magnifier: scale boundaries padding;

editor: pan fixes

lib/main_play_test_editor.dart

@@ -11,7 +11,7 @@ void main() => mainCommon(
       debugIntentData: {
         IntentDataKeys.action: IntentActions.edit,
         IntentDataKeys.mimeType: 'image/*',
-        IntentDataKeys.uri: 'content://media/external/images/media/183128',
+        IntentDataKeys.uri: 'content://media/external/images/media/1000064996', // landscape
-        // IntentDataKeys.uri: 'content://media/external/images/media/183534',
+        // IntentDataKeys.uri: 'content://media/external/images/media/1000064754', // portrait
       },
     );

lib/widgets/editor/control_panel.dart

@@ -7,6 +7,7 @@ import 'package:aves/widgets/common/identity/buttons/overlay_button.dart';
 import 'package:aves/widgets/editor/transform/control_panel.dart';
 import 'package:aves/widgets/editor/transform/controller.dart';
 import 'package:aves/widgets/viewer/overlay/viewer_buttons.dart';
+import 'package:aves_magnifier/aves_magnifier.dart';
 import 'package:aves_model/aves_model.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
@@ -125,6 +126,7 @@ class EditorControlPanel extends StatelessWidget {
 
   void _cancelAction(BuildContext context) {
     actionNotifier.value = null;
+    context.read<AvesMagnifierController>().reset();
     context.read<TransformController>().reset();
   }
 

lib/widgets/editor/entry_editor_page.dart

@@ -30,7 +30,7 @@ class ImageEditorPage extends StatefulWidget {
 class _ImageEditorPageState extends State<ImageEditorPage> {
   final List<StreamSubscription> _subscriptions = [];
   final ValueNotifier<EditorAction?> _actionNotifier = ValueNotifier(null);
-  final ValueNotifier<EdgeInsets> _paddingNotifier = ValueNotifier(EdgeInsets.zero);
+  final ValueNotifier<EdgeInsets> _marginNotifier = ValueNotifier(EdgeInsets.zero);
   final ValueNotifier<ViewState> _viewStateNotifier = ValueNotifier<ViewState>(ViewState.zero);
   final AvesMagnifierController _magnifierController = AvesMagnifierController();
   late final TransformController _transformController;
@@ -49,7 +49,7 @@ class _ImageEditorPageState extends State<ImageEditorPage> {
       ..forEach((sub) => sub.cancel())
       ..clear();
     _actionNotifier.dispose();
-    _paddingNotifier.dispose();
+    _marginNotifier.dispose();
     _viewStateNotifier.dispose();
     _magnifierController.dispose();
     _transformController.dispose();
@@ -59,8 +59,11 @@ class _ImageEditorPageState extends State<ImageEditorPage> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      body: Provider<TransformController>.value(
+      body: MultiProvider(
-        value: _transformController,
+        providers: [
+          Provider<AvesMagnifierController>.value(value: _magnifierController),
+          Provider<TransformController>.value(value: _transformController),
+        ],
         child: SafeArea(
           child: Column(
             children: [
@@ -72,7 +75,7 @@ class _ImageEditorPageState extends State<ImageEditorPage> {
                         magnifierController: _magnifierController,
                         transformController: _transformController,
                         actionNotifier: _actionNotifier,
-                        paddingNotifier: _paddingNotifier,
+                        marginNotifier: _marginNotifier,
                         viewStateNotifier: _viewStateNotifier,
                         entry: widget.entry,
                       ),
@@ -91,7 +94,7 @@ class _ImageEditorPageState extends State<ImageEditorPage> {
                             return Cropper(
                               magnifierController: _magnifierController,
                               transformController: _transformController,
-                              paddingNotifier: _paddingNotifier,
+                              marginNotifier: _marginNotifier,
                             );
                           case null:
                             return const SizedBox();
@@ -101,6 +104,7 @@ class _ImageEditorPageState extends State<ImageEditorPage> {
                   ],
                 ),
               ),
+              const Divider(height: 0),
               EditorControlPanel(
                 entry: widget.entry,
                 actionNotifier: _actionNotifier,
@@ -113,13 +117,13 @@ class _ImageEditorPageState extends State<ImageEditorPage> {
     );
   }
 
-  void _onActionChanged() => _updateImagePadding();
+  void _onActionChanged() => _updateImageMargin();
 
