add pagination

2020-11-13 02:38:16 +06:30
parent 08c90fce74
commit ca21f48dab
7 changed files with 412 additions and 190 deletions
--- a/lib/pagination/paginator_listview.dart
+++ b/lib/pagination/paginator_listview.dart
@@ -0,0 +1,99 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+
+import 'paginator_listener.dart';
+
+typedef RowBuilder = Widget Function(dynamic);
+typedef OnScroll = void Function(bool down);
+
+class PaginatorListView<T> extends StatelessWidget {
+  final PaginatorListener<T> paginatorListener;
+  final RowBuilder rowBuilder;
+  final OnScroll onScroll;
+  final ScrollController _scrollController;
+  final Color color;
+
+  PaginatorListView(
+      {Key key,
+      this.paginatorListener,
+      this.rowBuilder,
+      this.onScroll,
+      this.color = Colors.blueAccent})
+      : _scrollController = ScrollController(),
+        assert(paginatorListener != null),
+        assert(rowBuilder != null),
+        super(key: key) {
+    _scrollController.addListener(() async {
+      if (_scrollController.position.pixels ==
+          _scrollController.position.maxScrollExtent) {
+        paginatorListener.loadMore();
+      }
+      if (onScroll != null) {
+        var down = _scrollController.position.userScrollDirection ==
+            ScrollDirection.forward;
+        onScroll(down);
+      }
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    bool ended = paginatorListener.ended;
+    int count = paginatorListener.data.length;
+    if (ended) count++;
+
+    return Column(
+      children: [
+        Expanded(
+          child: RefreshIndicator(
+            onRefresh: () {
+              return paginatorListener.refresh();
+            },
+            child: ListView.separated(
+                separatorBuilder: (context, index) =>
+                    Divider(height: 1, color: Colors.black),
+                controller: _scrollController,
+                scrollDirection: Axis.vertical,
+                physics: const AlwaysScrollableScrollPhysics(),
+                shrinkWrap: true,
+                itemCount: count,
+                itemBuilder: (BuildContext context, int index) {
+                  if (ended && index == count - 1) {
+                    return Padding(
+                      padding: const EdgeInsets.all(8.0),
+                      child: Center(child: Text("No more data")),
+                    );
+                  }
+                  T t = paginatorListener.data[index];
+                  return rowBuilder(t);
+                }),
+          ),
+        ),
+        paginatorListener.isLoading ? _loadingRow() : Container()
+      ],
+    );
+  }
+
+  Widget _loadingRow() {
+    return Container(
+      padding: EdgeInsets.all(8),
+      color: Colors.transparent,
+      child: Row(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          Column(
+            children: [
+              CircularProgressIndicator(
+                  valueColor: new AlwaysStoppedAnimation<Color>(color)),
+              Text(
+                "Loading...",
+                style: TextStyle(color: color),
+              )
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+}