анимация circular reveal при смене темы

2026-05-22 18:17:56 +00:00
parent 9badd63879
commit 939dabbd86
3 changed files with 249 additions and 54 deletions
@@ -0,0 +1,70 @@
+import 'dart:math' as math;
+import 'dart:ui' as ui;
+
+import 'package:flutter/material.dart';
+
+class ThemeRevealOverlay {
+  static OverlayEntry build({
+    required ui.Image snapshot,
+    required Offset center,
+    required Animation<double> animation,
+  }) {
+    return OverlayEntry(
+      builder: (ctx) {
+        final size = MediaQuery.sizeOf(ctx);
+        final maxRadius = _maxRadius(center, size);
+        return IgnorePointer(
+          child: AnimatedBuilder(
+            animation: animation,
+            builder: (_, __) {
+              final t = Curves.easeInOutCubic.transform(
+                animation.value.clamp(0.0, 1.0),
+              );
+              return ClipPath(
+                clipper: _RevealClipper(
+                  center: center,
+                  radius: maxRadius * t,
+                ),
+                child: Opacity(
+                  opacity: 1.0 - (t * t * t * t),
+                  child: RawImage(
+                    image: snapshot,
+                    width: size.width,
+                    height: size.height,
+                    fit: BoxFit.fill,
+                  ),
+                ),
+              );
+            },
+          ),
+        );
+      },
+    );
+  }
+
+  static double _maxRadius(Offset center, Size size) {
+    final dx = math.max(center.dx, size.width - center.dx);
+    final dy = math.max(center.dy, size.height - center.dy);
+    return math.sqrt(dx * dx + dy * dy);
+  }
+}
+
+class _RevealClipper extends CustomClipper<Path> {
+  final Offset center;
+  final double radius;
+
+  _RevealClipper({required this.center, required this.radius});
+
+  @override
+  Path getClip(Size size) {
+    final full = Path()..addRect(Offset.zero & size);
+    if (radius <= 0) return full;
+    final hole = Path()
+      ..addOval(Rect.fromCircle(center: center, radius: radius));
+    return Path.combine(PathOperation.difference, full, hole);
+  }
+
+  @override
+  bool shouldReclip(covariant _RevealClipper old) =>
+      old.center != center || old.radius != radius;
+}