-  void _updateImagePadding() {
+  void _updateImageMargin() {
     if (_actionNotifier.value == EditorAction.transform) {
-      _paddingNotifier.value = Cropper.imagePadding;
+      _marginNotifier.value = Cropper.imageMargin;
     } else {
-      _paddingNotifier.value = EdgeInsets.zero;
+      _marginNotifier.value = EdgeInsets.zero;
     }
   }
 

lib/widgets/editor/image.dart

@@ -17,7 +17,7 @@ class EditorImage extends StatefulWidget {
   final AvesMagnifierController magnifierController;
   final TransformController transformController;
   final ValueNotifier<EditorAction?> actionNotifier;
-  final ValueNotifier<EdgeInsets> paddingNotifier;
+  final ValueNotifier<EdgeInsets> marginNotifier;
   final ValueNotifier<ViewState> viewStateNotifier;
   final AvesEntry entry;
 
@@ -26,7 +26,7 @@ class EditorImage extends StatefulWidget {
     required this.magnifierController,
     required this.transformController,
     required this.actionNotifier,
-    required this.paddingNotifier,
+    required this.marginNotifier,
     required this.viewStateNotifier,
     required this.entry,
   });
@@ -96,8 +96,8 @@ class _EditorImageState extends State<EditorImage> {
           final canvasSize = MatrixUtils.transformRect(imageToUserMatrix, Offset.zero & mediaSize).size;
 
           return ValueListenableBuilder<EdgeInsets>(
-            valueListenable: widget.paddingNotifier,
+            valueListenable: widget.marginNotifier,
-            builder: (context, padding, child) {
+            builder: (context, margin, child) {
               return Transform(
                 alignment: Alignment.center,
                 transform: imageToUserMatrix,
@@ -106,12 +106,12 @@ class _EditorImageState extends State<EditorImage> {
                   builder: (context, action, child) {
                     return LayoutBuilder(
                       builder: (context, constraints) {
-                        final viewportSize = padding.deflateSize(constraints.biggest);
+                        final viewportSize = margin.deflateSize(constraints.biggest);
                         final minScale = ScaleLevel(factor: ScaleLevel.scaleForContained(viewportSize, canvasSize));
                         return AvesMagnifier(
                           key: Key('${entry.uri}_${entry.pageId}_${entry.dateModifiedSecs}'),
                           controller: widget.magnifierController,
-                          viewportPadding: padding,
+                          viewportPadding: margin,
                           contentSize: mediaSize,
                           allowOriginalScaleBeyondRange: false,
                           allowGestureScaleBeyondRange: false,

lib/widgets/editor/transform/control_panel.dart

@@ -81,8 +81,10 @@ class _TransformControlPanelState extends State<TransformControlPanel> with Tick
         const SizedBox(height: padding),
         Row(
           children: [
-            const OverlayButton(
+            OverlayButton(
-              child: BackButton(),
+              child: BackButton(
+                onPressed: widget.onCancel,
+              ),
             ),
             Expanded(
               child: TabBar(

lib/widgets/editor/transform/crop_region.dart

@@ -1,25 +1,17 @@
 import 'dart:ui';
 
-import 'package:collection/collection.dart';
 import 'package:equatable/equatable.dart';
 import 'package:flutter/foundation.dart';
 
 @immutable
 class CropRegion extends Equatable {
+  // region corners in image pixel coordinates
   final Offset topLeft, topRight, bottomRight, bottomLeft;
 
   List<Offset> get corners => [topLeft, topRight, bottomRight, bottomLeft];
 
   Offset get center => (topLeft + bottomRight) / 2;
 
-  Rect get outsideRect {
-    final xMin = corners.map((v) => v.dx).min;
-    final xMax = corners.map((v) => v.dx).max;
-    final yMin = corners.map((v) => v.dy).min;
-    final yMax = corners.map((v) => v.dy).max;
-    return Rect.fromPoints(Offset(xMin, yMin), Offset(xMax, yMax));
-  }
-
   @override
   List<Object?> get props => [topLeft, topRight, bottomRight, bottomLeft];
 
@@ -30,7 +22,7 @@ class CropRegion extends Equatable {
     required this.bottomLeft,
   });
 
