diff --git a/mobile/lib/widgets/photo_view/src/core/photo_view_core.dart b/mobile/lib/widgets/photo_view/src/core/photo_view_core.dart index 80d7427d826..bb892737f6f 100644 --- a/mobile/lib/widgets/photo_view/src/core/photo_view_core.dart +++ b/mobile/lib/widgets/photo_view/src/core/photo_view_core.dart @@ -120,7 +120,6 @@ class PhotoViewCoreState extends State TickerProviderStateMixin, PhotoViewControllerDelegate, HitCornersDetector { - Offset? _normalizedPosition; double? _scaleBefore; double? _rotationBefore; @@ -153,23 +152,29 @@ class PhotoViewCoreState extends State void onScaleStart(ScaleStartDetails details) { _rotationBefore = controller.rotation; _scaleBefore = scale; - _normalizedPosition = details.focalPoint - controller.position; _scaleAnimationController.stop(); _positionAnimationController.stop(); _rotationAnimationController.stop(); } void onScaleUpdate(ScaleUpdateDetails details) { + final centeredFocalPoint = Offset( + details.focalPoint.dx - scaleBoundaries.outerSize.width / 2, + details.focalPoint.dy - scaleBoundaries.outerSize.height / 2, + ); final double newScale = _scaleBefore! * details.scale; - final Offset delta = details.focalPoint - _normalizedPosition!; + final double scaleDelta = newScale / scale; + final Offset newPosition = + (controller.position + details.focalPointDelta) * scaleDelta - + centeredFocalPoint * (scaleDelta - 1); updateScaleStateFromNewScale(newScale); updateMultiple( scale: newScale, position: widget.enablePanAlways - ? delta - : clampPosition(position: delta, scale: details.scale), + ? newPosition + : clampPosition(position: newPosition), rotation: widget.enableRotation ? _rotationBefore! + details.rotation : null, rotationFocusPoint: widget.enableRotation ? details.focalPoint : null,