data;
+        if (snapshot.connectionState == ConnectionState.done && file != null) {
+          return Image.file(
+            file,
+            fit: BoxFit.contain,
+            width: double.infinity,
+            height: double.infinity,
+          );
+        }
+        return Container();
+      },
+    );
+  }
+
+  @override
+  bool get wantKeepAlive => true;
+}

lib/src/ui/photo_app.dart

+import 'package:flutter/material.dart';
+import 'package:photo/src/entity/options.dart';
+import 'package:photo/src/provider/config_provider.dart';
+import 'package:photo/src/provider/i18n_provider.dart';
+import 'package:photo/src/ui/page/photo_main_page.dart';
+import 'package:photo_manager/photo_manager.dart';
+
+class PhotoApp extends StatelessWidget {
+  final Options options;
+  final I18nProvider provider;
+
+  const PhotoApp({Key key, this.options, this.provider}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return ConfigProvider(
+      provider: provider,
+      options: options,
+      child: PhotoMainPage(
+        onClose: (List<ImageEntity> value) {
+          Navigator.pop(context, value);
+        },
+      ),
+    );
+  }
+}