-  static const CropRegion zero = CropRegion(
+  static const zero = CropRegion(
     topLeft: Offset.zero,
     topRight: Offset.zero,
     bottomRight: Offset.zero,

lib/widgets/editor/transform/cropper.dart

@@ -21,16 +21,16 @@ import 'package:provider/provider.dart';
 class Cropper extends StatefulWidget {
   final AvesMagnifierController magnifierController;
   final TransformController transformController;
-  final ValueNotifier<EdgeInsets> paddingNotifier;
+  final ValueNotifier<EdgeInsets> marginNotifier;
 
   static const double handleDimension = kMinInteractiveDimension;
-  static const EdgeInsets imagePadding = EdgeInsets.all(kMinInteractiveDimension);
+  static const EdgeInsets imageMargin = EdgeInsets.all(kMinInteractiveDimension);
 
   const Cropper({
     super.key,
     required this.magnifierController,
     required this.transformController,
-    required this.paddingNotifier,
+    required this.marginNotifier,
   });
 
   @override
@@ -39,7 +39,6 @@ class Cropper extends StatefulWidget {
 
 class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
   final List<StreamSubscription> _subscriptions = [];
-  final ValueNotifier<Size> _viewportSizeNotifier = ValueNotifier(Size.zero);
   final ValueNotifier<Rect> _outlineNotifier = ValueNotifier(Rect.zero);
   final ValueNotifier<int> _gridDivisionNotifier = ValueNotifier(0);
   late AnimationController _gridAnimationController;
@@ -61,8 +60,6 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
   @override
   void initState() {
     super.initState();
-    final initialRegion = transformation.region;
-    _viewportSizeNotifier.addListener(() => _initOutline(initialRegion));
     _gridAnimationController = AnimationController(
       duration: context.read<DurationsData>().viewerOverlayAnimation,
       vsync: this,
@@ -72,7 +69,6 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
       curve: Curves.easeOutQuad,
     );
     _registerWidget(widget);
-    _initOutline(initialRegion);
   }
 
   @override
@@ -84,7 +80,6 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
 
   @override
   void dispose() {
-    _viewportSizeNotifier.dispose();
     _outlineNotifier.dispose();
     _gridDivisionNotifier.dispose();
     _gridOpacity.dispose();
@@ -95,7 +90,7 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
 
   void _registerWidget(Cropper widget) {
     _subscriptions.add(widget.magnifierController.stateStream.listen(_onViewStateChanged));
-    _subscriptions.add(widget.magnifierController.scaleBoundariesStream.listen(_onViewBoundariesChanged));
+    _subscriptions.add(widget.magnifierController.scaleBoundariesStream.map((v) => v.viewportSize).listen(_onViewportSizeChanged));
     _subscriptions.add(widget.transformController.eventStream.listen(_onTransformEvent));
     _subscriptions.add(widget.transformController.transformationStream.map((v) => v.orientation).distinct().listen(_onOrientationChanged));
     _subscriptions.add(widget.transformController.transformationStream.map((v) => v.straightenDegrees).distinct().listen(_onStraightenDegreesChanged));
@@ -113,14 +108,14 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
   Widget build(BuildContext context) {
     return Positioned.fill(
       child: ValueListenableBuilder<EdgeInsets>(
-        valueListenable: widget.paddingNotifier,
+        valueListenable: widget.marginNotifier,
-        builder: (context, padding, child) {
+        builder: (context, margin, child) {
           return ValueListenableBuilder<Rect>(
             valueListenable: _outlineNotifier,
             builder: (context, outline, child) {
               if (outline.isEmpty) return const SizedBox();
 
