fix-double-order (#326)

Author: renancaraujo

example/lib/screens/examples/gallery/gallery_example.dart

@@ -176,14 +176,14 @@ class _GalleryPhotoViewWrapperState extends State<GalleryPhotoViewWrapper> {
             childSize: const Size(300, 300),
             initialScale: PhotoViewComputedScale.contained,
             minScale: PhotoViewComputedScale.contained * (0.5 + index / 10),
-            maxScale: PhotoViewComputedScale.covered * 1.1,
+            maxScale: PhotoViewComputedScale.covered * 4.1,
             heroAttributes: PhotoViewHeroAttributes(tag: item.id),
           )
         : PhotoViewGalleryPageOptions(
             imageProvider: AssetImage(item.resource),
             initialScale: PhotoViewComputedScale.contained,
             minScale: PhotoViewComputedScale.contained * (0.5 + index / 10),
-            maxScale: PhotoViewComputedScale.covered * 1.1,
+            maxScale: PhotoViewComputedScale.covered * 4.1,
             heroAttributes: PhotoViewHeroAttributes(tag: item.id),
           );
   }

lib/src/core/photo_view_gesture_detector.dart

@@ -52,6 +52,14 @@ class PhotoViewGestureDetector extends StatelessWidget {
       );
     }
 
+    gestures[DoubleTapGestureRecognizer] =
+        GestureRecognizerFactoryWithHandlers<DoubleTapGestureRecognizer>(
+      () => DoubleTapGestureRecognizer(debugOwner: this),
+      (DoubleTapGestureRecognizer instance) {
+        instance..onDoubleTap = onDoubleTap;
+      },
+    );
+
     gestures[PhotoViewGestureRecognizer] =
         GestureRecognizerFactoryWithHandlers<PhotoViewGestureRecognizer>(
       () => PhotoViewGestureRecognizer(
@@ -64,16 +72,8 @@ class PhotoViewGestureDetector extends StatelessWidget {
       },
     );
 
-    gestures[DoubleTapGestureRecognizer] =
-        GestureRecognizerFactoryWithHandlers<DoubleTapGestureRecognizer>(
-      () => DoubleTapGestureRecognizer(debugOwner: this),
-      (DoubleTapGestureRecognizer instance) {
-        instance..onDoubleTap = onDoubleTap;
-      },
-    );
-
     return RawGestureDetector(
-      behavior: behavior ?? HitTestBehavior.translucent,
+      behavior: behavior,
       child: child,
       gestures: gestures,
     );
@@ -150,9 +150,7 @@ class PhotoViewGestureRecognizer extends ScaleGestureRecognizer {
       return;
     }
     final move = _initialFocalPoint - _currentFocalPoint;
-    final bool shouldMove = validateAxis == Axis.vertical
-        ? hitDetector.shouldMoveY(move)
-        : hitDetector.shouldMoveX(move);
+    final bool shouldMove = hitDetector.shouldMove(move, validateAxis);
     if (shouldMove || _pointerLocations.keys.length > 1) {
       acceptGesture(event.pointer);
     }

lib/src/core/photo_view_hit_corners.dart

@@ -1,12 +1,11 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
 import 'package:photo_view/src/controller/photo_view_controller_delegate.dart'
     show PhotoViewControllerDelegate;
 
 mixin HitCornersDetector on PhotoViewControllerDelegate {
-  HitAxis hitAxis() => HitAxis(hitCornersX(), hitCornersY());
-
-  HitCorners hitCornersX() {
+  HitCorners _hitCornersX() {
     final double childWidth = scaleBoundaries.childSize.width * scale;
     final double screenWidth = scaleBoundaries.outerSize.width;
     if (screenWidth >= childWidth) {
@@ -17,7 +16,7 @@ mixin HitCornersDetector on PhotoViewControllerDelegate {
     return HitCorners(x <= cornersX.min, x >= cornersX.max);
   }
 
-  HitCorners hitCornersY() {
+  HitCorners _hitCornersY() {
     final double childHeight = scaleBoundaries.childSize.height * scale;
     final double screenHeight = scaleBoundaries.outerSize.height;
     if (screenHeight >= childHeight) {
@@ -28,45 +27,46 @@ mixin HitCornersDetector on PhotoViewControllerDelegate {
     return HitCorners(y <= cornersY.min, y >= cornersY.max);
   }
 
-  bool shouldMoveX(Offset move) {
-    final hitCornersX = this.hitCornersX();
-
-    if (hitCornersX.hasHitAny && move != Offset.zero) {
-      if (hitCornersX.hasHitBoth) {
-        return false;
-      }
-      if (hitCornersX.hasHitMax) {
-        return move.dx < 0;
-      }
-      return move.dx > 0;
+  bool _shouldMoveAxis(
+      HitCorners hitCorners, double mainAxisMove, double crossAxisMove) {
+    if (mainAxisMove == 0) {
+      return false;
     }
-    return true;
-  }
-
-  bool shouldMoveY(Offset move) {
-    final hitCornersY = this.hitCornersY();
-    if (hitCornersY.hasHitAny && move != Offset.zero) {
-      if (hitCornersY.hasHitBoth) {
-        return false;
-      }
-      if (hitCornersY.hasHitMax) {
-        return move.dy < 0;
-      }
-      return move.dy > 0;
+    if (!hitCorners.hasHitAny) {
+      return true;
+    }
+    final axisBlocked = hitCorners.hasHitBoth ||
+        (hitCorners.hasHitMax ? mainAxisMove > 0 : mainAxisMove < 0);
+    if (axisBlocked) {
+      return false;
     }
     return true;
   }
-}
 
-class HitAxis {
-  HitAxis(this.hasHitX, this.hasHitY);
+  bool _shouldMoveX(Offset move) {
+    final hitCornersX = _hitCornersX();
+    final mainAxisMove = move.dx;
+    final crossAxisMove = move.dy;
+
+    return _shouldMoveAxis(hitCornersX, mainAxisMove, crossAxisMove);
+  }
 
-  final HitCorners hasHitX;
-  final HitCorners hasHitY;
+  bool _shouldMoveY(Offset move) {
+    final hitCornersY = _hitCornersY();
+    final mainAxisMove = move.dy;
+    final crossAxisMove = move.dx;
 
-  bool get hasHitAny => hasHitX.hasHitAny || hasHitY.hasHitAny;
+    return _shouldMoveAxis(hitCornersY, mainAxisMove, crossAxisMove);
+  }
 
-  bool get hasHitBoth => hasHitX.hasHitBoth && hasHitY.hasHitBoth;
+  bool shouldMove(Offset move, Axis mainAxis) {
+    assert(mainAxis != null);
+    assert(move != null);
+    if (mainAxis == Axis.vertical) {
+      return _shouldMoveY(move);
+    }
+    return _shouldMoveX(move);
+  }
 }
 
 class HitCorners {