Add multi inline adaptive banner example with recycling

Author: hellohuanlin

packages/google_mobile_ads/example/lib/main.dart

@@ -23,6 +23,7 @@ import 'dart:developer';
 import 'anchored_adaptive_example.dart';
 import 'fluid_example.dart';
 import 'inline_adaptive_example.dart';
+import 'multi_adaptive_inline_with_recycle_example.dart';
 import 'native_template_example.dart';
 import 'reusable_inline_example.dart';
 import 'webview_example.dart';
@@ -55,6 +56,7 @@ class _MyAppState extends State<MyApp> {
   static const rewardedInterstitialButtonText = 'RewardedInterstitialAd';
   static const fluidButtonText = 'Fluid';
   static const inlineAdaptiveButtonText = 'Inline adaptive';
+  static const mulipleInlineAdaptiveWithRecycleButtonText = 'Multiple inline adaptive with recycle';
   static const anchoredAdaptiveButtonText = 'Anchored adaptive';
   static const nativeTemplateButtonText = 'Native template';
   static const webviewExampleButtonText = 'Register WebView';
@@ -271,6 +273,13 @@ class _MyAppState extends State<MyApp> {
                             builder: (context) => InlineAdaptiveExample()),
                       );
                       break;
+                    case mulipleInlineAdaptiveWithRecycleButtonText:
+                      Navigator.push(
+                        context,
+                        MaterialPageRoute(
+                            builder: (context) => MultiInlineAdaptiveWithRecycleExample()),
+                      );
+                      break;
                     case anchoredAdaptiveButtonText:
                       Navigator.push(
                         context,
@@ -324,6 +333,10 @@ class _MyAppState extends State<MyApp> {
                     value: inlineAdaptiveButtonText,
                     child: Text(inlineAdaptiveButtonText),
                   ),
+                  PopupMenuItem<String>(
+                    value: mulipleInlineAdaptiveWithRecycleButtonText,
+                    child: Text(mulipleInlineAdaptiveWithRecycleButtonText),
+                  ),
                   PopupMenuItem<String>(
                     value: anchoredAdaptiveButtonText,
                     child: Text(anchoredAdaptiveButtonText),

packages/google_mobile_ads/example/lib/multi_adaptive_inline_with_recycle_example.dart

@@ -0,0 +1,106 @@
+import 'dart:io';
+import 'package:flutter/material.dart';
+import 'package:collection/collection.dart';
+import 'package:google_mobile_ads/google_mobile_ads.dart';
+
+class MultiInlineAdaptiveWithRecycleExample extends StatefulWidget {
+  const MultiInlineAdaptiveWithRecycleExample({super.key});
+
+  @override
+  State<StatefulWidget> createState() => _MultiInlineAdaptiveWithRecycleExampleState();
+}
+
+class _MultiInlineAdaptiveWithRecycleExampleState extends State<MultiInlineAdaptiveWithRecycleExample> {
+
+  // A list of all the banners created.
+  final List<BannerAd> _banners = [];
+  // Keep track of sizes of the banners (since they can be different sizes).
+  final Map<BannerAd, AdSize> _bannerSizes = {};
+
+  // The maximum number of banners we create.
+  static const _cacheSize = 10;
+  // Keep track of the positions of banners.
+  final Map<BannerAd, int> _bannerPositions = {};
+
+  BannerAd _createBannerAd() {
+    final String bannerId = Platform.isAndroid
+        ? 'ca-app-pub-3940256099942544/6300978111'
+        : 'ca-app-pub-3940256099942544/2934735716';
+    AdSize adSize = AdSize.getCurrentOrientationInlineAdaptiveBannerAdSize(360);
+    final BannerAd bannerAd = BannerAd(
+      adUnitId: bannerId,
+      request: const AdRequest(),
+      size: adSize,
+      listener: BannerAdListener(
+        onAdLoaded: (Ad ad) async {
+          BannerAd bannerAd = (ad as BannerAd);
+          final AdSize? adSize = await bannerAd.getPlatformAdSize();
+          // When the banner size is updated, we want to rebuild.
+          if (adSize != null && adSize != _bannerSizes[bannerAd]) {
+            setState(() {
+              _bannerSizes[bannerAd] = adSize;
+            });
+          }
+        },
+      ),
+    );
+    bannerAd.load();
+    return bannerAd;
+  }
+
+  BannerAd _getRecycledBannerAd(int bannerPosition) {
+    // If we already created a banner for this position, just reuse it.
+    BannerAd? bannerAd = _banners.firstWhereOrNull((banner) => _bannerPositions[banner] == bannerPosition);
+    if (bannerAd != null) {
+      return bannerAd;
+    }
+
+    // If the cache is not full, create a new banner
+    if (_banners.length < _cacheSize) {
+      BannerAd bannerAd = _createBannerAd();
+      _banners.add(bannerAd);
+      _bannerPositions[bannerAd] = bannerPosition;
+      return bannerAd;
+    }
+
+    // Now the cache is full, we should recycle the banner (if possible).
+    BannerAd banner = _banners[bannerPosition % _cacheSize];
+    if (banner.isMounted) {
+      // Create a new banner if it's not possible to recycle the banner
+      // e.g. show 15 banners on screen, but _cacheSize is only 10.
+      return _createBannerAd();
+    } else {
+      // Found a recyclable banner, mark it as being used by current banner position.
+      _bannerPositions[banner] = bannerPosition;
+      return banner;
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: Text('Adaptive Size, Recycle')),
+      body: ListView.builder(
+        // Arbitrary example of 1000 items in the list.
+        itemCount: 1000,
+        itemBuilder: (BuildContext context, int index) {
+          // We show a banner every 3 rows (i.e. row index 0, 3, 6, 9, 12, etc will be banner row)
+          if (index % 3 == 0) {
+            int bannerPosition = index ~/ 3;
+            BannerAd bannerAd = _getRecycledBannerAd(bannerPosition);
+            final AdSize? adSize = _bannerSizes[bannerAd];
+            if (adSize == null) {
+              // Null adSize means the banner's content is not fetched yet.
+              return SizedBox(height: 50, child: Text("banner is loading"));
+            } else {
+              // Now this banner is loaded with ad content and corresponding ad size.
+              return SizedBox(width: adSize.width.toDouble(), height: adSize.height.toDouble(), child: AdWidget(ad: bannerAd));
+            }
+          } else {
+            // Show your regular non-ad content.
+            return SizedBox(height: 200, child: ColoredBox(color: Colors.yellow));
+          }
+        }),
+    );
+  }
+}