-              final outlineVisualRect = outline.translate(padding.left, padding.top);
+              final outlineVisualRect = outline.translate(margin.left, margin.top);
               return Stack(
                 children: [
                   Positioned.fill(
@@ -155,35 +150,35 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
                     ),
                   ),
                   _buildVertexHandle(
-                    padding: padding,
+                    margin: margin,
                     getPosition: () => outline.topLeft,
                     setPosition: (v) => _handleOutline(
                       topLeft: Offset(min(outline.right - minDimension, v.dx), min(outline.bottom - minDimension, v.dy)),
                     ),
                   ),
                   _buildVertexHandle(
-                    padding: padding,
+                    margin: margin,
                     getPosition: () => outline.topRight,
                     setPosition: (v) => _handleOutline(
                       topRight: Offset(max(outline.left + minDimension, v.dx), min(outline.bottom - minDimension, v.dy)),
                     ),
                   ),
                   _buildVertexHandle(
-                    padding: padding,
+                    margin: margin,
                     getPosition: () => outline.bottomRight,
                     setPosition: (v) => _handleOutline(
                       bottomRight: Offset(max(outline.left + minDimension, v.dx), max(outline.top + minDimension, v.dy)),
                     ),
                   ),
                   _buildVertexHandle(
-                    padding: padding,
+                    margin: margin,
                     getPosition: () => outline.bottomLeft,
                     setPosition: (v) => _handleOutline(
                       bottomLeft: Offset(min(outline.right - minDimension, v.dx), max(outline.top + minDimension, v.dy)),
                     ),
                   ),
                   _buildEdgeHandle(
-                    padding: padding,
+                    margin: margin,
                     getEdge: () => Rect.fromPoints(outline.bottomLeft, outline.topLeft),
                     setEdge: (v) {
                       final left = min(outline.right - minDimension, v.left);
@@ -194,7 +189,7 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
                     },
                   ),
                   _buildEdgeHandle(
-                    padding: padding,
+                    margin: margin,
                     getEdge: () => Rect.fromPoints(outline.topLeft, outline.topRight),
                     setEdge: (v) {
                       final top = min(outline.bottom - minDimension, v.top);
@@ -205,7 +200,7 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
                     },
                   ),
                   _buildEdgeHandle(
-                    padding: padding,
+                    margin: margin,
                     getEdge: () => Rect.fromPoints(outline.bottomRight, outline.topRight),
                     setEdge: (v) {
                       final right = max(outline.left + minDimension, v.right);
@@ -216,7 +211,7 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
                     },
                   ),
                   _buildEdgeHandle(
-                    padding: padding,
+                    margin: margin,
                     getEdge: () => Rect.fromPoints(outline.bottomLeft, outline.bottomRight),
                     setEdge: (v) {
                       final bottom = max(outline.top + minDimension, v.bottom);
@@ -341,12 +336,12 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
   }
 
   VertexHandle _buildVertexHandle({
-    required EdgeInsets padding,
+    required EdgeInsets margin,
     required ValueGetter<Offset> getPosition,
     required ValueSetter<Offset> setPosition,
   }) {
     return VertexHandle(
-      padding: padding,
+      margin: margin,
       getPosition: getPosition,
       setPosition: setPosition,
       onDragStart: _onDragStart,
@@ -355,12 +350,12 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
   }
 
   EdgeHandle _buildEdgeHandle({
-    required EdgeInsets padding,
+    required EdgeInsets margin,
     required ValueGetter<Rect> getEdge,
     required ValueSetter<Rect> setEdge,
   }) {
     return EdgeHandle(
-      padding: padding,
+      margin: margin,
       getEdge: getEdge,
       setEdge: setEdge,
       onDragStart: _onDragStart,
@@ -392,11 +387,18 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
     _setOutline(_regionToContainedOutline(nextState, region));
   }
 
-  ViewState _viewStateForContainedRegion(ScaleBoundaries boundaries, CropRegion region) {
+  ViewState _viewStateForContainedRegion(ScaleBoundaries boundaries, CropRegion imageRegion) {
-    final regionSize = MatrixUtils.transformRect(transformation.matrix, region.outsideRect).size;
+    final matrix = transformation.matrix;
-    final nextScale = boundaries.clampScale(ScaleLevel.scaleForContained(boundaries.viewportSize, regionSize));
+    final displayRegion = imageRegion.corners.map(matrix.transformOffset).toSet();
+    final xMin = displayRegion.map((v) => v.dx).min;
+    final xMax = displayRegion.map((v) => v.dx).max;
+    final yMin = displayRegion.map((v) => v.dy).min;
+    final yMax = displayRegion.map((v) => v.dy).max;
+    final displayRegionSize = Size(xMax - xMin, yMax - yMin);
+
+    final nextScale = boundaries.clampScale(ScaleLevel.scaleForContained(boundaries.viewportSize, displayRegionSize));
     final nextPosition = boundaries.clampPosition(
-      position: boundaries.contentToStatePosition(nextScale, region.center),
+      position: boundaries.contentToStatePosition(nextScale, imageRegion.center),
       scale: nextScale,
     );
     return ViewState(
@@ -447,19 +449,30 @@ class _CropperState extends State<Cropper> with SingleTickerProviderStateMixin {
 
   void _onViewStateChanged(MagnifierState state) {
     final currentOutline = _outlineNotifier.value;
-    switch (state.source) {
+    // switch (state.source) {
-      case ChangeSource.internal:
+    //   case ChangeSource.internal:
-      case ChangeSource.animation:
+    //   case ChangeSource.animation:
-        _setOutline(currentOutline);
+    //     _setOutline(currentOutline);
-      case ChangeSource.gesture:
+    //   case ChangeSource.gesture:
     // TODO TLAD [crop] use other strat
     _setOutline(_applyCropRatioToOutline(currentOutline, _RatioStrategy.contain));
     _updateCropRegion();
-    }
+    // }
   }
 
