tweaks

Signed-off-by: dom <githubaccount56556@proton.me>

lib/common/widgets/colored_box_transition.dart

@@ -0,0 +1,21 @@
+import 'package:flutter/material.dart';
+
+class ColoredBoxTransition extends AnimatedWidget {
+  const ColoredBoxTransition({
+    super.key,
+    required this.color,
+    this.child,
+  }) : super(listenable: color);
+
+  final Animation<Color?> color;
+
+  final Widget? child;
+
+  @override
+  Widget build(BuildContext context) {
+    return ColoredBox(
+      color: color.value!,
+      child: child,
+    );
+  }
+}

lib/common/widgets/image_viewer/gallery_viewer.dart

@@ -17,6 +17,7 @@
 
 import 'dart:io' show File, Platform;
 
+import 'package:PiliPlus/common/widgets/colored_box_transition.dart';
 import 'package:PiliPlus/common/widgets/flutter/page/page_view.dart';
 import 'package:PiliPlus/common/widgets/gesture/image_horizontal_drag_gesture_recognizer.dart';
 import 'package:PiliPlus/common/widgets/gesture/image_tap_gesture_recognizer.dart';
@@ -52,7 +53,7 @@ class GalleryViewer extends StatefulWidget {
     this.maxScale = 8.0,
     required this.quality,
     required this.sources,
-    this.initIndex = 1,
+    this.initIndex = 0,
   });
 
   final double minScale;
@@ -87,14 +88,12 @@ class _GalleryViewerState extends State<GalleryViewer>
   late final LongPressGestureRecognizer _longPressGestureRecognizer;
 
   late final AnimationController _animateController;
-  late final Animation<Decoration> _opacityAnimation;
+  late final Animation<Color?> _opacityAnimation;
   double dx = 0, dy = 0;
 
   Offset _offset = Offset.zero;
   bool _dragging = false;
 
-  bool get _isActive => _dragging || _animateController.isAnimating;
-
   String _getActualUrl(String url) {
     return _quality != 100
         ? ImageUtils.thumbnailUrl(url, _quality)
@@ -138,14 +137,16 @@ class _GalleryViewerState extends State<GalleryViewer>
     });
 
     _animateController = AnimationController(
-      duration: const Duration(milliseconds: 300),
+      duration: const Duration(
+        milliseconds: 750,
+      ), // reverse only if value <= 0.2
       vsync: this,
     );
 
     _opacityAnimation = _animateController.drive(
-      DecorationTween(
-        begin: const BoxDecoration(color: Colors.black),
-        end: const BoxDecoration(color: Colors.transparent),
+      ColorTween(
+        begin: Colors.black,
+        end: Colors.transparent,
       ),
     );
   }
@@ -189,7 +190,7 @@ class _GalleryViewerState extends State<GalleryViewer>
   }
 
   void _onDragUpdate(ScaleUpdateDetails details) {
-    if (!_isActive || _animateController.isAnimating) {
+    if (!_dragging || _animateController.isAnimating) {
       return;
     }
 
@@ -202,16 +203,12 @@ class _GalleryViewerState extends State<GalleryViewer>
   }
 
   void _onDragEnd(ScaleEndDetails details) {
-    if (!_isActive || _animateController.isAnimating) {
+    if (!_dragging || _animateController.isAnimating) {
       return;
     }
 
     _dragging = false;
 
-    if (_animateController.isCompleted) {
-      return;
-    }
-
     if (!_animateController.isDismissed) {
       if (_animateController.value > 0.2) {
         Get.back();
@@ -256,37 +253,35 @@ class _GalleryViewerState extends State<GalleryViewer>
     return Listener(
       behavior: .opaque,
       onPointerDown: _onPointerDown,
-      child: DecoratedBoxTransition(
-        decoration: _opacityAnimation,
-        child: Stack(
-          fit: .expand,
-          alignment: .center,
-          clipBehavior: .none,
-          children: [
-            LayoutBuilder(
-              builder: (context, constraints) {
-                _containerSize = constraints.biggest;
-                return MatrixTransition(
-                  alignment: .topLeft,
-                  animation: _animateController,
-                  onTransform: _onTransform,
-                  child: PageView<ImageHorizontalDragGestureRecognizer>.builder(
-                    controller: _pageController,
-                    onPageChanged: _onPageChanged,
-                    physics: const CustomTabBarViewScrollPhysics(
-                      parent: AlwaysScrollableScrollPhysics(),
-                    ),
-                    itemCount: widget.sources.length,
-                    itemBuilder: _itemBuilder,
-                    horizontalDragGestureRecognizer: () =>
-                        _horizontalDragGestureRecognizer,
+      child: Stack(
+        fit: .expand,
+        alignment: .center,
+        clipBehavior: .none,
+        children: [
+          ColoredBoxTransition(color: _opacityAnimation),
+          LayoutBuilder(
+            builder: (context, constraints) {
+              _containerSize = constraints.biggest;
+              return MatrixTransition(
+                alignment: .topLeft,
+                animation: _animateController,
+                onTransform: _onTransform,
+                child: PageView<ImageHorizontalDragGestureRecognizer>.builder(
+                  controller: _pageController,
+                  onPageChanged: _onPageChanged,
+                  physics: const CustomTabBarViewScrollPhysics(
+                    parent: AlwaysScrollableScrollPhysics(),
                   ),
-                );
-              },
-            ),
-            _buildIndicator,
-          ],
-        ),
+                  itemCount: widget.sources.length,
+                  itemBuilder: _itemBuilder,
+                  horizontalDragGestureRecognizer: () =>
+                      _horizontalDragGestureRecognizer,
+                ),
+              );
+            },
+          ),
+          _buildIndicator,
+        ],
       ),
     );
   }

lib/common/widgets/image_viewer/viewer.dart

@@ -77,10 +77,26 @@ class _ViewerState extends State<Viewer> with SingleTickerProviderStateMixin {
 
   _GestureType? _gestureType;
 
+  final Matrix4 _matrix = Matrix4.identity();
+
+  late double __scale;
+  double get _scale => __scale;
+  set _scale(double value) {
+    __scale = value;
+    _matrix[0] = _matrix[5] = _matrix[10] = value;
+  }
+
+  late Offset __position;
+  Offset get _position => __position;
+  set _position(Offset value) {
+    __position = value;
+    _matrix
+      ..[12] = value.dx
+      ..[13] = value.dy;
+  }
+
   Offset? _scalePos;
-  late double _scale;
   double? _scaleStart;
-  late Offset _position;
   Offset? _referenceFocalPoint;
 
   late Size _imageSize;
@@ -97,10 +113,6 @@ class _ViewerState extends State<Viewer> with SingleTickerProviderStateMixin {
   late double _scaleFrom, _scaleTo;
   late Offset _positionFrom, _positionTo;
 
-  Matrix4 get _matrix =>
-      Matrix4.translationValues(_position.dx, _position.dy, 0.0)
-        ..scaleByDouble(_scale, _scale, _scale, 1.0);
-
   void _listener() {
     final t = Curves.easeOut.transform(_animationController.value);
     _scale = t.lerp(_scaleFrom, _scaleTo);
@@ -396,7 +408,7 @@ class _ViewerState extends State<Viewer> with SingleTickerProviderStateMixin {
       onPointerDown: _onPointerDown,
       onPointerPanZoomStart: _onPointerPanZoomStart,
       onPointerSignal: _onPointerSignal,
-      child: ClipRRect(
+      child: ClipRect(
         child: Transform(
           transform: _matrix,
           child: widget.child,