feat: implement cute events

Cute events help against social distancing. You can send googly eyes,
hugs and cuddles.

Fixes:
https://rail.chat/@AgathaSorceress@eldritch.cafe/109336005433123570

Signed-off-by: TheOneWithTheBraid <the-one@with-the-braid.cf>

lib/pages/chat/command_hints.dart

@@ -44,6 +44,12 @@ String commandHint(L10n l10n, String command) {
       return l10n.commandHint_markasdm;
     case 'markasgroup':
       return l10n.commandHint_markasgroup;
+    case 'googly':
+      return l10n.commandHint_googly;
+    case 'hug':
+      return l10n.commandHint_hug;
+    case 'cuddle':
+      return l10n.commandHint_cuddle;
     default:
       return "";
   }

lib/pages/chat/events/cute_events.dart

@@ -0,0 +1,128 @@
+import 'dart:math';
+
+import 'package:flutter/material.dart';
+
+import 'package:flutter_gen/gen_l10n/l10n.dart';
+import 'package:matrix/matrix.dart';
+
+import 'package:fluffychat/config/app_config.dart';
+
+class CuteContent extends StatefulWidget {
+  final Event event;
+
+  const CuteContent(this.event, {Key? key}) : super(key: key);
+
+  @override
+  State<CuteContent> createState() => _CuteContentState();
+}
+
+class _CuteContentState extends State<CuteContent> {
+  static final List<OverlayEntry> overlays = [];
+
+  @override
+  void initState() {
+    if (AppConfig.autoplayImages && overlays.isEmpty) {
+      addOverlay();
+    }
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return FutureBuilder<User?>(
+      future: widget.event.fetchSenderUser(),
+      builder: (context, snapshot) {
+        final label = generateLabel(snapshot.data);
+
+        return GestureDetector(
+          onTap: addOverlay,
+          child: SizedBox.square(
+            dimension: 300,
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              mainAxisAlignment: MainAxisAlignment.center,
+              children: [
+                Text(
+                  widget.event.text,
+                  style: const TextStyle(fontSize: 150),
+                ),
+                if (label != null) Text(label)
+              ],
+            ),
+          ),
+        );
+      },
+    );
+  }
+
+  Widget overlayBuilder(BuildContext context) {
+    return LayoutBuilder(builder: (context, constraints) {
+      final position = Size(
+          Random().nextInt(constraints.maxWidth.round() - 64).toDouble(),
+          Random().nextInt(constraints.maxHeight.round() - 64).toDouble());
+
+      return Padding(
+        padding: EdgeInsets.only(
+            top: position.height,
+            left: position.width,
+            bottom: constraints.maxHeight - 64 - position.height,
+            right: constraints.maxWidth - 64 - position.width),
+        child: SizedBox.square(
+          dimension: 64,
+          child: GestureDetector(
+            onTap: removeOverlay,
+            child: Text(
+              widget.event.text,
+              style: const TextStyle(fontSize: 48),
+            ),
+          ),
+        ),
+      );
+    });
+  }
+
+  Future<void> addOverlay() async {
+    await Future.delayed(const Duration(milliseconds: 50));
+    for (int i = 0; i < 5; i++) {
+      final overlay = OverlayEntry(
+        builder: overlayBuilder,
+      );
+      Overlay.of(context)?.insert(overlay);
+
+      Future.delayed(Duration(seconds: Random().nextInt(35))).then((_) {
+        overlay.remove();
+        overlays.remove(overlay);
+      });
+      overlays.add(overlay);
+    }
+  }
+
+  void removeOverlay() {
+    if (overlays.isEmpty) return;
+    final overlay = overlays.removeLast();
+    overlay.remove();
+  }
+
+  generateLabel(User? user) {
+    switch (widget.event.content['cute_type']) {
+      case 'googly_eyes':
+        return L10n.of(context)?.googlyEyesContent(
+          user?.displayName ??
+              widget.event.senderFromMemoryOrFallback.displayName ??
+              '',
+        );
+      case 'cuddle':
+        return L10n.of(context)?.cuddleContent(
+          user?.displayName ??
+              widget.event.senderFromMemoryOrFallback.displayName ??
+              '',
+        );
+      case 'hug':
+        return L10n.of(context)?.hugContent(
+          user?.displayName ??
+              widget.event.senderFromMemoryOrFallback.displayName ??
+              '',
+        );
+    }
+  }
+}

lib/pages/chat/events/message_content.dart

@@ -14,6 +14,7 @@ import '../../../utils/platform_infos.dart';
 import '../../../utils/url_launcher.dart';
 import '../../bootstrap/bootstrap_dialog.dart';
 import 'audio_player.dart';
+import 'cute_events.dart';
 import 'html_message.dart';
 import 'image_bubble.dart';
 import 'map_bubble.dart';
@@ -108,6 +109,8 @@ class MessageContent extends StatelessWidget {
           case MessageTypes.Sticker:
             if (event.redacted) continue textmessage;
             return Sticker(event);
+          case CuteEventContent.eventType:
+            return CuteContent(event);
           case MessageTypes.Audio:
             if (PlatformInfos.isMobile || PlatformInfos.isMacOS) {
               return AudioPlayerWidget(