-  void _onViewBoundariesChanged(ScaleBoundaries scaleBoundaries) {
+  void _onViewportSizeChanged(Size viewportSize) {
-    _viewportSizeNotifier.value = scaleBoundaries.viewportSize;
+    _initOutline(transformation.region);
+
+    final boundaries = magnifierController.scaleBoundaries;
+    if (boundaries != null) {
+      final double xPadding = (viewportSize.width - minDimension) / 2;
+      final double yPadding = (viewportSize.height - minDimension) / 2;
+      magnifierController.setScaleBoundaries(
+        boundaries.copyWith(
+          padding: EdgeInsets.symmetric(horizontal: xPadding, vertical: yPadding),
+        ),
+      );
+    }
   }
 
   ViewState? _getViewState() {

lib/widgets/editor/transform/handles.dart

@@ -2,14 +2,14 @@ import 'package:aves/widgets/editor/transform/cropper.dart';
 import 'package:flutter/material.dart';
 
 class VertexHandle extends StatefulWidget {
-  final EdgeInsets padding;
+  final EdgeInsets margin;
   final ValueGetter<Offset> getPosition;
   final ValueSetter<Offset> setPosition;
   final VoidCallback onDragStart, onDragEnd;
 
   const VertexHandle({
     super.key,
-    required this.padding,
+    required this.margin,
     required this.getPosition,
     required this.setPosition,
     required this.onDragStart,
@@ -26,13 +26,13 @@ class _VertexHandleState extends State<VertexHandle> {
 
   static const double _handleDim = Cropper.handleDimension;
 
-  EdgeInsets get padding => widget.padding;
+  EdgeInsets get margin => widget.margin;
 
   @override
   Widget build(BuildContext context) {
     return Positioned.fromRect(
       rect: Rect.fromCenter(
-        center: widget.getPosition().translate(padding.left, padding.right),
+        center: widget.getPosition().translate(margin.left, margin.right),
         width: _handleDim,
         height: _handleDim,
       ),
@@ -58,14 +58,14 @@ class _VertexHandleState extends State<VertexHandle> {
 }
 
 class EdgeHandle extends StatefulWidget {
-  final EdgeInsets padding;
+  final EdgeInsets margin;
   final ValueGetter<Rect> getEdge;
   final ValueSetter<Rect> setEdge;
   final VoidCallback onDragStart, onDragEnd;
 
   const EdgeHandle({
     super.key,
-    required this.padding,
+    required this.margin,
     required this.getEdge,
     required this.setEdge,
     required this.onDragStart,
@@ -82,7 +82,7 @@ class _EdgeHandleState extends State<EdgeHandle> {
 
   static const double _handleDim = Cropper.handleDimension;
 
-  EdgeInsets get padding => widget.padding;
+  EdgeInsets get margin => widget.margin;
 
   @override
   Widget build(BuildContext context) {
@@ -94,7 +94,7 @@ class _EdgeHandleState extends State<EdgeHandle> {
       // vertical edge
       edge = Rect.fromLTWH(edge.left - _handleDim / 2, edge.top + _handleDim / 2, _handleDim, edge.height - _handleDim);
     }
-    edge = edge.translate(padding.left, padding.right);
+    edge = edge.translate(margin.left, margin.right);
 
     return Positioned.fromRect(
       rect: edge,

plugins/aves_magnifier/lib/src/controller/controller.dart

@@ -32,7 +32,7 @@ class AvesMagnifierController {
     initial = initialState ?? const MagnifierState(position: Offset.zero, scale: null, source: source);
     previousState = initial;
     _currentState = initial;
-    _setState(initial);
+    reset();
 
     const _initialScaleState = ScaleStateChange(state: ScaleState.initial, source: source);
     previousScaleState = _initialScaleState;
@@ -70,6 +70,8 @@ class AvesMagnifierController {
 
   bool get isZooming => scaleState.state == ScaleState.zoomedIn || scaleState.state == ScaleState.zoomedOut;
 
+  void reset() => _setState(initial);
+
   void update({
     Offset? position,
     double? scale,

plugins/aves_magnifier/lib/src/controller/controller_delegate.dart

@@ -21,14 +21,12 @@ mixin AvesMagnifierControllerDelegate on State<AvesMagnifier> {
 
   Function(double? prevScale, double? nextScale, Offset nextPosition)? _animateScale;
 
