Added infinite favourite list

2025-08-06 14:51:08 +08:00 · 2018-04-05 16:58:10 +05:30
parent 6856898d8c
commit 9a98b3b87b
65 changed files with 1596 additions and 0 deletions
--- a/infinite_list/lib/main.dart
+++ b/infinite_list/lib/main.dart
@ -0,0 +1,125 @@
+import 'package:flutter/material.dart';
+import 'package:english_words/english_words.dart';
+
+void main() => runApp(new MyApp());
+
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return new MaterialApp(
+      title: 'Infinite List',
+      theme: new ThemeData(
+        primaryColorDark: Colors.blue,
+        primaryColorLight: Colors.lightBlue
+      ),
+      home: new RandomWords(),
+    );
+  }
+}
+
+class RandomWords extends StatefulWidget {
+  @override
+  createState() => new RandomWordsState();
+}
+
+class RandomWordsState extends State<RandomWords> {
+  final _suggestions = <WordPair>[];
+  final _saved = new Set<WordPair>();
+  final _biggerFont = const TextStyle(fontSize: 18.0);
+
+  @override
+  Widget build(BuildContext context) {
+    return new Scaffold(
+      appBar: new AppBar(
+        title: new Text('Infinite List'),
+        centerTitle: true,
+        actions: <Widget>[
+          new IconButton(icon: new Icon(Icons.list), onPressed: _pushSaved),
+        ],
+      ),
+      body: _buildSuggestions(),
+    );
+  }
+
+  void _pushSaved() {
+    Navigator.of(context).push(
+      new MaterialPageRoute(
+        builder: (context) {
+          final tiles = _saved.map(
+                (pair) {
+              return new ListTile(
+                title: new Text(
+                  pair.asPascalCase,
+                  style: _biggerFont,
+                ),
+              );
+            },
+          );
+          final divided = ListTile
+              .divideTiles(
+            context: context,
+            tiles: tiles,
+          )
+              .toList();
+
+          return new Scaffold(
+            appBar: new AppBar(
+              title: new Text('Saved lists'),
+            ),
+            body: new ListView(children: divided),
+          );
+        },
+      ),
+    );
+  }
+
+  Widget _buildRow(WordPair pair) {
+    final alreadySaved = _saved.contains(pair);
+    return new ListTile(
+      title: new Text(
+        pair.asPascalCase,
+        style: _biggerFont,
+      ),
+      trailing: new Icon(
+        alreadySaved ? Icons.favorite : Icons.favorite_border,
+        color: alreadySaved ? Colors.red : null,
+      ),
+      onTap: () {
+        setState(() {
+          if (alreadySaved) {
+            _saved.remove(pair);
+          } else {
+            _saved.add(pair);
+          }
+        });
+      },
+    );
+  }
+
+  Widget _buildSuggestions() {
+    return new ListView.builder(
+        padding: const EdgeInsets.all(16.0),
+        // The itemBuilder callback is called once per suggested word pairing,
+        // and places each suggestion into a ListTile row.
+        // For even rows, the function adds a ListTile row for the word pairing.
+        // For odd rows, the function adds a Divider widget to visually
+        // separate the entries. Note that the divider may be difficult
+        // to see on smaller devices.
+        itemBuilder: (context, i) {
+          // Add a one-pixel-high divider widget before each row in theListView.
+          if (i.isOdd) return new Divider();
+
+          // The syntax "i ~/ 2" divides i by 2 and returns an integer result.
+          // For example: 1, 2, 3, 4, 5 becomes 0, 1, 1, 2, 2.
+          // This calculates the actual number of word pairings in the ListView,
+          // minus the divider widgets.
+          final index = i ~/ 2;
+          // If you've reached the end of the available word pairings...
+          if (index >= _suggestions.length) {
+            // ...then generate 10 more and add them to the suggestions list.
+            _suggestions.addAll(generateWordPairs().take(10));
+          }
+          return _buildRow(_suggestions[index]);
+        });
+  }
+}