-  /// Mark if scale need recalculation, useful for scale boundaries changes.
-  bool markNeedsScaleRecalc = true;
-
   final List<StreamSubscription> _subscriptions = [];
 
   void registerDelegate(AvesMagnifier widget) {
     _subscriptions.add(widget.controller.stateStream.listen(_onMagnifierStateChanged));
     _subscriptions.add(widget.controller.scaleStateChangeStream.listen(_onScaleStateChanged));
+    _subscriptions.add(widget.controller.scaleBoundariesStream.listen(_onScaleBoundariesChanged));
   }
 
   void unregisterDelegate(AvesMagnifier oldWidget) {
@@ -38,12 +36,16 @@ mixin AvesMagnifierControllerDelegate on State<AvesMagnifier> {
       ..clear();
   }
 
+  void _onScaleBoundariesChanged(ScaleBoundaries boundaries) {
+    initScale();
+  }
+
   void _onScaleStateChanged(ScaleStateChange scaleStateChange) {
     if (scaleStateChange.source == ChangeSource.internal) return;
     if (!controller.hasScaleSateChanged) return;
 
     if (_animateScale == null || controller.isZooming) {
-      controller.update(scale: scale, source: scaleStateChange.source);
+      controller.update(scale: controller.scale, source: scaleStateChange.source);
       return;
     }
 
@@ -68,34 +70,24 @@ mixin AvesMagnifierControllerDelegate on State<AvesMagnifier> {
 
   void _onMagnifierStateChanged(MagnifierState state) {
     final boundaries = scaleBoundaries;
-    if (boundaries == null) return;
+    final currentScale = controller.scale;
+    if (boundaries == null || currentScale == null) return;
 
-    controller.update(position: boundaries.clampPosition(position: position, scale: scale!), source: state.source);
+    controller.update(position: boundaries.clampPosition(position: position, scale: currentScale), source: state.source);
-    if (controller.scale == controller.previousState.scale) return;
+    final newScale = controller.scale;
+    if (newScale == null || newScale == currentScale) return;
 
     if (state.source == ChangeSource.internal || state.source == ChangeSource.animation) return;
-    final newScaleState = (scale! > boundaries.initialScale) ? ScaleState.zoomedIn : ScaleState.zoomedOut;
+    final newScaleState = (newScale > boundaries.initialScale) ? ScaleState.zoomedIn : ScaleState.zoomedOut;
     controller.setScaleState(newScaleState, state.source);
   }
 
   Offset get position => controller.position;
 
-  double? recalcScale() {
+  void initScale() {
     final scaleState = controller.scaleState.state;
     final newScale = controller.getScaleForScaleState(scaleState);
-    markNeedsScaleRecalc = false;
     setScale(newScale, ChangeSource.internal);
-    return newScale;
-  }
-
-  double? get scale {
-    final scaleState = controller.scaleState.state;
-    final needsRecalc = markNeedsScaleRecalc && !(scaleState == ScaleState.zoomedIn || scaleState == ScaleState.zoomedOut);
-    final scaleExistsOnController = controller.scale != null;
-    if (needsRecalc || !scaleExistsOnController) {
-      return recalcScale();
-    }
-    return controller.scale;
   }
 
   void setScale(double? scale, ChangeSource source) => controller.update(scale: scale, source: source);
@@ -105,7 +97,7 @@ mixin AvesMagnifierControllerDelegate on State<AvesMagnifier> {
     if (boundaries == null) return;
 
     var newScaleState = ScaleState.initial;
-    if (scale != boundaries.initialScale) {
+    if (controller.scale != boundaries.initialScale) {
       newScaleState = (newScale > boundaries.initialScale) ? ScaleState.zoomedIn : ScaleState.zoomedOut;
     }
     controller.setScaleState(newScaleState, source);

plugins/aves_magnifier/lib/src/core/core.dart

@@ -97,8 +97,6 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
   late AnimationController _positionAnimationController;
   late Animation<Offset> _positionAnimation;
 
-  ScaleBoundaries? cachedScaleBoundaries;
-
   static const _flingPointerKind = PointerDeviceKind.unknown;
 
   @override
@@ -111,7 +109,7 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
     _registerWidget(widget);
     // force delegate scale computing on initialization
     // so that it does not happen lazily at the beginning of a scale animation
-    recalcScale();
+    initScale();
   }
 
   @override
@@ -144,13 +142,11 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
 
   void _registerWidget(AvesMagnifier widget) {
     registerDelegate(widget);
-    cachedScaleBoundaries = widget.controller.scaleBoundaries;
     setScaleStateUpdateAnimation(animateOnScaleStateUpdate);
   }
 
   void _unregisterWidget(AvesMagnifier oldWidget) {
     unregisterDelegate(oldWidget);
-    cachedScaleBoundaries = null;
   }
 
   void handleScaleAnimation() {
@@ -176,7 +172,7 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
     _mayFlingLTRB = const (true, true, true, true);
     _updateMayFling();
 
-    _startScale = scale;
+    _startScale = controller.scale;
     _startFocalPoint = details.localFocalPoint;
     _lastViewportFocalPosition = _startFocalPoint;
     _dropped = false;
@@ -214,7 +210,7 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
       final factor = _quickScaleMoved ? (focalPointY > _quickScaleLastY! ? (1 + spanDiff) : (1 - spanDiff)) : 1;
       _quickScaleLastDistance = distance;
       _quickScaleLastY = focalPointY;
-      newScale = scale! * factor;
+      newScale = controller.scale! * factor;
     } else {
       newScale = _startScale! * details.scale;
     }
@@ -227,7 +223,7 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
 
     final viewportCenter = boundaries.viewportCenter;
     final centerContentPosition = boundaries.viewportToContentPosition(controller, viewportCenter);
-    final scalePositionDelta = (scaleFocalPoint - viewportCenter) * (scale! / newScale - 1);
+    final scalePositionDelta = (scaleFocalPoint - viewportCenter) * (controller.scale! / newScale - 1);
     final panPositionDelta = scaleFocalPoint - _lastViewportFocalPosition!;
 
     final newPosition = boundaries.clampPosition(
@@ -434,7 +430,7 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
 
   /// Check if scale is equal to initial after scale animation update
   void onAnimationStatusCompleted() {
-    if (controller.scaleState.state != ScaleState.initial && scale == scaleBoundaries?.initialScale) {
+    if (controller.scaleState.state != ScaleState.initial && controller.scale == scaleBoundaries?.initialScale) {
       controller.setScaleState(ScaleState.initial, ChangeSource.animation);
     }
   }
@@ -446,12 +442,6 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
 
   @override
   Widget build(BuildContext context) {
-    // Check if we need a recalc on the scale
-    if (widget.controller.scaleBoundaries != cachedScaleBoundaries) {
-      markNeedsScaleRecalc = true;
-      cachedScaleBoundaries = widget.controller.scaleBoundaries;
-    }
-
     return StreamBuilder<MagnifierState>(
       stream: controller.stateStream,
       initialData: controller.previousState,
@@ -494,7 +484,7 @@ class _AvesMagnifierState extends State<AvesMagnifier> with TickerProviderStateM
                 controller.setScaleBoundaries(boundaries);
 
                 // `Matrix4.scale` uses dynamic typing and can throw `UnimplementedError` on wrong types
-                final double effectiveScale = (applyScale ? scale : null) ?? 1.0;
+                final double effectiveScale = (applyScale ? controller.scale : null) ?? 1.0;
                 return Transform(
                   transform: Matrix4.identity()
                     ..translate(position.dx, position.dy)

plugins/aves_magnifier/lib/src/pan/edge_hit_detector.dart

@@ -1,6 +1,5 @@
 import 'package:aves_magnifier/src/controller/controller_delegate.dart';
 import 'package:equatable/equatable.dart';
-import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 mixin EdgeHitDetector on AvesMagnifierControllerDelegate {
@@ -11,14 +10,9 @@ mixin EdgeHitDetector on AvesMagnifierControllerDelegate {
 
   EdgeHit getXEdgeHit() {
     final _boundaries = scaleBoundaries;
-    final _scale = scale;
+    final _scale = controller.scale;
     if (_boundaries == null || _scale == null) return const EdgeHit(false, false);
 
-    final contentWidth = _boundaries.contentSize.width * _scale;
-    final viewportWidth = _boundaries.viewportSize.width;
-    if (viewportWidth + precisionErrorTolerance >= contentWidth) {
-      return const EdgeHit(true, true);
-    }
     final x = -position.dx;
     final range = _boundaries.getXEdges(scale: _scale);
     return EdgeHit(x <= range.min, x >= range.max);
@@ -26,14 +20,9 @@ mixin EdgeHitDetector on AvesMagnifierControllerDelegate {
 
   EdgeHit getYEdgeHit() {
     final _boundaries = scaleBoundaries;
-    final _scale = scale;
+    final _scale = controller.scale;
     if (_boundaries == null || _scale == null) return const EdgeHit(false, false);
 
-    final contentHeight = _boundaries.contentSize.height * _scale;
-    final viewportHeight = _boundaries.viewportSize.height;
-    if (viewportHeight + precisionErrorTolerance >= contentHeight) {
-      return const EdgeHit(true, true);
-    }
     final y = -position.dy;
     final range = _boundaries.getYEdges(scale: _scale);
     return EdgeHit(y <= range.min, y >= range.max);

plugins/aves_magnifier/lib/src/scale/scale_boundaries.dart

@@ -16,12 +16,13 @@ class ScaleBoundaries extends Equatable {
   final ScaleLevel _initialScale;
   final Size viewportSize;
   final Size contentSize;
+  final EdgeInsets padding;
   final Matrix4? externalTransform;
 
   static const Alignment basePosition = Alignment.center;
 
   @override
-  List<Object?> get props => [_allowOriginalScaleBeyondRange, _minScale, _maxScale, _initialScale, viewportSize, contentSize, externalTransform];
+  List<Object?> get props => [_allowOriginalScaleBeyondRange, _minScale, _maxScale, _initialScale, viewportSize, contentSize, padding, externalTransform];
 
   const ScaleBoundaries({
     required bool allowOriginalScaleBeyondRange,
@@ -30,6 +31,7 @@ class ScaleBoundaries extends Equatable {
     required ScaleLevel initialScale,
     required this.viewportSize,
     required this.contentSize,
+    this.padding = EdgeInsets.zero,
     this.externalTransform,
   })  : _allowOriginalScaleBeyondRange = allowOriginalScaleBeyondRange,
         _minScale = minScale,
@@ -43,6 +45,7 @@ class ScaleBoundaries extends Equatable {
     initialScale: ScaleLevel(ref: ScaleReference.contained),
     viewportSize: Size.zero,
     contentSize: Size.zero,
+    padding: EdgeInsets.zero,
   );
 
   ScaleBoundaries copyWith({
@@ -52,6 +55,7 @@ class ScaleBoundaries extends Equatable {
     ScaleLevel? initialScale,
     Size? viewportSize,
     Size? contentSize,
+    EdgeInsets? padding,
     Matrix4? externalTransform,
   }) {
     return ScaleBoundaries(
@@ -61,6 +65,7 @@ class ScaleBoundaries extends Equatable {
       initialScale: initialScale ?? _initialScale,
       viewportSize: viewportSize ?? this.viewportSize,
       contentSize: contentSize ?? this.contentSize,
+      padding: padding ?? this.padding,
       externalTransform: externalTransform ?? this.externalTransform,
     );
   }
@@ -110,7 +115,7 @@ class ScaleBoundaries extends Equatable {
 
     final minX = ((positionX - 1).abs() / 2) * widthDiff * -1;
     final maxX = ((positionX + 1).abs() / 2) * widthDiff;
-    return EdgeRange(minX, maxX);
+    return EdgeRange(minX - padding.left, maxX + padding.right);
   }
 
   EdgeRange getYEdges({required double scale}) {
@@ -122,7 +127,7 @@ class ScaleBoundaries extends Equatable {
 
     final minY = ((positionY - 1).abs() / 2) * heightDiff * -1;
     final maxY = ((positionY + 1).abs() / 2) * heightDiff;
-    return EdgeRange(minY, maxY);
+    return EdgeRange(minY - padding.top, maxY + padding.bottom);
   }
 
   double clampScale(double scale) {
@@ -142,24 +147,11 @@ class ScaleBoundaries extends Equatable {
   }
 
   Offset clampPosition({required Offset position, required double scale}) {
-    final computedWidth = contentSize.width * scale;
+    final rangeX = getXEdges(scale: scale);
-    final computedHeight = contentSize.height * scale;
+    final rangeY = getYEdges(scale: scale);
-
+    return Offset(
-    final viewportWidth = _transformedViewportSize.width;
+      position.dx.clamp(rangeX.min, rangeX.max),
-    final viewportHeight = _transformedViewportSize.height;
+      position.dy.clamp(rangeY.min, rangeY.max),
-
+    );
-    var finalX = 0.0;
-    if (viewportWidth < computedWidth) {
-      final range = getXEdges(scale: scale);
-      finalX = position.dx.clamp(range.min, range.max);
-    }
-
-    var finalY = 0.0;
-    if (viewportHeight < computedHeight) {
-      final range = getYEdges(scale: scale);
-      finalY = position.dy.clamp(range.min, range.max);
-    }
-
-    return Offset(finalX, finalY);
   }
 }